| from low- to high-potential bioenergetic chains: thermodynamic constraints of q-cycle function. | the electrochemical parameters of all cofactors in the supercomplex formed by the rieske/cytb complex and the soxm/a-type o2-reductase from the menaquinone-containing firmicute geobacillus stearothermophilus were determined by spectroelectrochemistry and epr redox titrations. all redox midpoint potentials (em) were found to be lower than those of ubi- or plastoquinone-containing systems by a value comparable to the redox potential difference between the respective quinones. in particular, em val ... | 2016 | 27328272 |
| evaluating different concentrations of hydrogen peroxide in an automated room disinfection system. | a comparative study was made on the efficacy of 5, 10 and 35% weight by weight (w/w) hydrogen peroxide solutions when applied using an automated room disinfection system. six-log biological indicators of methicillin-resistant staphylococcus aureus (mrsa) and geobacillus stearothermophilus were produced on stainless steel coupons and placed within a large, sealed, environmentally controlled enclosure. five percent hydrogen peroxide was distributed throughout the enclosure using a bioquell hydroge ... | 2016 | 27324207 |
| active-loop dynamics within the michaelis complex of lactate dehydrogenase from bacillus stearothermophilus. | laser-induced temperature-jump relaxation spectroscopy was used to study the active site mobile-loop dynamics found in the binding of the nadh nucleotide cofactor and oxamate substrate mimic to lactate dehydrogenase in bacillus stearothermophilus thermophilic bacteria (bsldh). the kinetic data can be best described by a model in which nadh can bind only to the open-loop apoenzyme, oxamate can bind only to the bsldh·nadh binary complex in the open-loop conformation, and oxamate binding is followe ... | 2016 | 27319381 |
| catalytic properties of maltogenic α-amylase from bacillus stearothermophilus immobilized onto poly(urethane urea) microparticles. | the immobilization of maltogenic α-amylase from bacillus stearothermophilus (bsma) onto novel porous poly(urethane urea) (puu) microparticles synthesized from poly(vinyl alcohol) and isophorone diisocyanate was performed by covalent attachment to free isocyanate groups from puu microparticles, or by physical adsorption of enzyme onto the surface of the carrier. the influence of structure, surface area and porosity of microparticles on the catalytic properties of immobilized bsma was evaluated. t ... | 2016 | 27283635 |
| a hidden transhydrogen activity of a fmn-bound diaphorase under anaerobic conditions. | redox cofactors of nadh/nadph participate in many cellular metabolic pathways for facilitating the electron transfer from one molecule to another in redox reactions. transhydrogenase plays an important role in linking catabolism and anabolism, regulating the ratio of nadh/nadph in cells. the cytoplasmic transhydrogenases could be useful to engineer synthetic biochemical pathways for the production of high-value chemicals and biofuels. | 2016 | 27145082 |
| translesion synthesis past guanine(c8)-thymine(n3) intrastrand cross-links catalyzed by selected a- and y-family polymerases. | oxidatively generated guanine radicals in dna can undergo various nucleophilic reactions including the formation of c8-guanine cross-links with adjacent or nearby n3-thymines in dna in the presence of o2. these g[8-3]t lesions have been identified in the dna of human cells exposed to oxidative stress, and are most likely genotoxic if not removed by cellular defence mechanisms. the abilities of several representative polymerases to bypass the g[8-3]t lesions in two different sequence contexts, g* ... | 2016 | 27102383 |
| development and application of geobacillus stearothermophilus growth model for predicting spoilage of evaporated milk. | the presence of geobacillus stearothermophilus spores in evaporated milk constitutes an important quality problem for the milk industry. this study was undertaken to provide an approach in modelling the effect of temperature on g. stearothermophilus atcc 7953 growth and in predicting spoilage of evaporated milk. the growth of g. stearothermophilus was monitored in tryptone soy broth at isothermal conditions (35-67 °c). the data derived were used to model the effect of temperature on g. stearothe ... | 2016 | 27052699 |
| plasma decontamination: a case study on kill efficacy of geobacillus stearothermophilus spores on different carrier materials. | a new technology to the pharmaceutical field is presented: surface decontamination by plasmas the technology is comparable to established barrier systems like e-beam, volatile hydrogen peroxide, or radiation inactivation of microbiological contaminations. this plasma technology is part of a fully automated and validated syringe filling line at a major pharmaceutical company and is in production operation. incoming pre-sterilized syringe containers ("tubs") are processed by plasma, solely on the ... | 2016 | 27020647 |
| effectiveness of the system 1e liquid chemical sterilant processing system for reprocessing duodenoscopes. | a troubling number of health care-acquired infection outbreaks and transmission events, some involving highly resistant microbial pathogens and resulting in serious patient outcomes, have been traced to reusable, high-level disinfected duodenoscopes in the united states. the food and drug administration (fda) requested a study be conducted to verify liquid chemical sterilization efficacy of system 1e(®) liquid chemical sterilant processing system (steris corporation, mentor, oh) with varied duod ... | 2016 | 26948402 |
| risk of contamination in assembled vs disassembled instruments in hip arthroplasty surgery. | periprosthetic joint infection (pji) is one of the most common causes of revision total hip arthroplasty (tha) and associated with higher costs, prolonged pain, and worse clinical outcomes. many factors have been linked to increased infection rates, one being the operative equipment and instrumentation used during the surgical procedure. with few arthroplasty instruments designed for complete disassembly and increasingly complex instrument designs, this study seeks to understand the effect that ... | 2016 | 26948131 |
| die another day: fate of heat-treated geobacillus stearothermophilus atcc 12980 spores during storage under growth-preventing conditions. | geobacillus stearothermophilus spores are recognized as one of the most wet-heat resistant among aerobic spore-forming bacteria and are responsible for 35% of canned food spoilage after incubation at 55 °c. the purpose of this study was to investigate and model the fate of heat-treated survivor spores of g. stearothermophilus atcc 12980 in growth-preventing environment. g. stearothermophilus spores were heat-treated at four different conditions to reach one or two decimal reductions. heat-treate ... | 2016 | 26919821 |
| altering the enantioselectivity of tyrosyl-trna synthetase by insertion of a stereospecific editing domain. | translation of mrnas by the ribosome is stereospecific, with only l-amino acids being incorporated into the nascent polypeptide chain. this stereospecificity results from the exclusion of d-amino acids at three steps during protein synthesis: (1) the aminoacylation of trna by aminoacyl-trna synthetases, (2) binding of aminoacyl-trnas to ef-tu, and (3) recognition of aminoacyl-trnas by the ribosome. as a first step toward incorporating d-amino acids during protein synthesis, we have altered the e ... | 2016 | 26890980 |
| enzymatic saccharification and fermentation of cellulosic date palm wastes to glucose and lactic acid. | the bioconversion of cellulosic wastes into high-value bio-products by saccharification and fermentation processes is an important step that can reduce the environmental pollution caused by agricultural wastes. in this study, enzymatic saccharification of treated and untreated date palm cellulosic wastes by the cellulases from geobacillus stearothermophilus was optimized. the alkaline pre-treatment of the date palm wastes was found to be effective in increasing the saccharification percentage. t ... | 2017 | 26887233 |
| semi-rational design of geobacillus stearothermophilus l-lactate dehydrogenase to access various chiral α-hydroxy acids. | chiral α-hydroxy acids (ahas) are rapidly becoming important synthetic building blocks, in particular for the production of pharmaceuticals and other fine chemicals. chiral compounds of a variety of functionalities are now often derived using enzymes, and l-lactate dehydrogenase from the thermophilic organism geobacillus stearothermophilus (bsldh) has the potential to be employed for the industrial synthesis of chiral α-hydroxy acids. despite the thorough characterization of this enzyme, generat ... | 2016 | 26852025 |
| a sterilization system using ultraviolet photochemical reactions based on nitrous oxide and oxygen gases. | active oxygen species (aos) generated under ultraviolet (uv) lamps can be applied for various industrial processes owing to extremely strong oxidative abilities. we have already reported on an application of the aos for a sterilization process of microorganisms. here, a sterilization method using active oxygen generated under ultraviolet (uv) lamps introducing nitrous oxide (n2o) and oxygen gases into a vacuum chamber was investigated. nitrogen dioxide (no2) gas was readily produced from n2o by ... | 2016 | 26812575 |
| analysis of α-glucosidase enzyme activity used in a rapid test for steam sterilization assurance. | this study was to determine the sources, location and identity of α-glucosidases in dormant/germinating/outgrowing spores and growing cells of geobacillus stearothermophilus atcc 7953, an enzymatic activity in spores used in rapid tests of steam sterilization. | 2016 | 26808611 |
| ozone gas as a benign sterilization treatment for plga nanofiber scaffolds. | the use of electrospun nanofibers for tissue engineering and regenerative medicine applications is a growing trend as they provide improved support for cell proliferation and survival due, in part, to their morphology mimicking that of the extracellular matrix. sterilization is a critical step in the fabrication process of implantable biomaterial scaffolds for clinical use, but many of the existing methods used to date can negatively affect scaffold properties and performance. poly(lactic-co-gly ... | 2016 | 26757850 |
| effect of ph on thermoanaerobacterium thermosaccharolyticum dsm 571 growth, spore heat resistance and recovery. | thermophilic spore-forming bacteria are potential contaminants in several industrial sectors involving high temperatures (40-65 °c) in the manufacturing process. among those thermophilic spore-forming bacteria, thermoanaerobacterium thermosaccharolyticum, called "the swelling canned food spoiler", has generated interest over the last decade in the food sector. the aim of this study was to investigate and to model ph effect on growth, heat resistance and recovery abilities after a heat-treatment ... | 2016 | 26742617 |
| sterilization effect of wet oxygen plasma in the bubbling method. | a new low-temperature sterilization method to replace the ethylene oxide gas sterilization is needed. strong bactericidal effects of oh and o2h radicals are well known. the purpose of this study was to evaluate the sterilization effect of wet oxygen ("o2+h2o") plasma in the bubbling method, confirming the effect of humidity. sterility assurance was confirmed by using a biological indicator (geobacillus stearothermophilus atcc7953, namsa, usa). one hundred and eight samples (10(5) spores/carrier) ... | 2015 | 26699857 |
| characteristics of newly isolated geobacillus sp. zy-10 degrading hydrocarbons in crude oil. | an obligately thermophilic strain zy-10 was isolated from the crude oil in a high-temperature oilfield, which was capable of degrading heavy crude oil. phenotypic and phylogenetic analysis demonstrated that the isolate should be grouped in the genus geobacillus, which shared thd highest similarity (99%) of the 16s rdna sequence to geobacillus stearothermophilus. however, the major cellular fatty acid iso-15:0 (28.55%), iso-16:0 (24.93%), iso-17:0 (23.53%) and the characteristics including indole ... | 2015 | 26638533 |
| structure-function relationships in gan42b, an intracellular gh42 β-galactosidase from geobacillus stearothermophilus. | geobacillus stearothermophilus t-6 is a gram-positive thermophilic soil bacterium that contains a battery of degrading enzymes for the utilization of plant cell-wall polysaccharides, including xylan, arabinan and galactan. a 9.4 kb gene cluster has recently been characterized in g. stearothermophilus that encodes a number of galactan-utilization elements. a key enzyme of this degradation system is gan42b, an intracellular gh42 β-galactosidase capable of hydrolyzing short β-1,4-galactosaccharides ... | 2015 | 26627651 |
| simultaneous quantification of ten constituents of xanthoceras sorbifolia bunge using uhplc-ms methods and evaluation of their radical scavenging, dna scission protective, and α-glucosidase inhibitory activities. | the present study was designed to investigate the bioactive constituents of xanthoceras sorbifolia in terms of amounts and their antioxidant, dna scission protection, and α-glucosidase inhibitory activities. simultaneous quantification of 10 x. sorbifolia constituents was carried out by a newly established ultra-high performance liquid chromatography-quadrupole mass spectrometry method (uhplc-ms). the antioxidant activities were evaluated by measuring dpph radical scavenging and dna scission pro ... | 2015 | 26614463 |
| enhanced maltose production through mutagenesis of acceptor binding subsite +2 in bacillus stearothermophilus maltogenic amylase. | maltogenic amylases are used to decrease the maltotriose content of high maltose syrups. however, due to the interplay between the hydrolysis and transglycosylation activities of maltogenic amylases, the maltotriose contents of these syrups are still greater than that necessary for pure maltose preparation. in this study, the maltogenic amylase from bacillus stearothermophilus was engineered to decrease its transglycosylation activity with the expectation that this would enhance maltose producti ... | 2016 | 26597712 |
| cellulose binding domain assisted immobilization of lipase (gslip-cbd) onto cellulosic nanogel: characterization and application in organic medium. | a cbd gene was cloned into the c-terminal region of a lip gene from geobacillus stearothermophilus. the native lipase (43.5 kda) and cbd-lip fusion protein (60.2 kda) were purified to homogeneity by sds-page. a highly stable cellulosic nanogel was prepared by controlled hydrolysis of microcrystalline cellulose onto which the cbd-lip fusion protein was immobilized through bio-affinity based binding. the nanogel-bound lipase showed optimum activity at 55 °c, and it remains stable and active at ph ... | 2015 | 26590897 |
| draft genome sequences of three strains of geobacillus stearothermophilus isolated from a milk powder manufacturing plant. | three strains of geobacillus stearothermophilus (designated a1, p3, and d1) were isolated from a new zealand milk powder manufacturing plant. here, we describe their draft genome sequences. this information provided the first genomic insights into the nature of g. stearothermophilus strains present in the milk powder manufacturing environment. | 2015 | 26472822 |
| development of a quantitative pcr assay for thermophilic spore-forming geobacillus stearothermophilus in canned food. | the thermophilic spore forming bacteria geobacillus stearothermophilus is recognized as a major cause of spoilage in canned food. a quantitative real-time pcr assay was developed to specifically detect and quantify the species g. stearothermophilus in samples from canned food. the selected primer pairs amplified a 163-bp fragment of the 16s rrna gene in a specific pcr assay with a detection limit of 12.5 fg of pure culture dna, corresponding to dna extracted from approximately 0.7 cfu/ml of g. s ... | 2015 | 26412704 |
| [not available]. | the swiss center for quality control organizes external quality assessment schemes for medical laboratories as well as biological monitoring of the sterilization process for autoclaves. over the period from 2008 to 2012, 209 dental offices performed 4,709 sterilizations of biological indicators strips covered by geobacillus stearothermophilus spores. the median number of sterilizations per participant was 20. steam autoclaves obtained better results than the chemiclave. it turned out that 99 s ... | 2015 | 26345315 |
| rate-limiting steps of a stereochemistry retaining β-d-xylosidase from geobacillus stearothermophilus acting on four substrates. | kinetic experiments of gsxynb2, a gh52 retaining β-xylosidase, acting on 2-nitrophenyl-β-d-xylopyranoside (2npx), 4-nitrophenyl-β-d-xylopyranoside (4npx), 4-methylumbelliferyl-β-d-xylopyranoside (mux) and xylobiose (x2) were conducted at ph 7.0 and 25 °c. catalysis proceeds in two steps (xylodidation followed by dexylosidation): e + substrate to e-xylose + leaving group to e + xylose. kcat falls into two groups: 4npx (1.95 s(-1)) and 2npx, mux and x2 (15.8 s(-1), 12.6 s(-1), 12.8 s(-1), respecti ... | 2015 | 26271441 |
| post-translational modification of bionanoparticles as a modular platform for biosensor assembly. | context driven biosensor assembly with modular targeting and detection moieties is gaining significant attentions. although protein-based nanoparticles have emerged as an excellent platform for biosensor assembly, current strategies of decorating bionanoparticles with targeting and detection moieties often suffer from unfavorable spacing and orientation as well as bionanoparticle aggregation. herein, we report a highly modular post-translational modification approach for biosensor assembly based ... | 2015 | 26235232 |
| microencapsulation of maltogenic α-amylase in poly(urethane-urea) shell: inverse emulsion method. | the novel poly(urethane-urea) microcapsules (puumc) were obtained by the interfacial polyaddition reaction between the oil-soluble hexamethylene diisocyanate (hmdi) and the water soluble poly(vinyl alcohol) (pva) in a water-in-oil (w/o) emulsion. the pva was used instead of diols. maltogenase l (maltogenic α-amylase from bacillus stearothermophilus (e. c. 3.2.1.133) (mg) was encapsulated in the puumc during or after formation of capsules. the puumc were thoroughly characterised by chemical analy ... | 2015 | 26190216 |
| inactivation of geobacillus stearothermophilus spores by alkaline hydrolysis applied to medical waste treatment. | although alkaline hydrolysis treatment emerges as an alternative disinfection/sterilization method for medical waste, information on its effects on the inactivation of biological indicators is scarce. the effects of alkaline treatment on the resistance of geobacillus stearothermophilus spores were investigated and the influence of temperature (80 °c, 100 °c and 110 °c) and naoh concentration was evaluated. in addition, spore inactivation in the presence of animal tissues and discarded medical co ... | 2015 | 26150372 |
| thermostable, alkaline and detergent-tolerant lipase from a newly isolated thermophilic bacillus stearothermophilus. | lipases are the enzymes of choice for laundry detergent industries, owing to their triglyceride removing ability from the soiled fabric, which eventually reduces the usage of phosphate-based chemical cleansers in the detergent formulation. in this study, a novel thermo-alkaline lipase-producing strain identified as bacillus stearothermophilus was isolated from the soil samples of olive oil mill. enhanced lipase production was observed at 55 degrees c, ph 11 and after 48 h of incubation. among th ... | 2015 | 26118130 |
| expression and characterization of geobacillus stearothermophilus sr74 recombinant α-amylase in pichia pastoris. | geobacillus stearothermophilus sr74 is a locally isolated thermophilic bacteria producing thermostable and thermoactive α-amylase. increased production and commercialization of thermostable α-amylase strongly warrant the need of a suitable expression system. in this study, the gene encoding the thermostable α-amylase in g. stearothermophilus sr74 was amplified, sequenced, and subcloned into p. pastoris gs115 strain under the control of a methanol inducible promoter, alcohol oxidase (aox). methan ... | 2015 | 26090417 |
| structural insights into methanol-stable variants of lipase t6 from geobacillus stearothermophilus. | enzymatic production of biodiesel by transesterification of triglycerides and alcohol, catalyzed by lipases, offers an environmentally friendly and efficient alternative to the chemically catalyzed process while using low-grade feedstocks. methanol is utilized frequently as the alcohol in the reaction due to its reactivity and low cost. however, one of the major drawbacks of the enzymatic system is the presence of high methanol concentrations which leads to methanol-induced unfolding and inactiv ... | 2015 | 26026940 |
| orthodontic instrument sterilization with microwave irradiation. | this study was designed to evaluate the efficiency of microwave sterilization of orthodontic instruments and molar bands immersed in plain distilled water with and without oral rinse, and to ascertain the minimum time of exposure required to sterilize. | 2015 | 26015686 |
| the genus geobacillus and their biotechnological potential. | the genus geobacillus comprises a group of gram-positive thermophilic bacteria, including obligate aerobes, denitrifiers, and facultative anaerobes that can grow over a range of 45-75°c. originally classified as group five bacillus spp., strains of bacillus stearothermophilus came to prominence as contaminants of canned food and soon became the organism of choice for comparative studies of metabolism and enzymology between mesophiles and thermophiles. more recently, their catabolic versatility, ... | 2015 | 26003932 |
| calcium alginate matrix increases the stability and recycling capability of immobilized endo-β-1,4-xylanase from geobacillus stearothermophilus kibge-ib29. | exploration of microbial pool from extremely diversified ecosystem is significantly important for various industrial applications. bacterial communities from extreme habitats including volcanic vents, hot springs, and industrial sectors are eagerly explored for the isolation of thermophiles. geobacillus stearothermophilus kibge-ib29, isolated from blast furnace site of a steel processing industry, is capable of producing thermostable endo-β-1,4-xylanase. in the current study, this enzyme was imm ... | 2015 | 26001519 |
| backbone and side chain nmr assignments of geobacillus stearothermophilus zapa allow identification of residues that mediate the interaction of zapa with ftsz. | bacterial division begins with the formation of a contractile protein ring at midcell, which constricts the bacterial envelope to generate two daughter cells. the central component of the division ring is ftsz, a tubulin-like protein capable of self-assembling into filaments which further associate into a higher order structure known as the z ring. proteins that bind to ftsz play a crucial role in the formation and regulation of the z ring. one such protein is zapa, a widely conserved 21 kda hom ... | 2015 | 25967379 |
| direct fermentation of potato starch and potato residues to lactic acid by geobacillus stearothermophilus under non-sterile conditions. | lactic acid is an important biorefinery platform chemical. the use of thermophilic amylolytic microorganisms to produce lactic acid by fermentation constitutes an efficient strategy to reduce operating costs, including raw materials and sterilization costs. | 2015 | 25937690 |
| effect of essential oils on germination and growth of some pathogenic and spoilage spore-forming bacteria. | the use of essential oils as a food preservative has increased due to their capacity to inhibit vegetative growth of some bacteria. however, only limited data are available on their effect on bacterial spores. the aim of the present study was to evaluate the effect of some essential oils on the growth and germination of three bacillus species and geobacillus stearothermophilus. essential oils were chemically analyzed using gas chromatography and gas chromatography coupled to mass spectrometry. t ... | 2015 | 25884442 |
| biochemical and mutational characterization of n-succinyl-amino acid racemase from geobacillus stearothermophilus cect49. | n-succinyl-amino acid racemase (nsaar), long referred to as n-acyl- or n-acetyl-amino acid racemase, is an enolase superfamily member whose biotechnological potential was discovered decades ago, due to its use in the industrial dynamic kinetic resolution methodology first known as "acylase process". in previous works, an extended and enhanced substrate spectrum of the nsaar from geobacillus kaustophilus cect4264 toward different n-substituted amino acids was reported. in this work, we describe t ... | 2015 | 25875730 |
| relevance of glycosylation of s-layer proteins for cell surface properties. | elucidating the building principles and intrinsic features modulating certain water-associated processes (e.g., surface roughness in the nanometer scale, surface hydration and accompanied antifouling property, etc.) of surface structures from (micro)organisms is nowadays a highly challenging task in fields like microbiology, biomimetic engineering and (bio)material sciences. here, we show for the first time the recrystallization of the wild-type s-layer glycoprotein wtsgse from geobacillus stear ... | 2015 | 25818946 |
| partial purification and characterization of lipase from geobacillus stearothermophilus ah22. | the lipase was partially purified by ion exchange chromatography and gel filtration column chromatography, and was characterized from geobacillus stearothermophilus ah22 strain. the lipase was purified 18.3-folds with 19.7% recovery. the lipase activity was determined by using p-nitrophenyl esters (c2-c12) as substrates. the km values of the enzyme for these substrates were found as 0.16, 0.02, 0.19 and 0.55 mm, respectively, while vmax values were 0.52, 1.03, 0.72 and 0.15 u mg(-1). the enzyme ... | 2016 | 25798692 |
| modeling the behavior of geobacillus stearothermophilus atcc 12980 throughout its life cycle as vegetative cells or spores using growth boundaries. | geobacillus stearothermophilus is recognized as one of the most prevalent micro-organism responsible for flat sour in the canned food industry. to control these highly resistant spore-forming bacteria, the heat treatment intensity could be associated with detrimental conditions for germination and outgrowth. the purpose of this work was to study successively the impact of temperature and ph on the growth rate of g. stearothermophilus atcc 12980, its sporulation ability, its heat resistance in re ... | 2015 | 25791003 |
| contamination pathways of spore-forming bacteria in a vegetable cannery. | spoilage of low-acid canned food during prolonged storage at high temperatures is caused by heat resistant thermophilic spores of strict or facultative bacteria. here, we performed a bacterial survey over two consecutive years on the processing line of a french company manufacturing canned mixed green peas and carrots. in total, 341 samples were collected, including raw vegetables, green peas and carrots at different steps of processing, cover brine, and process environment samples. thermophilic ... | 2015 | 25755080 |
| a differentially conserved residue (ile42) of gh42 β-galactosidase from geobacillus stearothermophilus bgab is involved in both catalysis and thermostability. | the glycoside hydrolase family 42 (gh42) of thermophilic microorganisms consists of thermostable β-galactosidases that display significant variations in their temperature optima and stabilities. in this study, we compared the substrate binding modes of 2 gh42 β-galactosidases, bgab from geobacillus stearothermophilus and a4-β-gal from thermus thermophilus a4. the a4-β-gal has a catalytic triad (glu312-arg32-glu35) with an extended hydrogen bond network that has not been observed in bgab. in this ... | 2015 | 25682138 |
| improving thermal and detergent stability of bacillus stearothermophilus neopullulanase by rational enzyme design. | neopullulanase, a glycosyl hydrolase from bacillus stearothermophilus (bsnpl), is a potentially valuable enzyme for starch and detergent industries. however, as the protein is not active at elevated temperatures and high surfactant concentrations, we aimed to increase its stability by rational enzyme design. nine potentially destabilizing cavities were identified in the crystal structure of the enzyme. based on computational predictions, these cavities were filled by residues with bulkier side c ... | 2015 | 25680359 |
| enzymatic activities of rnase h domains of hiv-1 reverse transcriptase with substrate binding domains of bacterial rnases h1 and h2. | thermotoga maritima rnase h1 and bacillus stearothermophilus rnase h2 have an n-terminal substrate binding domain, termed hybrid binding domain (tmahbd), and n-terminal domain (bstntd), respectively. hiv-1 reverse transcriptase (rt) is a heterodimer consisting of a p66 subunit and a p51 subunit. the p66 subunit contains a c-terminal rnase h domain, which exhibits rnase h activity either in the presence of mg(2+) or mn(2+) ions. the isolated rnase h domain of hiv-1 rt (rnh(hiv)) is inactive, poss ... | 2015 | 25673083 |
| three-dimensional structure of a variant `termamyl-like' geobacillus stearothermophilus α-amylase at 1.9 å resolution. | the enzyme-catalysed degradation of starch is central to many industrial processes, including sugar manufacture and first-generation biofuels. classical biotechnological platforms involve steam explosion of starch followed by the action of endo-acting glycoside hydrolases termed α-amylases and then exo-acting α-glucosidases (glucoamylases) to yield glucose, which is subsequently processed. a key enzymatic player in this pipeline is the `termamyl' class of bacterial α-amylases and designed/evolve ... | 2015 | 25615972 |
| agar-agar entrapment increases the stability of endo-β-1,4-xylanase for repeated biodegradation of xylan. | microbial xylanases, specially endo-β-1,4-xylanase catalyzes the hydrolysis of xylan, is considered one of the most significant hydrolases. it has numerous applications but most extensively is utilized in paper and pulp industry as a bio-bleaching agent. immobilization technique is comprehensively studied with the expectation of modifying and improving enzyme stability and characteristics for commercial purposes. currently, matrix entrapment technique is applied to immobilize endo-β-1,4-xylanase ... | 2015 | 25603143 |
| crystal structures capture three states in the catalytic cycle of a pyridoxal phosphate (plp) synthase. | plp synthase (plps) is a remarkable single-enzyme biosynthetic pathway that produces pyridoxal 5'-phosphate (plp) from glutamine, ribose 5-phosphate, and glyceraldehyde 3-phosphate. the intact enzyme includes 12 synthase and 12 glutaminase subunits. plp synthesis occurs in the synthase active site by a complicated mechanism involving at least two covalent intermediates at a catalytic lysine. the first intermediate forms with ribose 5-phosphate. the glutaminase subunit is a glutamine amidotransfe ... | 2015 | 25568319 |
| multimeric scaffolds displaying the hiv-1 envelope mper induce mper-specific antibodies and cross-neutralizing antibodies when co-immunized with gp160 dna. | developing a vaccine that overcomes the diversity of hiv-1 is likely to require a strategy that directs antibody (ab) responses toward conserved regions of the viral envelope (env). however, the generation of neutralizing abs (nabs) targeting these regions through vaccination has proven to be difficult. one conserved region of particular interest is the membrane proximal external region (mper) of env located within the gp41 ectodomain. in order to direct the immune response to this region, the m ... | 2014 | 25514675 |
| preliminary crystallographic analysis of xyn52b2, a gh52 β-d-xylosidase from geobacillus stearothermophilus t6. | geobacillus stearothermophilus t6 is a thermophilic bacterium that possesses an extensive hemicellulolytic system, including over 40 specific genes that are dedicated to this purpose. for the utilization of xylan, the bacterium uses an extracellular xylanase which degrades xylan to decorated xylo-oligomers that are imported into the cell. these oligomers are hydrolyzed by side-chain-cleaving enzymes such as arabinofuranosidases, acetylesterases and a glucuronidase, and finally by an intracellula ... | 2014 | 25484225 |
| genotypic and phenotypic characterization of foodborne geobacillus stearothermophilus. | geobacillus stearothermophilus is the main thermophilic spore former involved in flat sour spoilage of canned foods. three typing methods were tested and applied to differentiate strains at intra-species level: panc sequence analysis, rep-pcr and m13-pcr. panc gene was highly conserved within the studied strains, suggesting a low intra-specific diversity. this was supported by rep-pcr primary assays and m13-pcr results. m13-pcr profile analysis succeeded in differentiating six closely related gr ... | 2015 | 25481066 |
| a thermostable transketolase evolved for aliphatic aldehyde acceptors. | directed evolution of the thermostable transketolase from geobacillus stearothermophilus based on a ph-based colorimetric screening of smart libraries yielded several mutants with up to 16-fold higher activity for aliphatic aldehydes and high enantioselectivity (>95% ee) in the asymmetric carboligation step. | 2015 | 25415647 |
| draft genome sequences of geobacillus stearothermophilus strains 22 and 53, isolated from the garga hot spring in the barguzin river valley of the russian federation. | geobacillus stearothermophilus strains 22 and 53 were isolated from sediment samples isolated from the garga hot spring (72°c) located in the valley of the river barguzin (the baikal region, russian federation) (54°19'3.72″n, 110°59'38.4″e). | 2014 | 25414504 |
| semi-rational approach for converting a gh36 α-glycosidase into an α-transglycosidase. | a large number of retaining glycosidases catalyze both hydrolysis and transglycosylation reactions. in order to use them as catalysts for oligosaccharide synthesis, the balance between these two competing reactions has to be shifted toward transglycosylation. we previously designed a semi-rational approach to convert the thermus thermophilus β-glycosidases into transglycosidases by mutating highly conserved residues located around the -1 subsite. in an attempt to verify that this strategy could ... | 2015 | 25395404 |
| structure-specificity relationships in abp, a gh27 β-l-arabinopyranosidase from geobacillus stearothermophilus t6. | l-arabinose sugar residues are relatively abundant in plants and are found mainly in arabinan polysaccharides and in other arabinose-containing polysaccharides such as arabinoxylans and pectic arabinogalactans. the majority of the arabinose units in plants are present in the furanose form and only a small fraction of them are present in the pyranose form. the l-arabinan-utilization system in geobacillus stearothermophilus t6, a gram-positive thermophilic soil bacterium, has recently been charact ... | 2014 | 25372689 |
| comparative analysis of the geobacillus hemicellulose utilization locus reveals a highly variable target for improved hemicellulolysis. | members of the thermophilic genus geobacillus can grow at high temperatures and produce a battery of thermostable hemicellulose hydrolytic enzymes, making them ideal candidates for the bioconversion of biomass to value-added products. to date the molecular determinants for hemicellulose degradation and utilization have only been identified and partially characterized in one strain, namely geobacillus stearothermophilus t-6, where they are clustered in a single genetic locus. | 2014 | 25273399 |
| enzymatic and cryoreduction epr studies of the hydroxylation of methylated n(ω)-hydroxy-l-arginine analogues by nitric oxide synthase from geobacillus stearothermophilus. | nitric oxide synthase (nos) catalyzes the conversion of l-arginine to l-citrulline and no in a two-step process involving the intermediate n(ω)-hydroxy-l-arginine (nha). it was shown that cpd i is the oxygenating species for l-arginine; the hydroperoxo ferric intermediate is the reactive intermediate with nha. methylation of the n(ω)-oh and n(ω)-h of nha significantly inhibits the conversion of nha into no and l-citrulline by mammalian nos. kinetic studies now show that n(ω)-methylation of nha h ... | 2014 | 25251261 |
| analysis of the tryptophanase expression in symbiobacterium thermophilum in a coculture with geobacillus stearothermophilus. | the tryptophanase-positive symbiobacterium thermophilum is a free-living syntrophic bacterium that grows effectively in a coculture with geobacillus stearothermophilus. our studies have shown that s. thermophilum growth depends on the high co2 and low o2 condition established by the precedent growth of g. stearothermophilus. the use of an anoxic atmosphere containing high co2 allows s. thermophilum to grow independently of g. stearothermophilus, but the cellular yield is ten times lower than tha ... | 2014 | 25200839 |
| reduction in acute ecotoxicity of paper mill effluent by sequential application of xylanase and laccase. | in order to reduce the ecotoxicity of paper mill, four different enzymatic pretreatment strategies were investigated in comparison to conventional chemical based processes. in strategy i, xylanase-aided pretreatment of pulp was carried out, and in strategy ii, xylanase and laccase-mediator systems were used sequentially. moreover, to compare the efficiency of bacillus stearothermophilus xylanase and ceriporiopsis subvermispora laccase in the reduction of ecotoxicity and pollution, parallel strat ... | 2014 | 25058160 |
| challenges to validation of a complex nonsterile medical device tray. | validation by steam sterilization of reusable medical devices requires careful attention to many parameters that directly influence whether or not complete sterilization occurs. complex implant/instrument tray systems have a variety of configurations and components. geobacillus stearothermophilus biological indicators (bis) are used in overkill cycles to to simulate worst case conditions and are intended to provide substantial sterilization assurance. survival of g. stearothermophilus spores was ... | 2016 | 25046511 |
| isolation and characterization of an α-glucosidase inhibitor from musa spp. (baxijiao) flowers. | the use of α-glucosidase inhibitors is considered to be an effective strategy in the treatment of diabetes. using a bioassay-guided fractionation technique, five bacillus stearothermophilus α-glucosidase inhibitors were isolated from the flowers of musa spp. (baxijiao). using nmr spectroscopy analysis they were identified as vanillic acid (1), ferulic acid (2), β-sitosterol (3), daucosterol (4) and 9-(4'-hydroxyphenyl)-2-methoxyphenalen-1-one (5). the half maximal inhibitory concentration (ic50) ... | 2014 | 25045894 |
| enzymatic dynamic kinetic resolution of racemic n-formyl- and n-carbamoyl-amino acids using immobilized l-n-carbamoylase and n-succinyl-amino acid racemase. | taking advantage of the catalytic promiscuity of l-carbamoylase from geobacillus stearothermophilus cect43 (bslcar) and n-succinyl-amino acid racemase from geobacillus kaustophilus cect4264 (gknsaar), we have evaluated the production of different optically pure l-α-amino acids starting from different racemic n-formyl- and n-carbamoyl-amino acids using a dynamic kinetic resolution approach. the enzymes were immobilized on two different solid supports, resulting in improved stability of the enzyme ... | 2015 | 24993356 |
| development of a multiplex-pcr assay for the rapid identification of geobacillus stearothermophilus and anoxybacillus flavithermus. | the presence of thermophilic bacilli in dairy products is indicator of poor hygiene. their rapid detection and identification is fundamental to improve the industrial reactivity in the implementation of corrective and preventive actions. in this study a rapid and reliable identification of geobacillus stearothermophilus and anoxybacillus flavithermus was achieved by species-specific pcr assays. two primer sets, targeting the its 16s-23s rrna region and the rpob gene sequence of the target specie ... | 2014 | 24929881 |
| structure of a his170tyr mutant of thermostable pnppase from geobacillus stearothermophilus. | using directed evolution based on random mutagenesis and heat-treated selection, a thermostable his170tyr mutant of geobacillus stearothermophilus thermostable p-nitrophenylphosphatase (tpnppase) was obtained. the temperature at which the his170tyr mutant lost 50% of its activity (t1/2) was found to be 4.40 k higher than that of wild-type tpnppase, and the melting temperature of the his170tyr mutant increased by 2.39 k. the crystal structure of the his170tyr mutant was then determined at 2.0 å r ... | 2014 | 24915075 |
| molecular dynamics of thermoenzymes at high temperature and pressure: a review. | lipases are known for their versatility in addition to their ability to digest fat. they can be used for the formulation of detergents, as food ingredients and as biocatalysts in many industrial processes. because conventional enzymes are frangible at high temperatures, the replacement of conventional chemical routes with biochemical processes that utilize thermostable lipases is vital in the industrial setting. recent theoretical studies on enzymes have provided numerous fundamental insights in ... | 2014 | 24871480 |
| designing non-native iron-binding site on a protein cage for biological synthesis of nanoparticles. | in biomineralization processes, a supramolecular organic structure is often used as a template for inorganic nanomaterial synthesis. the e2 protein cage derived from geobacillus stearothermophilus pyruvate dehydrogenase and formed by the self-assembly of 60 subunits, has been functionalized with non-native iron-mineralization capability by incorporating two types of iron-binding peptides. the non-native peptides introduced at the interior surface do not affect the self-assembly of e2 protein sub ... | 2014 | 24788938 |
| transformable facultative thermophile geobacillus stearothermophilus nub3621 as a host strain for metabolic engineering. | metabolic engineers develop inexpensive enantioselective syntheses of high-value compounds, but their designs are sometimes confounded by the misfolding of heterologously expressed proteins. geobacillus stearothermophilus nub3621 is a readily transformable facultative thermophile. it could be used to express and properly fold proteins derived from its many mesophilic or thermophilic bacillaceae relatives or to direct the evolution of thermophilic variants of mesophilic proteins. moreover, its ca ... | 2014 | 24788326 |
| inactivation of geobacillus stearothermophilus spores in low-acid foods by pressure-assisted thermal processing. | the effect of pressure-assisted thermal processing (patp) on the inactivation of geobacillus stearothermophilus spores was determined in deionized water, cooked ground beef, egg patty mince, whole milk and mashed potatoes at 105 °c under 500 and 700 mpa. | 2015 | 24752997 |
| in situ investigation of geobacillus stearothermophilus spore germination and inactivation mechanisms under moderate high pressure. | bacterial spores are a major concern for food safety due to their high resistance to conventional preservation hurdles. innovative hurdles can trigger bacterial spore germination or inactivate them. in this work, geobacillus stearothermophilus spore high pressure (hp) germination and inactivation mechanisms were investigated by in situ infrared spectroscopy (ft-ir) and fluorometry. g. stearothermophilus spores' inner membrane (im) was stained with laurdan fluorescent dye. time-dependent ft-ir an ... | 2014 | 24750808 |
| toxicity of the herbicide linuron as assessed by bacterial and mitochondrial model systems. | linuron is one of the most intensively used herbicides with predictable effects on the environment and non-target organisms. in the present study, two in vitro biological models (a bacillus sp. and rat liver mitochondria) were used to evaluate linuron toxicity at a cell/subcellular level. linuron inhibited bacterial growth and nadh-supported respiration, similar ic₅₀ values being estimated for both toxic responses (74 and 98 μm, respectively). at concentrations up to 120 μm, linuron perturbed th ... | 2014 | 24747295 |
| thermal adaptation of dihydrofolate reductase from the moderate thermophile geobacillus stearothermophilus. | the thermal melting temperature of dihydrofolate reductase from geobacillus stearothermophilus (bsdhfr) is ~30 °c higher than that of its homologue from the psychrophile moritella profunda. additional proline residues in the loop regions of bsdhfr have been proposed to enhance the thermostability of bsdhfr, but site-directed mutagenesis studies reveal that these proline residues contribute only minimally. instead, the high thermal stability of bsdhfr is partly due to removal of water-accessible ... | 2014 | 24730604 |
| preliminary crystallographic analysis of a double mutant of the acetyl xylo-oligosaccharide esterase axe2 in its dimeric form. | xylans are polymeric sugars constituting a significant part of the plant cell wall. they are usually substituted with acetyl side groups attached at positions 2 or 3 of the xylose backbone units. acetylxylan esterases are part of the hemicellulolytic system of many microorganisms which utilize plant biomass for growth. these enzymes hydrolyze the ester linkages of the xylan acetyl groups and thus improve the accessibility of main-chain-hydrolyzing enzymes and their ability to break down the suga ... | 2014 | 24699743 |
| purification, crystallization and preliminary crystallographic analysis of gan1d, a gh1 6-phospho-β-galactosidase from geobacillus stearothermophilus t1. | geobacillus stearothermophilus t1 is a gram-positive thermophilic soil bacterium that contains an extensive system for the utilization of plant cell-wall polysaccharides, including xylan, arabinan and galactan. the bacterium uses a number of extracellular enzymes that break down the high-molecular-weight polysaccharides into short oligosaccharides, which enter the cell and are further hydrolyzed into sugar monomers by dedicated intracellular glycoside hydrolases. the interest in the biochemical ... | 2014 | 24637762 |
| characterization of quinol-dependent nitric oxide reductase from geobacillus stearothermophilus: enzymatic activity and active site structure. | nitric oxide reductase (nor) catalyzes the reduction of nitric oxide to generate nitrous oxide. we recently reported on the crystal structure of a quinol-dependent nor (qnor) from geobacillus stearothermophilus [y. matsumoto, t. tosha, a.v. pisliakov, t. hino, h. sugimoto, s. nagano, y. sugita and y. shiro, nat. struct. mol. biol. 19 (2012) 238-246], and suggested that a water channel from the cytoplasm, which is not observed in cytochrome c-dependent nor (cnor), functions as a pathway transferr ... | 2014 | 24569054 |
| structural insights into conserved l-arabinose metabolic enzymes reveal the substrate binding site of a thermophilic l-arabinose isomerase. | structural genomics demonstrates that despite low levels of structural similarity of proteins comprising a metabolic pathway, their substrate binding regions are likely to be conserved. herein based on the 3d-structures of the α/β-fold proteins involved in the ara operon, we attempted to predict the substrate binding residues of thermophilic geobacillus stearothermophilus l-arabinose isomerase (gsai) with no 3d-structure available. comparison of the structures of l-arabinose catabolic enzymes re ... | 2014 | 24561191 |
| a unique octameric structure of axe2, an intracellular acetyl-xylooligosaccharide esterase from geobacillus stearothermophilus. | geobacillus stearothermophilus t6 is a thermophilic, gram-positive soil bacterium that possesses an extensive and highly regulated hemicellulolytic system, allowing the bacterium to efficiently degrade high-molecular-weight polysaccharides such as xylan, arabinan and galactan. as part of the xylan-degradation system, the bacterium uses a number of side-chain-cleaving enzymes, one of which is axe2, a 219-amino-acid intracellular serine acetylxylan esterase that removes acetyl side groups from xyl ... | 2014 | 24531461 |
| enhanced amino acid selection in fully evolved tryptophanyl-trna synthetase, relative to its urzyme, requires domain motion sensed by the d1 switch, a remote dynamic packing motif. | we previously showed (li, l., and carter, c. w., jr. (2013) j. biol. chem. 288, 34736-34745) that increased specificity for tryptophan versus tyrosine by contemporary bacillus stearothermophilus tryptophanyl-trna synthetase (trprs) over that of trprs urzyme results entirely from coupling between the anticodon-binding domain and an insertion into the rossmann-fold known as connecting peptide 1. we show that this effect is closely related to a long range catalytic effect, in which side chain repac ... | 2014 | 24394410 |
| protein engineering by random mutagenesis and structure-guided consensus of geobacillus stearothermophilus lipase t6 for enhanced stability in methanol. | the abilities of enzymes to catalyze reactions in nonnatural environments of organic solvents have opened new opportunities for enzyme-based industrial processes. however, the main drawback of such processes is that most enzymes have a limited stability in polar organic solvents. in this study, we employed protein engineering methods to generate a lipase for enhanced stability in methanol, which is important for biodiesel production. two protein engineering approaches, random mutagenesis (error- ... | 2014 | 24362426 |
| quantitative assessment of the risk of microbial spoilage in foods. prediction of non-stability at 55 °c caused by geobacillus stearothermophilus in canned green beans. | microbial spoilage of canned foods by thermophilic and highly heat-resistant spore-forming bacteria, such as geobacillus stearothermophilus, is a persistent problem in the food industry. an incubation test at 55 °c for 7 days, then validation of biological stability, is used as an indicator of compliance with good manufacturing practices. we propose a microbial risk assessment model predicting the percentage of non-stability due to g. stearothermophilus in canned green beans manufactured by a fr ... | 2014 | 24334097 |
| biocompatibility and antibacterial activity of photolytic products of sulfonamides. | this study assessed the photochemical fate of nine sulfonamides (sulfamerazine, sulfanilamide, sulfamethoxypyridazine, sulfamethoxazole, sulfachloropyridazine, sulfamethazine, sulfadiazine, sulfathiazole and sulfadimethoxine) during a 6h irradiation period with uva/uvb-light and uva-light and over 7 days under natural (sunlight) conditions. the cell growth inhibition effect and cytotoxicity of sulfonamides and their photodegradation products was investigated over 24 and 48 h with murine fibrobla ... | 2014 | 24321335 |
| identification of a microscopically selected microorganism in milk samples. | identification of unwanted microbial contaminants microscopically observed in food products is challenging due to their low abundance in a complex matrix, quite often containing other microorganisms. therefore, a selective identification method was developed using laser capture microdissection in combination with direct-captured cell pcr. this procedure was validated with geobacillus stearothermophilus and further used to identify microbial contaminants present in some industrial milk samples. t ... | 2014 | 24290827 |
| homotropic cooperativity from the activation pathway of the allosteric ligand-responsive regulatory trp rna-binding attenuation protein. | the trp rna-binding attenuation protein (trap) assembles into an 11-fold symmetric ring that regulates transcription and translation of trp-mrna in bacilli via heterotropic allosteric activation by the amino acid tryptophan (trp). whereas nuclear magnetic resonance studies have revealed that trp-induced activation coincides with both microsecond to millisecond rigidification and local structural changes in trap, the pathway of binding of the 11 trp ligands to the trap ring remains unclear. moreo ... | 2013 | 24224873 |
| theoretical study of the catalytic mechanism of e1 subunit of pyruvate dehydrogenase multienzyme complex from bacillus stearothermophilus. | pyruvate dehydrogenase multienzyme complex (pdhc) is a member of a family of 2-oxo acid dehydrogenase (oadh) multienzyme complexes involved in several central points of oxidative metabolism, and the e1 subunit is the most important component in the entire pdhc catalytic system, which catalyzes the reversible transfer of an acetyl group from a pyruvate to the lipoyl group of e2 subunit lipoly domain. in this article, the catalytic mechanism of the e1 subunit has been systematically studied using ... | 2013 | 24171427 |
| standard role for a conserved aspartate or more direct involvement in deglycosylation? an oniom and md investigation of adenine-dna glycosylase. | 8-oxoguanine (og) is one of the most frequently occurring forms of dna damage and is particularly deleterious since it forms a stable hoogsteen base pair with adenine (a). the repair of an og:a mispair is initiated by adenine-dna glycosylase (muty), which hydrolyzes the sugar-nucleobase bond of the adenine residue before the lesion is processed by other proteins. muty has been proposed to use a two-part chemical step involving protonation of the adenine nucleobase, followed by sn1 hydrolysis of ... | 2013 | 24168684 |
| improving catalytic efficiency of endo-β-1, 4-xylanase from geobacillus stearothermophilus by directed evolution and h179 saturation mutagenesis. | endo-β-1, 4-xylanase was cloned from geobacillus stearothermophilus 1a05583 by pcr. enzymes with improved catalytic efficiency were obtained using error-prone pcr and a 96-well plate high-throughout screening system. two variants 1-b8 and 2-h6 were screened from the mutant library containing 9000 colonies, which, when compared with the wild-type enzyme increased the catalytic efficiency (kcat/km) by 25% and 89%, respectively, acting on beechwood xylan. by sequencing 1-b8 and 2-h6, an identical m ... | 2013 | 24157442 |
| gh52 xylosidase from geobacillus stearothermophilus: characterization and introduction of xylanase activity by site‑directed mutagenesis of tyr509. | a xylosidase gene, gsxyn, was cloned from the deep-sea thermophilic geobacillus stearothermophilus, which consisted of 2,118 bp and encoded a protein of 705 amino acids with a calculated molecular mass of 79.8 kda. the gsxyn of glycoside hydrolase family 52 (gh52) displayed its maximum activity at 70 °c and ph 5.5. the k m and k cat values of gsxyn for ρnpx were 0.48 mm and 36.64 s−1, respectively. interestingly, a new exo-xylanase activity was introduced into gsxyn by mutating the tyrosine509 i ... | 2014 | 24122394 |
| characterization of thermophilic bacilli from a milk powder processing plant. | to determine whether strains of geobacillus stearothermophilus isolated from a milk powder manufacturing plant were different in their ability to form biofilms and produce spores. in addition, this study evaluated whether there were other physiological characteristics that could differentiate these strains. | 2014 | 24119100 |
| identification, characterization and preliminary x-ray diffraction analysis of the rolling-circle replication initiator protein from plasmid pstk1. | antibiotic resistance in bacterial pathogens poses an ever-increasing risk to human health. in antibiotic-resistant strains of staphylococcus aureus this resistance often resides in extra-chromosomal plasmids, such as those of the pt181 family, which replicate via a rolling-circle mechanism mediated by a plasmid-encoded replication initiation protein. currently, there is no structural information available for the pt181-family rep proteins. here, the crystallization of a catalytically active fra ... | 2013 | 24100563 |
| studies on the toxicity of an aqueous suspension of c60 nanoparticles using a bacterium (gen. bacillus) and an aquatic plant (lemna gibba) as in vitro model systems. | the increasing use of c60 nanoparticles and the diversity of their applications in industry and medicine has led to their production in a large scale. c60 release into wastewaters and the possible accumulation in the environment has raised concerns about their ecotoxicological impact. in the present study, an aqueous suspension of c60 nanoparticles was prepared and its potential toxicity studied in laboratory, using a bacterium (bacillus stearothermophilus) and an aquatic plant (lemna gibba) as ... | 2013 | 24084257 |
| kinetics of germination of individual spores of geobacillus stearothermophilus as measured by raman spectroscopy and differential interference contrast microscopy. | geobacillus stearothermophilus is a gram-positive, thermophilic bacterium, spores of which are very heat resistant. raman spectroscopy and differential interference contrast microscopy were used to monitor the kinetics of germination of individual spores of g. stearothermophilus at different temperatures, and major conclusions from this work were as follows. 1) the cadpa level of individual g. stearothermophilus spores was similar to that of bacillus spores. however, the raman spectra of protein ... | 2013 | 24058645 |
| structural and biochemical features of acidic α-amylase of bacillus acidicola. | the investigation is aimed at understanding structure-function aspect of α-amylase of an acidophilic bacterium bacillus acidicola (baamy), which is ca(2+)-independent and active at acidic ph of native starch, and thus, suits better in starch saccharification process. the cd spectroscopic data analysis revealed that the enzyme has 30% α-helices, 14.2% β-sheets, and 55.8% random coils at 60 °c and ph 4.0. using bacillus stearothermophilus α-amylase (bsta) as the template, 3-d structure of rbaamy h ... | 2013 | 23954129 |
| effect of dielectric and liquid on plasma sterilization using dielectric barrier discharge plasma. | plasma sterilization offers a faster, less toxic and versatile alternative to conventional sterilization methods. using a relatively small, low temperature, atmospheric, dielectric barrier discharge surface plasma generator, we achieved ≥ 6 log reduction in concentration of vegetative bacterial and yeast cells within 4 minutes and ≥ 6 log reduction of geobacillus stearothermophilus spores within 20 minutes. plasma sterilization is influenced by a wide variety of factors. two factors studied in t ... | 2013 | 23951023 |
| role of n-terminal extension of bacillus stearothermophilus rnase h2 and c-terminal extension of thermotoga maritima rnase h2. | bacillus stearothermophilus rnase h2 (bstrnh2) and thermotoga maritima rnase h2 (tmarnh2) have n-terminal and c-terminal extensions, respectively, as compared with aquifex aeolicus rnase h2 (aaernh2). to analyze the role of these extensions, bstrnh2 and tmarnh2 without these extensions were constructed, and their biochemical properties were compared with those of their intact partners and aaernh2. the far-uv cd spectra of all proteins were similar, suggesting that the protein structure is not si ... | 2013 | 23937561 |
| properties of geobacillus stearothermophilus levansucrase as potential biocatalyst for the synthesis of levan and fructooligosaccharides. | the production of levansucrase (ls) by thermophilic geobacillus stearothermophilus was investigated. ls production was more effective in the presence of sucrose (1%, w/v) than fructose, glucose, glycerol or raffinose. the results (top 57°c; stable for 6 h at 47°c) indicate the high stability of the transfructosylation activity of g. stearothermophilus ls as compared with lss from other microbial sources. contrary to temperature, the ph had a significant effect on the selectivity of g. stearother ... | 2014 | 23926090 |
| salt-induced changes in the subunit structure of the bacillus stearothermophilus lipoate acetyltransferase. | the bacillus stearothermophilus lipoate acetyltransferase (e2), composed of sixty identical, subunits is the core component of the pyruvate dehydrogenase complex (pdc). e2 polypeptide is composed of ld, psbd, and cd domains. most studies had focused on a truncated e2 that is deficient in ld and psbd, because cd mainly contributes to maintaining the multimeric structure. we examined salt-induced changes in e2 without truncation and constructed reaction models. we speculate that in the presence of ... | 2013 | 23924725 |
| arsenic-tolerant, arsenite-oxidising bacterial strains in the contaminated soils of west bengal, india. | as biological agents represent an affordable alternative to costly metal decontamination technologies, we isolated arsenic (as) oxidising bacteria from the as-contaminated soils of west bengal, india. these strains were closely related to various species of bacillus and geobacillus based on their 16s rrna gene sequences. they were found to be hyper-resistant to both as(v) (167-400 mm) and as(iii) (16-47 mm). elevated rates of as(iii) oxidation (278-1250 μm h(-1)) and arsenite oxidase activity (2 ... | 2013 | 23876545 |
| identifying critical unrecognized sugar-protein interactions in gh10 xylanases from geobacillus stearothermophilus using std nmr. | (1)h solution nmr spectroscopy is used synergistically with 3d crystallographic structures to map experimentally significant hydrophobic interactions upon substrate binding in solution under thermodynamic equilibrium. using saturation transfer difference spectroscopy (std nmr), a comparison is made between wild-type xylanase xt6 and its acid/base catalytic mutant e159q--a non-active, single-heteroatom alteration that has been previously utilized to measure binding thermodynamics across a series ... | 2013 | 23863045 |