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impact of organic loading rate on biohydrogen production in an up-flow anaerobic packed bed reactor (uanpbr).this study assesses the impact of organic loading rate on biohydrogen production from glucose in an up-flow anaerobic packed bed reactor (uanpbr). two mesophilic uapbrs (uanpbr1 and 2) were tested at organic loading rates (olrs) ranging from 6.5 to 51.4 g cod l(-1)d(-1). to overcome biomass washout, design modifications were made in the uanpbr2 to include a settling zone to capture the detached biomass. the design modifications in uanpbr2 increased the average hydrogen yield from 0.98 to 2.0 mol ...201424865326
evaluation of industrial dairy waste (milk dust powder) for acetone-butanol-ethanol production by solventogenic clostridium species.readily available inexpensive substrate with high product yield is the key to restoring acetone-butanol-ethanol (abe) fermentation to economic competitiveness. lactose-replete cheese whey tends to favor the production of butanol over acetone. in the current study, we investigated the fermentability of milk dust powder with high lactose content, for abe production by clostridium acetobutylicum and clostridium beijerinckii. both microorganisms produced 7.3 and 5.8 g/l of butanol respectively, with ...201425126487
cellulolytic enzymes production by utilizing agricultural wastes under solid state fermentation and its application for biohydrogen production.phanerochaete chrysosporium was evaluated for cellulase and hemicellulase production using various agricultural wastes under solid state fermentation. optimization of various environmental factors, type of substrate, and medium composition was systematically investigated to maximize the production of enzyme complex. using grass powder as a carbon substrate, maximum activities of endoglucanase (188.66 u/gds), exoglucanase (24.22 u/gds), cellobiase (244.60 u/gds), filter paperase (fpu) (30.22 u/gd ...201425374139
enhanced butanol production by immobilized clostridium beijerinckii tistr 1461 using zeolite 13x as a carrier.butanol production by cell immobilization onto porous materials-brick and zeolite 13x-was investigated using clostridium beijerinckii tistr 1461. characterization results of two materials were completed to evaluate their potential as an immobilization carrier. although zeolite has greater porosity than brick, it cannot be used for cell aggregation without treating with chemical. after immobilization, both materials can enhance butanol titers from 5.29 to 5.80g/l and 8.58g/l using brick and zeoli ...201425237776
complete genome sequence of solvent-tolerant clostridium beijerinckii strain sa-1.we report the complete genome sequence of clostridium beijerinckii sa-1, derived by directed evolution from c. beijerinckii ncimb 8052, selecting for enhanced solvent tolerance. this sequence allows for accurate placement of sa-1 as c. beijerinckii, permits functional analyses of mutant phenotypes, and suggests methods for distinguishing sa-1 from its parent.201425523769
elucidating and alleviating impacts of lignocellulose-derived microbial inhibitors on clostridium beijerinckii during fermentation of miscanthus giganteus to butanol.fermentation of liquid hot water (lhw) pretreated miscanthus giganteus (mg) by clostridium beijerinckii ncimb 8052 was investigated towards understanding the toxicity of lignocellulose-derived inhibitors to solventogenic clostridium species vis-à-vis butanol production. while c. beijerinckii ncimb 8052 did not grow in undiluted mg hydrolysate-based fermentation medium, supplementation of this medium with calcium carbonate enabled the growth of c. beijerinckii ncimb 8052 and production of butanol ...201425085743
chemocatalytic upgrading of tailored fermentation products toward biodiesel.biological and chemocatalytic processes are tailored in order to maximize the production of sustainable biodiesel from lignocellulosic sugar. thus, the combination of hydrotalcite-supported copper(ii) and palladium(0) catalysts with a modification of the fermentation from acetone-butanol-ethanol to isopropanol-butanol-ethanol predictably produces higher concentrations of diesel-range components in the alkylation reaction.201425044817
artificial symbiosis for acetone-butanol-ethanol (abe) fermentation from alkali extracted deshelled corn cobs by co-culture of clostridium beijerinckii and clostridium cellulovorans.butanol is an industrial commodity and also considered to be a more promising gasoline substitute compared to ethanol. renewed attention has been paid to solvents (acetone, butanol and ethanol) production from the renewable and inexpensive substrates, for example, lignocellulose, on account of the depletion of oil resources, increasing gasoline prices and deteriorating environment. limited to current tools for genetic manipulation, it is difficult to develop a genetically engineered microorganis ...201425023325
acetone-butanol-ethanol (abe) production by clostridium beijerinckii from wheat straw hydrolysates: efficient use of penta and hexa carbohydrates.abe fermentation by clostridium beijerinckii of steam-exploded and ozonated wheat straw hydrolysates was investigated. in steam-exploded hydrolysates, highest yields of 0.40 g/g abe yield and 127.71 g abe/kg wheat straw were achieved when the whole slurry from the pretreatment was used. in ozonated hydrolysates, 0.32 g/g abe yield and 79.65 g abe/kg wheat straw were obtained from washed ozonated wheat straw. diverse effects were observed in steam explosion and ozonolysis of wheat straw which res ...201424983690
glycerol supplementation of the growth medium enhances in situ detoxification of furfural by clostridium beijerinckii during butanol fermentation.lignocellulose-derived microbial inhibitors such as furfural and 5-hydroxymethyl furfural adversely affect fermentation of lignocellulosic biomass hydrolysates to fuels and chemicals due to their toxicity on fermenting microbes. to harness the potential of lignocellulose as a cheap source of fermentable sugars, in situ detoxification of furfural and other lignocellulose-derived microbial inhibitors is essential. to enhance in situ detoxification and tolerance of furfural by clostridium beijerinc ...201424839212
discovery of clostrubin, an exceptional polyphenolic polyketide antibiotic from a strictly anaerobic bacterium.genome mining of the strictly anaerobic bacterium clostridium beijerinckii, an industrial producer of solvents, revealed the presence of several cryptic gene clusters for secondary metabolite biosynthesis. to unearth its metabolic potential, a c. beijerinckii strain was cultured under various conditions, which led to the discovery of a deep purple pigment. this novel metabolite, named clostrubin (1), was isolated and its structure was fully elucidated. the pentacyclic polyphenol features a benzo ...201424827417
pretreatment of lignocellulosic biomass using fenton chemistry.in an attempt to mimic white-rot fungi lignin degradation via in vivo fenton chemistry, solution phase fenton chemistry (10 g biomass, 176 mmol hydrogen peroxide and 1.25 mmol fe(2+) in 200 ml of water) was applied to four different biomass feedstocks. an enzymatic saccharification of fenton pretreated biomass showed an average 212% increase relative to untreated control across all four feedstocks (p<0.05, statistically significant). a microbial fermentation of the same fenton pretreated biomass ...201424759643
use of fluorescent staining and flow cytometry for monitoring physiological changes in solventogenic clostridia.physiological changes in populations of clostridium beijerinckii and clostridium tetanomorphum were monitored by fluorescence staining and flow cytometry. to estimate the number of metabolically active cells in exponential growth, a combination of the dyes propidium iodide and carboxy fluorescein diacetate appeared to be a good choice for both species. during stationary phase, these stains did not reflect physiological changes sufficiently and therefore additional labeling with bis-(1,3-dibutylb ...201424211310
process integration for simultaneous saccharification, fermentation, and recovery (ssfr): production of butanol from corn stover using clostridium beijerinckii p260.a simultaneous saccharification, fermentation, and recovery (ssfr) process was developed for the production of acetone-butanol-ethanol (ab or abe), of which butanol is the main product, from corn stover employing clostridium beijerinckii p260. of the 86 g l(-1) corn stover provided, over 97% of the sugars were released during hydrolysis and these were fermented completely with an abe productivity of 0.34 g l(-1)h(-1) and yield of 0.39. this productivity is higher than 0.31 g l(-1)h(-1) when usin ...201424398150
enhanced abiotic and biotic contributions to dechlorination of pentachlorophenol during fe(iii) reduction by an iron-reducing bacterium clostridium beijerinckii z.a novel fe(iii) reducing bacterium, clostridium beijerinckii z, was isolated from glucose amended paddy slurries, and shown to dechlorinate pentachlorophenol (pcp). fifty percent of added pcp was removed by c. beijerinckii z alone, which increased to 83% in the presence of both c. beijerinckii z and ferrihydrite after 11 days of incubation. without c. beijerinckii z, the surface-bound fe(ii) also abiotically dechlorinated more than 40% of the added pcp. this indicated that the biotic dechlorinat ...201424370696
selection of clostridium spp. in biological sand filters neutralizing synthetic acid mine drainage.in this study, three biological sand filter (bsf) were contaminated with a synthetic iron- [1500 mg l⁻¹ fe(ii), 500 mg l⁻¹ fe(iii)] and sulphate-rich (6000 mg l⁻¹ so₄²⁻) acid mine drainage (amd) (ph = 2), for 24 days, to assess the remediation capacity and the evolution of autochthonous bacterial communities (monitored by t-rflp and 16s rrna gene clone libraries). to stimulate bsf bioremediation involving sulphate-reducing bacteria, a readily degradable carbon source (glucose, 8000 mg l⁻¹) was i ...201424251832
purification and characterization of a gh11 xylanase from biobutanol-producing clostridium beijerinckii g117.most biobutanol-producing clostridium strains are unable to ferment polysaccharides such as cellulose and xylan due to the lack of hydrolyzing enzymes. in this study, we show that clostridium beijerinckii g117, a newly isolated biobutanol-producing strain, expresses xylanase enzyme in the presence of 1% beechwood xylan. the xylanase activity in the medium containing actively growing culture and 1% of beechwood xylan can reach up to 2.66 u/ml after 14 h of fermentation. using salting-out and size ...201525564206
effect of phosphoric acid pretreatment of corncobs on the fermentability of clostridium beijerinckii tistr 1461 for biobutanol production.corncobs pretreated with h2so4, hno3, and h3po4 were compared to evaluate the fermentation ability of clostridium beijerinckii tistr 1461 to produce biobutanol via acetone-butanol-ethanol (abe) fermentation. it was found that the hydrolysate from h3po4 pretreatment could be used as a substrate without any inhibitor removal methods. however, in terms of sugar yield, it gave the lowest total sugars in both pretreatment and enzymatic hydrolysis. response surface methodology was applied to optimize ...201524678653
water-insoluble material from apple pomace makes changes in intracellular nad⁺/nadh ratio and pyrophosphate content and stimulates fermentative production of hydrogen.apple pomace is one of the major agricultural residues in aomori prefecture, japan, and it would be useful to develop effective applications for it. as apple pomace contains easily fermentable sugars such as glucose, fructose and sucrose, it can be used as a feedstock for the fermentation of fuels and chemicals. we previously isolated a new hydrogen-producing bacterium, clostridium beijerinckii hu-1, which could produce h2 at a production rate of 14.5 mmol of h2/l/h in a fed-batch culture at 37 ...201525468418
butanol production from food waste: a novel process for producing sustainable energy and reducing environmental pollution.waste is currently a major problem in the world, both in the developing and the developed countries. efficient utilization of food waste for fuel and chemical production can positively influence both the energy and environmental sustainability. this study investigated using food waste to produce acetone, butanol, and ethanol (abe) by clostridium beijerinckii p260.201526380581
clostridium beijerinckii mutant obtained atmospheric pressure glow discharge generates enhanced electricity in a microbial fuel cell.a clostridium beijerinckii mutant m13 was derived from c. beijerinckii ncimb 8052 by atmospheric pressure glow discharge. c. beijerinckii m13 generated a maximum output power density of 79.2 mw m(-2) and a maximum output voltage of 230 mv in a microbial fuel cell containing 1 g glucose l(-1) as carbon source and 0.15 g methyl viologen l(-1) as an electron carrier.201525179822
a novel three-component system-based regulatory model for d-xylose sensing and transport in clostridium beijerinckii.d-xylose is the most abundant fermentable pentose in nature and can serve as a carbon source for many bacterial species. since d-xylose constitutes the major component of hemicellulose, its metabolism is important for lignocellulosic biomass utilization. here, we report a six-protein module for d-xylose signaling, uptake and regulation in solvent-producing clostridium beijerinckii. this module consists of a novel 'three-component system' (a putative periplasmic abc transporter substrate-binding ...201525441682
inoculum optimization of clostridium beijerinckii for reproducible growth.spore-forming solventogenic clostridium spp. are receiving renewed attention due to their butanol production abilities. however, there is an absence of literature describing the preparation of dense, vigorous and homogeneous seed cultures of clostridium spp., guaranteeing reproducibility during fermentation. therefore, we performed a series of growth experiments of clostridium beijerinckii ncimb 8052 and its offspring sa-1 to evaluate the influence of inoculum age (harvest time) on the subsequen ...201526363015
draft genome sequence of clostridium beijerinckii ne1, clostridia from an enrichment culture obtained from australian subterranean termite, nasutitermes exitiosus.the draft genome of clostridium beijerinckii strain ne1 was reconstructed from the metagenomic sequence of a mixed-microbial consortium that produced commercially significant quantities of hydrogen from xylan as a sole feedstock. the organism possesses relatively limited hemicellulolytic capacity and likely requires the action of other organisms to completely degrade xylan.201525908128
analysis of clostridium beijerinckii ncimb 8052's transcriptional response to ferulic acid and its application to enhance the strain tolerance.plant-based cellulose presents the best source of renewable sugars for biofuel production. however, the lignin associated with plant cellulose presents a hurdle as hydrolysis of this component leads to the production of inhibitory compounds, such as ferulic acid.201525904983
electrochemical detoxification of phenolic compounds in lignocellulosic hydrolysate for clostridium fermentation.lignocellulosic biomass is being preferred as a feedstock in the biorefinery, but lignocellulosic hydrolysate usually contains inhibitors against microbial fermentation. among these inhibitors, phenolics are highly toxic to butyric acid-producing and butanol-producing clostridium even at a low concentration. herein, we developed an electrochemical polymerization method to detoxify phenolic compounds in lignocellulosic hydrolysate for efficient clostridium fermentation. after the electrochemical ...201525863199
a biorefining process: sequential, combinational lignocellulose pretreatment procedure for improving biobutanol production from sugarcane bagasse.here, for the first time, we designed a sequential, combinatorial lignocellulose pretreatment procedure (sclpp) for microbial biofuel fermentation to reduce generation of microbial growth inhibitors and furthermore increase sugar yields. we tested this pretreatment process using sugarcane bagasse as substrate and assessed the effectiveness by analysis of biobutanol production through microbial clostridium beijerinckii ncimb 8052 conversion. our results showed that there were no inhibitory effect ...201525846185
genome sequence of the solvent-producing clostridium beijerinckii strain 59b, isolated from staffordshire garden soil.the genome sequence of the solvent-producing, spore-forming, saccharolytic, mesophilic bacterium clostridium beijerinckii strain 59b, isolated from staffordshire garden soil, was obtained via a combination of sequencing with the 454 and illumina platforms. this information will allow for metabolic engineering of a potentially industrially useful strain.201525792046
total synthesis of clostrubin.clostrubin is a potent antibiotic against methicillin- and vancomycin-resistant bacteria that was isolated from a strictly anaerobic bacterium clostridium beijerinckii in 2014. this polyphenol possesses a fully substituted arene moiety on its pentacyclic scaffold, which poses a considerable challenge for chemical synthesis. here we report the first total synthesis of clostrubin in nine steps (the longest linear sequence). a desymmetrization strategy is exploited based on the inherent structural ...201525759087
improving biohydrogen production using clostridium beijerinckii immobilized with magnetite nanoparticles.in order to supplement the need for alternative energy resources within the near future, enhancing the production of biohydrogen with immobilized clostridium beijerinckii ncimb8052 was investigated. magnetite nanoparticles were functionalized, with chitosan and alginic acid polyelectrolytes using a layer-by-layer method, to promote bacterial attachment. cultivating c. beijerinckii with these nanoparticles resulted in a shorter lag growth phase and increased total biohydrogen production within 10 ...201525728446
allopurinol-mediated lignocellulose-derived microbial inhibitor tolerance by clostridium beijerinckii during acetone-butanol-ethanol (abe) fermentation.in addition to glucans, xylans, and arabinans, lignocellulosic biomass hydrolysates contain significant levels of nonsugar components that are toxic to the microbes that are typically used to convert biomass to biofuels and chemicals. to enhance the tolerance of acetone-butanol-ethanol (abe)-generating clostridium beijerinckii ncimb 8052 to these lignocellulose-derived microbial inhibitory compounds (ldmics; e.g., furfural), we have been examining different metabolic perturbation strategies to i ...201525690312
markerless chromosomal gene deletion in clostridium beijerinckii using crispr/cas9 system.the anaerobic spore-forming, gram-positive, solventogenic clostridia are notorious for being difficult to genetically engineer. based on crispr/cas9 assisted homologous recombination, we demonstrated that clean markerless gene deletion from the chromosome can be easily achieved with a high efficiency through a single-step transformation in clostridium beijerinckii ncimb 8052, one of the most prominent strains for acetone, butanol and ethanol (abe) production. this highly efficient genome enginee ...201525680931
novel clostridial fusants in comparison with co-cultured counterpart species for enhanced production of biobutanol using green renewable and sustainable feedstock.in this work, biobutanol was produced through simultaneous saccharification and fermentation (ssf) of wheat straw (ws) that traditionally produces acetone, butanol and ethanol solvents (abe). thermal stability was imparted to two mesophilic clostridial wild strains (clostridium beijerinckii and clostridium acetobutylicum) through protoplast fusion with that of a corresponding thermophilic clostridial species (clostridium thermocellum). production was pursued by the fused strains at 45 °c compare ...201526395807
metabolic engineering of clostridium tyrobutyricum for n-butanol production: effects of coa transferase.the overexpression of coa transferase (ctfab), which catalyzes the reaction: acetate/butyrate + acetoacetyl-coa → acetyl/butyryl-coa + acetoacetate, was studied for its effects on acid reassimilation and butanol biosynthesis in clostridium tyrobutyricum (δack, adhe2). the plasmid pmtl007 was used to co-express adhe2 and ctfab from clostridium acetobutylicum atcc 824. in addition, the sol operon containing ctfab, adc (acetoacetate decarboxylase), and ald (aldehyde dehydrogenase) was also cloned f ...201525851718
process development for biological production of butanol from eastern redcedar.eastern redcedar is an invasive softwood species in oklahoma and across grasslands in the central plains of the united states and potential feedstock for butanol production. butanol has higher energy content than ethanol and can be upgraded to jet and diesel fuels. the objective of this study was to develop a process for production of butanol from redcedar. results showed that clostridium acetobutylicum atcc 824 and clostridium beijerinckii ncimb 8052 did not grow in fermentation medium with cit ...201525460988
development of a triplex real-time pcr assay for the simultaneous detection of clostridium beijerinckii, clostridium sporogenes and clostridium tyrobutyricum in milk.clostridium beijerinckii, clostridium sporogenes and clostridium tyrobutyricum are considered the leading bacteria implicated in late blowing defects affecting semi-hard and hard cheese production. the aim of this study was to develop a multiplex real-time pcr (qpcr) analysis for a rapid and simultaneous detection of c. beijerinckii, c. sporogenes and c. tyrobutyricum, using specific primers respectively targeting the nifh, geraa and enr genes. the limits of detection in raw milk were 300 cfu/50 ...201525870135
development of agave as a dedicated biomass source: production of biofuels from whole plants.agave species can grow well in semi-arid marginal agricultural lands around the world. selected agave species are used largely for alcoholic beverage production in mexico. there are expanding research efforts to use the plentiful residues (bagasse) for ethanol production as the beverage manufacturing process only uses the juice from the central core of mature plants. here, we investigate the potential of over a dozen agave species, including three from cold semi-arid regions of the united states ...201526056533
identification, purification and characterization of furfural transforming enzymes from clostridium beijerinckii ncimb 8052.generation of microbial inhibitory compounds such as furfural and 5-hydroxymethylfurfural (hmf) is a formidable roadblock to fermentation of lignocellulose-derived sugars to butanol. bioabatement offers a cost effective strategy to circumvent this challenge. although clostridium beijerinckii ncimb 8052 can transform 2-3 g/l of furfural and hmf to their less toxic alcohols, higher concentrations present in biomass hydrolysates are intractable to microbial transformation. to delineate the mechanis ...201525796546
efficient acetone-butanol-ethanol production by clostridium beijerinckii from sugar beet pulp.sugar beet pulp (sbp) has been investigated as a promising feedstock for abe fermentation by clostridium beijerinckii. although lignin content in sbp is low, a pretreatment is needed to enhance enzymatic hydrolysis and fermentation yields. autohydrolysis at ph 4 has been selected as the best pretreatment for sbp in terms of sugars release and acetone and butanol production. the best overall sugars release yields from raw sbp ranged from 66.2% to 70.6% for this pretreatment. the highest abe yield ...201525965949
optimized transformation of newly constructed escherichia coli-clostridia shuttle vectors into clostridium beijerinckii.three escherichia coli-clostridia shuttle vectors, pkba411-mcs, pkbe411-mcs, and pkbm411-mcs, which contain p15a, cole1, and pmb1 origins for replication in e. coli, respectively, along with the pamb origin for replication in c. beijerinckii, were constructed and examined for their transformation efficiencies into clostridium beijerinckii ncimb8052. the transformation condition of pkbm411-mcs, which was optimized by varying resistance, buffer composition, and dna concentration, was further emplo ...201526152821
acetone-butanol-ethanol production from substandard and surplus dates by egyptian native clostridium strains.one hundred and seven mesophilic isolates of clostridium were isolated from agricultural soils cultivated with different plants in assuit governorate, egypt. eighty isolates (out of 107) showed the ability to produce abe (acetone, butanol and ethanol) on t6 medium ranging from 0.036 to 31.89 g/l. the highest numbers of abe producing isolates were obtained from soil samples of potato contributing 27 isolates, followed by 18 isolates from wheat and 10 isolates from onion. on the other hand, there ...201525557787
a roadmap for gene system development in clostridium.clostridium species are both heroes and villains. some cause serious human and animal diseases, those present in the gut microbiota generally contribute to health and wellbeing, while others represent useful industrial chassis for the production of chemicals and fuels. to understand, counter or exploit, there is a fundamental requirement for effective systems that may be used for directed or random genome modifications. we have formulated a simple roadmap whereby the necessary gene systems maybe ...201627234263
interactions between bacillus cereus cgmcc 1.895 and clostridium beijerinckii ncimb 8052 in coculture for butanol production under nonanaerobic conditions.low oxygen tolerance and substrate restriction continues to hamper the process of biobutanol industrialization. in this work, butanol fermentation with cocultures of bacillus cereus china general microbiological culture collection center (cgmcc) 1.895 and clostridium beijerinckii ncimb 8052 under nonanaerobic conditions was investigated, and the interactions between these two strains were examined. the addition of b. cereus cgmcc 1.895 resulted in higher oxygen tolerance and a wider range of sub ...201627306691
transcriptional analysis of degenerate strain clostridium beijerinckii dg-8052 reveals a pleiotropic response to caco3-associated recovery of solvent production.degenerate clostridium beijerinckii strain (dg-8052) can be partially recovered by supplementing caco3 to fermentation media. genome resequencing of dg-8052 showed no general regulator mutated. this study focused on transcriptional analysis of dg-8052 and its response to caco3 treatment via microarray. the expressions of 5168 genes capturing 98.6% of c. beijerinckii ncimb 8052 genome were examed. the results revealed that with addition of caco3 565 and 916 genes were significantly up-regulated, ...201627966599
butanol production by a clostridium beijerinckii mutant with high ferulic acid tolerance.a mutant strain of clostridium beijerinckii, with high tolerance to ferulic acid, was generated using atmospheric pressure glow discharge and high-throughput screening of c. beijerinckii ncimb 8052. the mutant strain m11 produced 7.24 g/l of butanol when grown in p2 medium containing 30 g/l of glucose and 0.5 g/l of ferulic acid, which is comparable to the production from non-ferulic acid cultures (8.11 g/l of butanol). when 0.8 g/l of ferulic acid was introduced into the p2 medium, c. beijerinc ...201626201246
oxygen stability in the new [fefe]-hydrogenase from clostridium beijerinckii sm10 (cba5h).the newly isolated clostridium beijerinckii [fefe]-hydrogenase cba5h was characterized by fourier transform infrared spectroscopy coupled to enzymatic activity assays. this showed for the first time that in this enzyme the oxygen-sensitive active state hox can be simply and reversibly converted to the oxygen-stable inactive hinact state. this suggests that oxygen sensitivity is not an intrinsic feature of the catalytic center of [fefe]-hydrogenases (h-cluster), opening new challenging perspectiv ...201627749036
gene transcription repression in clostridium beijerinckii using crispr-dcas9.crispr-cas9 has been explored as a powerful tool for genome engineering for many organisms. meanwhile, dcas9 which lacks endonuclease activity but can still bind to target loci has been engineered for efficient gene transcription repression. clostridium beijerinckii, an industrially significant species capable of biosolvent production, is generally difficult to metabolically engineer. recently, we reported our work in developing customized crispr-cas9 system for genome engineering in c. beijerin ...201627240718
bacterial genome editing with crispr-cas9: deletion, integration, single nucleotide modification, and desirable "clean" mutant selection in clostridium beijerinckii as an example.crispr-cas9 has been demonstrated as a transformative genome engineering tool for many eukaryotic organisms; however, its utilization in bacteria remains limited and ineffective. here we explored streptococcus pyogenes crispr-cas9 for genome editing in clostridium beijerinckii (industrially significant but notorious for being difficult to metabolically engineer) as a representative attempt to explore crispr-cas9 for genome editing in microorganisms that previously lacked sufficient genetic tools ...201627115041
enhanced isopropanol and n-butanol production by supplying exogenous acetic acid via co-culturing two clostridium strains from cassava bagasse hydrolysate.the focus of this study was to produce isopropanol and butanol (ib) from dilute sulfuric acid treated cassava bagasse hydrolysate (sacbh), and improve ib production by co-culturing clostridium beijerinckii (c. beijerinckii) with clostridium tyrobutyricum (c. tyrobutyricum) in an immobilized-cell fermentation system. concentrated sacbh could be converted to solvents efficiently by immobilized pure culture of c. beijerinckii. considerable solvent concentrations of 6.19 g/l isopropanol and 12.32 g/ ...201627116556
use of cupriavidus basilensis-aided bioabatement to enhance fermentation of acid-pretreated biomass hydrolysates by clostridium beijerinckii.lignocellulose-derived microbial inhibitors (ldmics) prevent efficient fermentation of miscanthus giganteus (mg) hydrolysates to fuels and chemicals. to address this problem, we explored detoxification of pretreated mg biomass by cupriavidus basilensis atcc(®)baa-699 prior to enzymatic saccharification. we document three key findings from our test of this strategy to alleviate ldmic-mediated toxicity on clostridium beijerinckii ncimb 8052 during fermentation of mg hydrolysates. first, we demonst ...201627400988
production of 1,3-propanediol by clostridium beijerinckii dsm 791 from crude glycerol and corn steep liquor: process optimization and metabolic engineering.1,3-propanediol (1,3-pdo) production from crude glycerol, a byproduct from biodiesel manufacturing, by clostridium beijerinckii dsm 791 was studied with corn steep liquor as an inexpensive nitrogen source replacing yeast extract in the fermentation medium. a stable, long-term 1,3-pdo production from glycerol was demonstrated with cells immobilized in a fibrous bed bioreactor operated in a repeated batch mode, which partially circumvented the 1,3-pdo inhibition problem. the strain was then engine ...201627085150
identification of a glucose-mannose phosphotransferase system in clostridium beijerinckii.effective uptake of fermentable substrates is a fundamentally important aspect of any fermentation process. the solventogenic bacterium clostridium beijerinckii is noted for its ability to ferment a wide range of carbohydrates, yet few of its sugar transport systems have been characterized. in common with other anaerobes, c. beijerinckii shows a marked dependence on the pep-dependent phosphotransferase system (pts) for sugar accumulation. in this study, the gene cbe0751 encoding the sugar-specif ...201626940293
construction of heterologous gene expression cassettes for the development of recombinant clostridium beijerinckii.gene-expression cassettes for the construction of recombinant clostridium beijerinckii were developed as potential tools for metabolic engineering of c. beijerinckii. gene expression cassettes containing cole1 origin and pamb origin along with the erythromycin resistance gene were constructed, in which promoters from escherichia coli, lactococcus lactis, ralstonia eutropha, c. acetobutylicum, and c. beijerinckii are examined as potential promoters in c. beijerinckii. zymogram analysis of the cel ...201626780375
genomic approach to studying nutritional requirements of clostridium tyrobutyricum and other clostridia causing late blowing defects.clostridium tyrobutyricum is the main microorganism responsible for the late blowing defect in hard and semi-hard cheeses, causing considerable economic losses to the cheese industry. deeper knowledge of the metabolic requirements of this microorganism can lead to the development of more effective control approaches. in this work, the amino acids and b vitamins essential for sustaining the growth of c. tyrobutyricum were investigated using a genomic approach. as the first step, the genomes of fo ...201627375262
seasonal occurrence and molecular diversity of clostridia species spores along cheesemaking streams of 5 commercial dairy plants.five commercial dairy plants were monitored over a 17-mo period to determine the seasonal occurrence of clostridium spores in streams from the cheesemaking process. every 2 mo, samples of raw milk (rm), separated cream (sc), pasteurized and standardized vat milk (psvm), psvm + lysozyme (psvm+l), and manufactured cheese aged for 60 to 90 d were processed for analysis. molecular diversity of the main species identified was determined using repetitive element palindromic pcr. the mean anaerobic spo ...201626923043
calorimetric studies of the growth of anaerobic microbes.this article aims to validate the use of calorimetry to measure the growth of anaerobic microbes. it has been difficult to monitor the growth of strict anaerobes while maintaining optimal growth conditions. traditionally, optical density and atp concentration are usually used as measures of the growth of anaerobic microbes. however, to take these measurements it is necessary to extract an aliquot of the culture, which can be difficult while maintaining anaerobic conditions. in this study, calori ...201627012376
an unexpected negative influence of light intensity on hydrogen production by dark fermentative bacteria clostridium beijerinckii.the role of light intensity on biohydrogen production from glucose by clostridium beijerinckii, clostridium acetobutylicum, and rhodobacter sphaeroides was studied to evaluate the performance and possible application in co-culture fermentation system. the applied source of light had spectrum similar to the solar radiation. the influence of light intensity on hydrogen production in dark process by c. acetobutylicum was negligible. in contrast, dark fermentation by c. beijerinckii bacteria showed ...201626602144
crispr-based genome editing and expression control systems in clostridium acetobutylicum and clostridium beijerinckii.solventogenic clostridia are important industrial microorganisms that produce various chemicals and fuels. effective genetic tools would facilitate physiological studies aimed both at improving our understanding of metabolism and optimizing solvent productivity through metabolic engineering. here we have developed an all-in-one, crispr-based genome editing plasmid, pnickclos, that can be used to achieve successive rounds of gene editing in clostridium acetobutylicum atcc 824 and clostridium beij ...201627213844
effect of ozonolysis parameters on the inhibitory compound generation and on the production of ethanol by pichia stipitis and acetone-butanol-ethanol by clostridium from ozonated and water washed sugarcane bagasse.sugarcane bagasse (scb) was ozone pretreated and detoxified by water washing, applying a l9(3)(4) orthogonal array (oa) design of experiments to study the effect of pretreatment parameters (moisture content, ozone concentration, ozone/oxygen flow and particle size) on the generation of inhibitory compounds and on the composition of hydrolysates of ozonated-washed samples. ozone concentration resulted the highest influence process parameter on delignification and sugar release after washing; whil ...201627428302
production of biobutanol from acid-pretreated corncob using clostridium beijerinckii tistr 1461: process optimization studies.corncob is a potential feedstock in thailand that can be used for fermentable sugar production through dilute sulfuric acid pretreatment and enzymatic hydrolysis. to recover high amounts of monomeric sugars from corncob, the sulfuric pretreatment conditions were optimized by using response surface methodology with three independent variables: sulfuric acid concentration, temperature, and time. the highest response of total sugars, 48.84 g/l, was found at 122.78°c, 4.65 min, and 2.82% (v/v) h2so4 ...201625569768
investigation of availability of a high throughput screening method for predicting butanol solvent -producing ability of clostridium beijerinckii.currently, efficient screening methods for selection of desired bacterial phenotypes from large populations are not easy feasible or readily available due to the complicated physiological and metabolic networks of solventogenic clostridia. in this study, to contribute to the improvement of methods for predicting the butanol-producing ability of clostridium beijerinckii based on starch substrate, we further investigate a simple, visualization screening method for selecting target strains from mut ...201627448996
engineering clostridium beijerinckii with the cbei_4693 gene knockout for enhanced ferulic acid tolerance.a mutant strain of clostridium beijerinckii ncimb 8052, c. beijerinckii m11, which exhibited ferulic acid tolerance up to 0.9g/l, was generated using atmospheric pressure glow discharge and high-throughput screening. comparative genomic analysis revealed that this strain harbored a mutation of the cbei_4693 gene, which encodes a hypothetical protein suspected to be an nadph-dependent fmn reductase. after disrupting the cbei_4693 gene in c. beijerinckii ncimb 8052 using the clostron group ii intr ...201627164255
proteomic analysis to elucidate degeneration of clostridium beijerinckii ncimb 8052 and role of ca(2+) in strain recovery from degeneration.degeneration of solventogenic clostridium strains is one of the major barriers in bio-butanol production. a degenerated clostridium beijerinckii ncimb 8052 strain (dg-8052) was obtained without any genetic manipulation. supplementation of caco3 to fermentation medium could partially recover metabolism of dg-8052 by more than 50 % increase of cell growth and solvent production. this study investigated the protein expression profile of dg-8052 and its response to caco3 treatment. compared with wt- ...201627021843
evaluation of viability, metabolic activity and spore quantity in clostridial cultures during abe fermentation.flow cytometry, in combination with fluorescent staining, was used to evaluate population heterogeneity in acetone-butanol-ethanol fermentation that was carried out with type strain clostridium beijerinckii ncimb 8052 and non-type c. pasteurianum nrrl b-598. a combination of propidium iodide (pi) and carboxyfluorescein diacetate (cfda), pi plus syto-9 and bis-oxonol (box) alone were employed to distinguish between active and damaged cells together with simultaneous detection of spores. these str ...201626862145
improving isopropanol tolerance and production of clostridium beijerinckii dsm 6423 by random mutagenesis and genome shuffling.random mutagenesis and genome shuffling was applied to improve solvent tolerance and isopropanol/butanol/ethanol (ibe) production in the strictly anaerobic bacteria clostridium beijerinckii dsm 6423. following chemical mutagenesis with n-methyl-n-nitro-n-nitrosoguanidine (ntg), screening of putatively improved strains was done by submitting the mutants to toxic levels of inhibitory chemicals or by screening for their tolerance to isopropanol (>35 g/l). suicide substrates, such as ethyl or methyl ...201626852409
ex situ product recovery for enhanced butanol production by clostridium beijerinckii.in situ butanol recovery fermentation has been intensively studied as an effective alternative to conventional butanol production, which is limited due to the cellular toxicity of butanol. however, the low biocompatibility of adsorbents often leads to failure of in situ recovery fermentations. in this study, clostridium beijerinckii ncimb 8052 was cultured in flasks without shaking and in situ recovery fermentation was performed by using an adsorbent l493. the amounts of acetone, butanol, and et ...201626846537
enhanced butanol production by increasing nadh and atp levels in clostridium beijerinckii ncimb 8052 by insertional inactivation of cbei_4110.clostridium beijerinckii is identified as a promising clostridium strain for industrialization of acetone and butanol (ab) fermentation. it has been reported that high reducing power levels are associated with high butanol yield. in this study, we regulated reducing power by blocking nad(p)h consumption in c. beijerinckii ncimb 8052. gene cbei_4110, encoding nadh-quinone oxidoreductase (nuog), is a subunit of the electron transport chain complex i. after inactivation of gene cbei_4110, the gener ...201626830101
glutamate and histidine improve both solvent yields and the acid tolerance response of clostridium beijerinckii ncp 260.this study aims to examine the effect of amino acid supplementation on solvent production by clostridium beijerinckii during the acetone-butanol fermentation and to determine whether amino acids are involved in the acid tolerance response (atr), which results in increased solvents.201626789025
simultaneous glucose and xylose uptake by an acetone/butanol/ethanol producing laboratory clostridium beijerinckii strain se-2.most butanol-producing strains of clostridium prefer glucose over xylose, leading to a slower butanol production from lignocellulose hydrolysates. it is therefore beneficial to find and use a strain that can simultaneously use both glucose and xylose.201626721235
efficient butanol recovery from acetone-butanol-ethanol fermentation cultures grown on sweet sorghum juice by pervaporation using silicalite-1 membrane.we investigated butanol recovery by pervaporation separation, using a silicalite-1 membrane, from batch cultures of butanol-producing clostridium beijerinckii sbp2 grown on sweet sorghum juice as a fermentation medium. the pervaporation system yielded 73% (w/v) butanol from intact feed cultures containing 1% (w/v) butanol, and had a butanol permeation flux of 11 g m(-2) h(-1). upon neutralization and activated charcoal treatment of the feed cultures, butanol yield and total flux increased to 82% ...201626718336
production of butanol and isopropanol with an immobilized clostridium.clostridium beijerinckii optinoii is a clostridium species that produces butanol, isopropanol and small amounts of ethanol. this study compared the performances of batch and continuous immobilized cell fermentations, investigating how media flow rates and nutritional modification affected solvent yields and productivity. in 96-h batch cultures, with 80 % of the 30 g l(-1) glucose consumed in synthetic media, solvent concentration was 9.45 g l(-1) with 66.0 % as butanol. in a continuous fermentat ...201626712323
enhanced butanol production in a microbial electrolysis cell by clostridium beijerinckii ib4.reducing power such as nadh is an essential factor for acetone/butanol/ethanol (abe) fermentation using clostridium spp. the objective of this study was to increase available nadh in clostridium beijerinckii ib4 by a microbial electrolysis cell (mec) with an electron carrier to enhance butanol production. first of all, a mec was performed without electron carrier to study the function of cathodic potential applying. then, various electron carriers were tested, and neutral red (nr)-amended cultur ...201626615415
feasibility of a facile butanol bioproduction using planetary mill pretreatment.a facile butanol bioproduction process was developed using planetary milling, and pinus rigida wood waste as a model substrate for fermentable sugars. the use of planetary milling as the pretreatment eliminates the need for washing and transfer of the biomass prior to enzymatic hydrolysis. moreover, using this pretreatment process resulted in the production of only 0.072 ± 0.003 g/l soluble phenolic compounds, a concentration that was not inhibitory towards clostridium beijerinckii ncimb 8052. a ...201626372608
biosynthesis of the fatty acid isopropyl esters by engineered escherichia coli.the fatty acid methyl esters and fatty acid ethyl esters are known as biodiesels which are considered to be renewable, nontoxic and biodegradable biofuels. however, the conventional biodiesels show a high crystallization temperature which is one of the most critical obstacles against the widespread biodiesel usage. the high crystallization temperature of biodiesel can be reduced by replacing the methyl or ethyl ester with an isopropyl moiety. here we report on a strategy to establish biosynthesi ...201728465060
evidence of mixotrophic carbon-capture by n-butanol-producer clostridium beijerinckii.recent efforts to combat increasing greenhouse gas emissions include their capture into advanced biofuels, such as butanol. traditionally, biobutanol research has been centered solely on its generation from sugars. our results show partial re-assimilation of co2 and h2 by n-butanol-producer c. beijerinckii. this was detected as synchronous co2/h2 oscillations by direct (real-time) monitoring of their fermentation gasses. additional functional analysis demonstrated increased total carbon recovery ...201728986542
ferric iron and extracellular electron shuttling increase xylose utilization and butanol production during fermentation with multiple solventogenic bacteria.xylose is the second most abundant sugar derived from lignocellulose; it is considered less desirable than glucose for fermentation, and strategies that specifically increase xylose utilization in wild-type cells are goals for biofuel production. xylose consumption, butanol production, and hydrogen production increased in both clostridium beijerinckii and a novel solventogenic bacterium (strain dc-1) when anthraquinone-2,6,-disulfonate (aqds) or riboflavin were used as redox mediators to transfe ...201728963627
biobutanol production from apple pomace: the importance of pretreatment methods on the fermentability of lignocellulosic agro-food wastes.apple pomace was studied as a possible raw material for biobutanol production. five different soft physicochemical pretreatments (autohydrolysis, acids, alkalis, organic solvents and surfactants) were compared in a high-pressure reactor, whose working parameters (temperature, time and reagent concentration) were optimised to maximise the amount of simple sugars released and to minimise inhibitor generation. the pretreated biomass was subsequently subjected to a conventional enzymatic treatment t ...201728932978
erratum to: improving isopropanol tolerance and production of clostridium beijerinckii dsm 6423 by random mutagenesis and genome shuffling. 201728914328
conversion of food processing wastes to biofuel using clostridia.this study aims to demonstrate the recycling of food processing wastes as a low cost-effective substrate for acetone - butanol - ethanol (abe) production. potato peels and cheese whey were utilized during fermentation with eight local clostridium strains in addition to the commercial strain, c. acetobutylicum atcc 824 for abe and organic acids production. from potato peels, clostridium beijerinckii asu10 produced the highest abe production (17.91 g/l) representing 61.3% butanol (10.98 g/l), 33.6 ...201728823884
biobutanol production from brewer's spent grain hydrolysates by clostridium beijerinckii.brewer's spent grain (bsg) is a promising feedstock for abe fermentation. sulfuric acid pretreatment of bsg at ph 1, 121°c and different solid loadings (5-15% w/w) was investigated. enzymatic hydrolysis and abe fermentation by clostridium beijerinckii dsm 6422 of non-washed and washed pretreated bsg were performed to compare monosaccharide release and butanol production. pretreatment at 15% w/w bsg resulted in higher availability of sugars in both the enzymatic hydrolysates and pretreatment liqu ...201728779668
genomic, transcriptional, and phenotypic analysis of the glucose derepressed clostridium beijerinckii mutant exhibiting acid crash phenotype.clostridium beijerinckii is a predominant solventogenic bacterium that is used for the abe fermentation. various c. beijerinckii mutants are constructed for desirable phenotypes. the c. beijerinckii mutant ba105 harboring a glucose derepression phenotype was previously isolated and demonstrated the enhanced amylolytic activity in the presence of glucose. despite its potential use, ba105 is not further characterized and utilized. therefore, the authors investigate fermentation phenotypes of ba105 ...201728762642
enhanced robustness in acetone-butanol-ethanol fermentation with engineered clostridium beijerinckii overexpressing adhe2 and ctfab.clostridium beijerinckii cc101 was engineered to overexpress aldehyde/alcohol dehydrogenase (adhe2) and coa-transferase (ctfab). solvent production and acid assimilation were compared between the parental and engineered strains expressing only adhe2 (cc101-sv4) and expressing adhe2, ald and ctfab (cc101-sv6). cc101-sv4 showed an early butanol production from glucose but stopped pre-maturely at a low butanol concentration of ∼6g/l. compared to cc101, cc101-sv6 produced more butanol (∼12g/l) from ...201728747008
enhanced n-butanol production by clostridium beijerinckii mcmb 581 in presence of selected surfactant.extractive butanol fermentation with non-ionic surfactant, a recently explored area, has shown promising results with several advantages but is relatively less investigated. this work reports the extractive fermentation with selected non-ionic surfactants (l62 and l62d) to enhance butanol production using a high-butanol producing strain (clostridium beijerinckii mcmb 581). biocompatibility studies with both the surfactants showed growth. higher concentrations of surfactant (>5%) affected the cel ...201728660448
a novel glycosylated solution from dioscorea zingiberensis c.h. wright significantly improves the solvent productivity of clostridium beijerinckii.the economics of bio-solvent production are largely dependent on the cost of the fermentation substrate. dioscorea zingiberensis c.h. wright (dzw), the main raw material used to produce saponin, contains 13-18% starch which can be directly saccharified to a saccharification liquid of dzw starch (slds) that contains abundant nutrients. in this study, the water-soluble micromolecule compounds in slds were quantified through 1h nmr. using slds as the substrate to conduct abe fermentation by clostri ...201728577480
mono- and co-substrate utilization kinetics using mono- and co-culture of clostridium beijerinckii and clostridium saccharoperbutylacetonicum.the effect of co-culturing c. beijerinckii and c. saccharoperbutylacetonicum for h2 production using mono- and co-substrates of glucose, starch, and cellulose was assessed. monod kinetic parameters (k, maximum specific substrate utilization rate; and ks, half-saturation constant) of the c. beijerinckii, c. saccharoperbutylacetonicum, and the co-culture were determined. co-cultures utilizing glucose competed for the substrate, but showed enhancement for utilizing starch. the maximum values for k ...201728554101
hydrogen production and microbial kinetics of clostridium termitidis in mono-culture and co-culture with clostridium beijerinckii on cellulose.cellulose utilization by hydrogen producers remains an issue due to the low hydrogen yields reported and the pretreatment of cellulose prior to fermentation requires complex and expensive steps. clostridium termitidis is able to breakdown cellulose into glucose and produce hydrogen. on the other hand, clostridium beijerinckii is not able to degrade cellulose but is adept at hydrogen production from glucose; therefore, it was chosen to potentially enhance hydrogen production when co-cultured with ...201728429329
genome editing in clostridium saccharoperbutylacetonicum n1-4 with the crispr-cas9 system.clostridium saccharoperbutylacetonicum n1-4 is well known as a hyper-butanol-producing strain. however, the lack of genetic engineering tools hinders further elucidation of its solvent production mechanism and development of more robust strains. in this study, we set out to develop an efficient genome engineering system for this microorganism based on the clustered regularly interspaced short palindromic repeats (crispr) and crispr-associated 9 (crispr-cas9) system. first, the functionality of t ...201728258147
transcriptome analysis of clostridium beijerinckii adaptation mechanisms in response to ferulic acid.clostridium beijerinckii 4693:int with high ferulic acid (fa) tolerance was engineered and characterized in our lab. in this study, the minimum inhibition concentrations of fa against c. beijerinckii ncimb 8052 (wild-type) and 4693:int were 1.0 and 1.5g/l, respectively; cell viability was 18.5% and 106.7%, respectively, in the presence of 0.5g/l fa. a comparative transcriptome analysis was carried out at two different growth stages to evaluate sensitivity to fa. genes that were differentially ex ...201728242360
sigma factor regulated cellular response in a non-solvent producing clostridium beijerinckii degenerated strain: a comparative transcriptome analysis.clostridium beijerinckii dg-8052, derived from ncimb 8052, cannot produce solvent or form spores, a phenomenon known as degeneration. to explore the mechanisms of degeneration at the gene level, transcriptomic profiles of the wild-type 8052 and dg-8052 strains were compared. expression of 5168 genes comprising 98.6% of the genome was assessed. interestingly, 548 and 702 genes were significantly up-regulated in the acidogenesis and solventogenesis phases of dg-8052, respectively, and mainly respo ...201728194137
modulation of the acetone/butanol ratio during fermentation of corn stover-derived hydrolysate by clostridium beijerinckii strain ncimb 8052.producing biobutanol from lignocellulosic biomass has shown promise to ultimately reduce greenhouse gases and alleviate the global energy crisis. however, because of the recalcitrance of a lignocellulosic biomass, a pretreatment of the substrate is needed which in many cases releases soluble lignin compounds (slcs), which inhibit growth of butanol-producing clostridia. in this study, we found that slcs changed the acetone/butanol ratio (a/b ratio) during butanol fermentation. the typical a/b mol ...201728130305
reclassification of non-type strain clostridium pasteurianum nrrl b-598 as clostridium beijerinckii nrrl b-598.the complete genome sequence of non-type strain clostridium pasteurianum nrrl b-598 was introduced last year; it is an oxygen tolerant, spore-forming, mesophilic heterofermentative bacterium with high hydrogen production and acetone-butanol fermentation ability. the basic genome statistics have shown its similarity to c. beijerinckii rather than the c. pasteurianum species. here, we present a comparative analysis of the strain with several other complete clostridial genome sequences. besides a 1 ...201728111164
degradation of the fungal cell wall by clostridial strains isolated from soil subjected to biological soil disinfestation and biocontrol of fusarium wilt disease of spinach.biological soil disinfestation (bsd) involves elimination of soil-borne plant pathogens in an environmentally friendly manner. two anaerobic bacterial strains (h110 and tb8) isolated from bsd-treated soil samples were analyzed for their roles in elimination of pathogenic fungi. the two strains were identified as clostridium beijerinckii based on 16s rrna gene sequences and phenotypic properties. the strains fermented various carbohydrates and produced acetate, butyrate, and n-butanol as major pr ...201728967048
[periodontal microbiota and microorganisms isolated from heart valves in patients undergoing valve replacement surgery in a clinic in cali, colombia].periodontitis is an infectious disease that affects the support tissue of the teeth and it is associated with different systemic diseases, including cardiovascular disease. microbiological studies facilitate the detection of microorganisms from subgingival and cardiovascular samples.201729373772
renewable synthesis of n-butyraldehyde from glucose by engineered escherichia coli.n-butyraldehyde is a high-production volume chemical produced exclusively from hydroformylation of propylene. it is a versatile chemical used in the synthesis of diverse c4-c8 alcohols, carboxylic acids, esters, and amines. its high demand and broad applications make it an ideal chemical to be produced from biomass.201729213330
characterization of a clostridium beijerinckii spo0a mutant and its application for butyl butyrate production.spo0a is a master regulator that governs the metabolic shift of solventogenic clostridium species such as clostridium beijerinckii. its disruption can thus potentially cause a significant alteration of cellular physiology as well as metabolic patterns. to investigate the specific effect of spo0a disruption in c. beijerinckii, a spo0a mutant of c. beijerinckii was characterized in this study. in a batch fermentation with ph control at 6.5, the spo0a mutant accumulated butyrate and butanol up to 8 ...201727474812
enhanced solvent production by metabolic engineering of a twin-clostridial consortium.the efficient fermentative production of solvents (acetone, n-butanol, and ethanol) from a lignocellulosic feedstock using a single process microorganism has yet to be demonstrated. herein, we developed a consolidated bioprocessing (cbp) based on a twin-clostridial consortium composed of clostridium cellulovorans and clostridium beijerinckii capable of producing cellulosic butanol from alkali-extracted, deshelled corn cobs (aecc). to accomplish this a genetic system was developed for c. cellulov ...201727794465
engineering cofactor flexibility enhanced 2,3-butanediol production in escherichia coli.enzymatic reduction of acetoin into 2,3-butanediol (2,3-bd) typically requires the reduced nicotinamide adenine dinucleotide (nadh) or its phosphate form (nadph) as electron donor. efficiency of 2,3-bd biosynthesis, therefore, is heavily influenced by the enzyme specificity and the cofactor availability which varies dynamically. this work describes the engineering of cofactor flexibility for 2,3-bd production by simultaneous overexpression of an nadh-dependent 2,3-bd dehydrogenase from klebsiell ...201729116429
the draft genome sequence of clostridium beijerinckii njp7, a unique bacterium capable of producing isopropanol-butanol from hemicellulose through consolidated bioprocessing.a wild type solventogenic clostridium beijerinckii njp7 capable of converting polysaccharides, such as hemicellulose, into butanol and isopropanol via a unique acetone-isopropanol-butanol (aib) pathway was isolated and characterized. this represents the first wild type isopropanol-butanol generating bacterium which could achieve butanol production directly from lignocellulose through consolidated bioprocessing (cbp). strain njp7 was isolated from decomposite soil from laoshan nature park, china, ...201729063966
comparison of expression of key sporulation, solventogenic and acetogenic genes in c. beijerinckii nrrl b-598 and its mutant strain overexpressing spo0a.the production of acetone, butanol and ethanol by fermentation of renewable biomass has potential to become a valuable industrial process. mechanisms of solvent production and sporulation involve some common regulators in some abe-producing clostridia, although details of the links between the pathways are not clear. in this study, we compare a wild-type (wt) clostridium beijerinckii nrrl b-598 with its mutant strain oespo0a, in which the gene encoding spo0a, an important regulator of both sporu ...201728990140
development of an oxygen-independent flavin mononucleotide-based fluorescent reporter system in clostridium beijerinckii and its potential applications.clostridium beijerinckii is a predominant solventogenic clostridia with great attraction for renewable liquid biofuel and biochemical production. metabolic engineering and synthetic biology can be employed to engineer the strain toward desirable phenotypes. however, current limited information such as promoter strength and gene regulation may hinder the efficient engineering of the strain. to investigate genetic information and complex cellular bioprocesses of c. beijerinckii, an in vivo fluores ...201829158189
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