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thermotolerant and mesophylic fungi from sugarcane bagasse and their prospection for biomass-degrading enzyme production.nineteen fungi and seven yeast strains were isolated from sugarcane bagasse piles from an alcohol plant located at brazilian cerrado and identified up to species level on the basis of the gene sequencing of 5.8s-its and 26s ribosomal dna regions. four species were identified: kluyveromyces marxianus, aspergillus niger, aspergillus sydowii and aspergillus fumigatus, and the isolates were screened for the production of key enzymes in the saccharification of lignocellulosic material. among them, th ...201726413077
taggiasca extra virgin olive oil colonization by yeasts during the extraction process.the opalescent appearance of the newly produced olive oil is due to the presence of solid particles and microdrops of vegetation water in which the microorganisms from the olives' carposphere are trapped. present research has demonstrated that the microbiota of the fresh extracted olive oil, produced in the mills, is mainly composed of yeasts and to a lesser extent of molds. the close link between the composition of the microbiota of the olives' carposphere undergoing to processing, and that of ...201727889166
encapsulated whey-native yeast kluyveromyces marxianus as a feed additive for animal production.whey is the main byproduct of the cheese industry. while the composition is variable, it retains up to 55% of milk nutrients. the beneficial features of whey indicates a promising source of new potentially probiotic strains for the development of food additives destined for animal production. the aim of this study was to identify kluyveromyces spp. isolated from whey, to study some probiotic properties and to select the best strain to be encapsulated using derivatised chitosan. kluyveromyces mar ...201728277172
anti-salmonella activity and probiotic trends of kluyveromyces marxianus s-2-05 and kluyveromyces lactis s-3-05 isolated from a french cheese, tomme d'orchies.kluyveromyces marxianus s-2-05 and kluyveromyces lactis s-3-05 were recently isolated from a traditional french cheese, tomme d'orchies, and characterized here for their advantages using a different application perspective. first, we established their anti-salmonella activity and downregulation of the virulence sopd gene of salmonella enterica subsp. enterica serovar typhimurium, mainly in the presence of k. marxianus s-2-05. in addition to their antagonism, these non-saccharomyces yeasts were a ...201728366839
enhanced fermentative performance under stresses of multiple lignocellulose-derived inhibitors by overexpression of a typical 2-cys peroxiredoxin from kluyveromyces marxianus.bioethanol from lignocellulosic materials is of great significance to the production of renewable fuels due to its wide sources. however, multiple inhibitors generated from pretreatments represent great challenges for its industrial-scale fermentation. despite the complex toxicity mechanisms, lignocellulose-derived inhibitors have been reported to be related to the levels of intracellular reactive oxygen species (ros), which makes oxidoreductase a potential target for the enhancement of the tole ...201728360937
utilization of inulin-containing waste in industrial fermentations to produce biofuels and bio-based chemicals.inulins are polysaccharides that belong to an important class of carbohydrates known as fructans and are used by many plants as a means of storing energy. inulins contain 20 to several thousand fructose units joined by β-2,1 glycosidic bonds, typically with a terminal glucose unit. plants with high concentrations of inulin include: agave, asparagus, coffee, chicory, dahlia, dandelion, garlic, globe artichoke, jerusalem artichoke, jicama, onion, wild yam, and yacón. to utilize inulin as its carbo ...201728341907
identification of hexose kinase genes in kluyveromyces marxianus and thermo-tolerant one step producing glucose-free fructose strain construction.in yeast, the hexose assimilation is started at hexose phosphorylation. however, in kluyveromyces marxianus, the hexokinase (hxk) and glucokinase (glk) genes were not identified by experiments. meanwhile, the glucose-free fructose product requires more cost-efficient method. in this study, the kmhxk1 and kmglk1 genes were functionally identified through gene disruption, over-expression and recombinant enzymes characterization. both glucose and fructose assimilation ability decreased significantl ...201728338054
transforming sugars into fat-lipid biosynthesis using different sugars in yarrowia lipolytica.in an era of ever-increasing energy demands, a promising technology is being developed: the use of oleaginous microorganisms such as yarrowia lipolytica to convert waste materials into biofuels. here, we constructed two y. lipolytica strains that displayed both increased lipid accumulation and a more efficient use of biomass-derived sugars, including glucose, fructose, galactose, and inulin. the first strain, y. lipolytica ylz150, was derived from the french wild-type strain w29. it had inhibite ...201728303649
comparative analysis of oxidative stress during aging of kluyveromyces marxianus in synthetic and whey media.during the aging of yeast culture, kluyveromyces marxianus undergoes a number of changes in physiology and these changes play a significant role during fermentation. aged stationary phase cells were found to contain more reactive oxygen species. additionally, the level of oxidant is counteracted by the antioxidant defense system of the cells. comparison of 3-day-old culture of k. marxianus with 45-day stationary phase culture represents an increased level of ros inside the cells. moreover, a dec ...201728281180
electron transport chain in a thermotolerant yeast.yeasts capable of growing and surviving at high temperatures are regarded as thermotolerant. for appropriate functioning of cellular processes and cell survival, the maintenance of an optimal redox state is critical of reducing and oxidizing species. we studied mitochondrial functions of the thermotolerant kluyveromyces marxianus slp1 and the mesophilic off1 yeasts, through the evaluation of its mitochondrial membrane potential (δψm), atpase activity, electron transport chain (etc) activities, a ...201728181110
genetic improvement of xylose metabolism by enhancing the expression of pentose phosphate pathway genes in saccharomyces cerevisiae ir-2 for high-temperature ethanol production.the pentose phosphate pathway (ppp) plays an important role in the efficiency of xylose fermentation during cellulosic ethanol production. in simultaneous saccharification and co-fermentation (sscf), the optimal temperature for cellulase hydrolysis of lignocellulose is much higher than that of fermentation. successful use of sscf requires optimization of the expression of ppp genes at elevated temperatures. this study examined the combinatorial expression of ppp genes at high temperature. the re ...201728181081
erratum for inokuma et al., complete genome sequence of kluyveromyces marxianus nbrc1777, a nonconventional thermotolerant yeast. 201728153883
oxidative stress and antioxidant response in a thermotolerant yeast.stress tolerance is a key attribute that must be considered when using yeast cells for industrial applications. high temperature is one factor that can cause stress in yeast. high environmental temperature in particular may exert a natural selection pressure to evolve yeasts into thermotolerant strains. in the present study, three yeasts (saccharomyces cerevisiae, mc4, and kluyveromyces marxianus, off1 and slp1) isolated from hot environments were exposed to increased temperatures and were then ...201728094115
cellulose biorefinery based on a combined catalytic and biotechnological approach for production of 5-hmf and ethanol.in this study, a combination of catalytic and biotechnological processes was proposed for the first time for application in a cellulose biorefinery for the production of 5-hydroxymethylfurfural (5-hmf) and bioethanol. hydrolytic dehydration of the mechanically activated microcrystalline cellulose over a carbon-based mesoporous sibunt-4 catalyst resulted in moderate yields of glucose and 5-hmf (21.1-25.1 and 6.6-9.4 %). 5-hmf was extracted from the resulting mixture with isobutanol and subjected ...201727995758
chemical structure, antiproliferative and antioxidant activities of a cell wall α-d-mannan from yeast kluyveromyces marxianus.cell wall polysaccharides from filamentous fungi and yeasts have been reported as antioxidant and antiproliferative polymers. thus, we evaluated these activities from cell wall polysaccharides from kluyveromyces marxianus cct7735. by using a centrifugal filter, a 203kda α-d-mannan (kmm-5) was obtained. kmm-5 exhibited no effect on hela cells and a weak antiproliferative activity against hep-g2 cells. in addition, at higher concentrations, it presented a cytotoxicity to the normal cell line, 3t3. ...201727987836
engineered kluyveromyces marxianus for pyruvate production at elevated temperature with simultaneous consumption of xylose and glucose.xylose and glucose from lignocellulose are sustainable sources for production of pyruvate, which is the starting material for the synthesis of many drugs and agrochemicals. in this study, the pyruvate decarboxylase gene (kmpdc1) and glycerol-3-phosphate dehydrogenase gene (kmgpd1) of kluyveromyces marxianus yzj051 were disrupted to prevent ethanol and glycerol accumulation. the deficient growth of pdc disruption was rescued by overexpressing mutant kmmth1-δt. then pentose phosphate pathway and x ...201727955868
volatile metabolites produced from agro-industrial wastes by na-alginate entrapped kluyveromyces marxianus.the aim of this study was to evaluate the effects of alginate entrapment on fermentation metabolites of kluyveromyces marxianus grown in agrowastes that served as the liquid culture media. k. marxianus cells entrapped in na-alginate were prepared using the traditional liquid-droplet-forming method. whey and pomaces from processed tomatoes, peppers, and grapes were used as the culture media. the changes in the concentrations of sugar, alcohol, organic acids, and flavor compounds were analyzed usi ...201727515464
immobilization of yeast inulinase on chitosan beads for the hydrolysis of inulin in a batch system.an extracellular inulinase was partially purified by ethanol precipitation and gel exclusion chromatography from a cell free extract of kluyveromyces marxianus. partially purified inulinase exhibited 420 iu/mg specific activity and it was immobilized on chitosan beads. activity yield of immobilized inulinase was optimized with glutaraldehyde concentration (1-5%), glutaraldehyde treatment time (30-240min), enzyme coupling-time (2-16h) and enzyme loading (5-30 iu) as functions. under the optimized ...201727845224
modeling of exo-inulinase biosynthesis by kluyveromyces marxianus in fed-batch mode: correlating production kinetics and metabolic heat fluxes.a metabolic heat-based model was used for estimating the growth of kluyveromyces marxianus, and the modified luedeking-piret kinetic model was used for describing the inulinase production kinetics. for the first time, a relationship was developed to relate inulinase production kinetics directly to metabolic heat generated, which corroborated well with the experimental data (with r (2) values of above 0.9). it also demonstrated the predominantly growth-associated nature of the inulinase productio ...201727844140
selection of error-less synthetic genes in yeast.conventional gene synthesis is usually accompanied by sequence errors, which are often deletions derived from chemically synthesized oligonucleotides. such deletions lead to frame shifts and mostly result in premature translational terminations. therefore, in-frame fusion of a marker gene to the downstream of a synthetic gene is an effective strategy to select for frame-shift-free synthetic genes. functional expression of fused marker genes indicates that synthetic genes are translated without p ...201727671945
co-expression of two heterologous lactate dehydrogenases genes in kluyveromyces marxianus for l-lactic acid production.lactic acid (la) is a versatile compound used in the food, pharmaceutical, textile, leather, and chemical industries. biological production of la is possible by yeast strains expressing a bacterial gene encoding l-lactate dehydrogenase (ldh). kluyveromyces marxianus is an emerging non-conventional yeast with various phenotypes of industrial interest. however, it has not been extensively studied for la production. in this study, k. marxianus was engineered to express and co-express various hetero ...201727867078
yeast derived from lignocellulosic biomass as a sustainable feed resource for use in aquaculture.the global expansion in aquaculture production implies an emerging need of suitable and sustainable protein sources. currently, the fish feed industry is dependent on high-quality protein sources of marine and plant origin. yeast derived from processing of low-value and non-food lignocellulosic biomass is a potential sustainable source of protein in fish diets. following enzymatic hydrolysis, the hexose and pentose sugars of lignocellulosic substrates and supplementary nutrients can be converted ...201727558451
high throughput, colorimetric screening of microbial ester biosynthesis reveals high ethyl acetate production from kluyveromyces marxianus on c5, c6, and c12 carbon sources.advances in genome and metabolic pathway engineering have enabled large combinatorial libraries of mutant microbial hosts for chemical biosynthesis. despite these advances, strain development is often limited by the lack of high throughput functional assays for effective library screening. recent synthetic biology efforts have engineered microbes that synthesize acetyl and acyl esters and many yeasts naturally produce esters to significant titers. short and medium chain volatile esters have valu ...201627528369
probiotic yeast kluyveromyces marxianus cidca 8154 shows anti-inflammatory and anti-oxidative stress properties in in vivo models.inflammatory bowel diseases (ibds) are complex affections with increasing incidence worldwide. multiple factors are involved in the development and maintenance of the symptoms including enhanced oxidative stress in intestinal mucosa. the conventional therapeutic approaches for ibds are based on the use anti-inflammatory drugs with important collateral effects and partial efficacy. in the present work we tested the anti-inflammatory capacity of kluyveromyces marxianus cidca 8154 in different mode ...201626565081
survival of the functional yeast kluyveromyces marxianus b0399 in fermented milk with added sorbic acid.in this study, the survival of the functional yeast kluyveromyces marxianus b0399 in an industrially produced fermented milk was evaluated. in particular, the yeast viability was assessed throughout the entire shelf-life of the product (30 d) to ensure the presence of the effective yeast dose (20 million viable cells for each serving of 125 g) while avoiding, by sorbic acid addition, yeast growth, which could affect product quality and stability. to find the best combination of yeast and sorbic ...201626547644
potential application of aqueous two-phase systems and three-phase partitioning for the recovery of superoxide dismutase from a clarified homogenate of kluyveromyces marxianus.superoxide dismutase (sod; ec 1.15.1.1) is an antioxidant enzyme that represents the primary cellular defense against superoxide radicals and has interesting applications in the medical and cosmetic industries. in the present work, the partition behavior of sod in aqueous two-phase systems (atps) (using a standard solution and a complex extract from kluyveromyces marxianus as sample) was characterized on different types of atps (polymer-polymer, polymer-salt, alcohol-salt, and ionic liquid (il)- ...201625138773
isolation, identification and characterization of yeasts from fermented goat milk of the yaghnob valley in tajikistan.the geographically isolated region of the yaghnob valley, tajikistan, has allowed its inhabitants to maintain a unique culture and lifestyle. their fermented goat milk constitutes one of the staple foods for the yaghnob population, and is produced by backslopping, i.e., using the previous fermentation batch to inoculate the new one. this study addresses the yeast composition of the fermented milk, assessing genotypic, and phenotypic properties. the 52 isolates included in this study revealed sma ...201627857705
draft genome sequence of the probiotic yeast kluyveromyces marxianus fragilis b0399.here, we report the draft genome sequence of kluyveromyces marxianus fragilis b0399, the first yeast approved as a probiotic for human consumption not belonging to the genus saccharomyces the genome is composed of 8 chromosomes, with a total size of 11.44 mb, including mitochondrial dna.201627587830
batch and fed-batch simultaneous saccharification and fermentation of primary sludge from pulp and paper mills.primary sludge from a portuguese pulp and paper mill, containing 60% of carbohydrates, and unbleached pulp (as reference material), with 93% of carbohydrates, were used to produce ethanol by simultaneous saccharification and fermentation (ssf). ssf was performed in batch or fed-batch conditions without the need of a pretreatment. cellic(®) ctec2 was the cellulolytic enzymatic complex used and saccharomyces cerevisiae (baker's yeast or atcc 26602 strain) or the thermotolerant yeast kluyveromyces ...201627611735
dynamics of yeast immobilized-cell fluidized-bed bioreactors systems in ethanol fermentation from lactose-hydrolyzed whey and whey permeate.we studied the dynamics of ethanol production on lactose-hydrolyzed whey (lhw) and lactose-hydrolyzed whey permeate (lhwp) in batch fluidized-bed bioreactors using single and co-cultures of immobilized cells of industrial strains of saccharomyces cerevisiae and non-industrial strains of kluyveromyces marxianus. although the co-culture of s. cerevisiae cat-1 and k. marxianus cct 4086 produced two- to fourfold the ethanol productivity of single cultures of s. cerevisiae, the single cultures of the ...201626527573
kefir-isolated bacteria and yeasts inhibit shigella flexneri invasion and modulate pro-inflammatory response on intestinal epithelial cells.the aim of this work was to evaluate the ability of a kefir-isolated microbial mixture containing three bacterial and two yeast strains (mm) to protect intestinal epithelial cells against shigella flexneri invasion, as well as to analyse the effect on pro-inflammatory response elicited by this pathogen. a significant decrease in s. flexneri strain 72 invasion was observed on both ht-29 and caco-2 cells pre-incubated with mm. pre-incubation with the individual strains saccharomyces cerevisiae cid ...201626503738
cloning, expression, characterization, and mutagenesis of a thermostable exoinulinase from kluyveromyces cicerisporus.inulinase is an enzyme that belongs to glycoside hydrolase family 32. it converts inulin into high-fructose syrups and fructoligosaccharides, both of which are widely used in pharmaceutical and food industries. in this study, the kcinu1 gene (genbank accession number af178979) encoding an exoinulinase was cloned from kluyveromyces cicerisporus cbs4857 and expressed in pichia pastoris x-33, yielding a maximum of 45.2 ± 0.6 u ml(-1) of inulinase activity of culture supernatant. the expressed inuli ...201626446826
acquisition of the yeast kluyveromyces marxianus from unpasteurised milk by a kefir grain enhances kefir quality.kefir is a fermented milk beverage consumed for nutritional and health tonic benefits in many parts of the world. it is produced by the fermentation of milk with a consortium of bacteria and yeast embedded within a polysaccharide matrix. this consortium is not well defined and can vary substantially between kefir grains. there are little data on the microbial stability of kefir grains, nor on interactions between microbes in the grain and in the milk. to study this, a grain was split, with one h ...201627369085
differential rna-seq, multi-network analysis and metabolic regulation analysis of kluyveromyces marxianus reveals a compartmentalised response to xylose.we investigated the transcriptomic response of a new strain of the yeast kluyveromyces marxianus, in glucose and xylose media using rna-seq. the data were explored in a number of innovative ways using a variety of networks types, pathway maps, enrichment statistics, reporter metabolites and a flux simulation model, revealing different aspects of the genome-scale response in an integrative systems biology manner. the importance of the subcellular localisation in the transcriptomic response is emp ...201627315089
multilocus analysis reveals large genetic diversity in kluyveromyces marxianus strains isolated from parmigiano reggiano and pecorino di farindola cheeses.in the present study, we have analysed the genetic diversity in kluyveromyces marxianus isolated from parmigiano reggiano and pecorino di farindola cheesemaking environment. molecular typing methods inter-rtl fingerprint and mtdna rflps, as well as, sequence diversity and heterozygosity in the intergenic region between kmssb1 and kmrio2 genes and analysis of the mating locus were applied to 54 k. marxianus strains. inter-rtl fingerprint revealed a large degree of genetic heterogeneity and cluste ...201627294555
isolation, identification and oenological characterization of non-saccharomyces yeasts in a mediterranean island.we isolated, identified and characterized yeast strains from grapes, and their fermented musts, sampled in the small island of linosa, where there are no wineries and therefore the possibility of territory contamination by industrial strains is minimal. by traditional culture-dependent methods, we isolated 3805 colonies, distinguished by molecular methods in 17 different species. five hundred and forty-four isolates were analysed for the main oenological characteristics such as fermentative vigo ...201627261362
kluyveromyces marxianus as a host for heterologous protein synthesis.the preferentially respiring and thermotolerant yeast kluyveromyces marxianus is an emerging host for heterologous protein synthesis, surpassing the traditional preferentially fermenting yeast saccharomyces cerevisiae in some important aspects: k . marxianus can grow at temperatures 10 °c higher than s. cerevisiae, which may result in decreased costs for cooling bioreactors and reduced contamination risk; has ability to metabolize a wider variety of sugars, such as lactose and xylose; is the fas ...201627260286
simultaneous fermentation of glucose and xylose at elevated temperatures co-produces ethanol and xylitol through overexpression of a xylose-specific transporter in engineered kluyveromyces marxianus.engineered kluyveromyces marxianus strains were constructed through over-expression of various transporters for simultaneous co-fermentation of glucose and xylose. the glucose was converted into ethanol, whereas xylose was converted into xylitol which has higher value than ethanol. over-expressing xylose-specific transporter scgal2-n376f mutant enabled yeast to co-ferment glucose and xylose and the co-fermentation ability was obviously improved through increasing scgal2-n376f expression. the pro ...201627240239
enhanced exo-inulinase activity and stability by fusion of an inulin-binding module.in this study, an inulin-binding module from bacillus macerans was successfully fused to an exo-inulinase from kluyveromyces marxianus, creating a hybrid functional enzyme. the recombinant exo-inulinase (rinu), the hybrid enzyme (rinuibm), and the recombinant inulin-binding module (ribm) were, respectively, heterologously expressed and biochemically characterized. it was found that both the inulinase activity and the catalytic efficiency (k cat/k m(app)) of the rinuibm were considerably higher t ...201627164865
growth, ethanol production, and inulinase activity on various inulin substrates by mutant kluyveromyces marxianus strains nrrl y-50798 and nrrl y-50799.economically important plants contain large amounts of inulin. disposal of waste resulting from their processing presents environmental issues. finding microorganisms capable of converting inulin waste to biofuel and valuable co-products at the processing site would have significant economic and environmental impact. we evaluated the ability of two mutant strains of kluyveromyces marxianus (km7 and km8) to utilize inulin for ethanol production. in glucose medium, both strains consumed all glucos ...201627130462
immobilized kluyveromyces marxianus cells in carboxymethyl cellulose for production of ethanol from cheese whey: experimental and kinetic studies.cheese whey fermentation to ethanol using immobilized kluyveromyces marxianus cells was investigated in batch and continuous operation. in batch fermentation, the yeast cells were immobilized in carboxymethyl cellulose (cmc) polymer and also synthesized graft copolymer of cmc with n-vinyl-2-pyrrolidone, denoted as cmc-g-pvp, and the efficiency of the two developed cell entrapped beads for lactose fermentation to ethanol was examined. the yeast cells immobilized in cmc-g-pvp performed slightly be ...201627126500
a new method to determine optimum temperature and activation energies for enzymatic reactions.a new method for determination of the optimum temperature and activation energies based on an idea of the average rate of enzymatic reaction has been developed. a mathematical model describing the effect of temperature on a dimensionless activity for enzyme deactivation following the first-order kinetics has been derived. the necessary condition for existence of the function extreme of the optimal temperature has been applied in the model. the developed method has been verified using the experim ...201627066801
utilization of cheese whey using synergistic immobilization of β-galactosidase and saccharomyces cerevisiae cells in dual matrices.whey is a byproduct of the dairy industry, which has prospects of using as a source for production of various valuable compounds. the lactose present in whey is considered as an environmental pollutant and its utilization for enzyme and fuel production, may be effective for whey bioremediation. the dairy yeast kluyveromyces marxianus have the ability to utilize lactose sharply as the major carbon source for the production of the enzyme. five strains were tested for the production of the β-galact ...201627059625
evaluation of galactose adapted yeasts for bioethanol fermentation from kappaphycus alvarezii hydrolyzates.bioethanol was produced from kappaphycus alvarezii seaweed biomass using separate hydrolysis and fermentation (shf). pretreatment was evaluated for 60 min at 121°c using 12% (w/v) biomass slurry with 364 mm h2so4. enzymatic saccharification was then carried out at 45°c for 48 h using celluclast 1.5 l. ethanol fermentation with 12% (w/v) k. alvarezii hydrolyzate was performed using the yeasts saccharomyces cerevisiae kctc1126, kluyveromyces marxianus kctc7150, and candida lusitaniae atcc42720 wit ...201627056472
indigenous georgian wine-associated yeasts and grape cultivars to edit the wine quality in a precision oenology perspective.in georgia, one of the most ancient vine-growing environment, the homemade production of wine is still very popular in every rural family and spontaneous fermentation of must, without addition of chemical preservatives, is the norm. the present work investigated the yeast biodiversity in five georgian areas (guria, imereti, kakheti, kartli, ratcha-lechkhumi) sampling grapes and wines from 22 different native cultivars, in 26 vineyards and 19 family cellars. one hundred and eighty-two isolates we ...201627047468
efficient conversion of xylose to ethanol by stress-tolerant kluyveromyces marxianus bunl-21.the fermentation ability of thermotolerant kluyveromyces marxianus bunl-21 isolated in laos was investigated. comparison with thermotolerant k. marxianus dmku3-1042 as one of the most thermotolerant yeasts isolated previously revealed that the strain possesses stronger ability for conversion of xylose to ethanol, resistance to 2-deoxyglucose in the case of pentose, and tolerance to various stresses including high temperature and hydrogen peroxide. k. marxianus bunl-21 was found to have ethanol f ...201627026881
effects of glucose, ethanol and acetic acid on regulation of adh2 gene from lachancea fermentati.background. not all yeast alcohol dehydrogenase 2 (adh2) are repressed by glucose, as reported in saccharomyces cerevisiae. pichia stipitis adh2 is regulated by oxygen instead of glucose, whereas kluyveromyces marxianus adh2 is regulated by neither glucose nor ethanol. for this reason, adh2 regulation of yeasts may be species dependent, leading to a different type of expression and fermentation efficiency. lachancea fermentati is a highly efficient ethanol producer, fast-growing cells and adapte ...201626989608
evaluation of hyper thermal acid hydrolysis of kappaphycus alvarezii for enhanced bioethanol production.hyper thermal (ht) acid hydrolysis of kappaphycus alvarezii, a red seaweed, was optimized to 12% (w/v) seaweed slurry content, 180mm h2so4 at 140°c for 5min. the maximum monosaccharide concentration of 38.3g/l and 66.7% conversion from total fermentable monosaccharides of 57.6g/l with 120gdw/l k. alvarezii slurry were obtained from ht acid hydrolysis and enzymatic saccharification. ht acid hydrolysis at a severity factor of 0.78 efficiently converted the carbohydrates of seaweed to monosaccharid ...201626950757
functional elucidation of the non-coding rnas of kluyveromyces marxianus in the exponential growth phase.non-coding rnas (ncrnas), which perform diverse regulatory roles, have been found in organisms from all superkingdoms of life. however, there have been limited numbers of studies on the functions of ncrnas, especially in nonmodel organisms such as kluyveromyces marxianus that is widely used in the field of industrial biotechnology.201626923790
effects of acetate on kluyveromyces marxianus dsm 5422 growth and metabolism.metabolically active cells produce a wide array of metabolites that can inhibit their growth. acetate is a widely known preservative, and it is also produced by yeast cells during their growth. kluyveromyces marxianus dsm 5422 is a promising yeast strain that could be employed in biotechnological processes, but the knowledge of its stress physiology is scarce. here, we investigate the effects of acetate on growth and changes in cell population structure during adaptation to elevated concentratio ...201626910042
enhancement in xylose utilization using kluyveromyces marxianus nire-k1 through evolutionary adaptation approach.the evolutionary adaptation was carried out on the thermotolerant yeast kluyveromyces marxianus nire-k1 at 45 °c up to 60 batches to enhance its xylose utilization capability. the adapted strain showed higher specific growth rate and 3-fold xylose uptake rate and short lag phase as compared to the native strain. during aerobic growth adapted yeast showed 2.81-fold higher xylose utilization than that of native. in anaerobic batch fermentation, adapted yeast utilized about 91% of xylose in 72 h an ...201626886223
the bioconversion of pretreated cashew apple bagasse into ethanol by shf and ssf processes.ethanol production from acidic-alkaline pretreated cashew apple bagasse (cab-oh) was investigated using separated hydrolysis and fermentation (shf) and simultaneous saccharification and fermentation (ssf) processes. first, a screening of kluyveromyces strains was conducted by shf and a maximum ethanol concentration of 24.1 g l(-1) was obtained using kluyveromyces marxianus atcc36907, which presented similar profiles when compared to results obtained by a saccharomyces strain. the effect of tempe ...201626634842
bioethanol production from taro waste using thermo-tolerant yeast kluyveromyces marxianus k21.in the present study, evaluation and optimization of taro waste (tw), which was mainly composed of taro peels that contain many starch residues, as the main carbon source in medium were studied. the flask studies showed the optimal medium was using 170g/l of tw which is about 100g/l of glucose and 9g/l of cgm as alternative nitrogen source. simultaneous saccharification and fermentation (ssf) exhibited higher bioethanol productivity toward separation hydrolysis and fermentation (shf). the optima ...201626615498
[research of uv-induced changes in the structural and functional properties of inulinases].uv-induced changes in the catalytic activity and radiuses of inulinases molecules from various producers (plants, fungy, yeast) are studied. it is established that specific enzymes activity and the sizes of inulinases molecules from helianthus tuberosus and kluyveromyces marxianus under the influence of uv-light in the ranges of doses 4530-6040 and 755-6040 j/m2, respectively, are subjected to changes more than structural and functional characteristics of inulinase fromaspergillus niger. it is p ...201626601544
kluyveromyces marxianus and saccharomyces boulardii induce distinct levels of dendritic cell cytokine secretion and significantly different t cell responses in vitro.interactions between members of the intestinal microbiota and the mucosal immune system can significantly impact human health, and in this context, fungi and food-related yeasts are known to influence intestinal inflammation through direct interactions with specialized immune cells in vivo. the aim of the present study was to characterize the immune modulating properties of the food-related yeast kluyveromyces marxianus in terms of adaptive immune responses indicating inflammation versus toleran ...201627898740
production of bioactive protein hydrolysate using the yeasts isolated from soft chhurpi.the aim of this work was to study the production of bioactive protein hydrolysates using yeasts isolated from chhurpi. for this, a total of 125 proteolytic yeasts were isolated and molecular identification was carried out by analysis of the restriction digestion pattern generated by digesting the pcr amplified internal transcribed spacer region and 5.8s rrna gene (its1-5.8s-its2) using three endonucleases (haeiii, cfoi and hinfi). the results obtained showed that different proteolytic yeasts wer ...201627494105
trichoderma sp. spores and kluyveromyces marxianus cells magnetic separation: immobilization on chitosan-coated magnetic nanoparticles.in the present study, the interactions between chitosan-coated magnetic nanoparticles (c-mnp) and trichoderma sp. spores as well as kluyveromyces marxianus cells were studied. by means of plackett-burman design, it was demonstrated that factors which directly influenced on yeast cells immobilization and magnetic separation were: inoculum and c-mnp quantity, stirring speed, interaction time, and volume of medium, while in the case of fungal spores, the temperature also was disclosed as an influen ...201628032818
progress in the microbial production of s-adenosyl-l-methionine.s-adenosyl-l-methionine (sam), which exists in all living organisms, serves as an activated group donor in a range of metabolic reactions, including trans-methylation, trans-sulfuration and trans-propylamine. compared with its chemical synthesis and enzyme catalysis production, the microbial production of sam is feasible for industrial applications. the current clinical demand for sam is constantly increasing. therefore, vast interest exists in engineering the sam metabolism in cells for increas ...201627465853
effect of evolutionary adaption on xylosidase activity in thermotolerant yeast isolates kluyveromyces marxianus nire-k1 and nire-k3.efficient use of xylose along with glucose is necessary for the economic production of lignocellulosic based biofuels. xylose transporters play an important role in the microorganisms for efficient utilization of xylose. in the present study, a novel method has been developed for a rapid assay of xylose transport activity in the xylose-utilizing isolates and other known yeasts. an assay was conducted to compare the activity of β-xylosidase using p-nitrophenyl-β-d-xylopyranoside (pnpx) in the int ...201627008328
isolation and characterisation of lactic acid bacteria from donkey milk.during the last years the interest in donkey milk has increased significantly mainly because of its compelling functional elements. even if the composition and nutritional properties of donkey milk are known, its microbiota is less studied. this research communication aimed to provide a comprehensive characterisation of the lactic acid bacteria in raw donkey milk. rapd-pcr assay combined with 16s rdna sequencing analysis were used to describe the microbial diversity of several donkey farms in th ...201627600975
antifungal properties of hypericin, hypericin tetrasulphonic acid and fagopyrin on pathogenic fungi and spoilage yeasts.the role of hypericin-mediated photodynamic antimicrobial properties on pathogenic fungi and photodynamic therapy for human cancer cells is known. antifungal properties of hypericum perforatum l. (hypericaceae) and fagopyrum esculentum moench. (polygonaceae) extracts were also studied. the different polarities of solvents can cause complication in the identification of antifungal effects of separate biologically active compounds. in recent experimental work, we compared antifungal properties of ...201627564138
occurrence of mycotoxins and yeasts and moulds identification in corn silages in tropical climate.this study was aimed to identify yeasts and moulds as well as to detect mycotoxin in corn silages in southern minas gerais, brazil.201626787003
manganese tolerance in yeasts involves polyphosphate, magnesium, and vacuolar alterations.basidiomycetous and ascomycetous yeast species were tested for manganese tolerance. basidiomycetous cryptococcus humicola, cryptococcus terricola, cryptococcus curvatus and ascomycetous candida maltosa, kluyveromyces marxianus, kuraishia capsulata, lindnera fabianii and sacharomyces cerevisiae were able to grow at manganese excess (2.5 mmol/l), while the growth of basidiomycetous rhodotorula bogoriensis was completely suppressed. the lag phase duration increased and the exponential growth rate d ...201626646947
genomic analyses of thermotolerant microorganisms used for high-temperature fermentations.environmental adaptation is considered as one of the most challenging subjects in biology to understand evolutionary or ecological diversification processes and in biotechnology to obtain useful microbial strains. temperature is one of the important environmental stresses; however, microbial adaptation to higher temperatures has not been studied extensively. for industrial purposes, the use of thermally adapted strains is important, not only to reduce the cooling expenses of the fermentation sys ...201626566045
the evaluation of kefir pure culture starter: liquid-core capsule entrapping microorganisms isolated from kefir grains.the main purpose of this study was to develop a pure culture starter for producing kefir. in order to accomplish starter recycling, yeasts (kluyveromyces marxianus strain, pichia kudriavzevii clone), lactic acid bacteria (lactobacillus kefiri strain f4aa, lactobacillus kefiri strain nm131-7, lactobacillus kefiri strain nm132-3, lactobacillus kefiri strain nm180-3, respectively), and acetic acid bacteria (acetobacter lovaniensis strain) were entrapped in liquid core capsules based on the distribu ...201626924844
short communication: evaluation of the microbiota of kefir samples using metagenetic analysis targeting the 16s and 26s ribosomal dna fragments.milk kefir is produced by fermenting milk in the presence of kefir grains. this beverage has several benefits for human health. the aim of this experiment was to analyze 5 kefir grains (and their products) using a targeted metagenetic approach. of the 5 kefir grains analyzed, 1 was purchased in a supermarket, 2 were provided by the ministry of agriculture (namur, belgium), and 2 were provided by individuals. the metagenetic approach targeted the v1-v3 fragment of the 16s ribosomal (r)dna for the ...201525828663
feasibility of biohydrogen production from industrial wastes using defined microbial co-culture.the development of clean or novel alternative energy has become a global trend that will shape the future of energy. in the present study, 3 microbial strains with different oxygen requirements, including clostridium acetobutylicum atcc 824, enterobacter cloacae atcc 13047 and kluyveromyces marxianus 15d, were used to construct a hydrogen production system that was composed of a mixed aerobic-facultative anaerobic-anaerobic consortium. the effects of metal ions, organic acids and carbohydrate su ...201525943991
the effect of lactic acid bacteria on cocoa bean fermentation.cocoa beans (theobroma cacao l.) are the raw material for chocolate production. fermentation of cocoa pulp by microorganisms is crucial for developing chocolate flavor precursors. yeasts conduct an alcoholic fermentation within the bean pulp that is essential for the production of good quality beans, giving typical chocolate characters. however, the roles of bacteria such as lactic acid bacteria and acetic acid bacteria in contributing to the quality of cocoa bean and chocolate are not fully und ...201525889523
the thermotolerant yeast kluyveromyces marxianus is a useful organism for structural and biochemical studies of autophagy.autophagy is a conserved degradation process in which autophagosomes are generated by cooperative actions of multiple autophagy-related (atg) proteins. previous studies using the model yeast saccharomyces cerevisiae have provided various insights into the molecular basis of autophagy; however, because of the modest stability of several atg proteins, structural and biochemical studies have been limited to a subset of atg proteins, preventing us from understanding how multiple atg proteins functio ...201526442587
a new search for thermotolerant yeasts, its characterization and optimization using response surface methodology for ethanol production.the progressive rise in energy crisis followed by green house gas (ghg) emissions is serving as the driving force for bioethanol production from renewable resources. current bioethanol research focuses on lignocellulosic feedstocks as these are abundantly available, renewable, sustainable and exhibit no competition between the crops for food and fuel. however, the technologies in use have some drawbacks including incapability of pentose fermentation, reduced tolerance to products formed, costly ...201526388844
cloning and characterization of an inulinase gene from the marine yeast candida membranifaciens subsp. flavinogenie w14-3 and its expression in saccharomyces sp. w0 for ethanol production.the inu1 gene encoding an exo-inulinase from the marine-derived yeast candida membranifaciens subsp. flavinogenie w14-3 was cloned and characterized. it had an open reading frame of 1,536 bp long encoding an inulinase. the coding region of it was not interrupted by any intron. the cloned gene encoded 512 amino acid residues of a protein with a putative signal peptide of 23 amino acids and a calculated molecular mass of 57.8 kda. the protein sequence deduced from the inulinase gene contained the ...201525432793
microbial biogeography of the transnational fermented milk matsoni.the fermented milk matsoni is a traditional, national food product of both georgia and armenia. little is known about the effects of biogeography and milk type on the microbial biodiversity of matsoni or the fungal composition of matsoni fermentations. high-throughput marker-gene sequencing was used to survey the bacterial and fungal communities of matsoni from different milk types and regions throughout armenia and georgia. results demonstrate that both production region and milk type influence ...201525998810
phytase-producing capacity of yeasts isolated from traditional african fermented food products and phypk gene expression of pichia kudriavzevii strains.phytate is known as a strong chelate of minerals causing their reduced uptake by the human intestine. ninety-three yeast isolates from traditional african fermented food products, belonging to nine species (pichia kudriavzevii, saccharomyces cerevisiae, clavispora lusitaniae, kluyveromyces marxianus, millerozyma farinosa, candida glabrata, wickerhamomyces anomalus, hanseniaspora guilliermondii and debaryomyces nepalensis) were screened for phytase production on solid and liquid media. 95% were a ...201525910031
yeast diversity in a traditional french cheese "tomme d'orchies" reveals infrequent and frequent species with associated benefits.this study is aimed at unrevealing the yeast diversity of handmade cheese, tomme d'orchies, produced and marketed in the north of france. a total of 185 yeast colonies were isolated from the surface and core of this cheese. from these, 80 morphologically different colonies were selected and subjected to rep-pcr analysis. the isolates were clustered into six distinct groups based on their dna fingerprints. from each group, at least 30% of isolates were selected and identified to species level by ...201526338133
genetic diversity of medically important and emerging candida species causing invasive infection.genetic variation in the ribosomal dna (rdna) internal transcribed spacer (its) region has been studied among fungi. however, the numbers of its sequence polymorphisms in the various candida species and their associations with sources of invasive fungal infections remain poorly investigated. here, we characterized the intraspecific and interspecific its diversity of candida spp. strains collected from patients with bloodstream or oroesophageal candidiasis.201525887032
characterization of osmotolerant yeasts and yeast-like molds from apple orchards and apple juice processing plants in china and investigation of their spoilage potential.yeasts and yeast-like fungal isolates were recovered from apple orchards and apple juice processing plants located in the shaanxi province of china. the strains were evaluated for osmotolerance by growing them in 50% (w/v) glucose. of the strains tested, 66 were positive for osmotolerance and were subsequently identified by 26s or 5.8s-its ribosomal rna (rrna) gene sequencing. physiological tests and rapd-pcr analysis were performed to reveal the polymorphism of isolates belonging to the same sp ...201526130165
lipid production from hemicellulose and holocellulose hydrolysate of palm empty fruit bunches by newly isolated oleaginous yeasts.palm empty fruit bunches (efbs) are abundant lignocellulosic wastes from palm oil mills. they are potential sources of sugars which can be converted to microbial lipids by oleaginous yeasts. to produce sugars from efb, two-step and one-step hydrolysis reactions were performed. in the first step, the use of diluted sulfuric acid (0.5 % w/v) hydrolyzed hemicelluloses and released mainly pentoses, and in the second step of hydrolysis of residual pulp using 2.5 % (w/v), sulfuric acid released more h ...201526026262
molecular cloning and characterization of two ygl039w genes encoding broad specificity nadph-dependent aldehyde reductases from kluyveromyces marxianus strain dmb1.two genes from kluyveromyces marxianus strain dmb1, ygl039w1 and ygl039w2, encode putative uncharacterized oxidoreductases that respectively share 42 and 44% identity with the saccharomyces cerevisiae s288c nadph-dependent methylglyoxal reductase (ec 1.1.1.283). to determine the enzymatic characteristics of their products, the two genes were expressed in recombinant escherichia coli cells, after which the ygl039w1 and ygl039w2 proteins were purified to homogeneity. in the presence of nadph, both ...201526223585
characterization of the kluyveromyces marxianus strain dmb1 ygl157w gene product as a broad specificity nadph-dependent aldehyde reductase.the open reading frame ygl157w in the genome of the yeast kluyveromyces marxianus strain dmb1 encodes a putative uncharacterized oxidoreductase. however, this protein shows 46% identity with the saccharomyces cerevisiae s288c nadph-dependent methylglyoxal reductase, which exhibits broad substrate specificity for aldehydes. in the present study, the ygl157w gene product (kmgre2) was purified to homogeneity from overexpressing escherichia coli cells and found to be a monomer. the enzyme was strict ...201525852994
coexistence of lactic acid bacteria and potential spoilage microbiota in a dairy processing environment.microbial contamination in food processing plants can play a fundamental role in food quality and safety. in this study, the microbiota in a dairy plant was studied by both 16s rrna- and 26s rrna-based culture-independent high-throughput amplicon sequencing. environmental samples from surfaces and tools were studied along with the different types of cheese produced in the same plant. the microbiota of environmental swabs was very complex, including more than 200 operational taxonomic units with ...201526341209
bioflavour production from tomato and pepper pomaces by kluyveromyces marxianus and debaryomyces hansenii.bioflavours are called natural flavour and/or fragrance compounds which are produced using metabolic pathway of the microorganism and/or plant cells or their enzyme systems with bioengineering approaches. the aim of this study was to investigate bioflavour production from tomato and red pepper pomaces by kluyveromyces marxianus and debaryomyces hansenii. obtained specific growth rates of k. marxianus and d. hansenii in tomato pomace were 0.081/h and 0.177/h, respectively. the bioflavour profile ...201525614449
construction of recombinant kluyveromyces marxianus ufv-3 to express dengue virus type 1 nonstructural protein 1 (ns1).the yeast kluyveromyces marxianus is a convenient host for industrial synthesis of biomolecules. however, despite its potential, there are few studies reporting the expression of heterologous proteins using this yeast. here, we report expression of a dengue virus protein in k. marxianus for the first time. the dengue virus type 1 nonstructural protein 1 (ns1) was integrated into the k. marxianus ufv-3 genome at the lac4 locus using an adapted integrative vector designed for high-level expression ...201525085614
improving xylitol production at elevated temperature with engineered kluyveromyces marxianus through over-expressing transporters.three transporter genes including kluyveromyces marxianus aquaglyceroporin gene (kmfps1), candida intermedia glucose/xylose facilitator gene (cigxf1) or glucose/xylose symporter gene (cigxs1) were over-expressed in k. marxianus yzj017 to improve xylitol production at elevated temperatures. the xylitol production of yzj074 that harbored cigxf1 was improved to 147.62g/l in erlenmeyer flask at 42°c. in fermenter, 99.29 and 149.60g/l xylitol were produced from 99.55 and 151.91g/l xylose with product ...201525465792
[heterologous expression, purification and characterization of exo-inulinase from kluyveromyces marxianus yx01].to improve the inulinase application in biotechnology, the characteristic of inulinase from kluyveromyces marxianus yx01 was investigated. the inu gene of k. marxianus yx01 was transformed into pichiapastoris gs115 host cells with molecular biology techniques. then we achieved the heterologous expression of exo-inulinase whose molecular mass was about 86.0 kda by sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page). furthermore, six his-tag was added to the inulinase and a two-st ...201526571688
chromosome arrangement, differentiation of growth kinetics and volatile molecule profiles in kluyveromyces marxianus strains from italian cheeses.thirty-nine strains of kluyveromyces marxianus from pecorino di farindola cheese in comparison with 3 strains from parmigiano reggiano cheese, 1 from fermented milk, 3 from cow whey and two type strains k. marxianus cbs 834(t) and kluyveromyces lactis cbs 683(t) were tested for genetic and metabolic characteristics. intraspecific diversity of chromosome arrangements was evaluated by pulsed field gel electrophoresis (pfge) analysis. among k. marxianus strains chromosome polymorphisms were evident ...201526310129
non-saccharomyces yeasts protect against epithelial cell barrier disruption induced by salmonella enterica subsp. enterica serovar typhimurium.the human gastrointestinal epithelium makes up the largest barrier separating the body from the external environment. whereas invasive pathogens cause epithelial barrier disruption, probiotic micro-organisms modulate tight junction regulation and improve epithelial barrier function. in addition, probiotic strains may be able to reduce epithelial barrier disruption caused by pathogenic species. the aim of this study was to explore non-saccharomyces yeast modulation of epithelial cell barrier func ...201526280244
transcriptional analysis of kluyveromyces marxianus for ethanol production from inulin using consolidated bioprocessing technology.ethanol production from non-crop materials, such as jerusalem artichokes, would make a great contribution to the energy industry. the non-conventional yeast, kluyveromyces marxianus, is able to carry out ethanol fermentation of sugar molecules obtained from inulin-containing materials by consolidated bioprocessing. lower inulin concentrations and micro-aeration can lead to a relatively fast and ideal fermentation process; however, it is unclear what causes the inhibition of higher concentrations ...201526273319
hypocholesterolemic effects of kluyveromyces marxianus m3 isolated from tibetan mushrooms on diet-induced hypercholesterolemia in rat.to investigate the effects of kluyveromyces marxianus m3 isolated from tibetan mushrooms on diet-induced hypercholesterolemia in rats, female wistar rats were fed a high-cholesterol diet (hcd) for 28 d to generate hyperlipidemic models. hyperlipidemic rats were assigned to four groups, which were individually treated with three different dosages of k. marxianus m3+hcd or physiological saline+hcd via oral gavage for 28 d. the total cholesterol (tc), triglycerides (tg), high-density lipoprotein ch ...201526273253
yeast kluyveromyces lactis as host for expression of the bacterial lipase: cloning and adaptation of the new lipase gene from serratia sp.many microbial lipases have been successfully expressed in yeasts, but not in industrially attractive kluyveromyces lactis, which among other benefits can be cultivated on a medium supplemented with whey--cheap and easily available industrial waste. a new bacterial lipase from serratia sp. was isolated and for the first time expressed into the yeast kluyveromyces lactis by heterologous protein expression system based on a strong promoter of kluyveromyces marxianus triosephosphate isomerase gene ...201526254038
rapid ethanol production at elevated temperatures by engineered thermotolerant kluyveromyces marxianus via the nadp(h)-preferring xylose reductase-xylitol dehydrogenase pathway.conversion of xylose to ethanol by yeasts is a challenge because of the redox imbalances under oxygen-limited conditions. the thermotolerant yeast kluyveromyces marxianus grows well with xylose as a carbon source at elevated temperatures, but its xylose fermentation ability is weak. in this study, a combination of the nadph-preferring xylose reductase (xr) from neurospora crassa and the nadp(+)-preferring xylitol dehydrogenase (xdh) mutant from scheffersomyces stipitis (pichia stipitis) was cons ...201526253204
the modeling of ethanol production by kluyveromyces marxianus using whey as substrate in continuous a-stat bioreactors.we investigated the kinetics of whey bioconversion into ethanol by kluyveromyces marxianus in continuous bioreactors using the "accelerostat technique" (a-stat). cultivations using free and ca-alginate immobilized cells were evaluated using two different acceleration rates (a). the kinetic profiles of these systems were modeled using four different unstructured models, differing in the expressions for the specific growth (μ) and substrate consumption rates (r s), taking into account substrate li ...201526233317
characterizing yeast promoters used in kluyveromyces marxianus.fermentation at higher temperatures can potentially reduce the cooling cost in large-scale fermentation and reduce the contamination risk. thus, the thermotolerant yeast, kluyveromyces marxianus, which can grow and ferment at elevated temperatures, is a promising biotechnological tool for future applications. however, the promoters used in k. marxianus are not well characterized, especially at elevated temperatures, which is important in efficient metabolic pathway construction. in this study, s ...201526164057
gene expression analysis using strains constructed by nhej-mediated one-step promoter cloning in the yeast kluyveromyces marxianus.gene expression analysis provides valuable information to evaluate cellular state. unlike quantitative mrna analysis techniques like reverse-transcription pcr and microarray, expression analysis using a reporter gene has not been commonly used for multiple-gene analysis, probably due to the difficulty in preparing multiple reporter-gene constructs. to circumvent this problem, we developed a novel one-step reporter-gene construction system mediated by non-homologous end joining (nhej) in the yeas ...201526136515
novel transporters from kluyveromyces marxianus and pichia guilliermondii expressed in saccharomyces cerevisiae enable growth on l-arabinose and d-xylose.genes encoding l-arabinose transporters in kluyveromyces marxianus and pichia guilliermondii were identified by functional complementation of saccharomyces cerevisiae whose growth on l-arabinose was dependent on a functioning l-arabinose transporter, or by screening a differential display library, respectively. these transporters also transport d-xylose and were designated kmaxt1 (arabinose-xylose transporter) and pgaxt1, respectively. transport assays using l-arabinose showed that kmaxt1p has k ...201526129747
looking beyond saccharomyces: the potential of non-conventional yeast species for desirable traits in bioethanol fermentation.saccharomyces cerevisiae has been used for millennia in the production of food and beverages and is by far the most studied yeast species. currently, it is also the most used microorganism in the production of first-generation bioethanol from sugar or starch crops. second-generation bioethanol, on the other hand, is produced from lignocellulosic feedstocks that are pretreated and hydrolyzed to obtain monomeric sugars, mainly d-glucose, d-xylose and l-arabinose. recently, s. cerevisiae recombinan ...201526126524
cell lysis induced by membrane-damaging detergent saponins from quillaja saponaria.this paper presents the results of a study to determine the effect of quillaja saponaria saponins on the lysis of industrial yeast strains. cell lysis induced by saponin from q. saponaria combined with the plasmolysing effect of 5% nacl for saccharomyces cerevisiae, kluyveromyces marxianus yeasts biomass was conducted at 50 °c for 24-48 h. membrane permeability and integrity of the yeast cells were monitored using fluorescent techniques and concentrations of proteins, free amino nitrogen (fan) a ...201526047915
enhanced xylitol production by mutant kluyveromyces marxianus 36907-fmel1 due to improved xylose reductase activity.a directed evolution and random mutagenesis were carried out with thermotolerant yeast kluyveromyces marxianus atcc 36907 for efficient xylitol production. the final selected strain, k. marxianus 36907-fmel1, exhibited 120 and 39 % improvements of xylitol concentration and xylitol yield, respectively, as compared to the parental strain, k. marxianus atcc 36907. according to enzymatic assays for xylose reductase (xr) activities, xr activity from k. marxianus 36907-fmel1 was around twofold higher ...201526043853
a kluyveromyces marxianus 2-deoxyglucose-resistant mutant with enhanced activity of xylose utilization.thermotolerant ethanologenic yeast kluyveromyces marxianus is capable of fermenting various sugars including xylose but glucose represses to hamper the utilization of other sugars. to acquire glucose repression-defective strains, 33 isolates as 2-deoxyglucose (2-dog)-resistant mutants were acquired from about 100 colonies grown on plates containing 2-dog, which were derived from an efficient strain dmku 3-1042. according to the characteristics of sugar consumption abilities and cell growth and e ...201527611676
production of lactulose oligosaccharides by isomerisation of transgalactosylated cheese whey permeate obtained by β-galactosidases from dairy kluyveromyces.β-galactosidases from kluyveromyces lactis and kluyveromyces marxianus isolated from artisanal ewes' milk cheeses, were used to transgalactosylate lactose from cheese whey permeate (wp). the content of galactooligosaccharides (gos) obtained by transgalactosylation was comparable with that formed using pure lactose as substrate. in order to obtain a mixture with higher prebiotic oligosaccharide content, isomerisation of the transgalactosylated wp was carried out using sodium aluminate as catalyst ...201526004434
ethanol production from jerusalem artichoke tubers at high temperature by newly isolated thermotolerant inulin-utilizing yeast kluyveromyces marxianus using consolidated bioprocessing.thermotolerant inulin-utilizing yeast strains were successfully isolated in this study. among the isolated strains, kluyveromyces marxianus dbkku y-102 was found to be the most effective strain for direct ethanol fermentation at high temperature from fresh jerusalem artichoke (ja) tubers without inulin hydrolysis under consolidated bioprocessing (cbp). the maximum ethanol concentrations produced by this strain under the optimum culture conditions were 104.83 and 97.46 g l(-1) at 37 and 40 °c, re ...201525980834
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