Publications

TitleAbstractYear
Filter
PMID(sorted ascending)
Filter
characteristics of microbial biofilm on wooden vats ('gerles') in pdo salers cheese.the purpose of this study was to characterize microbial biofilms from 'gerles' (wooden vats for making pdo salers cheese) and identify their role in milk inoculation and in preventing pathogen development. gerles from ten farms producing pdo salers cheese were subjected to microbial analysis during at least 4 periods spread over two years. they were distinguished by their levels of lactobacillus (between 4.50 and 6.01 log cfu/cm(2)), gram negative bacteria (between 1.45 and 4.56 log cfu/cm(2)), ...201222483401
a highly efficient β-glucosidase from the buffalo rumen fungus neocallimastix patriciarum w5.cellulose, which is the most abundant renewable biomass on earth, is a potential bio-resource of alternative energy. the hydrolysis of plant polysaccharides is catalyzed by microbial cellulases, including endo-β-1,4-glucanases, cellobiohydrolases, cellodextrinases, and β-glucosidases. converting cellobiose by β-glucosidases is the key factor for reducing cellobiose inhibition and enhancing the efficiency of cellulolytic enzymes for cellulosic ethanol production.201222515264
susceptibility of clinical candida species isolates to antifungal agents by e-test, southern iran: a five year study.the incidence of fungal infections in immunocompromised patients, especially by candida species, has increased in recent years. this study was designed to identify candida species and determine antifungal susceptibility patterns of 595 yeast strains isolated from various clinical specimens.201122530086
nomimicin, a new spirotetronate-class polyketide from an actinomycete of the genus actinomadura.nomimicin (1), a new spirotetronate-class polyketide, was isolated from the culture broth of an actinomycete of the genus actinomadura. its structure was established by spectroscopic methods, and the absolute configuration was determined by a combination of noesy experiment, j-based configuration analysis and the modified mosher method. nomimicin (1) showed antimicrobial activity against micrococcus luteus, candida albicans and kluyveromyces fragilis.201222534651
evaluation of oligosaccharide synthesis from lactose and lactulose using β-galactosidases from kluyveromyces isolated from artisanal cheeses.the β-galactosidase activity of 15 kluyveromyces strains isolated from cheese belonging to kluyveromyces lactis and kluyveromyces marxianus species was tested for the production of oligosaccharides derived from lactose (gos) and lactulose (oslu). all kluyveromyces crude cell extracts (cees) produced gos, such as 6-galactobiose and 3'-, 4'-, and 6'-galactosyl-lactose. at 4 h of reaction, the main trisaccharide formed was 6'-galactosyl-lactose (20 g/100 g of total carbohydrates). the formation of ...201222559148
cloning and characterization of the orotidine-5'-phosphate decarboxylase gene (ura3) from the osmotolerant yeast candida magnoliae.we determined the nucleotide sequence of the ura3 gene encoding orotidine-5'-phosphate decarboxylase (ompdcase) of the erythritol-producing osmotolerant yeast candida magnoliae by degenerate polymerase chain reaction and genome walking. sequence analysis revealed the presence of an uninterrupted open-reading frame of 795 bp, encoding a 264 amino acid residue protein with the highest identity to the ompdcase of the yeast kluyveromyces marxianus. phylogenetic analysis of the deduced amino acid seq ...201222561858
formation of ethyl acetate by kluyveromyces marxianus on whey during aerobic batch cultivation at specific trace element limitation.kluyveromyces marxianus is able to transform lactose into ethyl acetate as a bulk product which offers a chance for an economical reuse of whey-borne sugar. ethyl acetate is highly volatile and allows its process-integrated recovery by stripping from the aerated bioreactor. extensive formation of ethyl acetate by k. marxianus dsm 5422 required restriction of yeast growth by a lack of trace elements. several aerobic batch processes were done in a 1-l stirred reactor using whey-borne culture mediu ...201222573271
over-expression of daao and catalase in kluyveromyces marxianus through media optimization, permeabilization and ga stabilization techniques.the selected thermotolerant, lactose-utilizing yeast strain kluyveromyces marxianus nbimcc 8362 possesses high specific d-amino acid oxidase activity (60ug(-1)), which was increased nine-fold (545ug(-1)) by design of the growth medium and conditions for d-amino oxidase induction. applying an optimized simple and rapid procedure for chemical permeabilization of k. marxianus cells with the cationic detergent cetyltrimethylammonium bromide, the enzyme activities (d-amino acid oxidase and catalase) ...200822578860
detection and identification of wild yeast in koumiss.koumiss is a slightly alcoholic fermented mare's milk beverage, originally obtained by using a natural mixed starter of lactic acid bacteria and yeasts. yeast is an important component of koumiss processing which can affect the aroma, texture, as well as the nutrients beneficial to human health, but few reports have examined the yeast ecology of local ecosystems. the purpose of this study was to isolate and identify the yeast present in koumiss from three representative regions of china using a ...201222608237
high-temperature ethanol fermentation by immobilized coculture of kluyveromyces marxianus and saccharomyces cerevisiae.suspended and immobilized cocultures of the thermotolerant yeast, kluyveromyces marxianus dmku 3-1042 and the mesophilic flocculent yeast, saccharomyces cerevisiae m30 were studied for their abilities to improve production and stability of ethanol fermentation. sugarcane juice and blackstrap molasses, at initial sugar concentrations of 220 g/l, were used as carbon sources. the results indicated that the coculture system could improve ethanol production from both sugarcane juice and blackstrap mo ...201222608995
structural insights into atg10-mediated formation of the autophagy-essential atg12-atg5 conjugate.the atg12-atg5 conjugate, which is formed by an ubiquitin-like conjugation system, is essential to autophagosome formation, a central event in autophagy. despite its importance, the molecular mechanism of the atg12-atg5 conjugate formation has not been elucidated. here, we report the solution and crystal structures of atg10 and atg5 homologs from kluyveromyces marxianus (km), a thermotolerant yeast. kmatg10 comprises an e2-core fold with characteristic accessories, including two β strands, where ...201222682742
[molecular-genetic and physiologic differentiation of yeasts kluyveromyces lactis and kluyveromyces marxianus: analysis of strains fron russian microorganisms collection]. 201222693833
formation of ethyl acetate by kluyveromyces marxianus on whey during aerobic batch and chemostat cultivation at iron limitation.the ability of kluyveromyces marxianus to convert lactose into ethyl acetate offers a chance for an economic reuse of whey. former experiments with k. marxianus dsm 5422 proved limitation of growth by iron (fe) or copper as a precondition for significant ester synthesis. several aerobic batch and chemostat cultivations were done with whey-borne media of a variable fe content for exploring the effect of fe on growth, the fe content of biomass, and metabolite synthesis. at low fe doses, fe was the ...201222695802
kefir grains as a starter for whey fermentation at different temperatures: chemical and microbiological characterisation.we report here a comparative analysis of the growth, acidification capacity, and chemical and microbiologic composition between kefir grains after 20 subcultures in whey at 20, 30, and 37°c and the original kefir grains coming from milk along with a determination of the microbiological composition of the fermented whey as compared with that of traditional fermented milk. when fermentation was carried out repeatedly at 30 or 37°c, kefir grains changed their kefir-like appearance, exhibited reduce ...201222717048
thermotolerant kluyveromyces marxianus and saccharomyces cerevisiae strains representing potentials for bioethanol production from jerusalem artichoke by consolidated bioprocessing.thermotolerant inulin-utilizing yeast strains are desirable for ethanol production from jerusalem artichoke tubers by consolidated bioprocessing (cbp). to obtain such strains, 21 naturally occurring yeast strains isolated by using an enrichment method and 65 previously isolated saccharomyces cerevisiae strains were investigated in inulin utilization, extracellular inulinase activity, and ethanol fermentation from inulin and jerusalem artichoke tuber flour at 40 °c. the strains kluyveromyces marx ...201222760784
growth characteristics and physiological functionality of yeasts in pear marc extracts.kluyveromyces fragilis kctc 7260 and saccharomyces cerevisiae kctc 7904, which both grew well in pear marc extract, were selected and their growth profiles and physiological functionalities were determined. both of the selected yeasts established maximal growth by 20 hr of cultivation at 30℃ in pear marc extract. the cell-free extracts showed high antihypertensive angiotensin i-converting enzyme inhibitory activity of 68.9% and 52.1%, respectively. the extracts also displayed 9.2 u/ml and 12.0 u ...201122783099
temperature and relative humidity influence the microbial and physicochemical characteristics of camembert-type cheese ripening.to evaluate the effects of temperature and relative humidity (rh) on microbial and biochemical ripening kinetics, camembert-type cheeses were prepared from pasteurized milk seeded with kluyveromyces marxianus, geotrichum candidum, penicillium camemberti, and brevibacterium aurantiacum. microorganism growth and biochemical changes were studied under different ripening temperatures (8, 12, and 16°c) and rh (88, 92, and 98%). the central point runs (12°c, 92% rh) were both reproducible and repeatab ...201222818481
stoichiometric identification with maximum likelihood principal component analysis.this study presents an effective procedure for the determination of a biologically inspired, black-box model of cultures of microorganisms (including yeasts, bacteria, plant and animal cells) in bioreactors. this procedure is based on sets of experimental data measuring the time-evolution of a few extracellular species concentrations, and makes use of maximum likelihood principal component analysis to determine, independently of the kinetics, an appropriate number of macroscopic reactions and th ...201322821205
a novel kluyveromyces marxianus strain with an inducible flocculation phenotype.flocculation is a very useful phenotype for industrial yeast strains, since it facilitates cell harvest and represents an easy way of cell immobilization in continuous fermentation processes. the present work represents the first time that an inducible flocculation phenotype has been generated in a non flocculent strain of kluyveromyces marxianus. this was accomplished by expressing saccharomyces cerevisiae flo5 gene in k. marxianus cect 11769 strain. the flo 5 gene was placed under the control ...201222838397
experimental investigation and optimization of process variables affecting the production of extracellular lipase by kluyveromyces marxianus ifo 0288.in this study, the production and optimization of extracellular lipase from kluyveromyces marxianus ifo 0288 was investigated by using optimized nutritional and cultural conditions in a yeast medium containing glucose as the carbon source in fully aerobic batch fermentation (150 rpm). the influence of four fermentation parameters (type of lipidic source, initial culture ph, temperature, and length of fermentation) on growth and lipase production was investigated and evaluated using the conventio ...201222843062
structure-based analyses reveal distinct binding sites for atg2 and phosphoinositides in atg18.autophagy is an intracellular degradation system by which cytoplasmic materials are enclosed by an autophagosome and delivered to a lysosome/vacuole. atg18 plays a critical role in autophagosome formation as a complex with atg2 and phosphatidylinositol 3-phosphate (ptdins(3)p). however, little is known about the structure of atg18 and its recognition mode of atg2 or ptdins(3)p. here, we report the crystal structure of kluyveromyces marxianus hsv2, an atg18 paralog, at 2.6 å resolution. the struc ...201222851171
investigation on culturable microflora in tibetan kefir grains from different areas of china.four samples of tibetan kefir grains (tk-zjuj 01-04) from tibet and surrounding areas were investigated via phenotypic and genotypic methods to compare and analyze the diversity of culturable microflora among different origins. as a result, 4 genera of microorganisms from tk-zjuj01: bacillus subtilis (2.9 × 10(7) cfu/ml), lactococcus lactis (8.2 × 10(7) cfu/ml), kluyveromyces marxianus (3.0 × 10(6) cfu/ml), saccharomyces cerevisiae (9.0 × 10(6) cfu/ml); 4 genera from tk-zjuj02: lactobacillus kef ...201222860591
determination of the total phenolic and anthocyanin contents and antimicrobial activity of viburnum opulus fruit juice.viburnum opulus is a plant with fruits that are rich in biologically active substances, making it valuable to the food and pharmaceutical industries. here, we present our study of the total phenolic and anthocyanin contents and antimicrobial activity in the fruit juice of six v. opulus l. accessions. the cultivar 'krasnaya grozd' was notable for its exceptionally large amount of total phenolics, 1168 mg/100 g, with anthocyanins comprising 3-5 % of the total phenolic content. the evaluation of th ...201222865031
bioethanol production from scenedesmus obliquus sugars: the influence of photobioreactors and culture conditions on biomass production.a closed-loop vertical tubular photobioreactor (pbr), specially designed to operate under conditions of scarce flat land availability and irregular solar irradiance conditions, was used to study the potential of scenedesmus obliquus biomass/sugar production. the results obtained were compared to those from an open-raceway pond and a closed-bubble column. the influence of the type of light source and the regime (natural vs artificial and continuous vs light/dark cycles) on the growth of the micro ...201222899495
characterization of saccharomyces cerevisiae promoters for heterologous gene expression in kluyveromyces marxianus.kluyveromyces marxianus is now considered one of the best choices of option for industrial applications of yeast because the strain is able to grow at high temperature, utilizes various carbon sources, and grows fast. however, the use of k. marxianus as a host for industrial applications is still limited. this limitation is largely due to a lack of knowledge on the characteristics of the promoters since the time and amount of protein expression is strongly dependent on the promoter employed. in ...201322911091
yeasts from colombian kumis as source of peptides with angiotensin i converting enzyme (ace) inhibitory activity in milk.this study investigated the possibility of using yeast strains in fermented milks to obtain products with high angiotensin i-converting enzyme (ace) inhibitory activity and low bitter taste. ninety-three yeast strains isolated from colombian kumis in different geographic regions were molecularly identified, and their milk fermentation performances were determined. molecular identification evidenced that galactomyces geotrichum, pichia kudriavzevii, clavispora lusitaniae and candida tropicalis, w ...201222938834
purification, kinetic characterization and properties of a novel thermo-tolerant extracellular protease from kluyveromyces marxianus ifo 0288 with potential biotechnological interest.a novel extracellular hydrolase of ∼45kda molecular mass was purified from kluyveromyces marxianus ifo 0288 cultures and characterized as serine protease. the k(m)-value of protease (designated protease-km-ifo-0288-a), which was found active in media containing elevated [nacl] but lacking edtak(2), decreased with increasing [ca(2+)]. the protease maintained considerable activity at the range of 10-60°c and ph 6.00-10.25, with optimum k(cat)/k(m)-value at 35.5°c and ph 7.75. it was strongly affec ...201222940322
kinetics of growth and ethanol formation from a mix of glucose/xylose substrate by kluyveromyces marxianus ufv-3.the fermentation of both glucose and xylose is important to maximize ethanol yield from renewable biomass feedstocks. in this article, we analyze growth, sugar consumption, and ethanol formation by the yeast kluyveromyces marxianus ufv-3 using various glucose and xylose concentrations and also under conditions of reduced respiratory activity. in almost all the conditions analyzed, glucose repressed xylose assimilation and xylose consumption began after glucose had been exhausted. a remarkable di ...201322965752
synthesis of duloxetine intermediate (s)-3-chloro-1-(2-thienyl)-1-propanol with liquid-core immobilized candida pseudotropicalis 104.(s) -3-chloro-1-(2-thienyl)-1-propanol was synthesized by the asymmetric reduction of 3-chloro-1-(2-thienyl)propanone with liquid-core immobilized candida pseudotropicalis 104. the optimum time was 28 h for the re-cultivation of immobilized cells. the optimum film solvent for the liquid-core capsule was 0.3 % chitosan (m (w) 1.0 × 10(5)). conversion decreased with the increase of the liquid-core capsule diameter and with the addition of more substrates at the same reduction time. the immobilized ...201223070716
biodiversity and probiotic potential of yeasts isolated from fura, a west african spontaneously fermented cereal.fura is a spontaneously fermented pearl millet product consumed in west africa. the yeast species involved in the fermentation were identified by pheno- and genotypic methods to be candida krusei, kluyveromyces marxianus, candida tropicalis, candida rugosa, candida fabianii, candida norvegensis and trichosporon asahii. c. krusei and k. marxianus were found to be the dominant species. survival in ph 2.5 or in the presence of bile salts (0.3% (w/v) oxgall) and growth at 37°c were independently det ...201223072700
formation of ethyl acetate from whey by kluyveromyces marxianus on a pilot scale.whey arising in huge amounts during milk processing is a valuable renewable resource in the field of white biotechnology. kluyveromyces marxianus is able to convert whey-borne lactose into ethyl acetate, an environmentally friendly solvent. formation of ethyl acetate as a bulk product is triggered by iron (fe). k. marxianus dsm 5422 was cultivated aerobically in whey-borne medium originally containing 40 μg/l fe, supplemented with 1, 3 or 10 mg/l fe in the pre-culture, using an 1 l or 70 l stirr ...201323089728
production of β-galactosidase by kluyveromyces marxianus mtcc 1388 using whey and effect of four different methods of enzyme extraction on β-galactosidase activity.whey containing 4.4% (w/v) lactose was inoculated with kluyveromyces marxianus mtcc 1389 for carrying out studies related to β-galactosidase production. β-galactosidase activity was found to be maximum after 30 h and further incubation resulted in decline in activity. the maximum cell biomass of 2.54 mg ml(-1) was observed after 36 h of incubation. lactose concentration dropped drastically to 0.04 % from 4.40% after 36 h of incubation. out of the four methods tested for extraction of enzyme, sds ...200823100731
novel technology development through thermal drying of encapsulated kluyveromyces marxianus in micro- and nano-tubular cellulose in lactose fermentation and its evaluation for food production.a novel technology development based on the production of a low-cost starter culture for ripening of cheeses and baking is reported in the present study. the starter culture comprises thermally dried cells of kluyveromyces marxianus encapsulated in micro- and nano-tubular cellulose. for production of a low-cost and effective biocatalyst, whey was used as raw material for biomass production and thermal drying methods (convective, conventional, and vacuum) were applied and evaluated at drying temp ...201223111921
bioprospecting of thermo- and osmo-tolerant fungi from mango pulp-peel compost for bioethanol production.the persistent edaphic stress on microbial succession due to dynamic changes during composting was explored for selection of multi-stress tolerant microbe(s) desirable for ethanol production. a total of 23 strains were isolated from mango compost using four successive enrichments in yp broth (g l(-1)): glucose, 100; 150; 250 with ethanol (40) and cycloheximide (0.4) at 40 °c, ph 6.0. based on multi-gene ribotyping, 14 yeasts (61 %) of saccharomycetaceae, 2 filamentous fungi (8.6 %) and 7 bacteri ...201323180376
genome sequence of the thermotolerant yeast kluyveromyces marxianus var. marxianus kctc 17555.kluyveromyces marxianus is a thermotolerant yeast that has been explored for potential use in biotechnological applications, such as production of biofuels, single-cell proteins, enzymes, and other heterologous proteins. here, we present the high-quality draft of the 10.9-mb genome of k. marxianus var. marxianus kctc 17555 (= cbs 6556 = atcc 26548).201223193140
production of bioethanol from effluents of the dairy industry by kluyveromyces marxianus.whey and scotta are effluents coming from cheese and ricotta processing respectively. whey contains minerals, lipids, lactose and proteins; scotta contains mainly lactose. whey can be reused in several ways, such as protein extraction or animal feeding, while nowadays scotta is just considered as a waste; moreover, due to very high volumes of whey produced in the world, it poses serious environmental and disposal problems. alternative destinations of these effluents, such as biotechnological tra ...201323201075
kefir-isolated lactococcus lactis subsp. lactis inhibits the cytotoxic effect of clostridium difficile in vitro.kefir is a dairy product obtained by fermentation of milk with a complex microbial population and several health-promoting properties have been attributed to its consumption. in this work, we tested the ability of different kefir-isolated bacterial and yeast strains (lactobacillus kefir, lb. plantarum, lactococcus lactis subps. lactis, saccharomyces cerevisiae and kluyveromyces marxianus) or a mixture of them (mm) to antagonise the cytopathic effect of toxins from clostridium difficile (tcda and ...201323217732
the structure of desr from streptomyces venezuelae, a β-glucosidase involved in macrolide activation.antibiotics have, indeed, altered the course of human history as is evidenced by the increase in human life expectancy since the 1940s. many of these natural compounds are produced by bacteria that, by necessity, must have efficient self-resistance mechanisms. the methymycin/pikromycin producing species streptomyces venezuelae, for example, utilizes β-glucosylation of its macrolide products to neutralize their effects within the confines of the cell. once released into the environment, these com ...201323225731
enzymatic synthesis of fructooligosaccharides by inulinases from aspergillus niger and kluyveromyces marxianus nrrl y-7571 in aqueous-organic medium.this work is focused on the synthesis of the fructooligosaccharides (fos) from sucrose and inulin, using free, immobilized and pre-treated immobilized inulinase from kluyveromyces marxianus nrrl y 7571 and aspergillus niger in an aqueous-organic system. initially, the influence of pre-treatment using four different gases, propane, n-butane, co(2) and liquefied petroleum gas (lpg), was investigated towards fos production and best results were found when both enzymes were previously treated with l ...201223265469
comparing cell viability and ethanol fermentation of the thermotolerant yeast kluyveromyces marxianus and saccharomyces cerevisiae on steam-exploded biomass treated with laccase.in this study, the thermotolerant yeast kluyveromyces marxianus cect 10875 was compared to the industrial strain saccharomyces cerevisiae ethanol red for lignocellulosic ethanol production. for it, whole slurry from steam-exploded wheat straw was used as raw material, and two process configurations, simultaneous saccharification and fermentation (ssf) and presaccharification and simultaneous saccharification and fermentation (pssf), were evaluated. compared to s. cerevisiae, which was able to pr ...201223265821
cloning, characterization and heterelogous expression of the inu1 gene from cryptococcus aureus hya.the inu1 gene (accession number: jx073660) encoding exo-inulinase from cryptococcus aureus hya was cloned and characterized. the gene had an open reading frame (orf) of 1653 bp long encoding an inulinase. the coding region of the gene was not interrupted by any intron. it encoded 551 amino acid residues of a protein with a putative signal peptide of 23 amino acids and the calculated molecular mass of 59.5 kda. the protein sequence deduced from the inulinase structural gene contained the inulinas ...201223268348
interaction between lactic acid bacteria and yeasts in airag, an alcoholic fermented milk.the interaction between nine lactic acid bacteria (lab) and five yeast strains isolated from airag of inner mongolia autonomic region, china was investigated. three representative lab and two yeasts showed symbioses were selected and incubated in 10% (w/v) reconstituted skim milk as single and mixed cultures to measure viable count, titratable acidity, ethanol and sugar content every 24 h for 1 week. lab and yeasts showed high viable counts in the mixed cultures compared to the single cultures. ...201223302085
ethanol production using whole plant biomass of jerusalem artichoke by kluyveromyces marxianus cbs1555.jerusalem artichoke is a low-requirement sugar crop containing cellulose and hemicellulose in the stalk and a high content of inulin in the tuber. however, the lignocellulosic component in jerusalem artichoke stalk reduces the fermentability of the whole plant for efficient bioethanol production. in this study, jerusalem artichoke stalk was pretreated sequentially with dilute acid and alkali, and then hydrolyzed enzymatically. during enzymatic hydrolysis, approximately 88 % of the glucan and xyl ...201323322254
performance evaluation of pichia kluyveri, kluyveromyces marxianus and saccharomyces cerevisiae in industrial tequila fermentation.traditionally, industrial tequila production has used spontaneous fermentation or saccharomyces cerevisiae yeast strains. despite the potential of non-saccharomyces strains for alcoholic fermentation, few studies have been performed at industrial level with these yeasts. therefore, in this work, agave tequilana juice was fermented at an industrial level using two non-saccharomyces yeasts (pichia kluyveri and kluyveromyces marxianus) with fermentation efficiency higher than 85 %. pichia kluyveri ...201323329062
essentiality of respiratory activity for pentose utilization in thermotolerant yeast kluyveromyces marxianus dmku 3-1042.by random integrative mutagenesis with a kanmx4 cassette in kluyveromyces marxianus dmku 3-1042, we obtained three mutants of cox15, atp25 and cyc3 encoding a cytochrome oxidase assembly factor (singleton), a transcription factor required for assembly of the atp9p subunit of mitochondrial atp synthase and cytochrome c heme lyase, respectively, as mutants lacking growth capability on xylose and/or arabinose. they exhibited incapability of growth on non-fermentable carbon sources, such as acetate ...201323338601
construction of lactose-consuming saccharomyces cerevisiae for lactose fermentation into ethanol fuel.two lactose-consuming diploid saccharomyces cerevisiae strains, ay-51024a and ay-51024m, were constructed by expressing the lac4 and lac12 genes of kluyveromyces marxianus in the host strain ay-5. in ay-51024a, both genes were targeted to the ath1 and nth1 gene-encoding regions to abolish the activity of acid/neutral trehalase. in ay-51024m, both genes were respectively integrated into the mig1 and nth1 gene-encoding regions to relieve glucose repression. physiologic studies of the two transform ...201323344501
assembling a cellulase cocktail and a cellodextrin transporter into a yeast host for cbp ethanol production.many microorganisms possess enzymes that can efficiently degrade lignocellulosic materials, but do not have the capability to produce a large amount of ethanol. thus, attempts have been made to transform such enzymes into fermentative microbes to serve as hosts for ethanol production. however, an efficient host for a consolidated bioprocess (cbp) remains to be found. for this purpose, a synthetic biology technique that can transform multiple genes into a genome is instrumental. moreover, a strat ...201323374631
improving ethanol and xylitol fermentation at elevated temperature through substitution of xylose reductase in kluyveromyces marxianus.thermo-tolerant yeast kluyveromyces marxianus is able to utilize a wide range of substrates, including xylose; however, the xylose fermentation ability is weak because of the redox imbalance under oxygen-limited conditions. alleviating the intracellular redox imbalance through engineering the coenzyme specificity of nadph-preferring xylose reductase (xr) and improving the expression of xr should promote xylose consumption and fermentation. in this study, the native xylose reductase gene (kmxyl1) ...201323392758
ethanol-based organosolv treatment with trace hydrochloric acid improves the enzymatic digestibility of japanese cypress (chamaecyparis obtusa) by exposing nanofibers on the surface.the effects of adding trace acids in ethanol based organosolv treatment were investigated to increase the enzymatic digestibility of japanese cypress. a high glucose yield (60%) in the enzymatic hydrolysis was obtained by treating the sample at 170 °c for 45 min in 50% ethanol liquor containing 0.4% hydrochloric acid. moreover, the enzymatic digestibility of the treated sample was improved to ∼70% by changing the enzyme from acremonium cellulase to accellerase1500. field emission scanning electr ...201323395739
respiratory capacity of the kluyveromyces marxianus yeast isolated from the mezcal process during oxidative stress.during the mezcal fermentation process, yeasts are affected by several stresses that can affect their fermentation capability. these stresses, such as thermal shock, ethanol, osmotic and growth inhibitors are common during fermentation. cells have improved metabolic systems and they express stress response genes in order to decrease the damage caused during the stress, but to the best of our knowledge, there are no published works exploring the effect of oxidants and prooxidants, such as h2o2 an ...201323417282
growth of the yeast kluyveromyces marxianus cbs 6556 on different sugar combinations as sole carbon and energy source.the yeast kluyveromyces marxianus has been pointed out as a promising microorganism for a variety of industrial bioprocesses. although genetic tools have been developed for this yeast and different potential applications have been investigated, quantitative physiological studies have rarely been reported. here, we report and discuss the growth, substrate consumption, metabolite formation, and respiratory parameters of k. marxianus cbs 6556 during aerobic batch bioreactor cultivations, using a de ...201323435899
characterization and stability of lactobacilli and yeast microbiota in kefir grains.characterization and stability of lactobacilli and yeasts from kefir grains using culture-dependent and culture-independent methods were investigated in this study. culture-dependent analysis, followed by sequencing of 16s ribosomal dna for bacteria and 26s rrna gene for yeasts, revealed 3 different species of lactobacilli and yeasts, respectively. the most frequently isolated bacterial species were lactobacillus kefiranofaciens ssp. kefirgranum, lb. parakefiri, and lb. kefiri, whereas yeasts be ...201323497996
[identification of three candida africana strains in senegal].the frequency of candidiasis has increased dramatically in recent years. candida albicans is the most common species. however, other species which are pathogenic and resistant to usual antifungal agents beginning to emerge. these include candida dubliniensis and candida africana, which share morphological similarities with candida albicans. thus, it is of interest to correctly identify the fungal isolates.201223518168
protective effect of a mixture of kefir-isolated lactic acid bacteria and yeasts in a hamster model of clostridium difficile infection.the objective of this work was to test the protective effect of a mixture (mm) constituted by kefir-isolated microorganisms (lactobacillus plantarum, lactobacillus kefir, lc. lactis, kluyveromyces marxianus and saccharomyces cerevisiae) in a hamster model of infection with clostridium difficile, an anaerobic gram-positive bacterium that causes diarrhoea. placebo or mm was administered ad libitum in drinking water from day 0 to the end of treatment. hamsters received orally 200 μg of clyndamicin ...201323542116
automated uv-c mutagenesis of kluyveromyces marxianus nrrl y-1109 and selection for microaerophilic growth and ethanol production at elevated temperature on biomass sugars.the yeast kluyveromyces marxianus is a potential microbial catalyst for fuel ethanol production from a wide range of biomass substrates. to improve its growth and ethanol yield at elevated temperature under microaerophilic conditions, k. marxianus nrrl y-1109 was irradiated with uv-c using automated protocols on a robotic platform for picking and spreading irradiated cultures and for processing the resulting plates. the plates were incubated under anaerobic conditions on xylose or glucose for 5 ...201323543482
effects of storage temperature and ensiling period on fermentation products, aerobic stability and microbial communities of total mixed ration silage.to examine how storage temperatures influence ensiling fermentation, aerobic stability and microbial communities of total mixed ration (tmr) silage.201323565809
thermal adaptability of kluyveromyces marxianus in recombinant protein production.kluyveromyces marxianus combines the ease of genetic manipulation and fermentation with the ability to efficiently secrete high molecular weight proteins, performing eukaryotic post-translational modifications. it is able to grow efficiently in a wide range of temperatures. the secretion performances were analyzed in the host k. marxianus l3 in the range between 5°c and 40°c by means of 3 different reporter proteins, since temperature appears a key parameter for production and secretion of recom ...201323587421
yeasts from autochthonal cheese starters: technological and functional properties.the aim of this work was to identify 20 yeasts isolated from autochthonal cheese starters and evaluate their technological and functional properties.201323600736
evaluation of hardboard manufacturing process wastewater as a feedstream for ethanol production.waste streams from the wood processing industry can serve as feedstream for ethanol production from biomass residues. hardboard manufacturing process wastewater (hpw) was evaluated on the basis of monomeric sugar recovery and fermentability as a novel feedstream for ethanol production. dilute acid hydrolysis, coupled with concentration of the wastewater resulted in a hydrolysate with 66 g/l total fermentable sugars. as xylose accounted for 53 % of the total sugars, native xylose-fermenting yeast ...201323604526
improved xylose fermentation of kluyveromyces marxianus at elevated temperature through construction of a xylose isomerase pathway.to improve the xylose fermentation ability of kluyveromyces marxianus, a xylose assimilation pathway through xylose isomerase was constructed. the genes encoding xylose reductase (kmxyl1) and xylitol dehydrogenase (kmxyl2) were disrupted in k. marxianus yhj010 and the resultant strain was named yrl002. a codon-optimized xylose isomerase gene from orpinomyces was transformed into k. marxianus yrl002 and expressed under gapdh promoter. the transformant was adapted in the sd medium containing 1 % c ...201323657586
susceptibility of species within the sporothrix schenckii complex to a panel of killer yeasts.the sporothrix schenckii complex is the etiologic agent of sporotrichosis, a subacute or chronic mycosis which can affect humans and animals. killer yeasts have been used in the medical field for development of novel antimycotics and biotyping of pathogenic fungi. the action of 18 killer yeasts on the growth of 88 characterized s. schenckii, sporothrix globosa, sporothrix brasiliensis, and sporothrix mexicana clinical and environmental isolates was evaluated. killer studies were performed on pet ...201423686831
inulinase production in a packed bed reactor by solid state fermentation.in this work, production of inulinase was carried out in a packed bed reactor (pbr) under solid state fermentation. kluyveromyces marxianus var. marxianus was used to produce the inulinase using pressmud as substrate. the parameters like air flow rate, packing density and particle size were optimized using response surface methodology (rsm) to maximize the inulinase production. the optimum conditions for the maximum inulinase production were: air flow rate - 0.82 l/min, packing density - 40 g/l ...201323688470
determination of yeast diversity in ogi, mawè, gowé and tchoukoutou by using culture-dependent and -independent methods.the maize based ogi and mawè and the sorghum based gowé and tchoukoutou are traditional, spontaneously fermented products widely consumed by the population of benin (west africa). yeast occurrence in the products, as sold on local markets at different locations, was studied using a combination of culture-dependent and independent methods. number of yeasts is varied from 3.75 log10 colony forming units (cfu)/g for ogi to 5.60 log10 cfu/g for tchoukoutou. isolated yeasts (236) were identified base ...201323727651
expression of exoinulinase genes in saccharomyces cerevisiae to improve ethanol production from inulin sources.to improve inulin utilization and ethanol fermentation, exoinulinase genes from the yeast kluyveromyces marxianus and the recently identified yeast, candida kutaonensis, were expressed in saccharomyces cerevisiae. s. cerevisiae harboring the exoinulinase gene from c. kutaonensis gave higher ethanol yield and productivity from both inulin (0.38 vs. 0.34 g/g and 1.35 vs. 1.22 g l(-1) h(-1)) and jerusalem artichoke tuber flour (0.47 vs. 0.46 g/g and 1.62 vs. 1.54 g l(-1) h(-1)) compared with the st ...201323743955
yeast dynamics during spontaneous fermentation of mawè and tchoukoutou, two traditional products from benin.mawè and tchoukoutou are two traditional fermented foods largely consumed in benin, west africa. their preparations remain as a house art and they are the result of spontaneous fermentation processes. in this study, dynamics of the yeast populations occurring during spontaneous fermentations of mawè and tchoukoutou were investigated using both culture-dependent and -independent approaches. for each product, two productions were followed. samples were taken at different fermentation times and yea ...201323756236
discarded oranges and brewer's spent grains as promoting ingredients for microbial growth by submerged and solid state fermentation of agro-industrial waste mixtures.the exploitation of various agro-industrial wastes for microbial cell mass production of kluyveromyces marxianus, kefir, and saccharomyces cerevisiae is reported in the present investigation. specifically, the promotional effect of whole orange pulp on cell growth in mixtures consisting of cheese whey, molasses, and potato pulp in submerged fermentation processes was examined. a 2- to 3-fold increase of cell mass was observed in the presence of orange pulp. likewise, the promotional effect of br ...201323780341
[effect of aeration and inulin concentration on ethanol production by kluyveromyces marxinaus yx01].consolidated bioprocessing technology can be used for kluyveromyces marxianus yx01 to produce ethanol from jerusalem artichoke, which is one of the potential processes to produce biofuel from non-cereal crops. in this study, we combined the aeration rate with the substrate concentration to conduct cross-over experiments for k. marxinaus yx01, and studied ethanol fermentation and the influence of inulin enzyme activity. the substrate concentration had a little repressive effect on ethanol product ...201323789273
yeasts from kefir grains: isolation, identification, and probiotic characterization.kefir-a traditional beverage whose consumption has been associated with health benefits-is a logical natural product to investigate for new probiotic strains. the aim of the present work was to isolate and identify kefir yeasts and select those with acid and bile tolerance to study their adhesion to epithelial cells and their transit through mouse gut. from 4 milky and 3 sugary kefir grains, 34 yeast strains were isolated and identified by means of classical microbiological and molecular-genetic ...201423824665
bioethanol production from lignocellulosic biomass by a novel kluyveromyces marxianus strain.the yeast kluyveromyces marxianus is considered as a potential alternative to saccharomyces cerevisiae in producing ethanol as a biofuel. in this study, we investigated the ethanol fermentation properties of novel k. marxianus strain dmb1, isolated from bagasse hydrolysates. this strain utilized sorbitol as well as various pentoses and hexoses as single carbon sources under aerobic conditions and produced ethanol from glucose in hydrolysates of the japanese cedar at 42 °c. reference strains k. m ...201323832346
role of hydrophobicity in adhesion of wild yeast isolated from the ultrafiltration membranes of an apple juice processing plant.the role of cell surface hydrophobicity in the adhesion to stainless steel (ss) of 11 wild yeast strains isolated from the ultrafiltration membranes of an apple juice processing plant was investigated. the isolated yeasts belonged to four species: candida krusei (5 isolates), candida tropicalis (2 isolates), kluyveromyces marxianus (3 isolates) and rhodotorula mucilaginosa (1 isolate). surface hydrophobicity was measured by the microbial adhesion to solvents method. yeast cells and surfaces were ...201323837866
simultaneous integration of multiple genes into the kluyveromyces marxianus chromosome.while kluyveromyces marxianus is a promising yeast strain for biotechnological applications, genetic engineering of this strain is still challenging, especially when multiple genes are to be transformed. sequential gene integration, which takes advantage of repetitive insertion/excision of the ura3 gene as a marker, has been the best option until now, because the ura3-deletion mutant is the only precondition for this method. however, we found that the introduced gene is co-excised during the ura ...201323845272
influencing cocoa flavour using pichia kluyveri and kluyveromyces marxianus in a defined mixed starter culture for cocoa fermentation.the potential impact of aromatic and pectinolytic yeasts on cocoa flavour was investigated using two defined mixed starter cultures encompassing strains of pichia kluyveri and kluyveromyces marxianus for inoculating cocoa beans in small scale tray fermentations. samples for microbial and metabolite analysis were collected at 12-24 hour intervals during 120 h of fermentation. yeast isolates were grouped by (gtg)5-based rep-pcr fingerprinting and identified by sequencing of the d1/d2 region of the ...201323866910
ethanol fermentation from xylose by metabolically engineered strains of kluyveromyces marxianus.we constructed a xylose-fermenting recombinant strain of thermotolerant yeast kluyveromyces marxianus, dmb3-7. both xylose consumption and ethanol production were remarkably increased in dmb3-7 compared to the control strain at 30°c. furthermore, dmb3-7 produced ethanol from xylose at both 42°c and 45°c, above which xylose metabolic activity decreased.201323871200
impact of high temperature on ethanol fermentation by kluyveromyces marxianus immobilized on banana leaf sheath pieces.ethanol fermentation was carried out with kluyveromyces marxianus cells at various temperatures (30, 35, 40, and 45 °c). fermentation performance of the immobilized yeast on banana leaf sheath pieces and the free yeast were evaluated and compared. generally, ethanol production of the immobilized and free yeast was stable in a temperature range of 30-40 °c. temperature of 45 °c restricted yeast growth and lengthened the fermentation. the immobilized yeast demonstrated faster sugar assimilation an ...201323900619
simultaneous saccharification and fermentation of agave tequilana fructans by kluyveromyces marxianus yeasts for bioethanol and tequila production.agave tequilana fructans (atf) constitute a substrate for bioethanol and tequila industries. as kluyveromyces marxianus produces specific fructanases for atf hydrolysis, as well as ethanol, it can perform simultaneous saccharification and fermentation. in this work, fifteen k. marxianus yeasts were evaluated to develop inoculums with fructanase activity on atf. these inoculums were added to an atf medium for simultaneous saccharification and fermentation. all the yeasts, showed exo-fructanhydrol ...201323941710
diversity of fungal flora in raw milk from the italian alps in relation to pasture altitude.the present paper explores the diversity of mycobiota inhabiting raw milk sampled at different altitudes (1400 m, 1800 m, 2200 m) from cows grazing alpine pastures of valle d'aosta (north-western italian alps). to this aim, multilocus sequencing was performed at barcodes commonly used for fungal identification (its1, d1/d2 domains of the 26s rrna gene, and part of the β-tubulin gene). a total of 31 species were detected, most of them yeasts, followed by moulds and by 2 sequences of macroscopic f ...201324024093
production of inulinase from kluyveromyces marxianus using dahlia tuber extract.various carbon sources were evaluated for production of inulinase by yeast, kluyveromyces marxianus mtcc 3995. highest inulinase activity was observed with dahlia extract (25.3 nkat ml(-1)) as carbon source. the enzyme activity was 1.4 folds higher than that observed in media containing pure chicory inulin (17.8 nkat ml(-1)). the yeast showed good growth on a simple medium containing dahlia extract (20% w/v) and yeast extract (2%w/v) as carbon and nitrogen source respectively, in 96 h. at 28°c a ...201224031804
comparison of ethanol production from cheese whey permeate by two yeast strains.the objective of the present laboratory scale experiment was to compare ethanol production by kluyveromyces marxianus strain atcc8554 and candida kefyr atcc 14245 from unconcentrated and concentrated cheese whey permeate. the results indicated that ethanol production was greater when using concentrated whey permeate (9.8% lactose) compared to unconcentrated whey permeate (4.9% lactose) by both the yeasts, especially in presence of growth supplements. the rate and extent of ethanol formation incr ...201224082274
growth of kluyveromyces marxianus and formation of ethyl acetate depending on temperature.conversion of lactose into ethyl acetate by kluyveromyces marxianus allows economic reuse of whey-borne sugar. the high volatility of ethyl acetate enables its process-integrated recovery by stripping. this stripping is governed by both the aeration rate and the partition coefficient, k ea,l/g. cultivation at elevated temperatures should decrease the k ea,l/g value and thus favor stripping. k. marxianus dsm 5422 as a potent producer of ethyl acetate was cultivated aerobically in whey-borne media ...201324104467
albariño wine aroma enhancement through the use of a recombinant polygalacturonase from kluyveromyces marxianus.the possible biotechnological application of a recombinant endopolygalacturonase of kluyveromyces marxianus (kmpg) for the aroma enhancement of albariño wine was studied. the addition of this enzyme to the must gives rise to a significant increase of the total compounds responsible for the aroma as opposed to the effect when using a commercial pectic enzyme. this increase also results in a significant rise of the odoriferous aglycones which are direct determinants of the aroma. wines made by usi ...201424128465
solid state fermentation of food waste mixtures for single cell protein, aroma volatiles and fat production.growth of selected microorganisms of industrial interest (saccharomyces cerevisiae, kluyveromyces marxianus and kefir) by solid state fermentation (ssf) of various food industry waste mixtures was studied. the fermented products were analysed for protein, and nutrient minerals content, as well as for aroma volatile compounds by gc/ms. the substrate fermented by k. marxianus contained the highest sum of fat and protein concentration (59.2% w/w dm) and therefore it could be considered for utilisat ...201424128535
effects of signal sequences and folding accessory proteins on extracellular expression of carboxypeptidase y in recombinant saccharomyces cerevisiae.carboxypeptidase y (cpy) is a yeast vacuolar protease with useful applications including c-terminal sequencing of peptides and terminal modification of target proteins. to overexpress cpy with the pro-sequence (procpy) encoded by the saccharomyces cerevisiae prc1 gene in recombinant s. cerevisiae, the procpy gene was combined with the gene coding for a signal sequence of s. cerevisiae mating factor α (mfα), invertase (suc2), or kluyveromyces marxianus inulinase (inu1). among the three constructs ...201424146283
identification of auxotrophic mutants of the yeast kluyveromyces marxianus by non-homologous end joining-mediated integrative transformation with genes from saccharomyces cerevisiae.the isolation and application of auxotrophic mutants for gene manipulations, such as genetic transformation, mating selection and tetrad analysis, form the basis of yeast genetics. for the development of these genetic methods in the thermotolerant fermentative yeast kluyveromyces marxianus, we isolated a series of auxotrophic mutants with defects in amino acid or nucleic acid metabolism. to identify the mutated genes, linear dna fragments of nutrient biosynthetic pathway genes were amplified fro ...201324150815
identification and assessment of kefir yeast potential for sugar/ethanol-resistance.biochemical and molecular analysis was used for identification of different kefir yeasts species from brazil, canada and the united states of america. the sugar/ethanol-resistant activity of the yeasts was evaluated. saccharomyces cerevisiae and kluyveromyces marxianus had the highest growth rates, suggesting biotechnological applications possible for these strains.201324159292
simultaneous single-cell protein production and cod removal with characterization of residual protein and intermediate metabolites during whey fermentation by k. marxianus.cheese whey fermentation with kluyveromyces marxianus was carried out at 40 °c and ph 3.5 to examine simultaneous single-cell protein production and chemical oxygen demand (cod) removal, determine the fate of soluble whey protein and characterize intermediate metabolites. after 36 h of batch fermentation, the biomass concentration increased from 2.0 to 6.0 g/l with 55 % cod reduction (including protein), whereas soluble whey protein concentration decreased from 5.6 to 4.1 g/l. it was confirmed t ...201424185705
the use of mitochondrial mutants in hybridization of industrial yeasts : iii. restoration of mitochondrial funktion in petites of industrial yeast strains by fusion with respiratory-competent protoplasts of other yeast species.protoplasts of petites of strains 625-c(i) of saccharomyces diastaticus and ncyc 1085 of saccharomyces cerevisiae, originally obtained from the national collection of yeast cultures, england, were fused with protoplasts of candida pseudotropicalis, saccharomyces rosei, yaccharbmycesmontanus, pichiamembranefaciens, hansenula anomala, hansenula capsulata, and schizosac-charomyces pombe. the respiratory-competent products of the fusions were selected on the basis of using at least one of the carbon ...198124185989
selection of a thermotolerant kluyveromyces marxianus strain with potential application for cellulosic ethanol production by simultaneous saccharification and fermentation.the development of technologies for cellulosic ethanol production by simultaneous saccharification and fermentation (ssf) depends on the use of microorganisms with high fermentative rates and thermotolerance. in this study, the ability of five kluyveromyces marxianus strains to produce ethanol from glucose at 45 °c was investigated. the highest fermentative parameters were observed with k. marxianus nrrl y-6860, which was then further studied. an initial evaluation of the oxygen supply on ethano ...201424222495
optimization, kinetics, and modeling of inulinase production by k. marxianus var. marxianus.pressmud, a by-product from the sugarcane industry, was used as a carbon source for the production of inulinase in solid-state fermentation (ssf). statistical experimental designs were employed to screen the nutrients and optimize the media composition for the production of inulinase by kluyveromyces marxianus var. marxianus. eighteen various nutrients were selected for preliminary screening of production medium component by plackett-burman design (pbd) technique. five nutrients were found to be ...201424274017
microbial diversity and dynamics during the production of may bryndza cheese.diversity and dynamics of microbial cultures were studied during the production of may bryndza cheese, a traditional slovak cheese produced from unpasteurized ewes' milk. quantitative culture-based data were obtained for lactobacilli, lactococci, total mesophilic aerobic counts, coliforms, e. coli, staphylococci, coagulase-positive staphylococci, yeasts, fungi and geotrichum spp. in ewes' milk, curd produced from it and ripened for 0 - 10 days, and in bryndza cheese produced from the curd, in th ...201424291178
xylitol production at high temperature by engineered kluyveromyces marxianus.several recombinant kluyveromyces marxianus strains were constructed through overexpressing the neurospora crassa xylose reductase genes. yzj015, which maintained the original xylitol dehydrogenase gene, produced xylitol with the highest productivity (1.49 g l(-1) h(-1)) from 100 g l(-1) xylose at 42 °c. even at 45 °c, yzj015 was still able to produce 60.03 g l(-1) xylitol from 100 g l(-1) xylose with a productivity of 1.25 g l(-1)h(-1). in addition, for 20 rounds of cell recycling at 42 °c, yzj ...201424291795
non-homologous end joining-mediated functional marker selection for dna cloning in the yeast kluyveromyces marxianus.the cloning of dna fragments into vectors or host genomes has traditionally been performed using escherichia coli with restriction enzymes and dna ligase or homologous recombination-based reactions. we report here a novel dna cloning method that does not require dna end processing or homologous recombination, but that ensures highly accurate cloning. the method exploits the efficient non-homologous end-joining (nhej) activity of the yeast kluyveromyces marxianus and consists of a novel functiona ...201424307396
variation in phenolic compounds, anthocyanins, and color in red wine treated with enzymatic extract of kluyveromyces marxianus.the effect of the addition of enzymatic extract of kluyveromyces marxianus nrrl-y-7571 during the maceration and fermentation steps of cabernet sauvignon wine production was evaluated. the results obtained in the analytical determinations of the wines showed levels within the limits established by legislation and similar to values found in other studies. the results show that by adding the enzyme to the red wines these showed color characteristics considered to be superior to those of the contro ...201424347085
candida utilis and chlorella vulgaris counteract intestinal inflammation in atlantic salmon (salmo salar l.).intestinal inflammation, caused by impaired intestinal homeostasis, is a serious condition in both animals and humans. the use of conventional extracted soybean meal (sbm) in diets for atlantic salmon and several other fish species is known to induce enteropathy in the distal intestine, a condition often referred to as sbm induced enteropathy (sbmie). in the present study, we investigated the potential of different microbial ingredients to alleviate sbmie in atlantic salmon, as a model of feed-i ...201324386162
production and characterization of β-glucanase secreted by the yeast kluyveromyces marxianus.an extracellular β-glucanase secreted by kluyveromyces marxianus was identified for the first time. the optimal conditions for the production of this enzyme were evaluated by response surface methodology. the optimal conditions to produce β-glucanase were a glucose concentration of 4% (w/v), a ph of 5.5, and an incubation temperature of 35 °c. response surface methodology was also used to determine the ph and temperature required for the optimal enzymatic activity. the highest enzyme activity wa ...201424390854
characterization and potential industrial applications of five novel, thermotolerant, fermentative, yeast strains.all five novel, thermotolerant, alcohol-producing kluyveromyces marxianus yeast strains, capable of growth at 52°c, grew aerobically on lactose (growth rates of 0.43 to 0.5 h(-1)), whey permeate (0.38 to 0.43 h(-1)), cellobiose (0.18 to 0.3 h(-1)) and xylose (0.18 to 0.26 h(-1)). they also grew anaerobically at 40 (0.18 to 0.19 h(-1)) and 45°c (0.09 to 0.14 h(-1)). all fermented glucose to ethanol and tolerated ethanol at ≤95 g l(-1) at 45°c. their potential for industrial alcohol production, po ...199524414653
short communication: ethanol production from cellulose at 45°c using a batch-fed system containing alginate-immobilized kluyveromyces marxianus imb3.the thermotolerant yeast, kluyveromyces marxianus imb3, was grown in batch culture at 45°c on cellulose-containing media, supplemented with exogenous cellulase activity. at various stages during fermentation, both substrate and enzyme were added in batch mode and fermentation was continued for 220 h. ethanol production increased to 20 g/l at 200 h, representing 45% of the maximum theoretical yield. in subsequent experiments, the organism was immobilized in calcium alginate beads and these were u ...199624415101
microbial flora and some chemical properties of ersho, a starter for teff (eragrostis tef) fermentation.ersho is a clear, yellow liquid that accumulates on the surface of fermenting teff-flour batter and is collected to serve as an inoculum for the next fermentation. the ph of ersho samples was about 3.5 and titratable acidity ranged between 3.1% and 5.7%. the mean aerobic mesophilic counts from four households varied between 6.9×10(6) and 1.3×10(8) c.f.u./ml and the aerobic bacterial flora consisted of bacillus spp. mean yeast counts ranged between 5.2×10(5) and 1.8×10(6) c.f.u./ml and comprised, ...199424420890
effect of inulin on yeast inulinase production in sauerkraut brine.kluyveromyces marxianus nrrl y-1196 produced the highest inulinase activity (38 u/mg protein) of six yeasts examined after 24 h growth in sauerkraut brine in shaking flasks at 30°c with 0.3% inulin as an enzyme inducer. the enzyme was recovered by acetone fractionation, with a yield of 81%. it had maximum activity at ph 4.4 and 55°c with k m values for inulin and sucrose of 3.92 mm and 11.9 mm, respectively. the yeast raised the ph from 3.4 to above 7.0, using all the lactic acid in the brine. g ...199424421029
kluyveromyces marxianus: a potential source of diacetyl reductase.kluyveromyces marxianus had a higher specific activity of diacetyl reductase (ec 1.1.1.5) than all other organisms previously reported. the enzyme was nadh-dependent and irreversibly catalysed the conversion of diacetyl to acetoin with an optimum ph of 7.0. it was stable at 40°c but lost 50% of its activity at 50°c in 30 min. the k m and v max values for diacetyl were 1.8 mm and 0.053 mm/min, respectively.199424421081
high ethanol productivity from lactose by immobilized cells of kluyveromyces fragilis and zymomonas mobilis.ethanol production from 200 g lactose/l by kluyveromyces fragilis immobilized in calcium alginate was 63 g/l whereas with co-immobilized k. fragilis and zymomonas mobilis 72 g ethanol/l was attained. with free cells of k. fragilis, only 52 g ethanol/l was obtained. the beads were relatively stable without significant reduction in activity for about six batches of fermentation.199124425196
Refresh
firstprev
12345678910
nextlast
Displaying items 701 - 800 of 963