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Mercedes Ballesteros - One of the best experts on this subject based on the ideXlab platform.
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different laccase detoxification strategies for ethanol production from lignocellulosic biomass by the thermotolerant yeast Kluyveromyces marxianus cect 10875
Bioresource Technology, 2012Co-Authors: Antonio D Moreno, David Ibarra, Jose Vicente De Lucio Fernandez, Mercedes BallesterosAbstract:In this work, laccase enzymes were evaluated to detoxify the whole slurry from steam-exploded wheat straw. For it, two different strategies, laccase treatment before or after enzymatic hydrolysis, were employed. The detoxification efficiency was analyzed on enzymatic hydrolysis and fermentation levels by the thermotolerant yeast Kluyveromyces marxianus. Laccases reduced phenolic compounds without affecting weak acids and furan derivates. A lower glucose recovery was observed when laccase treatments were carried out before enzymatic hydrolysis, phenomenon that was not showed after enzymatic hydrolysis. In contrast, both laccase treatment strategies enhanced ethanol concentrations, reducing significantly the lag phase of the yeast and allowing substrate loading increments of saccharification and fermentation broths.
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effect of different cellulase dosages on cell viability and ethanol production by Kluyveromyces marxianus in ssf processes
Bioresource Technology, 2009Co-Authors: Elia Tomaspejo, Maria Jose Negro, J M Oliva, M P Garciaaparicio, Mercedes BallesterosAbstract:This study was aimed to study the effect of commercial cellulases (Celluclast 1.5 LFG) on Kluyveromyces marxianus CECT 10875 growth and ethanol production in SSF processes. Preliminary tests carried out in glucose (50 g/L) fermentation medium showed that high enzyme amounts (2.5-3.5 FPU/mL) could cause a negative effect on K. marxianus growth rate and viable cells number. However, the maximum ethanol production was not affected and about 86% of the theoretical (22 g/L) was reached in all cases independently of the enzyme dosage. In SSF experiments, cell viability was always affected by enzyme loading. Nevertheless, slight differences observed on cell viability during glucose fermentation processes with the detected concentrations of the additives did not justify the negative effect observed in SSF experiments.
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ethanol from lignocellulosic materials by a simultaneous saccharification and fermentation process sfs with Kluyveromyces marxianus cect 10875
Process Biochemistry, 2004Co-Authors: Mercedes Ballesteros, J M Oliva, Paloma Manzanares, M J Negro, Ignacio BallesterosAbstract:Abstract Simultaneous saccharification and fermentation (SSF) process for ethanol production from various lignocellulosic woody (poplar and eucalyptus) and herbaceous ( Sorghum sp. bagasse, wheat straw and Brassica carinata residue) materials has been assayed using the thermotolerant yeast strain Kluyveromyces marxianus CECT 10875. Biomass samples were previously treated in a steam explosion pilot plant to provide pretreated biomass with increased cellulose content relative to untreated materials and to enhance cellulase accessibility. SSF experiments were performed in laboratory conditions at 42 °C, 10% (w/v) substrate concentration and 15 FPU/g substrate of commercial cellulase. The results indicate that it is possible to reach SSF yields in the range of 50–72% of the maximum theoretical SSF yield, based on the glucose available in pretreated materials, in 72–82 h. Maximum ethanol contents from 16 to 19 g/l were obtained in fermentation media, depending on the material tested.
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effect of lignocellulosic degradation compounds from steam explosion pretreatment on ethanol fermentation by thermotolerant yeast Kluyveromyces marxianus
Applied Biochemistry and Biotechnology, 2003Co-Authors: J M Oliva, Felicia Saez, Ignacio Ballesteros, Alberto Gonzalez, Maria Jose Negro, Paloma Manzanares, Mercedes BallesterosAbstract:The filtrate from steam-pretreated poplar was analyzed to identify degradation compounds. The effect of selected compounds on growth and ethanolic fermentation of the thermotolerant yeast strain Kluyveromyces marxianus CECT 10875 was tested. Several fermentations on glucose medium, containing individual inhibitory compounds found in the hydrolysate, were carried out. The degree of inhibition on yeast strain growth and ethanolic fermentation was determined. At concentrations found in the prehy-drolysate, none of the individual compounds significantly affected the fermentation. For all tested compounds, growth was inhibited to a lesser extent than ethanol production. Lower concentrations of catechol (0.96 g/L) and 4-hydroxybenzaldehyde (1.02 g/L) were required to produce the 50% reduction in cell mass in comparison to other tested compounds.
Munish Puri - One of the best experts on this subject based on the ideXlab platform.
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optimization of medium and process parameters for the production of inulinase from a newly isolated Kluyveromyces marxianus ys 1
Bioresource Technology, 2007Co-Authors: Ram Sarup Singh, Balwinder Singh Sooch, Munish PuriAbstract:Abstract A newly isolated strain of Kluyveromyces marxianus YS-1 was used for the production of extra cellular inulinase in a medium containing inulin, meat extract, CaCl 2 and sodium dodecyl sulphate (SDS). Fermentation medium pH 6.5, cultivation temperature 30 °C and 5% (v/v) inoculum of 12 h-old culture were optimal for enzyme production (30.8 IU/ml) with a fermentation time of 72 h at shake flask level. Raw inulin (2%, w/v) extracted from dahlia tubers by processing at 15 kg/cm 2 for 10 min was optimum for bioreactor studies. Maximum enzyme production (55.4 IU/ml) was obtained at an agitation rate of 200 rpm and aeration of 0.75 vvm in a stirred tank reactor with a fermentation time of 60 h.
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production of inulinase from Kluyveromyces marxianus ys 1 using root extract of asparagus racemosus
Process Biochemistry, 2006Co-Authors: Ram Sarup Singh, Rajesh Dhaliwal, Munish PuriAbstract:Roots of Asparagus racemosus were used as a source of inulin for the production of inulinase from Kluyveromyces marxianus YS-1. Root extract prepared at 10 kg/cm2 for 10 min showed the maximum production of inulinase. Various parameters of fermentation have been examined in order to improve overall enzyme yield. Inulinase yield of 40.5 IU/mL in an optimized medium containing inulin (3.5%), beef extract (0.5%), MnSO4 (0.5 mM), CoCl2 (0.05 mM), SDS (0.4 mM) and pH 6.5 at 30 °C under agitation (150 rpm) for 60 h has been obtained at shake flask level. After optimization the enzyme production has been increased 6.1 times at flask level. In a bioreactor (working volume 1 L) fermentation medium containing 4% inulin has shown maximum inulinase production (47.3 IU/mL) under optimized parameters of 200 rpm, 0.75 vvm aeration at 30 °C after 60 h.
A A Koutinas - One of the best experts on this subject based on the ideXlab platform.
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lactic acid production by mixed cultures of Kluyveromyces marxianus lactobacillus delbrueckii ssp bulgaricus and lactobacillus helveticus
Bioresource Technology, 2008Co-Authors: Stavros Plessas, A A Koutinas, C Psarianos, Loulouda Bosnea, Roger Marchant, Ibrahim M BanatAbstract:Lactic acid production using Kluyveromyces marxianus (IFO 288), Lactobacillus delbrueckii ssp. bulgaricus (ATCC 11842) and Lactobacillus helveticus (ATCC 15009) individually or as mixed culture on cheese whey in stirred or static fermentation conditions was evaluated. Lactic acid production, residual sugar and cell biomass were the main features examined. Increased lactic acid production was observed, when mixed cultures were used in comparison to individual ones. The highest lactic acid concentrations were achieved when K. marxianus yeast was combined with L. delbrueckii ssp. bulgaricus, and when all the strains were used revealing possible synergistic effects between the yeast and the two lactic acid bacteria. The same synergistic effects were further observed and verified when the mixed cultures were applied in sourdough fermentations, proving that the above microbiological system could be applied in the food fermentations where high lactic acid production is sought.
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application of Kluyveromyces marxianus lactobacillus delbrueckii ssp bulgaricus and l helveticus for sourdough bread making
Food Chemistry, 2008Co-Authors: Stavros Plessas, Ann Fisher, Katerina Koureta, C Psarianos, Poonam Singh Nee Nigam, A A KoutinasAbstract:Abstract The application of Kluyveromyces marxianus (IFO 288), Lactobacillus delbrueckii ssp. bulgaricus (ATCC 11842) and Lactobacillus helveticus (ATCC 15009) as starter cultures for sourdough bread making was examined. Production of lactic and acetic acids, bread rising, volatile composition, shelf-life and organoleptic quality of the sourdough breads were evaluated. The amount of starter culture added to the flour, the dough fermentation temperature and the amount of sourdough used were examined in order to optimise the bread making process. The use of mixed cultures led to higher total titratable acidities and lactic acid concentrations compared to traditionally made breads. Highest acidity (3.41 g lactic acid/kg of bread) and highest resistance to mould spoilage were observed when bread was made using 50% sourdough containing 1% K. marxianus and 4% L. delbrueckii ssp. bulgaricus. The use of these cultures also improved the aroma of sourdough breads, as shown by sensory evaluations and as revealed by GC–MS analysis.
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high temperature alcoholic fermentation of whey using Kluyveromyces marxianus imb3 yeast immobilized on delignified cellulosic material
Bioresource Technology, 2002Co-Authors: Yiannis Kourkoutas, Poonam Singh Nee Nigam, Roger Marchant, Ibrahim M Banat, Maria Kanellaki, S Dimitropoulou, A A KoutinasAbstract:A novel system for high-temperature alcoholic fermentation of whey is described. This system consists of Kluyveromyces marxianus yeast immobilized on delignified cellulosic material (DCM). The effect of pH, initial lactose concentration and temperature on the fermentation of a synthetic medium containing lactose was studied. Batch fermentations of whey were also carried out and the formation of volatile by-products was examined. The concentrations of higher alcohols were found to be in very low levels leading to a product of improved quality. The fermented whey had an improved characteristic aroma compared to unfermented whey. The possibility to use fermented whey as raw material for the production of a novel, low alcohol content drink was also investigated.
Monique Furlan - One of the best experts on this subject based on the ideXlab platform.
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engineering Kluyveromyces marxianus as a robust synthetic biology platform host
Mbio, 2018Co-Authors: Paul Cernak, Raissa Estrela, Snigdha Poddar, Jeffrey M Skerker, Yafang Cheng, Annika K Carlson, Berling Chen, Victoria M Glynn, Monique FurlanAbstract:Throughout history, the yeast Saccharomyces cerevisiae has played a central role in human society due to its use in food production and more recently as a major industrial and model microorganism, because of the many genetic and genomic tools available to probe its biology. However, S. cerevisiae has proven difficult to engineer to expand the carbon sources it can utilize, the products it can make, and the harsh conditions it can tolerate in industrial applications. Other yeasts that could solve many of these problems remain difficult to manipulate genetically. Here, we engineered the thermotolerant yeast Kluyveromyces marxianus to create a new synthetic biology platform. Using CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats with Cas9)-mediated genome editing, we show that wild isolates of K. marxianus can be made heterothallic for sexual crossing. By breeding two of these mating-type engineered K. marxianus strains, we combined three complex traits-thermotolerance, lipid production, and facile transformation with exogenous DNA-into a single host. The ability to cross K. marxianus strains with relative ease, together with CRISPR-Cas9 genome editing, should enable engineering of K. marxianus isolates with promising lipid production at temperatures far exceeding those of other fungi under development for industrial applications. These results establish K. marxianus as a synthetic biology platform comparable to S. cerevisiae, with naturally more robust traits that hold potential for the industrial production of renewable chemicals.IMPORTANCE The yeast Kluyveromyces marxianus grows at high temperatures and on a wide range of carbon sources, making it a promising host for industrial biotechnology to produce renewable chemicals from plant biomass feedstocks. However, major genetic engineering limitations have kept this yeast from replacing the commonly used yeast Saccharomyces cerevisiae in industrial applications. Here, we describe genetic tools for genome editing and breeding K. marxianus strains, which we use to create a new thermotolerant strain with promising fatty acid production. These results open the door to using K. marxianus as a versatile synthetic biology platform organism for industrial applications.
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Kluyveromyces marxianus as a robust synthetic biology platform host
bioRxiv, 2018Co-Authors: Paul Cernak, Raissa Estrela, Snigdha Poddar, Jeffrey M Skerker, Yafang Cheng, Annika K Carlson, Berling Chen, Victoria M Glynn, Monique Furlan, Owen W RyanAbstract:Throughout history, the yeast Saccharomyces cerevisiae has played a central role in human society due to its use in food production and more recently as a major industrial and model microorganism, because of the many genetic and genomic tools available to probe its biology. However S. cerevisiae has proven difficult to engineer to expand the carbon sources it can utilize, the products it can make, and the harsh conditions it can tolerate in industrial applications. Other yeasts that could solve many of these problems remain difficult to manipulate genetically. Here, we engineer the thermotolerant yeast Kluyveromyces marxianus to create a new synthetic biology platform. Using CRISPR-Cas9 mediated genome editing, we show that wild isolates of K. marxianus can be made heterothallic for sexual crossing. By breeding two of these mating-type engineered K. marxianus strains, we combined three complex traits−thermotolerance, lipid production, and facile transformation with exogenous DNA−into a single host. The ability to cross K. marxianus strains with relative ease, together with CRISPR-Cas9 genome editing, should enable engineering of K. marxianus isolates with promising lipid production at temperatures far exceeding those of other fungi under development for industrial applications. These results establish K. marxianus as a synthetic biology platform comparable to S. cerevisiae, with naturally more robust traits that hold potential for the industrial production of renewable chemicals.
Ibrahim M Banat - One of the best experts on this subject based on the ideXlab platform.
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lactic acid production by mixed cultures of Kluyveromyces marxianus lactobacillus delbrueckii ssp bulgaricus and lactobacillus helveticus
Bioresource Technology, 2008Co-Authors: Stavros Plessas, A A Koutinas, C Psarianos, Loulouda Bosnea, Roger Marchant, Ibrahim M BanatAbstract:Lactic acid production using Kluyveromyces marxianus (IFO 288), Lactobacillus delbrueckii ssp. bulgaricus (ATCC 11842) and Lactobacillus helveticus (ATCC 15009) individually or as mixed culture on cheese whey in stirred or static fermentation conditions was evaluated. Lactic acid production, residual sugar and cell biomass were the main features examined. Increased lactic acid production was observed, when mixed cultures were used in comparison to individual ones. The highest lactic acid concentrations were achieved when K. marxianus yeast was combined with L. delbrueckii ssp. bulgaricus, and when all the strains were used revealing possible synergistic effects between the yeast and the two lactic acid bacteria. The same synergistic effects were further observed and verified when the mixed cultures were applied in sourdough fermentations, proving that the above microbiological system could be applied in the food fermentations where high lactic acid production is sought.
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high temperature alcoholic fermentation of whey using Kluyveromyces marxianus imb3 yeast immobilized on delignified cellulosic material
Bioresource Technology, 2002Co-Authors: Yiannis Kourkoutas, Poonam Singh Nee Nigam, Roger Marchant, Ibrahim M Banat, Maria Kanellaki, S Dimitropoulou, A A KoutinasAbstract:A novel system for high-temperature alcoholic fermentation of whey is described. This system consists of Kluyveromyces marxianus yeast immobilized on delignified cellulosic material (DCM). The effect of pH, initial lactose concentration and temperature on the fermentation of a synthetic medium containing lactose was studied. Batch fermentations of whey were also carried out and the formation of volatile by-products was examined. The concentrations of higher alcohols were found to be in very low levels leading to a product of improved quality. The fermented whey had an improved characteristic aroma compared to unfermented whey. The possibility to use fermented whey as raw material for the production of a novel, low alcohol content drink was also investigated.
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decolorization of remazol black b using a thermotolerant yeast Kluyveromyces marxianus imb3
Environment International, 2000Co-Authors: C Meehan, Poonam Singh Nee Nigam, Ibrahim M Banat, Geoffrey Mcmullan, Franklin Smyth, Roger MarchantAbstract:The ability of Kluyveromyces marxianus IMB3 to decolorize Remazol Black-B dye was investigated. The effect of environmental conditions, such as pH and temperature were examined. No noticeable effects on decolorization were observed when pH varied from 3.0-55. Maximum colour removal, 98%, was achieved at 37 degreesC. Little or no colour removal was detected when K. marxianus IMB3 was incubated under anaerobic conditions. Further investigation, in which decolorization was monitored under extreme temperatures and low pH (to inhibit growth) and using ten fold dense inoculum, revealed that decolorization was due to biosorption to the yeast cells and not due to a metabolic reaction. (C) 2000 Elsevier Science Ltd. All rights reserved.