• The aim of this study was to quantify uptake of pentose and hexose monosaccharides in an industrial substrate and to present a kinetic growth model of C. saccharolyticus that includes sugar uptake on defined and industrial media. (biomedcentral.com)
  • Moreover, the observation indicates a regulation system that has fundamental research relevance, since pentose and glucose uptake in C. saccharolyticus has only been described with ABC transporters, whereas previously reported diauxic growth phenomena have been correlated mainly to PTS systems for sugar uptake. (biomedcentral.com)
  • An expression cassette containing 13 genes including Clostridium phytofermentans XylA , encoding D-xylose isomerase (XI), and enzymes of the pentose phosphate pathway was inserted in two copies in the genome of Ethanol Red. (biomedcentral.com)
  • Unfortunately, baker's yeast is unable to efficiently metabolize pentose sugars, particularly D-xylose, which accounts for up to 35% of total sugars in xylan-rich lignocellulosic biomass such as hard woods and straw [ 3 ]. (biomedcentral.com)
  • Mathematical expressions were developed to describe hydrogen production by C. saccharolyticus consuming glucose, xylose, and arabinose. (biomedcentral.com)
  • The chemical composition of the carbohydrate component of delignified palm fiber is 56.4% glucose, 36.0% xylose, 5.9% arabinose, and 1.7% mannose (1). (banksolar.ru)
  • The experimental data included four different cases: glucose, xylose, sugar mixture, and wheat straw hydrolysate (WSH) fermentations. (biomedcentral.com)
  • The substrate uptake rate of C. saccharolyticus on single sugar-defined media was higher on glucose compared to xylose. (biomedcentral.com)
  • In contrast, in the defined sugar mixture and WSH, the pentoses were consumed faster than glucose. (biomedcentral.com)
  • Subsequently, the cultures entered a lag phase when all pentoses were consumed after which glucose uptake rate increased. (biomedcentral.com)
  • However, once all pentoses were consumed, C. saccharolyticus most probably expressed another uptake system to account for the observed increased glucose uptake rate. (biomedcentral.com)
  • The high D-xylose fermentation capacity was stable after extended growth in glucose. (biomedcentral.com)
  • The strain uses glucose and D-xylose with high consumption rates and partial cofermentation in various lignocellulose hydrolysates with very high ethanol yield. (biomedcentral.com)
  • Our experiments showed that delignified palm fiber can be digested to form glucose and xylose by commercial cellulases such as Meicellase and Onozuka and the hydrolysate can be subjected to fermentation to produce biofuel and chemicals (1). (banksolar.ru)
  • Our study estimates that 3,000,0001 of glucose and 2,000,000 t of xylose could be recovered from this waste per year. (banksolar.ru)
  • protein_coding" "AAC74850","yeaD","Escherichia coli","D-hexose-6-phosphate epimerase-like protein [Ensembl]. (ntu.edu.sg)
  • In addition, global warming has led to an increase in temperature of water, which has affected the normal lifecycles of bacteria and algae, mainly by increasing the duration of bloom seasons. (ncsu.edu)
  • Yeasts lack chlorophyll and are unable to manufacture by photosynthesis from inorganic substrates the organic compounds required for growth, as do higher plants, algae, and even some bacteria. (biologydiscussion.com)
  • Subsequent EMS mutagenesis, genome shuffling and selection in D-xylose-enriched lignocellulose hydrolysate, followed by multiple rounds of evolutionary engineering in complex medium with D-xylose, gradually established efficient D-xylose fermentation. (biomedcentral.com)
  • In simultaneous saccharification and fermentation of Arundo hydrolysate, GS1.11-26 produced 32% more ethanol than the parent strain Ethanol Red, due to efficient D-xylose utilization. (biomedcentral.com)
  • In separate hydrolysis and fermentation of lignocellulose hydrolysates of Arundo donax (giant reed), spruce and a wheat straw/hay mixture, the maximum specific D-xylose consumption rate was 0.36, 0.23 and 1.1 g/g DW inoculum/h, and the final ethanol titer was 4.2, 3.9 and 5.8% (v/v), respectively. (biomedcentral.com)
  • Although there are various species of bacteria, filamentous fungi and other yeast species that are naturally capable of efficiently metabolizing D-xylose, they lack the other crucial advantages of the yeast S. cerevisiae , which have made it the most prominent industrial microorganism. (biomedcentral.com)
  • The best-performing strain, GS1.11-26, showed a maximum specific D-xylose consumption rate of 1.1 g/g DW/h in synthetic medium, with complete attenuation of 35 g/L D-xylose in about 17 h. (biomedcentral.com)
  • The high D-xylose consumption rate was due to synergistic interaction between the high XI activity and one or more mutations in the genome. (biomedcentral.com)
  • Cell extracts of strain GS1.11-26 displayed 17-fold higher XI activity compared to the parent strain, but overexpression of XI alone was not enough to establish D-xylose fermentation. (biomedcentral.com)
  • The inherently higher robustness and tolerance of S. cerevisiae to various inhibitors gives it a head start in programs aimed at developing strains with extreme inhibitor tolerance, able to efficiently ferment hexoses and pentoses in concentrated lignocellulose hydrolysates [ 6 ]. (biomedcentral.com)
  • Anaerobic xylose fermentation by recombinant Saccharomyces cerevisiae carrying XYL1 , XYL2 , and XKS1 in mineral medium chemostat cultures. (microbiologyresearch.org)
  • Here, we present a systematic strategy for optimizing non-native sugar fermentation by recombinant S. cerevisiae , using cellobiose as a model. (biomedcentral.com)
  • Pretreatment is the key step to overcome the recalcitrance of lignocellulosic biomass making sugars available for subsequent enzymatic hydrolysis and microbial fermentation. (springeropen.com)
  • The toxic nature of the lignocellulosic hydrolysate severely impedes its efficient substrate utilization and bioethanol fermentation. (springeropen.com)
  • Although methods to remove inhibitors physically, chemically, or biologically may help moderate the problem of toxic compounds in lignocellulosic hydrolysates, it is not economically feasible to remove inhibitors from hydrolysate prior to fermentation due to the cost associated with additional processing steps and the potential loss of fermentable sugars (Jönsson et al. (springeropen.com)
  • Although Z. mobilis demonstrates advantages in ethanol fermentation, the inhibitors derived from biomass deconstruction and hydrolysis still have detrimental effects on Z. mobilis , especially when high biomass solid loading is used during pretreatment and enzymatic hydrolysis steps to generate high concentration of sugars besides the potential additive or synergistic inhibitions of various inhibitors in the hydrolysate (Franden et al. (springeropen.com)
  • they are responsible for the conversion of sugars to ethanol and carbon dioxide, which make a relatively small contribution to flavour, and hundreds of by-products, some of them not yet identified, that greatly contribute to the fermentation bouquet. (moam.info)
  • Sucrose and other sugars, such as xylose, rhamnose and arabinose, are present in very low concentrations, and it is widely accepted that S. cerevisiae strains do not use these sugars as carbon or energy sources during alcoholic fermentation (Bisson, 1993). (moam.info)
  • This work demonstrated an effective approach of improved butanol fermentation and its probable mechanisms of this positive effect, i.e. the adsorption of ABE solvent and the adhesion of bacteria on porous substrate accounted for the production improvement and the proportional variation of solvent constituents. (biomedcentral.com)
  • As a model bioethanol producer, Zymomonas mobilis has attracted considerable attention over the past decades due to its excellent industrial characteristics, such as the unique Entner-Doudoroff (ED) pathway under anaerobic conditions resulting in low cell mass formation, high specific rate of sugar uptake, high ethanol yield, notable ethanol tolerance, and the generally regarded as safe (GRAS) status (Panesar et al. (springeropen.com)
  • Increased abundance of methanogenic archaea and hydrolytic bacteria indicated improved anaerobic digestion. (preprints.org)
  • Saccharomyces cerevisiae , a key organism used for the manufacture of renewable fuels and chemicals, has been engineered to utilize non-native sugars derived from plant cell walls, such as cellobiose and xylose. (biomedcentral.com)
  • Saccharomyces cerevisiae is a key organism used for the manufacture of renewable fuels and chemicals, but it is not capable of using mixed sugars derived from the plant cell wall [ 1 ]-[ 4 ]. (biomedcentral.com)
  • Several microorganisms have been applied for ethanol production from lignocellulose, including both bacteria and yeasts (Olsson and Hahn-Hägerdal 1996 ). (springeropen.com)
  • However, the yield of solvent decreased with the increased initial sugar concentration. (biomedcentral.com)
  • Our results suggest that a decrease in mRNAs encoding high-affinity/active sugar transport systems may be a widespread and conserved mechanism in yeasts, limiting expression of these proteins whenever their activity is dispensable. (microbiologyresearch.org)
  • High capacity xylose transport in Candida intermedia PYCC 4715. (microbiologyresearch.org)
  • In wine, some aroma compounds arise from the must with minor or no modifications, while others are products of yeast metabolism, in particular from the sugar and nitrogen compounds initially present in the grapes. (moam.info)