Untitled

Yablochkova, E. N.; Bolotnikova, O. I.; Mikhailova, N. P.; Немова, Н. Н.; Гинак, А. И.

doi:10.1023/a:1025032404238

Cited by 27 publications

(6 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this respect, the biochemical data well supported how, also in K. marxianus , impairment in xylose metabolism under micro-aerobic condition can be ascribed to the difference in cofactor preference between Km XR and Km XDH [25,29,41]. Zhang and co-authors [44] overexpressed in K. marxianus a NADPH-preferring xylose reductase and engineered its cofactor preference to revert it to NADH.…”

Section: Discussionmentioning

confidence: 65%

“…In fact, it is well reported in literature that not only the pentose phosphate pathway, but also the acetaldehyde dehydrogenase can significantly contribute to the overall NADPH pool [39,40]. Additional data would be necessary to fully elucidate this point: however it should be noted that NADPH is the Km XR cofactor [41]. Moreover, since reducing power is required for the neutralization of reactive oxygen species [42,43], NADPH formation through the acetate pathway might be required for counteracting ROS accumulation.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of oxygenation and temperature on glucose-xylose fermentation in Kluyveromyces marxianus CBS712 strain

et al. 2014

View full text Add to dashboard Cite

BackgroundThe yeast Kluyveromyces marxianus features specific traits that render it attractive for industrial applications. These include production of ethanol which, together with thermotolerance and the ability to grow with a high specific growth rate on a wide range of substrates, could make it an alternative to Saccharomyces cerevisiae as an ethanol producer. However, its ability to co-ferment C5 and C6 sugars under oxygen-limited conditions is far from being fully characterized.ResultsIn the present study, K. marxianus CBS712 strain was cultivated in defined medium with glucose and xylose as carbon source. Ethanol fermentation and sugar consumption of CBS712 were investigated under different oxygen supplies (1.75%, 11.00% and 20.95% of O2) and different temperatures (30°C and 41°C). By decreasing oxygen supply, independently from the temperature, both biomass production as well as sugar utilization rate were progressively reduced. In all the tested conditions xylose consumption followed glucose exhaustion. Therefore, xylose metabolism was mainly affected by oxygen depletion. Loss in cell viability cannot explain the decrease in sugar consumption rates, as demonstrated by single cell analyses, while cofactor imbalance is commonly considered as the main cause of impairment of the xylose reductase (KmXR) - xylitol dehydrogenase (KmXDH) pathway. Remarkably, when these enzyme activities were assayed in vitro, a significant decrease was observed together with oxygen depletion, not ascribed to reduced transcription of the corresponding genes.ConclusionsIn the present study both oxygen supply and temperature were shown to be key parameters affecting the fermentation capability of sugars in the K. marxianus CBS712 strain. In particular, a direct correlation was observed between the decreased efficiency to consume xylose with the reduced specific activity of the two main enzymes (KmXR and KmXDH) involved in its catabolism. These data suggest that, in addition to the impairment of the oxidoreductive pathway being determined by the cofactor imbalance, post-transcriptional and/or post-translational regulation of the pathway enzymes contributes to the efficiency of xylose catabolism in micro-aerobic conditions. Overall, the presented work provides novel information on the fermentation capability of the CBS712 strain that is currently considered as the reference strain of the genus K. marxianus.

show abstract

Section: Discussionmentioning

confidence: 65%

Section: Discussionmentioning

confidence: 99%

Effect of oxygenation and temperature on glucose-xylose fermentation in Kluyveromyces marxianus CBS712 strain

et al. 2014

View full text Add to dashboard Cite

show abstract

“…The first step in the metabolism of D-xylose occurring in yeast and fungi involves xylose reductase which reduces D-xylose to xylitol (Verduyn et al, 1985). The xylitol thus produced is secreted out of the cell or otherwise, it is oxidized by xylitol dehydrogenase to produce D-xylulose (Rizzi et al, 1989;Yablochkova et al, 2003). The secretion or oxidation of xylitol depends on the availability of cofactors.…”

Section: Xylitol Production By Microorganismsmentioning

confidence: 99%

“…In a recent study by Carneiro and Almeida (2019) involving 44 isolates, it was found that Meyerozyma species were the best utilizers of xylose and Wickerhamomyces anomalus produced high xylitol yield. Candida strains such as C. tropicalis and C. silvanorum are the most promising xylitol producers as they have been found to have the highest xylose reductase activity (Yablochkova et al, 2003). López-Linares et al ( 2018) compared the production of xylitol by Debaryomyces hansenii and Candida guilliermondii and observed that C. guilliermondii showed high tolerance to inhibitors like furans and acids thus possessing the advantage of not requiring additional detoxification steps.…”

Section: Xylitol Production By Microorganismsmentioning

confidence: 99%

Xylitol: Bioproduction and Applications-A Review

et al. 2022

View full text Add to dashboard Cite

Xylitol, a natural compound classified as a sugar alcohol, is found diversely in fruits and vegetables in small quantities. Commercial production of xylitol has expanded due to its health benefits and wide applications as an alternative sweetener in food and pharmaceutical products. Production of xylitol on large scale is industrially being achieved by the chemical method. However, the biotechnological method offers the possibilities of lowered cost and energy compared to the chemical methods. It involves the conversion of xylose to xylitol by microbes or enzymes which is environmentally safe. This review highlights the prospects of the biotechnological method of xylitol production. Various microorganisms that have been used to produce xylitol, the bioprocess parameters, and genetic modifications to increase xylitol yield have been reviewed. In addition, the applications, benefits, and safety concerns to health have been discussed.

show abstract

“…According to the report of Yablochkova, Bolotnikova, Mikhailova, Nemova, and Ginak (2003), either ethanol or xylitol may be produced from D-xylose by the activities of P. tannophilus strains, a xylose-utilizing yeast, though, the wild-type was reported to produce these two solvents simultaneously. This behavior is presumed to have a link with imbalance between NADPH/NADH coenzymes (Yablochkova et al, 2003). The metabolic selection criteria for either of these hydroxyl compounds are still under investigation.…”

Section: Introductionmentioning

confidence: 99%

Genetics and metabolic engineering of yeast strains for efficient ethanol production

Adebami

Kuila

Ajunwa

et al. 2021

J Food Process Engineering

View full text Add to dashboard Cite

Bioethanol production from monomeric sugar is performed by several yeasts. But there are several limitations associated with yeast strains such as their low tolerance to ethanol, toxic inhibitors, and high sugar concentration. Genetic and metabolic engineering of potential yeast strains can overcome the above limitations. The present article summarized current genetic and metabolic engineering approaches for the development of yeast strain for efficient ethanol production. The review systematically examined bioethanol generations based on substrate utilization, criteria for strain selections, strategies for strain improvements including randomized mutagenesis, genetic engineering, metabolic engineering, genome editing, whole genome (re)sequencing, promoter engineering, quantitative trait locus analysis, protein engineering, and evolutionary engineering. Different fermentation technologies employed in hydrolysate fermentation including low gravity (LG), high gravity (HG), and very high gravity (VHG) as well as challenges of yeast strains development and its future prospect have been critically evaluated in this article. Significant engineering efforts are imminent for yeast‐based second‐generation biofuel to leave a demonstration phase through strain improvement and become economically competitive with fossil fuel. Practical Applications This is a comprehensive review of yeast strain development for bioethanol production. The readers should be able to acquire some basic knowledge on: The accompanied substrates for bioethanol generations as well as the technologies and challenges behind them. The criteria to consider in selecting yeast strain for bioengineering development. Different strategies and their reported applications employed in yeast strain development including randomized mutagenesis, genetic engineering, metabolic engineering, genome editing, whole genome (re)sequencing, promoter engineering, quantitative trait locus (QTL) analysis, protein engineering, and evolutionary engineering. Challenges and merits of different fermentation technologies employed in hydrolysate fermentation including LG, HG, and VHG. Possible challenges to encounter in developing yeast strain for bioethanol production. Desirable traits to consider in the selection and development of yeast strains for bioethanol production.

show abstract

Untitled

Cited by 27 publications

References 8 publications

Effect of oxygenation and temperature on glucose-xylose fermentation in Kluyveromyces marxianus CBS712 strain

Effect of oxygenation and temperature on glucose-xylose fermentation in Kluyveromyces marxianus CBS712 strain

Xylitol: Bioproduction and Applications-A Review

Genetics and metabolic engineering of yeast strains for efficient ethanol production

Contact Info

Product

Resources

About