scholarly journals Saccharomyces cerevisiae Cells Lacking the Zinc Vacuolar Transporter Zrt3 Display Improved Ethanol Productivity in Lignocellulosic Hydrolysates

2022 ◽  
Vol 8 (1) ◽  
pp. 78
Author(s):  
Joana Terra-Matos ◽  
Marta Oliveira Teixeira ◽  
Cátia Santos-Pereira ◽  
Henrique Noronha ◽  
Lucília Domingues ◽  
...  
Keyword(s):  
Ethanol Productivity ◽  
Biofuel Production ◽  
Yeast Fermentation ◽  
Lignocellulosic Ethanol ◽  
Wild Type ◽  
Lignocellulosic Hydrolysates ◽  
Promising Strategy ◽  
Yeast Strains ◽  
Regulated Cell Death ◽  
Fermentative Yeast

Yeast-based bioethanol production from lignocellulosic hydrolysates (LH) is an attractive and sustainable alternative for biofuel production. However, the presence of acetic acid (AA) in LH is still a major problem. Indeed, above certain concentrations, AA inhibits yeast fermentation and triggers a regulated cell death (RCD) process mediated by the mitochondria and vacuole. Understanding the mechanisms involved in AA-induced RCD (AA-RCD) may thus help select robust fermentative yeast strains, providing novel insights to improve lignocellulosic ethanol (LE) production. Herein, we hypothesized that zinc vacuolar transporters are involved in vacuole-mediated AA-RCD, since zinc enhances ethanol production and zinc-dependent catalase and superoxide dismutase protect from AA-RCD. In this work, zinc limitation sensitized wild-type cells to AA-RCD, while zinc supplementation resulted in a small protective effect. Cells lacking the vacuolar zinc transporter Zrt3 were highly resistant to AA-RCD, exhibiting reduced vacuolar dysfunction. Moreover, zrt3Δ cells displayed higher ethanol productivity than their wild-type counterparts, both when cultivated in rich medium with AA (0.29 g L−1 h−1 versus 0.11 g L−1 h−1) and in an LH (0.73 g L−1 h−1 versus 0.55 g L−1 h−1). Overall, the deletion of ZRT3 emerges as a promising strategy to increase strain robustness in LE industrial production.

scholarly journals Yeasts as Complementary Model Systems for the Study of the Pathological Repercussions of Enhanced Synphilin-1 Glycation and Oxidation

2021 ◽  
Vol 22 (4) ◽  
pp. 1677
Author(s):  
David Seynnaeve ◽  
Daniel P. Mulvihill ◽  
Joris Winderickx ◽  
Vanessa Franssens
Keyword(s):  
Lewy Bodies ◽  
Inhibitory Effect ◽  
Model Systems ◽  
Wild Type ◽  
Glyoxalase System ◽  
Inclusion Formation ◽  
Growth Defects ◽  
Yeast Strains ◽  
Autophagic Degradation ◽  
Detrimental Impact

Synphilin-1 has previously been identified as an interaction partner of α-Synuclein (αSyn), a primary constituent of neurodegenerative disease-linked Lewy bodies. In this study, the repercussions of a disrupted glyoxalase system and aldose reductase function on Synphilin-1 inclusion formation characteristics and cell growth were investigated. To this end, either fluorescent dsRed-tagged or non-tagged human SNCAIP, which encodes the Synphilin-1 protein, was expressed in Saccharomyces cerevisiae and Schizosaccharomyces pombe yeast strains devoid of enzymes Glo1, Glo2, and Gre3. Presented data shows that lack of Glo2 and Gre3 activity in S. cerevisiae increases the formation of large Synphilin-1 inclusions. This correlates with enhanced oxidative stress levels and an inhibitory effect on exponential growth, which is most likely caused by deregulation of autophagic degradation capacity, due to excessive Synphilin-1 aggresome build-up. These findings illustrate the detrimental impact of increased oxidation and glycation on Synphilin-1 inclusion formation. Similarly, polar-localised inclusions were observed in wild-type S. pombe cells and strains deleted for either glo1+ or glo2+. Contrary to S. cerevisiae, however, no growth defects were observed upon expression of SNCAIP. Altogether, our findings show the relevance of yeasts, especially S. cerevisiae, as complementary models to unravel mechanisms contributing to Synphilin-1 pathology in the context of neurodegenerative diseases.

scholarly journals The Use of Urea and Kelp Waste Extract is A Promising Strategy for Maximizing the Biomass Productivity and Lipid Content in Chlorella sorokiniana

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 463 ◽  
Author(s):  
Ali Nawaz Kumbhar ◽  
Meilin He ◽  
Abdul Razzaque Rajper ◽  
Khalil Ahmed Memon ◽  
Muhammad Rizwan ◽  
...  
Keyword(s):  
Lipid Content ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Lipid Production ◽  
Total Lipid Content ◽  
Biomass Productivity ◽  
Chlorella Sorokiniana ◽  
Biofuel Production ◽  
Promising Strategy ◽  
Waste Extract

The decline in fossil fuel reserves has forced researchers to seek out alternatives to fossil fuels. Microalgae are considered to be a promising feedstock for sustainable biofuel production. Previous studies have shown that urea is an important nitrogen source for cell growth and the lipid production of microalgae. The present study investigated the effect of different concentrations of urea combined with kelp waste extract on the biomass and lipid content of Chlorella sorokiniana. The results revealed that the highest cell density, 20.36 × 107 cells−1, and maximal dry biomass, 1.70 g/L, were achieved in the presence of 0.5 g/L of urea combined with 8% kelp waste extract. Similarly, the maximum chlorophyll a, b and beta carotenoid were 10.36 mg/L, 7.05, and 3.01 mg/L, respectively. The highest quantity of carbohydrate content, 290.51 µg/mL, was achieved in the presence of 0.2 g/L of urea and 8% kelp waste extract. The highest fluorescence intensity, 40.05 × 107 cells−1, and maximum total lipid content (30%) were achieved in the presence of 0.1 g/L of urea and 8% kelp waste extract. The current study suggests that the combination of urea and kelp waste extract is the best strategy to enhance the biomass and lipid content in Chlorella sorokiniana.

scholarly journals Yeast-Based Biosynthesis of Natural Products From Xylose

2021 ◽  
Vol 9 ◽  
Author(s):  
Jian Zha ◽  
Miaomiao Yuwen ◽  
Weidong Qian ◽  
Xia Wu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Natural Products ◽  
Metabolic Engineering ◽  
State Of The Art ◽  
Commercial Production ◽  
Scheffersomyces Stipitis ◽  
Lignocellulosic Hydrolysates ◽  
Yeast Strains ◽  
Future Challenges ◽  
Biomass Materials

Xylose is the second most abundant sugar in lignocellulosic hydrolysates. Transformation of xylose into valuable chemicals, such as plant natural products, is a feasible and sustainable route to industrializing biorefinery of biomass materials. Yeast strains, including Saccharomyces cerevisiae, Scheffersomyces stipitis, and Yarrowia lipolytica, display some paramount advantages in expressing heterologous enzymes and pathways from various sources and have been engineered extensively to produce natural products. In this review, we summarize the advances in the development of metabolically engineered yeasts to produce natural products from xylose, including aromatics, terpenoids, and flavonoids. The state-of-the-art metabolic engineering strategies and representative examples are reviewed. Future challenges and perspectives are also discussed on yeast engineering for commercial production of natural products using xylose as feedstocks.

Genetic background affects relative nonsense mRNA accumulation in wild-type and upf mutant yeast strains

2003 ◽  
Vol 43 (3) ◽  
pp. 171-177 ◽  
Author(s):  
Bessie Kebaara ◽  
Tara Nazarenus ◽  
Rachel Taylor ◽  
Audrey L. Atkin
Keyword(s):  
Genetic Background ◽  
Wild Type ◽  
Mrna Accumulation ◽  
Yeast Strains

Expression of serpins by Clostridium thermocellum and simultaneous saccharification of lignocellulosic biomass to enhance ethanol production

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8662-8676
Author(s):  
Maria Mushtaq ◽  
Muhammad Javaid Asad ◽  
Muhammad Zeeshan Hyder ◽  
Syed Muhammad Saqlan Naqvi ◽  
Saad Imran Malik ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Wheat Straw ◽  
Corn Stover ◽  
Rice Straw ◽  
Clostridium Thermocellum ◽  
Ethanol Yield ◽  
Biofuel Production ◽  
Yeast Fermentation ◽  
Second Generation Bioethanol ◽  
Simultaneous Saccharification

Utilization of biomass for production of second generation bioethanol was considered as a way to reduce burdens of fossil fuel in Pakistan. The materials wheat straw, rice straw, cotton stalk, corn stover, and peel wastes were used in this experiment. Various parameters, such as acidic and alkali pretreatment, enzymatic hydrolysis by cellulases, and effect of proteases inhibitors on ethanol production, were examined. Fermentation was completed by the yeasts Saccharomyces cerevisiae and Clostridium thermocellum separately, and their ethanol production were compared and maximum ethanol yield was obtained with wheat straw i.e.,11.3 g/L by S. cerevisiae and 8.5 g/L by C. thermocellum. Results indicated that a higher quantity of sugar was obtained from wheat straw (19.6 ± 1.6 g/L) followed by rice straw (17.6 ± 0.6 g/L) and corn stover (16.1 ± 0.9 g/L) compared to the other evaluated biomass samples. A higher yield of ethanol (11.3 g/L) was observed when a glucose concentration of 21.7 g/L was used, for which yeast fermentation efficiency was 92%. Results also revealed the increased in ethanol production (93%) by using celluases in combination with recombinant Serine protease inhibitors from C. thermocellum. It is expected that the use of recombinant serpins with cellulases will play a major role in the biofuel production by using agricultural biomass. This will also help in the economics of the biofuel.

A comparative study of the ori sequences from the mitochondrial genomes of twenty wild-type yeast strains

Gene ◽  
1984 ◽  
Vol 32 (3) ◽  
pp. 459-473 ◽  
Author(s):  
Godeleine Faugeron-Fonty ◽  
Caroline Le Van Kim ◽  
Miklos de Zamaroczy ◽  
Regina Goursot ◽  
Giorgio Bernardi
Keyword(s):  
Comparative Study ◽  
Mitochondrial Genomes ◽  
Wild Type ◽  
Yeast Strains ◽  
Wild Type Yeast

scholarly journals Engineering of sugar transporters for improvement of xylose utilization during high-temperature alcoholic fermentation in Ogataea polymorpha yeast

2020 ◽  
Author(s):  
Roksolana Vasylyshyn ◽  
Olena Kurylenko ◽  
Justyna Ruchala ◽  
Nadiya Shevchuk ◽  
Neringa Kuliesiene ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Xylose Fermentation ◽  
Xylose Utilization ◽  
Wild Type ◽  
Xylose Consumption ◽  
Lignocellulosic Hydrolysates ◽  
Xylose Transport ◽  
Positive Effects ◽  
Arginine Residues ◽  
Ogataea Polymorpha

Abstract Background Xylose transport is one of the bottlenecks in the conversion of lignocellulosic biomass to ethanol. Xylose consumption by the wild-type strains of xylose-utilizing yeasts occurs once glucose is depleted resulting in a long fermentation process and overall slow and incomplete conversion of sugars liberated from lignocellulosic hydrolysates. Therefore, the engineering of endogenous transporters for the facilitation of glucose-xylose co-consumption is an important prerequisite for efficient ethanol production from lignocellulosic hydrolysates. Results In this study, several engineering approaches formerly used for the low-affinity glucose transporters in Saccharomyces cerevisiae , were successfully applied for earlier identified transporter Hxt1 in Ogataea polymorpha to improve xylose consumption (engineering involved asparagine substitution to alanine at position 358 and replacement of N-terminal lysine residues predicted to be the target of ubiquitination for arginine residues). Moreover, the modified versions of S. cerevisiae Hxt7 and Gal2 transporters also led to improved xylose fermentation when expressed in O. polymorpha . Conclusions The O. polymorpha strains with modified Hxt1 were characterized by simultaneous utilization of both glucose and xylose, in contrast to the wild-type and parental strain with elevated ethanol production from xylose. When the engineered Hxt1 transporter was introduced into constructed earlier advanced ethanol producer form xylose, the resulted strain showed further increase in ethanol accumulation during xylose fermentation. The overexpression of heterologous S. cerevisiae Gal2 had a less profound positive effects on sugars uptake rate, while overexpression of Hxt7 revealed the least impact on sugars consumption.

scholarly journals Improvement of enzymatic saccharification in Arabidopsis thaliana by ectopic expression of the rice SUB1A-1 transcription factor

2015 ◽  
Author(s):  
Lizeth Núñez-López ◽  
Andrés Aguirre-Cruz ◽  
Blanca Estela Barrera-Figueroa ◽  
Julian Mario Peña-Castro
Keyword(s):  
Transcription Factor ◽  
Ectopic Expression ◽  
Enzymatic Saccharification ◽  
Biofuel Production ◽  
Starch Accumulation ◽  
Starch Degradation ◽  
Photosynthetic Parameters ◽  
Wild Type ◽  
Submergence Stress ◽  
Saccharification Yield

Saccharification of polysaccharides releases monosaccharides that can be used by ethanol-producing microorganisms in biofuel production. To improve plant biomass as a raw material for saccharification, factors controlling the accumulation and structure of carbohydrates must be identified. Rice SUB1A-1 is a transcription factor that represses the turnover of starch and postpones energy-consuming growth processes under submergence stress. Arabidopsis was employed to test if heterologous expression of SUB1A-1 or SUB1C-1 (a related gene) can be used to improve saccharification. Cellulolytic and amylolytic enzymatic treatments confirmed that SUB1A-1 transgenics had better saccharification yield than wild-type (Col-0), mainly from accumulated starch. This high saccharification yield was developmentally controlled since juvenile transgenic plants yielded 200-300% more glucose than Col-0. We measured photosynthetic parameters, starch granule microstructure, and transcript abundance of genes involved in starch degradation (SEX4, GWD1), juvenile transition (SPL3-5) and meristematic identity (FUL, SOC1) but found no differences to Col-0, indicating that starch accumulation may be controlled by down-regulation of CONSTANS and FLOWERING LOCUS T by SUB1A-1 as previously reported. SUB1A-1 transgenics also offered less resistance to deformation than wild-type concomitant to up-regulation of AtEXP2 expansin and BGL2 glucan-1,3,-beta-glucosidase. We conclude that heterologous SUB1A-1 expression can improve saccharification yield and softness, two traits needed in bioethanol production.

scholarly journals Engineering of sugar transporters for improvement of xylose utilization during high-temperature alcoholic fermentation in Ogataea polymorpha yeast

2020 ◽  
Author(s):  
Roksolana Vasylyshyn ◽  
Olena Kurylenko ◽  
Justyna Ruchala ◽  
Nadiya Shevchuk ◽  
Neringa Kuliesiene ◽  
...  
Keyword(s):  
Ethanol Production ◽  
Xylose Fermentation ◽  
Xylose Utilization ◽  
Wild Type ◽  
Xylose Consumption ◽  
Lignocellulosic Hydrolysates ◽  
Xylose Transport ◽  
Positive Effects ◽  
Arginine Residues ◽  
Ogataea Polymorpha

Abstract Background Xylose transport is one of the bottlenecks in the conversion of lignocellulosic biomass to ethanol. Xylose consumption by the wild-type strains of xylose-utilizing yeasts occurs once glucose is depleted resulting in a long fermentation process and overall slow and incomplete conversion of sugars liberated from lignocellulosic hydrolysates. Therefore, the engineering of endogenous transporters for the facilitation of glucose-xylose co-consumption is an important prerequisite for efficient ethanol production from lignocellulosic hydrolysates. Results In this study, several engineering approaches formerly used for the low-affinity glucose transporters in Saccharomyces cerevisiae , were successfully applied for earlier identified transporter Hxt1 in Ogataea polymorpha to improve xylose consumption (engineering involved asparagine substitution to alanine at position 358 and replacement of N-terminal lysine residues predicted to be the target of ubiquitination for arginine residues). Moreover, the modified versions of S. cerevisiae Hxt7 and Gal2 transporters also led to improved xylose fermentation when expressed in O. polymorpha . Conclusions The O. polymorpha strains with modified Hxt1 were characterized by simultaneous utilization of both glucose and xylose, in contrast to the wild-type and parental strain with elevated ethanol production from xylose. When the engineered Hxt1 transporter was introduced into constructed earlier advanced ethanol producer form xylose, the resulted strain showed further increase in ethanol accumulation during xylose fermentation. The overexpression of heterologous S. cerevisiae Gal2 had a less profound positive effects on sugars uptake rate, while overexpression of Hxt7 revealed the least impact on sugars consumption.

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