Improvement of D ‐lactic acid production at low pH through expressing acid‐resistant gene IoGAS1 in engineered Saccharomyces cerevisiae

2020 ◽  
Author(s):  
Wei Zhong ◽  
Maohua Yang ◽  
Xuemi Hao ◽  
Moustafa Mohamed Sharshar ◽  
Qinhong Wang ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lactic Acid ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Low Ph ◽  
Resistant Gene ◽  
Engineered Saccharomyces Cerevisiae

scholarly journals Improvement of Lactic Acid Production in Saccharomyces cerevisiae by Cell Sorting for High Intracellular pH

2006 ◽  
Vol 72 (8) ◽  
pp. 5492-5499 ◽  
Author(s):  
Minoska Valli ◽  
Michael Sauer ◽  
Paola Branduardi ◽  
Nicole Borth ◽  
Danilo Porro ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lactic Acid ◽  
Intracellular Ph ◽  
Cell Sorting ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Low Ph ◽  
The Mean ◽  
High Level ◽  
Lactate Dehydrogenases

ABSTRACT Yeast strains expressing heterologous l-lactate dehydrogenases can produce lactic acid. Although these microorganisms are tolerant of acidic environments, it is known that at low pH, lactic acid exerts a high level of stress on the cells. In the present study we analyzed intracellular pH (pHi) and viability by staining with cSNARF-4F and ethidium bromide, respectively, of two lactic-acid-producing strains of Saccharomyces cerevisiae, CEN.PK m850 and CEN.PK RWB876. The results showed that the strain producing more lactic acid, CEN.PK m850, has a higher pHi. During batch culture, we observed in both strains a reduction of the mean pHi and the appearance of a subpopulation of cells with low pHi. Simultaneous analysis of pHi and viability proved that the cells with low pHi were dead. Based on the observation that the better lactic-acid-producing strain had a higher pHi and that the cells with low pHi were dead, we hypothesized that we might find better lactic acid producers by screening for cells within the highest pHi range. The screening was performed on UV-mutagenized populations through three consecutive rounds of cell sorting in which only the viable cells within the highest pHi range were selected. The results showed that lactic acid production was significantly improved in the majority of the mutants obtained compared to the parental strains. The best lactic-acid-producing strain was identified within the screening of CEN.PK m850 mutants.

Lactic acid production from xylose by engineered Saccharomyces cerevisiae without PDC or ADH deletion

2015 ◽  
Vol 99 (19) ◽  
pp. 8023-8033 ◽  
Author(s):  
Timothy L. Turner ◽  
Guo-Chang Zhang ◽  
Soo Rin Kim ◽  
Vijay Subramaniam ◽  
David Steffen ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lactic Acid ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Engineered Saccharomyces Cerevisiae

d-Lactic acid production by metabolically engineered Saccharomyces cerevisiae

2006 ◽  
Vol 101 (2) ◽  
pp. 172-177 ◽  
Author(s):  
Nobuhiro Ishida ◽  
Tomiko Suzuki ◽  
Kenro Tokuhiro ◽  
Eiji Nagamori ◽  
Toru Onishi ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lactic Acid ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Engineered Saccharomyces Cerevisiae

scholarly journals l-Lactic Acid Production Using Engineered Saccharomyces cerevisiae with Improved Organic Acid Tolerance

2021 ◽  
Vol 7 (11) ◽  
pp. 928
Author(s):  
Byeong-Kwan Jang ◽  
Yebin Ju ◽  
Deokyeol Jeong ◽  
Sung-Keun Jung ◽  
Chang-Kil Kim ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Acid Tolerance ◽  
Production Costs ◽  
High Concentration ◽  
Adaptive Laboratory Evolution ◽  
Engineered Saccharomyces Cerevisiae

Lactic acid is mainly used to produce bio-based, bio-degradable polylactic acid. For industrial production of lactic acid, engineered Saccharomyces cerevisiae can be used. To avoid cellular toxicity caused by lactic acid accumulation, pH-neutralizing agents are used, leading to increased production costs. In this study, lactic acid-producing S. cerevisiae BK01 was developed with improved lactic acid tolerance through adaptive laboratory evolution (ALE) on 8% lactic acid. The genetic basis of BK01 could not be determined, suggesting complex mechanisms associated with lactic acid tolerance. However, BK01 had distinctive metabolomic traits clearly separated from the parental strain, and lactic acid production was improved by 17% (from 102 g/L to 119 g/L). To the best of our knowledge, this is the highest lactic acid titer produced by engineered S. cerevisiae without the use of pH neutralizers. Moreover, cellulosic lactic acid production by BK01 was demonstrated using acetate-rich buckwheat husk hydrolysates. Particularly, BK01 revealed improved tolerance against acetic acid of the hydrolysates, a major fermentation inhibitor of lignocellulosic biomass. In short, ALE with a high concentration of lactic acid improved lactic acid production as well as acetic acid tolerance of BK01, suggesting a potential for economically viable cellulosic lactic acid production.

Improvement of lactic acid production in Saccharomyces cerevisiae by a deletion of ssb1

2015 ◽  
Vol 43 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Jinsuk J. Lee ◽  
Nathan Crook ◽  
Jie Sun ◽  
Hal S. Alper
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lactic Acid ◽  
Acid Production ◽  
Lactic Acid Production

scholarly journals Plasticity of the Pyruvate Node Modulates Hydrogen Peroxide Production and Acid Tolerance in Multiple Oral Streptococci

2017 ◽  
Vol 84 (2) ◽  
Author(s):  
Xingqun Cheng ◽  
Sylvio Redanz ◽  
Nyssa Cullin ◽  
Xuedong Zhou ◽  
Xin Xu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Environmental Conditions ◽  
Dental Plaque ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Acid Tolerance ◽  
Oral Bacteria ◽  
Low Ph ◽  
Content Type ◽  
Pyruvate Node

ABSTRACTCommensalStreptococcus sanguinisandStreptococcus gordoniiare pioneer oral biofilm colonizers. Characteristic for both is the SpxB-dependent production of H2O2, which is crucial for inhibiting competing biofilm members, especially the cariogenic speciesStreptococcus mutans. H2O2production is strongly affected by environmental conditions, but few mechanisms are known. Dental plaque pH is one of the key parameters dictating dental plaque ecology and ultimately oral health status. Therefore, the objective of the current study was to characterize the effects of environmental pH on H2O2production byS. sanguinisandS. gordonii.S. sanguinisH2O2production was not found to be affected by moderate changes in environmental pH, whereasS. gordoniiH2O2production declined markedly in response to lower pH. Further investigation into the pyruvate node, the central metabolic switch modulating H2O2or lactic acid production, revealed increased lactic acid levels forS. gordoniiat pH 6. The bias for lactic acid production at pH 6 resulted in concomitant improvement in the survival ofS. gordoniiat low pH and seems to constitute part of the acid tolerance response ofS. gordonii. Differential responses to pH similarly affect other oral streptococcal species, suggesting that the observed results are part of a larger phenomenon linking environmental pH, central metabolism, and the capacity to produce antagonistic amounts of H2O2.IMPORTANCEOral biofilms are subject to frequent and dramatic changes in pH.S. sanguinisandS. gordoniican compete with caries- and periodontitis-associated pathogens by generating H2O2. Therefore, it is crucial to understand howS. sanguinisandS. gordoniiadapt to low pH and maintain their competitiveness under acid stress. The present study provides evidence that certain oral bacteria respond to environmental pH changes by tuning their metabolic output in favor of lactic acid production, to increase their acid survival, while others maintain their H2O2production at a constant level. The differential control of H2O2production provides important insights into the role of environmental conditions for growth competition of the oral flora.

Construction of lactic acid-tolerant Saccharomyces cerevisiae by using CRISPR-Cas-mediated genome evolution for efficient d-lactic acid production

2020 ◽  
Vol 104 (21) ◽  
pp. 9147-9158
Author(s):  
Ryosuke Mitsui ◽  
Ryosuke Yamada ◽  
Takuya Matsumoto ◽  
Shizue Yoshihara ◽  
Hayato Tokumoto ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lactic Acid ◽  
Genome Evolution ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Acid Tolerant
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