scholarly journals Efficient Homofermentative l-(+)-Lactic Acid Production from Xylose by a Novel Lactic Acid Bacterium,Enterococcus mundtiiQU 25

2010 ◽  
Vol 77 (5) ◽  
pp. 1892-1895 ◽  
Author(s):  
Mohamed Ali Abdel-Rahman ◽  
Yukihiro Tashiro ◽  
Takeshi Zendo ◽  
Katsuhiro Hanada ◽  
Keisuke Shibata ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Optical Purity ◽  
Acetate Production ◽  
High Optical Purity ◽  
Enterococcus Mundtii

ABSTRACTEnterococcus mundtiiQU 25, a newly isolated lactic acid bacterium, efficiently metabolized xylose intol-lactate. In batch fermentations, the strain produced 964 mMl-(+)-lactate from 691 mM xylose, with a yield of 1.41 mol/mol xylose consumed and an extremely high optical purity of ≥99.9% without acetate production.

scholarly journals Major Role of NAD-Dependent Lactate Dehydrogenases in the Production of l-Lactic Acid with High Optical Purity by the Thermophile Bacillus coagulans

2014 ◽  
Vol 80 (23) ◽  
pp. 7134-7141 ◽  
Author(s):  
Limin Wang ◽  
Yumeng Cai ◽  
Lingfeng Zhu ◽  
Honglian Guo ◽  
Bo Yu
Keyword(s):  
Lactic Acid ◽  
Lactate Dehydrogenase ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Optical Purity ◽  
Bacillus Coagulans ◽  
Lactobacillus Delbrueckii ◽  
Content Type ◽  
High Optical Purity ◽  
Optically Pure

ABSTRACTBacillus coagulans2-6 is an excellent producer of optically purel-lactic acid. However, little is known about the mechanism of synthesis of the highly optically purel-lactic acid produced by this strain. Three enzymes responsible for lactic acid production—NAD-dependentl-lactate dehydrogenase (l-nLDH; encoded byldhL), NAD-dependentd-lactate dehydrogenase (d-nLDH; encoded byldhD), and glycolate oxidase (GOX)—were systematically investigated in order to study the relationship between these enzymes and the optical purity of lactic acid.Lactobacillus delbrueckiisubsp.bulgaricusDSM 20081 (ad-lactic acid producer) andLactobacillus plantarumsubsp.plantarumDSM 20174 (adl-lactic acid producer) were also examined in this study as comparative strains, in addition toB. coagulans. The specific activities of key enzymes for lactic acid production in the three strains were characterizedin vivoandin vitro, and the levels of transcription of theldhL,ldhD, and GOX genes during fermentation were also analyzed. The catalytic activities ofl-nLDH andd-nLDH were different inl-,d-, anddl-lactic acid producers. Onlyl-nLDH activity was detected inB. coagulans2-6 under native conditions, and the level of transcription ofldhLinB. coagulans2-6 was much higher than that ofldhDor the GOX gene at all growth phases. However, for the twoLactobacillusstrains used in this study,ldhDtranscription levels were higher than those ofldhL. The high catalytic efficiency ofl-nLDH toward pyruvate and the high transcription ratios ofldhLtoldhDandldhLto the GOX gene provide the key explanations for the high optical purity ofl-lactic acid produced byB. coagulans2-6.

scholarly journals Betaine Improves Polymer-Grade D-Lactic Acid Production by Sporolactobacillus inulinus Using Ammonia as Green Neutralizer

2017 ◽  
Vol 66 (2) ◽  
pp. 273-276 ◽  
Author(s):  
Guoping Lv ◽  
Chengchuan Che ◽  
Li Li ◽  
Shujing Xu ◽  
Wanyi Guan ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Acid Production ◽  
Fermentation Process ◽  
Specific Activity ◽  
Lactic Acid Production ◽  
Optical Purity ◽  
Ammonium Ion ◽  
High Concentration ◽  
Acid Fermentation ◽  
High Optical Purity

The traditional CaCO3-based fermentation process generates huge amount of insoluble waste. To solve this problem, we have developed an efficient and green D-lactic acid fermentation process by using ammonia as neutralizer. The 106.7 g/l of D-lactic acid production and 0.89 g/g of consumed sugar were obtained by Sporolactobacillus inulinus CASD with a high optical purity of 99.7% by adding 100 mg/l betaine in the simple batch fermentation. The addition of betaine was experimentally proven to protect cell at high concentration of ammonium ion, increase the D-lactate dehydrogenase specific activity and thus promote the production of D-lactic acid.

Enterococcus faecium QU 50: a novel thermophilic lactic acid bacterium for high-yield l-lactic acid production from xylose

2014 ◽  
Vol 362 (2) ◽  
pp. 1-7 ◽  
Author(s):  
Mohamed Ali Abdel-Rahman ◽  
Yukihiro Tashiro ◽  
Takeshi Zendo ◽  
Kenji Sakai ◽  
Kenji Sonomoto
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Enterococcus Faecium ◽  
Acid Production ◽  
Lactic Acid Production ◽  
High Yield

D-Lactic Acid Production from Xylose in Engineered Escherichia coli SZ470

2013 ◽  
Vol 641-642 ◽  
pp. 721-724
Author(s):  
Zhao Min Zheng ◽  
Tian Tian ◽  
Jin Hua Wang ◽  
Yong Ze Wang ◽  
Sheng De Zhou
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Acid Production ◽  
Shake Flask ◽  
Lactic Acid Production ◽  
Lactate Production ◽  
Pyruvate Decarboxylase ◽  
Genetically Engineered ◽  
Acetate Production ◽  
A Minor

WD100, knocked out adhE of Escherichia coli SZ470 and inserted ldhA into Escherichia coli WD01, was genetically engineered to utilize xylose. D-lactate production was investigated for shake flask cultures with xylose. In 64h WD100 produce 10.1g/L D-lactate in the shaking flask And it consumed 25g/L xylose during the ending of fermentation.This volumetric productivity with xylose is 0.14 g·L-1·h-1.Because of pyruvate decarboxylase (poxB) expressed in flask fermention,acetate production was up to 4.7g/L.Succinate,formate,ethanol was also produced as a minor product during fermentation.

scholarly journals Dynamic Simulation of Continuous Mixed Sugars Fermentation with Increasing Cell Retention Time for Lactic Acid Production using Enterococcus mundtii QU 25

2020 ◽  
Author(s):  
Ying Wang ◽  
Ka-Lai Chan ◽  
Mohamed Ali Abdel-Rahman ◽  
Kenji Sonomoto ◽  
Shao-Yuan Leu
Keyword(s):  
Lactic Acid ◽  
Retention Time ◽  
Acid Production ◽  
Fermentation Process ◽  
Lactic Acid Production ◽  
Critical Role ◽  
Cell Retention ◽  
Mixed Sugars ◽  
Enterococcus Mundtii ◽  
Mixed Sugar

Abstract Background: Simultaneous and effective conversion of both pentose and hexoses in fermentation is a critical and challenging task toward the lignocellulosic economy. This study aims to investigate the feasibility of an innovative co-fermentation process featured with cell recycle unit (CF/CR) for mixed sugar utilization. A l-lactic acid producing strain Enterococcus mundtii QU 25 was applied in the continuous fermentation process to utilize the mixed sugar at different productivities over the changes of flowing conditions. Structured numerical platform were constructed with the experiments to optimize the biological process and clarify the cell metabolisms through kinetics analysis. The structured model, kinetic parameters, and achievement of the fermentation strategy shall provide new insights towards whole sugar fermentation via real-time monitoring for process control and optimization.Results: Significant carbon catabolite repression of co-fermentation using glucose/xylose mixture was overcome by replacing glucose with cellobiose, of which the consumption ratio of hexose to pentose was improved dramatically from 10.4:1 to 2.17:1. An outstanding product concentration of 65.15 g·L -1 and productivity of 13.03 g·L -1 ·h -1 were achieved with 50 g·L -1 cellobiose and 30 g·L -1 xylose, at an optimized dilution rate of 0.2 h -1 with gradually increased cell retention time. Among the total lactic acid production, xylose contributed to more than 34% of the mixed sugars, which was close to the related contents in agricultural residuals. The model successfully simulated the transition of sugar consumption, cell growth, and lactic acid production among the batch, continuous process, and CF/CR system.Conclusion: Cell retention time played a critical role in balancing pentose and hexose consumption, cell decay, and lactic acid production in the CF/CR process. With the increase of cell concentration, consumption of mixed sugars increased with the productivity of final products, hence the impacts of substrate inhibiting reduced. With the validated parameters, the model showed highest accuracy simulating the CF/CR process, of which significantly longer cell retention times over hydraulic retention time were tested.

Utilizing Gelatinized Starchy Waste from Rice Noodle Factory as Substrate for L(+)-Lactic Acid Production by Amylolytic Lactic Acid Bacterium Enterococcus faecium K-1

2020 ◽  
Vol 192 (2) ◽  
pp. 353-366 ◽  
Author(s):  
Kridsada Unban ◽  
Ramita Khanongnuch ◽  
Apinun Kanpiengjai ◽  
Kalidas Shetty ◽  
Chartchai Khanongnuch
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Enterococcus Faecium ◽  
Acid Production ◽  
Lactic Acid Production

Modelling pH evolution and lactic acid production in the growth medium of a lactic acid bacterium: Application to set a biological TTI

2008 ◽  
Vol 128 (1) ◽  
pp. 101-107 ◽  
Author(s):  
M. Ellouze ◽  
M. Pichaud ◽  
C. Bonaiti ◽  
L. Coroller ◽  
O. Couvert ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacterium ◽  
Growth Medium ◽  
Acid Production ◽  
Lactic Acid Production
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