The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Kenji Sonomoto - One of the best experts on this subject based on the ideXlab platform.
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Enterococcus faecium QU 50: a novel thermophilic Lactic Acid bacterium for high-yield l-Lactic Acid production from xylose.
FEMS Microbiology Letters, 2014Co-Authors: Mohamed Ali Abdel-rahman, Yukihiro Tashiro, Takeshi Zendo, Kenji Sakai, Kenji SonomotoAbstract:Production of optically pure Lactic Acid from lignocellulosic material for commercial purposes is hampered by several difficulties, including heterofermentation of pentose sugars and high energy consumption by mesophilic Lactic Acid bacteria. Here, we report a novel Lactic Acid bacterium, strain QU 50, that has the potential to produce optically pure l-Lactic Acid (≥99.2%) in a homofermentative manner from xylose under thermophilic conditions. Strain QU 50 was isolated from Egyptian fertile soil and identified as Enterococcus faecium QU 50 by analyzing its sugar fermentation pattern and 16S rRNA gene sequence. Enterococcus faecium QU 50 fermented xylose efficiently to produce Lactic Acid over wide pH (6.0-10.0) and temperature ranges (30-52°C), with a pH of 6.5 and temperature of 50°C being optimal. To our knowledge, this is the first report of homofermentative Lactic Acid production from xylose by a thermophilic Lactic Acid bacterium.
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Lactic Acid production from lignocellulose derived sugars using Lactic Acid bacteria overview and limits
Journal of Biotechnology, 2011Co-Authors: Mohamed Ali Abdelrahman, Yukihiro Tashiro, Kenji SonomotoAbstract:Lactic Acid is an industrially important product with a large and rapidly expanding market due to its attractive and valuable multi-function properties. The economics of Lactic Acid production by fermentation is dependent on many factors, of which the cost of the raw materials is very significant. It is very expensive when sugars, e.g., glucose, sucrose, starch, etc., are used as the feedstock for Lactic Acid production. Therefore, lignocellulosic biomass is a promising feedstock for Lactic Acid production considering its great availability, sustainability, and low cost compared to refined sugars. Despite these advantages, the commercial use of lignocellulose for Lactic Acid production is still problematic. This review describes the "conventional" processes for producing Lactic Acid from lignocellulosic materials with Lactic Acid bacteria. These processes include: pretreatment of the biomass, enzyme hydrolysis to obtain fermentable sugars, fermentation technologies, and separation and purification of Lactic Acid. In addition, the difficulties associated with using this biomass for Lactic Acid production are especially introduced and several key properties that should be targeted for low-cost and advanced fermentation processes are pointed out. We also discuss the metabolism of lignocellulose-derived sugars by Lactic Acid bacteria.
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Efficient conversion of Lactic Acid to butanol with pH-stat continuous Lactic Acid and glucose feeding method by Clostridium saccharoperbutylacetonicum
Applied Microbiology and Biotechnology, 2010Co-Authors: Mugihito Oshiro, Yukihiro Tashiro, Katsuhiro Hanada, Kenji SonomotoAbstract:In order to achieve high butanol production by Clostridium saccharoperbutylacetonicum N1-4, the effect of Lactic Acid on acetone–butanol–ethanol fermentation and several fed-batch cultures in which Lactic Acid is fed have been investigated. When a medium containing 20 g/l glucose was supplemented with 5 g/l of closely racemic Lactic Acid, both the concentration and yield of butanol increased; however, supplementation with more than 10 g/l Lactic Acid did not increase the butanol concentration. It was found that when fed a mixture of Lactic Acid and glucose, the final concentration of butanol produced by a fed-batch culture was greater than that produced by a batch culture. In addition, a pH-controlled fed-batch culture resulted in not only acceleration of Lactic Acid consumption but also a further increase in butanol production. Finally, we obtained 15.5 g/l butanol at a production rate of 1.76 g/l/h using a fed-batch culture with a pH-stat continuous Lactic Acid and glucose feeding method. To confirm whether Lactic Acid was converted to butanol by the N1-4 strain, we performed gas chromatography–mass spectroscopy (GC-MS) analysis of butanol produced by a batch culture during fermentation in a medium containing [1,2,3-^13C_3] Lactic Acid as the initial substrate. The results of the GC-MS analysis confirmed the bioconversion of Lactic Acid to butanol.
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direct l Lactic Acid fermentation with sago starch by a novel amylolytic Lactic Acid bacterium enterococcus faecium
Enzyme and Microbial Technology, 2007Co-Authors: Keisuke Shibata, Dulce M Flores, Genta Kobayashi, Kenji SonomotoAbstract:Abstract Novel amylolytic Lactic Acid bacterium from puto, fermented raw rice in Philippine, was isolated and characterized. The strain was identified as Enterococcus faecium No. 78 (BIOTECH 10375) by sugar fermentative test and 16S rDNA sequence analysis. Optimum pH and temperature were 6.5 and 30 °C, respectively. Direct l -Lactic Acid fermentation was carried out with various starches, Lactic Acid productivity with sago starch being similar to that with glucose. Yield of Lactic Acid from sago starch was higher than those from glucose and other starches. Strain No. 78 was superior to the other amylolytic Lactic Acid bacteria so far reported on the direct Lactic Acid fermentation with starches and produced Lactic Acid of high optical purity (98.6%). In direct Lactic Acid fermentation with starch, continuous culture has hardly been reported. Continuous culture system with high cell density of strain No. 78 showed higher Lactic Acid productivity (3.04 g l−1 h−1) than those of batch culture (1.105 g l−1 h−1) and conventional continuous culture (1.56 g l−1 h−1). Even if the dilution rate was increased up to 0.26 h−1, the residual starch concentration was controlled at moderately low level below 3.24 g l−1.
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Direct l-Lactic Acid fermentation with sago starch by a novel amylolytic Lactic Acid bacterium, Enterococcus faecium
Enzyme and Microbial Technology, 2006Co-Authors: Keisuke Shibata, Dulce M Flores, Genta Kobayashi, Kenji SonomotoAbstract:Abstract Novel amylolytic Lactic Acid bacterium from puto, fermented raw rice in Philippine, was isolated and characterized. The strain was identified as Enterococcus faecium No. 78 (BIOTECH 10375) by sugar fermentative test and 16S rDNA sequence analysis. Optimum pH and temperature were 6.5 and 30 °C, respectively. Direct l -Lactic Acid fermentation was carried out with various starches, Lactic Acid productivity with sago starch being similar to that with glucose. Yield of Lactic Acid from sago starch was higher than those from glucose and other starches. Strain No. 78 was superior to the other amylolytic Lactic Acid bacteria so far reported on the direct Lactic Acid fermentation with starches and produced Lactic Acid of high optical purity (98.6%). In direct Lactic Acid fermentation with starch, continuous culture has hardly been reported. Continuous culture system with high cell density of strain No. 78 showed higher Lactic Acid productivity (3.04 g l−1 h−1) than those of batch culture (1.105 g l−1 h−1) and conventional continuous culture (1.56 g l−1 h−1). Even if the dilution rate was increased up to 0.26 h−1, the residual starch concentration was controlled at moderately low level below 3.24 g l−1.
Keisuke Shibata - One of the best experts on this subject based on the ideXlab platform.
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direct l Lactic Acid fermentation with sago starch by a novel amylolytic Lactic Acid bacterium enterococcus faecium
Enzyme and Microbial Technology, 2007Co-Authors: Keisuke Shibata, Dulce M Flores, Genta Kobayashi, Kenji SonomotoAbstract:Abstract Novel amylolytic Lactic Acid bacterium from puto, fermented raw rice in Philippine, was isolated and characterized. The strain was identified as Enterococcus faecium No. 78 (BIOTECH 10375) by sugar fermentative test and 16S rDNA sequence analysis. Optimum pH and temperature were 6.5 and 30 °C, respectively. Direct l -Lactic Acid fermentation was carried out with various starches, Lactic Acid productivity with sago starch being similar to that with glucose. Yield of Lactic Acid from sago starch was higher than those from glucose and other starches. Strain No. 78 was superior to the other amylolytic Lactic Acid bacteria so far reported on the direct Lactic Acid fermentation with starches and produced Lactic Acid of high optical purity (98.6%). In direct Lactic Acid fermentation with starch, continuous culture has hardly been reported. Continuous culture system with high cell density of strain No. 78 showed higher Lactic Acid productivity (3.04 g l−1 h−1) than those of batch culture (1.105 g l−1 h−1) and conventional continuous culture (1.56 g l−1 h−1). Even if the dilution rate was increased up to 0.26 h−1, the residual starch concentration was controlled at moderately low level below 3.24 g l−1.
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Direct l-Lactic Acid fermentation with sago starch by a novel amylolytic Lactic Acid bacterium, Enterococcus faecium
Enzyme and Microbial Technology, 2006Co-Authors: Keisuke Shibata, Dulce M Flores, Genta Kobayashi, Kenji SonomotoAbstract:Abstract Novel amylolytic Lactic Acid bacterium from puto, fermented raw rice in Philippine, was isolated and characterized. The strain was identified as Enterococcus faecium No. 78 (BIOTECH 10375) by sugar fermentative test and 16S rDNA sequence analysis. Optimum pH and temperature were 6.5 and 30 °C, respectively. Direct l -Lactic Acid fermentation was carried out with various starches, Lactic Acid productivity with sago starch being similar to that with glucose. Yield of Lactic Acid from sago starch was higher than those from glucose and other starches. Strain No. 78 was superior to the other amylolytic Lactic Acid bacteria so far reported on the direct Lactic Acid fermentation with starches and produced Lactic Acid of high optical purity (98.6%). In direct Lactic Acid fermentation with starch, continuous culture has hardly been reported. Continuous culture system with high cell density of strain No. 78 showed higher Lactic Acid productivity (3.04 g l−1 h−1) than those of batch culture (1.105 g l−1 h−1) and conventional continuous culture (1.56 g l−1 h−1). Even if the dilution rate was increased up to 0.26 h−1, the residual starch concentration was controlled at moderately low level below 3.24 g l−1.
Dulce M Flores - One of the best experts on this subject based on the ideXlab platform.
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direct l Lactic Acid fermentation with sago starch by a novel amylolytic Lactic Acid bacterium enterococcus faecium
Enzyme and Microbial Technology, 2007Co-Authors: Keisuke Shibata, Dulce M Flores, Genta Kobayashi, Kenji SonomotoAbstract:Abstract Novel amylolytic Lactic Acid bacterium from puto, fermented raw rice in Philippine, was isolated and characterized. The strain was identified as Enterococcus faecium No. 78 (BIOTECH 10375) by sugar fermentative test and 16S rDNA sequence analysis. Optimum pH and temperature were 6.5 and 30 °C, respectively. Direct l -Lactic Acid fermentation was carried out with various starches, Lactic Acid productivity with sago starch being similar to that with glucose. Yield of Lactic Acid from sago starch was higher than those from glucose and other starches. Strain No. 78 was superior to the other amylolytic Lactic Acid bacteria so far reported on the direct Lactic Acid fermentation with starches and produced Lactic Acid of high optical purity (98.6%). In direct Lactic Acid fermentation with starch, continuous culture has hardly been reported. Continuous culture system with high cell density of strain No. 78 showed higher Lactic Acid productivity (3.04 g l−1 h−1) than those of batch culture (1.105 g l−1 h−1) and conventional continuous culture (1.56 g l−1 h−1). Even if the dilution rate was increased up to 0.26 h−1, the residual starch concentration was controlled at moderately low level below 3.24 g l−1.
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Direct l-Lactic Acid fermentation with sago starch by a novel amylolytic Lactic Acid bacterium, Enterococcus faecium
Enzyme and Microbial Technology, 2006Co-Authors: Keisuke Shibata, Dulce M Flores, Genta Kobayashi, Kenji SonomotoAbstract:Abstract Novel amylolytic Lactic Acid bacterium from puto, fermented raw rice in Philippine, was isolated and characterized. The strain was identified as Enterococcus faecium No. 78 (BIOTECH 10375) by sugar fermentative test and 16S rDNA sequence analysis. Optimum pH and temperature were 6.5 and 30 °C, respectively. Direct l -Lactic Acid fermentation was carried out with various starches, Lactic Acid productivity with sago starch being similar to that with glucose. Yield of Lactic Acid from sago starch was higher than those from glucose and other starches. Strain No. 78 was superior to the other amylolytic Lactic Acid bacteria so far reported on the direct Lactic Acid fermentation with starches and produced Lactic Acid of high optical purity (98.6%). In direct Lactic Acid fermentation with starch, continuous culture has hardly been reported. Continuous culture system with high cell density of strain No. 78 showed higher Lactic Acid productivity (3.04 g l−1 h−1) than those of batch culture (1.105 g l−1 h−1) and conventional continuous culture (1.56 g l−1 h−1). Even if the dilution rate was increased up to 0.26 h−1, the residual starch concentration was controlled at moderately low level below 3.24 g l−1.
Genta Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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direct l Lactic Acid fermentation with sago starch by a novel amylolytic Lactic Acid bacterium enterococcus faecium
Enzyme and Microbial Technology, 2007Co-Authors: Keisuke Shibata, Dulce M Flores, Genta Kobayashi, Kenji SonomotoAbstract:Abstract Novel amylolytic Lactic Acid bacterium from puto, fermented raw rice in Philippine, was isolated and characterized. The strain was identified as Enterococcus faecium No. 78 (BIOTECH 10375) by sugar fermentative test and 16S rDNA sequence analysis. Optimum pH and temperature were 6.5 and 30 °C, respectively. Direct l -Lactic Acid fermentation was carried out with various starches, Lactic Acid productivity with sago starch being similar to that with glucose. Yield of Lactic Acid from sago starch was higher than those from glucose and other starches. Strain No. 78 was superior to the other amylolytic Lactic Acid bacteria so far reported on the direct Lactic Acid fermentation with starches and produced Lactic Acid of high optical purity (98.6%). In direct Lactic Acid fermentation with starch, continuous culture has hardly been reported. Continuous culture system with high cell density of strain No. 78 showed higher Lactic Acid productivity (3.04 g l−1 h−1) than those of batch culture (1.105 g l−1 h−1) and conventional continuous culture (1.56 g l−1 h−1). Even if the dilution rate was increased up to 0.26 h−1, the residual starch concentration was controlled at moderately low level below 3.24 g l−1.
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Direct l-Lactic Acid fermentation with sago starch by a novel amylolytic Lactic Acid bacterium, Enterococcus faecium
Enzyme and Microbial Technology, 2006Co-Authors: Keisuke Shibata, Dulce M Flores, Genta Kobayashi, Kenji SonomotoAbstract:Abstract Novel amylolytic Lactic Acid bacterium from puto, fermented raw rice in Philippine, was isolated and characterized. The strain was identified as Enterococcus faecium No. 78 (BIOTECH 10375) by sugar fermentative test and 16S rDNA sequence analysis. Optimum pH and temperature were 6.5 and 30 °C, respectively. Direct l -Lactic Acid fermentation was carried out with various starches, Lactic Acid productivity with sago starch being similar to that with glucose. Yield of Lactic Acid from sago starch was higher than those from glucose and other starches. Strain No. 78 was superior to the other amylolytic Lactic Acid bacteria so far reported on the direct Lactic Acid fermentation with starches and produced Lactic Acid of high optical purity (98.6%). In direct Lactic Acid fermentation with starch, continuous culture has hardly been reported. Continuous culture system with high cell density of strain No. 78 showed higher Lactic Acid productivity (3.04 g l−1 h−1) than those of batch culture (1.105 g l−1 h−1) and conventional continuous culture (1.56 g l−1 h−1). Even if the dilution rate was increased up to 0.26 h−1, the residual starch concentration was controlled at moderately low level below 3.24 g l−1.
Paola Branduardi - One of the best experts on this subject based on the ideXlab platform.
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Changes in SAM2 expression affect Lactic Acid tolerance and Lactic Acid production in Saccharomyces cerevisiae
Microbial cell factories, 2014Co-Authors: Laura Dato, Nadia Maria Berterame, Maria Antonietta Ricci, Paola Paganoni, Luigi Palmieri, Danilo Porro, Paola BranduardiAbstract:The great interest in the production of highly pure Lactic Acid enantiomers comes from the application of polyLactic Acid (PLA) for the production of biodegradable plastics. Yeasts can be considered as alternative cell factories to Lactic Acid bacteria for Lactic Acid production, despite not being natural producers, since they can better tolerate Acidic environments. We have previously described metabolically engineered Saccharomyces cerevisiae strains producing high amounts of L-Lactic Acid (>60g/L) at low pH. The high product concentration represents the major limiting step of the process, mainly because of its toxic effects. Therefore, our goal was the identification of novel targets for strain improvement possibly involved in the yeast response to Lactic Acid stress. The enzyme S-adenosylmethionine (SAM) synthetase catalyses the only known reaction leading to the biosynthesis of SAM, an important cellular cofactor. SAM is involved in phospholipid biosynthesis and hence in membrane remodelling during Acid stress. Since only the enzyme isoform 2 seems to be responsive to membrane related signals (e.g. myo-inositol), Sam2p was tagged with GFP to analyse its abundance and cellular localization under different stress conditions. Western blot analyses showed that Lactic Acid exposure correlates with an increase in protein levels. The SAM2 gene was then overexpressed and deleted in laboratory strains. Remarkably, in the BY4741 strain its deletion conferred higher resistance to Lactic Acid, while its overexpression was detrimental. Therefore, SAM2 was deleted in a strain previously engineered and evolved for industrial Lactic Acid production and tolerance, resulting in higher production. Here we demonstrated that the modulation of SAM2 can have different outcomes, from clear effects to no significant phenotypic responses, upon Lactic Acid stress in different genetic backgrounds, and that at least in one genetic background SAM2 deletion led to an industrially relevant increase in Lactic Acid production. Further work is needed to elucidate the molecular basis of these observations, which underline once more that strain robustness relies on complex cellular mechanisms, involving regulatory genes and proteins. Our data confirm cofactor engineering as an important tool for cell factory improvement.
