Continuous fermentation of clarified corn stover hydrolysate for the production of lactic acid at high yield and productivity

Ahring, Birgitte Kiær; Traverso, Joseph J.; Murali, N.; Srinivas, Keerthi

doi:10.1016/j.bej.2016.01.012

Cited by 70 publications

(33 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Although several thermophiles, such as Clostridium thermohydrosulfuricum , Thermoanaerobacter ethanolicus , and B. coagulans, can innately co-ferment pentoses and hexoses, their poor properties for using lignocellulosic biomass and the lack of optimized genetic tools have hindered their industrial application [2, 10]. For instance, most B. coagulans strains used for l -lactic acid production from lignocellulose-derived sugars exhibited low output [11–14] and were difficult to manipulate genetically [15]. B. licheniformis , a more recently developed thermophilic host, has been successfully used for the production of butane-2,3-diol (2,3-BD) [8, 16, 17], l -lactic acid [18], and d -lactic acid [9].…”

Section: Introductionmentioning

confidence: 99%

RETRACTED ARTICLE: Engineering Bacillus licheniformis as a thermophilic platform for the production of l-lactic acid from lignocellulose-derived sugars

Gai

Wang

et al. 2017

Biotechnol Biofuels

View full text Add to dashboard Cite

Background Bacillus licheniformis MW3 as a GRAS and thermophilic strain is a promising microorganism for chemical and biofuel production. However, its capacity to co-utilize glucose and xylose, the major sugars found in lignocellulosic biomass, is severely impaired by glucose-mediated carbon catabolite repression (CCR). In this study, a “dual-channel” process was implemented to engineer strain MW3 for simultaneous utilization of glucose and xylose, using l-lactic acid as a target product.ResultsA non-phosphotransferase system (PTS) glucose uptake route was activated via deletion of the glucose transporter gene ptsG and introduction of the galactose permease gene galP. After replacing the promoter of glucokinase gene glck with the strong promoter P als, the engineered strain recovered glucose consumption and utilized glucose and xylose simultaneously. Meanwhile, to improve the consumption rate of xylose in this strain, several measures were undertaken, such as relieving the regulation of the xylose repressor XylR, reducing the catabolite-responsive element, and optimizing the rate-limiting step. Knockout of ethanol and acetic acid pathway genes further increased lactic acid yield by 6.2%. The resultant strain, RH15, was capable of producing 121.9 g/L l-lactic acid at high yield (95.3%) after 40 h of fermentation from a mixture of glucose and xylose. When a lignocellulosic hydrolysate was used as the substrate, 99.3 g/L l-lactic acid was produced within 40 h, with a specific productivity of 2.48 g/[L h] and a yield of 94.6%.ConclusionsOur engineered strain B. licheniformis RH15 could thermophilically produced l-lactic acid from lignocellulosic hydrolysate with relatively high concentration and productivity at levels that were competitive with most reported cases of l-lactic acid-producers. Thus, the engineered strain might be used as a platform for the production of other chemicals. In addition to engineering the B. licheniformis strain, the “dual-channel” process might serve as an alternative method for engineering a variety of other strains.Electronic supplementary materialThe online version of this article (doi:10.1186/s13068-017-0920-z) contains supplementary material, which is available to authorized users.

show abstract

Section: Introductionmentioning

confidence: 99%

RETRACTED ARTICLE: Engineering Bacillus licheniformis as a thermophilic platform for the production of l-lactic acid from lignocellulose-derived sugars

Gai

Wang

et al. 2017

Biotechnol Biofuels

View full text Add to dashboard Cite

show abstract

“…A high lactate-producing bacterial strain such as B. coagulans showed as much as 92% lactic acid yield from sucrose [88]. Continuous fermentation of lignocellulosic biomass using an isolated B. coagulans strain resulted in lactic acid yield of 0.95 g/g biomass sugars with a productivity as high as 3.69 g/L/h at the optimum pH of 6 with a residence time as low as 6 h [90]. Similar lactic acid yields were obtained with batch fermentation of pure glucose using the B. coagulans WCP10-4 strain with a productivity as high as 3.5 g/L/h [91].…”

Section: Microbes Used For Lactic Acid Productionmentioning

confidence: 98%

“…Only limited focus was devoted to the different types of fermentation processes used since a number of studies have concluded that, for most biochemical processes, continuous fermentation (by controlling feeding rate and retention time) has significant advantages over fed-batch or batch fermentations [90,164]. The production of specific carboxylic acids usually necessitates specific pure cultures.…”

Section: Conclusion and Future Perspectivesmentioning

confidence: 99%

“…Based on the nature of the fermentation, lactic acid bacteria in general have been classified as homo-fermentative, resulting primarily in L-lactic acid as the only product, and hetero-fermentative, which produce small amounts of acetic acid and ethanol as byproducts. Major homo-fermentative products includes Lactococcus lactic [83], Lactobacillus delbrueckii [84]; Lactobacillus helveticus [85]; Lactobacillus casei [86], Bacillus subtilis [87], and Bacillus coagulans [88][89][90]. Similar to the VFA-producing bacteria, the Lactobacillus or Bacillus strains are rod-shaped bacteria that have a tendency to sporulate [80].…”

Section: Microbes Used For Lactic Acid Productionmentioning

confidence: 99%

See 1 more Smart Citation

Biochemical Production and Separation of Carboxylic Acids for Biorefinery Applications

2017

Self Cite

View full text Add to dashboard Cite

Carboxylic acids are traditionally produced from fossil fuels and have significant applications in the chemical, pharmaceutical, food, and fuel industries. Significant progress has been made in replacing such fossil fuel sources used for production of carboxylic acids with sustainable and renewable biomass resources. However, the merits and demerits of each carboxylic acid processing platform are dependent on the application of the final product in the industry. There are a number of studies that indicate that separation processes account for over 30% of the total processing costs in such processes. This review focuses on the sustainable processing of biomass resources to produce carboxylic acids. The primary focus of the review will be on a discussion of and comparison between existing biochemical processes for producing lower-chain fatty acids such as acetic-, propionic-, butyric-, and lactic acids. The significance of these acids stems from the recent progress in catalytic upgrading to produce biofuels apart from the current applications of the carboxylic acids in the food, pharmaceutical, and plastics sectors. A significant part of the review will discuss current state-of-art of techniques for separation and purification of these acids from fermentation broths for further downstream processing to produce high-value products.

show abstract

“…wheat or corn grains) in DDGS have become a concern for the farming industry [34]. However, this is economically unfavorable as pure sugars have a higher economic value than the lactic acid produced [13,36]. As DDGS is also characterized by a high fibre content, it could potentially be used as an alternative carbon source for lactic acid fermentation [35].…”

mentioning

confidence: 99%

Microbial production of d‐lactic acid from dried distiller's grains with solubles

Zaini

Chatzifragkou

Charalampopoulos

2018

Engineering in Life Sciences

View full text Add to dashboard Cite

d‐Lactic acid production is gaining increasing attention due to the thermostable properties of its polymer, poly‐d‐lactic acid . In this study, Lactobacillus coryniformis subsp. torquens, was evaluated for its ability to produce d‐lactic acid using Dried Distiller's Grains with Solubles (DDGS) hydrolysate as the substrate. DDGS was first subjected to alkaline pretreatment with sodium hydroxide to remove the hemicellulose component and the generated carbohydrate‐rich solids were then subjected to enzymatic hydrolysis using cellulase mixture Accellerase® 1500. When comparing separate hydrolysis and fermentation and simultaneous saccharification and fermentation (SSF) of L. coryniformis on DDGS hydrolysate, the latter method demonstrated higher d‐lactic acid production (27.9 g/L, 99.9% optical purity of d‐lactic acid), with a higher glucose to d‐lactic acid conversion yield (84.5%) compared to the former one (24.1 g/L, 99.9% optical purity of d‐lactic acid). In addition, the effect of increasing the DDGS concentration in the fermentation system was investigated via a fed‐batch SSF approach, where it was shown that the d‐lactic acid production increased to 38.1 g/L and the conversion yield decreased to 70%. In conclusion, the SSF approach proved to be an efficient strategy for the production of d‐lactic acid from DDGS as it reduced the overall processing time and yielded high d‐lactic acid concentrations.

show abstract

Continuous fermentation of clarified corn stover hydrolysate for the production of lactic acid at high yield and productivity

Cited by 70 publications

References 31 publications

RETRACTED ARTICLE: Engineering Bacillus licheniformis as a thermophilic platform for the production of l-lactic acid from lignocellulose-derived sugars

RETRACTED ARTICLE: Engineering Bacillus licheniformis as a thermophilic platform for the production of l-lactic acid from lignocellulose-derived sugars

Biochemical Production and Separation of Carboxylic Acids for Biorefinery Applications

Microbial production of d‐lactic acid from dried distiller's grains with solubles

Contact Info

Product

Resources

About