scholarly journals Production and Purification of l-lactic Acid in Lab and Pilot Scales Using Sweet Sorghum Juice

Fermentation ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 36 ◽  
Author(s):  
Agata Olszewska-Widdrat ◽  
Maria Alexandri ◽  
José Pablo López-Gómez ◽  
Roland Schneider ◽  
Michael Mandl ◽  
...  

Sweet sorghum juice (SSJ) was evaluated as fermentation substrate for the production of l-lactic acid. A thermophilic Bacillus coagulans isolate was selected for batch fermentations without the use of additional nutrients. The first batch of SSJ (Batch A) resulted on higher lactic acid concentration, yield and productivity with values of 78.75 g∙L−1, 0.78 g∙g−1 and 1.77 g∙L−1 h−1, respectively. Similar results were obtained when the process was transferred into the pilot scale (50 L), with corresponding values of 73 g∙L−1, 0.70 g∙g−1 and 1.47 g∙L−1 h−1. A complete downstream process scheme was developed in order to separate lactic acid from the fermentation components. Coarse and ultra-filtration were employed as preliminary separation steps. Mono- and bipolar electrodialysis, followed by chromatography and vacuum evaporation were subsequently carried out leading to a solution containing 905.8 g∙L−1 lactic acid, with an optical purity of 98.9%. The results of this study highlight the importance of the downstream process with respect to using SSJ for lactic acid production. The proposed downstream process constitutes a more environmentally benign approach to conventional precipitation methods.

2014 ◽  
Vol 80 (23) ◽  
pp. 7134-7141 ◽  
Author(s):  
Limin Wang ◽  
Yumeng Cai ◽  
Lingfeng Zhu ◽  
Honglian Guo ◽  
Bo Yu

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.


2015 ◽  
Vol 9 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Mark S. Ou ◽  
Deepika Awasthi ◽  
Ismael Nieves ◽  
Liang Wang ◽  
John Erickson ◽  
...  

Processes ◽  
2018 ◽  
Vol 6 (10) ◽  
pp. 175 ◽  
Author(s):  
Yuming Zhang ◽  
Mengran Li ◽  
Tian Nie ◽  
Zhihua Ni

Phragmites australis straw (PAS) is an abundant and renewable wetland lignocellulose. Bacillus coagulans IPE22 is a robust thermophilic strain with pentose-utilizing capability and excellent resistance to growth inhibitors. This work is focused on the process study of lactic acid (LA) production from P. australis lignocellulose which has not been attempted previously. By virtue of thermophilic feature of strain IPE22, two fermentation processes (i.e., separated process and integrated process), were developed and compared under non-sterilized conditions. The integrated process combined dilute-acid pretreatment, hemicellulosic hydrolysates fermentation, and cellulose utilization. Sugars derived from hemicellulosic hydrolysates and cellulose enzymatic hydrolysis were efficiently fermented to LA in a single vessel. Using the integrated process, 41.06 g LA was produced from 100 g dry PAS. The established integrated process results in great savings in terms of time and labor, and the fermentation process under non-sterilized conditions is easy to scale up for economical production of lactic acid from PAS.


BIOspektrum ◽  
2020 ◽  
Vol 26 (7) ◽  
pp. 803-805
Author(s):  
Linda Schroedter ◽  
Friedrich Streffer ◽  
Katrin Streffer ◽  
Peter Unger ◽  
Joachim Venus

AbstractInvestigating alternatives for petrobased substrates, lignocellulose is an interesting yet complex feedstock that offers various possibilities for the design of new and sustainable chemical routes. The novel energy-saving LX-pretreatment was combined with thermophilic Bacillus coagulans. By this, corn straw was used in an innovative cascade obtaining biogas, lignin as well as polymerisable L-(+)-lactic acid of over 99 percents optical purity.


RSC Advances ◽  
2016 ◽  
Vol 6 (42) ◽  
pp. 35771-35777 ◽  
Author(s):  
Y. Wang ◽  
M. Wang ◽  
D. Cai ◽  
B. Wang ◽  
Z. Wang ◽  
...  

An open SSF process using B. coagulans LA1507 introduces an effective way to produce l-lactic acid from abundant SSB.


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