Journal of South China University of Technology (Natural Science Edition) ›› 2017, Vol. 45 ›› Issue (9): 81-87.doi: 10.3969/j.issn.1000-565X.2017.09.012

• Food Science & Technology • Previous Articles     Next Articles

Identification of a Bacillus coagulans and Production of High Optical Purity L-Lactic Acid via Synchronous Saccharifying Fermentation

LIU Dong-mei ZHOU Quan-xing ZHOU Jin-song   

  1. School of Food Science and Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China
  • Received:2016-11-10 Revised:2017-03-19 Online:2017-09-25 Published:2017-08-30
  • Contact: 刘冬梅( 1972-) ，女，博士，教授，主要从事食品微生物的利用和控制研究． E-mail:liudm@scut.edu.cn
  • About author:刘冬梅( 1972-) ，女，博士，教授，主要从事食品微生物的利用和控制研究．
  • Supported by:
    Supported by the National Natural Science Foundation of China( 31101254，31771908) ; the Natural Science foundation of Guangdong Province( S2011010005679) ; the Science and Technology Research Project Foundation of Guangdong Province( 2013B020312002，2014A020208019)

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Abstract: A Bacillus coagulans ( BCS 13002) isolated from pickle was identified by using 16S RNA and on the basis of physiology and biochemistry,and the effects of carbon source and neutralizer on the production of L-lactic acid were analyzed.Then,the fed-batch fermentation with glucose and the synchronous saccharifying fermentation ( SSF) with corn starch were respectively carried out at 5L fermentation tanks.The results show that ( 1) glucose is a kind of ideal carbon source,while xylose and corn starch are not beneficial to the production of L-lactic acid; ( 2) as a kind of neutralizer,NaOH is better than Ca( OH) 2 and CaCO3 ; ( 3) through the fed-batch fermentation with glucose in a tank,the L-lactic acid content reaches up to 115. 86 g /L with a sugar acid conversion ratio of about 82. 31%,and MnSO4·H2O and MgCl2·6H2O play a special role in the fermentation; and ( 4) through the synchronous saccharifying fermentation with corn starch,the L-lactic acid content reaches up to 123. 3 g /L,with a sugar acid conversion ratio of 70. 03 % and an optical purity of L-lactic acid of more than 99. 8%.

Key words: Bacillus coagulans, L-lactic acid, corn starch, synchronous saccharifying fermentation