Media evaluation of lactic acid repeated-batch fermentation with Lactobacillus plantarum and Lactobacillus casei subsp. rhamnosus

This paper describes a methodology to evaluate different fermentation media without interruption for long-term repeated batch fermentation by Lactobacillus casei subsp. rhamnosus or Lactobacillus plantarum. A repeated-batch fermenter was designed to evaluate various food byproducts as nitrogen source to replace yeast extract in lactic acid fermentation. Seven types of livestock- or marine-based byproducts were used in addition to corn steep liquor and yeast extract. Also, further enrichment of vitamins and minerals in the fermentation media was performed by the addition of 0.1% cane molasses. Data from lactic acid fermentation in duplicate were analyzed by analysis of variance and least significant difference. Marine hydrolysate BAP5301 supplemented with cane molasses resulted in a higher lactic acid production rate than that of yeast extract medium for L. plantarum. On the other hand, marine hydrolysate BAP5300 supplemented with cane molasses was the best for L. casei, which produced lactic acid similar to yeast extract supplemented medium.