Potential Use of Gelidium amansii Acid Hydrolysate for Lactic Acid Production by Lactobacillus rhamnosus

Sung-Soo Jang¹, Yoshihito Shirai¹, Motoharu Uchida² and Minato Wakisaka¹*

¹Department of Biological Functions and Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2–4 Hibikino, Wakamatsu-ku, Kitakyushu, Fukuoka 808-0196, Japan
²National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, Japan

Article history:
Received May 27, 2011
Accepted January 13, 2012

Key words:
Gelidium amansii, galactose, lactic acid fermentation, Lactobacillus rhamnosus, acid hydrolysis

Summary:                                                                                                                                                                                 
Galactose and glucose are the main monosaccharides produced from the saccharification of Gelidium amansii. They were hydrolysed with 3 % (by volume) H2SO4 at 140 °C for 5 min and obtained at concentrations of 19.60 and 10.21 g/L, respectively. G. amansii hydrolysate (5 %, by mass per volume) was used as a substrate for L(+)-lactic acid production by Lactobacillus rhamnosus. The maximum lactic acid yield (Y_P/S) was 42.03 % with optical purity of 84.54 %. Lactic acid produced from G. amansii hydrolysate can be applicable, among others, for the production of lactic acid esters, like ethyl or methyl lactate, and disinfectant in seaweed cultivation. 

*Corresponding author:          wakisaka@life.kyutech.ac.jp
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