Premium
Brewers' spent grain and thin stillage as raw materials in l ‐(+)‐lactic acid fermentation
Author(s) -
Radosavljević Miloš,
Pejin Jelena,
KocićTanackov Sunčica,
Mladenović Dragana,
DjukićVuković Aleksandra,
Mojović Ljiljana
Publication year - 2017
Publication title -
journal of the institute of brewing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.523
H-Index - 51
eISSN - 2050-0416
pISSN - 0046-9750
DOI - 10.1002/jib.462
Subject(s) - stillage , fermentation , hydrolysate , lactobacillus rhamnosus , free amino nitrogen , food science , lactic acid , brewing , chemistry , raw material , corn steep liquor , lactobacillus , nitrogen , biochemistry , bacteria , biology , hydrolysis , organic chemistry , genetics
Brewer's spent grain (BSG) hydrolysates were used for l ‐(+)‐lactic acid (LA) fermentation by Lactobacillus rhamnosus ATCC 7469. In this study the effect of the addition of various amounts of thin stillage (TS) in BSG hydrolysate on LA fermentation parameters were evaluated. TS addition significantly increased utilization of glucose by up to 43.0%. In batch fermentation the highest LA concentration and volumetric productivity of 31.0 g/L, and 0.93 g/L/h, respectively, were obtained with the addition of 50% TS. L. rhamnosus cell viability also increased with the addition of 50% TS (by 2.4%). TS addition significantly increased free amino nitrogen concentration (by up to 209%) which is important for bacterial growth. A strong positive correlation between free amino nitrogen and LA concentration was noted. Compared with the results obtained in the batch fermentation (50% TS), significantly higher LA concentration, yield and volumetric productivity (54.8, 1.9 and 4.0%, respectively) were achieved in fed‐batch fermentation with glucose and TS addition. The results suggest that the combination of the by‐products of brewing and bioethanol industries could be suitable for LA production. Copyright © 2017 The Institute of Brewing & Distilling