Department of Chemical Engineering and Food Technology, IVAGRO Institute, Universidad de Cádiz, Puerto Real, Spain.
J Sci Food Agric. 2020 May;100(7):3036-3045. doi: 10.1002/jsfa.10334. Epub 2020 Feb 28.
Exhausted sugar beet pulp pellets (ESBPP), a sugar industry by-product generated after sugar extraction in the sugar production process, have been used as a raw material for lactic acid (LA) production via hydrolysis and fermentation by Lactobacillus casei. To design a more cost-effective process, simultaneous saccharification and fermentation (SSF) of ESBPP is proposed in the present study. The effects of pH control, nutrient supplementation and solid addition in fed-batch SSF on lactic acid production were investigated.
The highest LA concentration (26.88 g L ) was reached in fed-batch SSF at a solid/liquid loading of 0.2 g mL , with pH control (by adding 30 g L CaCO to the medium) and nutrient supplementation (by adding 20 mL of MRS medium per 100 mL of buffer). Under these conditions, a maximum productivity of 0.63 g L h was achieved, which is 2.7 times higher than that attained in the control experiment (SSF inoculated at time 0 h). However, a slightly lower LA yield was obtained, revealing the need of an increasing dose of enzymes at high solid loading SSF.
An efficient fed-batch SSF strategy with pH control and MRS supplementation is described in the present study, attaining higher LA productivity compared to separate hydrolysis and fermentation and SSF. © 2020 Society of Chemical Industry.
废弃的糖甜菜浆颗粒（ESBPP）是糖生产过程中糖提取后产生的糖工业副产物，已被用作通过干酪乳杆菌水解和发酵生产乳酸（LA）的原料。为了设计更具成本效益的工艺，本研究提出了 ESBPP 的同步糖化和发酵（SSF）。考察了 pH 值控制、营养物补加和分批补料 SSF 中固体添加对乳酸生产的影响。
在固液比为 0.2 g/mL 的分批补料 SSF 中，通过向培养基中添加 30 g/L CaCO3 进行 pH 控制和通过添加 20 mL MRS 培养基/每 100 mL 缓冲液进行营养物补加，达到了最高的 LA 浓度（26.88 g/L）。在此条件下，实现了 0.63 g/L/h 的最大产率，比对照实验（0 h 时 SSF 接种）高 2.7 倍。然而，LA 收率略低，表明在高固载 SSF 中需要增加酶的剂量。
本研究描述了一种具有 pH 值控制和 MRS 补加的高效分批补料 SSF 策略，与单独的水解和发酵以及 SSF 相比，LA 生产率更高。© 2020 英国化学学会。
