L-Lactic acid production from fructose by chitosan film-coated sodium alginate-polyvinyl alcohol immobilized Lactobacillus pentosus cells and its kinetic analysis

Jianfei Wang,Shaoming Jiang,Jiaqi Huang,Maolin Hou,Ruiyi Yang,Hebei Lin,Jinyue Qiao,Hujie Lv,Huanyu Guo,Xingyu Chen,Xudong Bi,Yuming Lu,Shijie Liu,Shibo Hou

doi:10.1186/s40643-021-00380-8

Abstract

Under the optimal conditions of immobilization and fermentation, the highest LA yield of 0.966 ± 0.006 g/g fructose and production rate of 2.426 ± 0.018 g/(L × h) with an error of -0.5% and -0.2% to the predicted results were obtained from batch fermentation by the CS film-coated SA-PVA immobilized L. pentosus cells. The LA yield and production rate of these immobilized cells were 2.7% and 10.1% higher than that of normal SA-PVA immobilized cells respectively, and they were 5.7% and 48.4% higher than that of free cells, respectively. The effect of temperature on different types of immobilized cells and free cells was significantly different, but the effect of pH on different types of cells was not much different. The kinetic models could effectively describe the different fermentation performances of three types of cells. The immobilized cells have excellent reusability to conduct 9 runs of repeated batch fermentation.

Highlights

Lactic acid (LA) is considered to be an important precursor for the synthesis of some oxygen-containing compounds and other chemical intermediates (Olszewska-Widdrat et al 2019)
The freeze-dried L. pentosus ATCC 8041 strain obtained from the American Type Culture Collection (ATCC) was activated in de Man, Rogosa and Sharpe (MRS) medium for 20 h on a rotary shaker before batch fermentation
Single-factor preliminary experiments were applied to determine the range of each parameter for the highest LA yield and production rate, which can be selected for Box–Behnken design

Summary

Introduction

Lactic acid (LA) is considered to be an important precursor for the synthesis of some oxygen-containing compounds and other chemical intermediates (Olszewska-Widdrat et al 2019). Polylactic acid (PLA) has received extensive attention due to its biocompatibility and biodegradability, which has led to a further increase in the demand and production of LA (Agarwal et al 1998; Abd Alsaheb et al 2015). LA can be obtained through chemical synthesis or fermentation (Abdel-Rahman et al 2011). Compared with the chemical synthesis that produces DL-LA racemic mixture as a by-product, fermentation by lactic acid bacteria (LAB) can produce. L-LA or D-LA with high optical purity, thereby further reducing the cost of separation and purification of LA products (Zhao et al 2016; Ricci et al 2019). LAB to synthesize L-LA from different carbon sources by different fermentation types (Bustos et al 2005).

Methods

Results

Conclusion