小麦蛋白胨促进乳酸菌增殖的研究

Promoting growth of four lactic acid bacteria by using prepared wheat peptones

对比分析了制备的小麦蛋白胨(WP)与市售蛋白胨的理化性质及其部分(全部)替代发酵氮源对乳酸菌增殖的影响。结果表明,该小麦蛋白胨理化性质已基本达到市售蛋白胨的质量标准要求。小麦蛋白胨所含的非游离氨基酸大分子量(M_w)肽段(>500 u)的比例高于其他市售植物蛋白胨,但其有利于乳酸乳球菌、干酪乳杆菌、罗伊氏乳杆菌和植物乳杆菌等增殖,活菌数分别达到9.64×10~8CFU/m L,2.30×10~9CFU/m L,1.60×10~9CFU/m L和1.14×10~9CFU/m L。对比发酵前后肽段分子质量分布发现,干酪乳杆菌可能主要吸收和/或降解小麦蛋白胨中分子量大于180 u的肽段为氮源供其生长。

The physical and chemical features of prepared wheat peptone（ WP） and its effect on lactic acid bacteria（ LABs） growth were investigated and compared with other commercial peptones. Results showed that the prepared WP met the requirements of peptone quality standards and contained higher percentages of high-molecularweight peptides（ 500 u） than those in other commercial peptones. WP promoted the growth of four LABs including Lactococcus lactis subsp lactis,Lactobacillus reuteri,Lactobacillus casei,and Lactobacillus plantarum with the highest OD600 nmvalues and the microbial viable counts reached to 9. 64 × 10^8CFU/m L,2. 30 × 10^9CFU/m L,1. 60 × 10^9CFU/m L,1. 14 × 10^9CFU/m L,respectively. Further studies indicated that L. casei seemed to preferably utilize high-molecular-weight peptides（ 180 u） in WP as the nitrogen source for cell growth.