Rapid isolation of exopolysaccharide-producing Streptococcus thermophilus based on molecular marker screening
Rapid isolation of exopolysaccharide-producing Streptococcus thermophilus based on molecular marker screening
复制标题
基于分子标记筛选快速分离产胞外多糖嗜热链球菌
DOI：
10.1002/jsfa.11398
复制
发表时间：
2022
影响因子：
4.1
通讯作者：
Ai Lian-Zhong
中科院分区：
文献类型：
--
作者：
Xiong Zhi-Qiang;Chen Huan-Lan;Song Xin;Xia Yong-Jun;Ai Lian-Zhong
BACKGROUNDAs a natural food additive, exopolysaccharide (EPS) produced byStreptococcus thermophiluscan improve product viscosity and texture. The protein EpsA is a putative pathway‐specific transcriptional regulator for EPS biosynthesis inS. thermophilus.RESULTSAccording to comparative analysis of EPS biosynthetic gene clusters, a conserved region ofepsA(609 bp) was employed to design primer pairepsA‐F/R as a molecular marker for the isolation of EPS‐producing (EPS+)S. thermophilus. Two EPS+S. thermophilesstrains, AR333 and S‐3, were band‐positive, whereasLactococcus lactisNZ9000 (non‐EPS‐producing, EPS−),Lactobacillus caseiLC2W (EPS+) andL. plantarumAR113 (EPS+) were negative by polymerase chain reaction (PCR) amplicon bands using theepsAprobe. This indicated good specificity of theepsAprobe to EPS+S. thermophilus. Moreover, based on PCR screening with theepsAprobe, 23 positive strains were isolated and identified asS. thermophilusfrom our microbial library and natural fermented milk with 141.3–309.2 mg L−1of EPS production, demonstrating the validity of our molecular marker screening method.CONCLUSIONThe designed molecular marker ofepsAcan rapidly screen EPS+S. thermophilus, which has potential application in the dairy and other food industries. © 2021 Society of Chemical Industry.
