红茶菌中降解亚硝酸盐乳酸菌的筛选、鉴定及其功能特性

Studies on Screening,Identification and Functional Properties of Nitrite Degrading Lactic Acid Bacteria in Kombucha

从红茶菌中筛选优良乳酸菌,为制备功能性红茶菌饮料提供优质安全菌株。从红茶菌中分离出27株乳酸菌,筛选出3株产酸且降解亚硝酸盐的优良乳酸菌,鉴定为植物乳杆菌和干酪乳杆菌。研究这3株乳酸菌的发酵特性、耐胃肠道性和黏附性能,并进行安全性评价。结果表明:3株乳酸菌产酸性能好,发酵至27 h,亚硝酸盐降解率大于93%;人工胃液消化3 h后存活率大于39%,人工肠液消化6 h后存活率大于50%;黏附性能方面存在一定差异,HCR-8和HCR-20对二甲苯表面疏水性大于50%,自凝聚性HCR-8和HCR-20大于32%,HCR-20对Caco-2细胞黏附率为17%;对抗生素未产生耐药性,均未产生有害代谢物。结论:从红茶菌中筛选出的3株乳酸菌均具有较好的降解亚硝酸盐功能特性,可作为潜在的功能性菌株开发利用。

The excellent lactic acid bacteria were screened from kombucha to provide high quality and safe strains for the preparation of functional kombucha beverages.27 strains of lactic acid bacteria were isolated from Kombucha,and 3 strains of lactic acid bacteria degrading nitrite were screened and identified as Lactobacillus plantarum and Lactobacillus casei.The fermentation characteristics,gastrointestinal resistance and adhesion properties of three strains of lactic acid bacteria were studied and evaluated for safety.The results showed that the three strains of lactic acid bacteria had good acid production performance,and the nitrite degradation rate was more than 93%after fermentation for 27 h;the survival rate was more than 39%after artificial gastric juice digestion for 3 h,and the survival rate was greater than 50%after 6 h of artificial intestinal juice digestion.There are some differences in adhesion properties.The hydrophobicity of HCR-8 and HCR-20 on xylene surface was more than 50%,the self-cohesive HCR-8 and HCR-20 were more than 32%,and the adhesion rate of HCR-20 to Caco-2 cells was 17%;no resistance to antibiotics,no harmful metabolites.The three strains of lactic acid bacteria screened from the kombucha have good function of degrading nitrite,which can be used as potential functional strains.