陕西泡菜中降解亚硝酸盐乳酸菌的筛选及其发酵特性与耐受性研究

为从泡菜中筛选出具有较强亚硝酸盐降解能力且能应用于泡菜发酵的乳酸菌,从陕西家庭自制泡菜中筛选出了1株菌PC5。菌株PC5通过生化鉴定和16S rDNA测序鉴定为植物乳杆菌。对菌株PC5的发酵特性进行研究,结果显示菌株PC5发酵24 h后,发酵液pH值为3.73±0.01,滴定总酸为(1.99±0.01)%。菌株PC5在含有150 mg/L NaNO 2的培养基中培养24 h,亚硝酸盐降解率可达到(99.37±0.56)%。对菌株PC5的耐受性进行研究,结果表明菌株PC5对ρ(NaNO₂)≤200 mg/L和ρ(NaCl)≤60 g/L有较强的耐受性。菌株PC5具有较好的发酵特性和耐受性,可作为泡菜接种发酵菌株。

Screening,fermentation characteristics and tolerance of nitrite-degrading lactic acid bacteria in Shaanxi Paocai

In order to screen out lactic acid bacteria with strong nitrite degradation ability from Paocai(Chinese pickle),which can be used in the fermentation of Paocai,a strain PC5 was screened from the Shaanxi homemade Paocai.Strain PC5 was identified as Lactobacillus plantarum by biochemical characteristics and 16S rDNA sequencing.The fermentation characteristics of strain PC5 showed that after 24 h of fermentation,the pH value of the fermentation broth was 3.73±0.01,and the total acid titrated was(1.99±0.01)%.After cultivation in a medium containing 150 mg/L NaNO 2 for 24 h,the degradation rate of nitrite could reach(99.37±0.56)%.In addition,tolerance test of strain PC5 revealed that it had a strong tolerance to NaNO 2 within a mass concentration of 200 mg/L and NaCl within a mass concentration of 60 g/L.Therefore,strain PC5 had good fermentation characteristics and tolerance,which could be used as a Paocai inoculation fermentation strain.