东北酸菜发酵乳酸菌的筛选及评价

Screening and Evaluation of Lactic Acid Bacteria for Dongbei Suancai Fermentation

为获得适用东北酸菜发酵的乳酸菌菌株,该研究通过对来源于发酵蔬菜10株乳酸菌的生长性能和发酵特性进行评价,发现植物乳植杆菌YJ132和肠膜明串珠菌肠膜亚种UA107显示出显著的发酵潜力:培养16 h后,发酵液OD600值分别升高至1.707和1.672,而pH值分别降低至3.93和3.88,培养24 h后,可滴定酸度(TA)含量为65.62 g/L和63.21 g/L,对亚硝酸盐的降解率达到96.41%和95.78%,在5%NaCl溶液中培养24 h后OD600值仍达到1.51以上,综合评价菌株YJ132和UA107可作为发酵菌种用于东北酸菜发酵。利用YJ132和UA107制备酸菜,发酵末期酸菜样品中TA含量为35.96 g/L,还原糖和可溶性蛋白含量降低至6.51 mg/g和111.27μg/g,并在发酵初期显著降低亚硝酸盐的含量,与对照组相比差异极显著(P<0.01)。接种乳酸菌可抑制有害菌肠杆菌的增殖(P<0.01),增加酸菜中微生物群落的多样性,同时乳杆菌在发酵中后期始终是优势菌群,由此推断YJ132和UA107是通过调控微生物群落来提升东北酸菜的品质。综上所述,YJ132和UA107是适用于东北酸菜发酵的优良乳酸菌菌种。

In order to obtain the lactic acid bacteria strains suitable for the fermentation of Dongbei Suancai,the growth performance and fermentation characteristics of 10 lactic acid bacteria strains isolated from fermented vegetables were evaluated in this study.It was found that Lactiplantibacillus plantarum YJ132 and Leuconostoc mesenterides subsp.mesenterides UA107 exhibited significant fermentation potential:After 16 h of fermentation,the optical densities at 600 nm(OD600)of their fermentation broth increased to 1.707 and 1.672,respectively,whilst their pHs decreased to 3.93 and 3.88,respectively.After 24 h of fermentation,the titratable acidity(TA)reached 65.62 g/L and 63.21 g/L,respectively,and the degradation rate of nitrite reached 96.41%and 95.78%,respectively.Even after 24 h of cultivation in a 5%NaCl solution,the OD_(600) remained above 1.51.Overall evaluation of YJ132 and UA107 revealed their suitability as fermentation strains for Dongbei Suancai.Using YJ132 and UA107 for Suancai fermentation,the final product had a TA content of 35.96 g/L.The contents of reducing sugar and soluble protein decreased to 6.51 mg/g and 111.27μg/g,respectively.The nitrite content was significantly reduced in the early stage of fermentation compared with the control group(P<0.01).The inoculated LAB inhibited the proliferation of harmful bacteria,such as Escherichia coli(P<0.01),and increased the microbial diversity in the Suancai with Lactobacillus being the dominant bacterial group during the middle and late fermentation stages.Accordingly,it is inferred that YJ132 and UA107 improve the quality of Suancai by regulating the microbial community.In summary,YJ132 and UA107 are excellent LAB strains that are suitable for the fermentation of Dongbei Suancai.