风干武昌鱼中乳酸菌的分离鉴定及发酵性能研究

Isolation, Identification, and Fermentation Properties of Lactic acid bacteria from Air Dried and Fermented Megalobrama amblycephala

为获得具备优良性能的乳酸菌发酵剂,以我国极具特色的发酵肉制品—风干武昌鱼为基础原料,对传统风干武昌鱼在自然发酵过程中不同时期的乳酸菌进行分离鉴定与发酵性能测定。研究通过平板分离、菌落与菌体形态观察、糖醇发酵试验及生理生化试验鉴定所分离乳酸菌。结果表明所分离乳酸菌分属于7个种属:嗜盐四联球菌(Tetragenococcus halophilus)、弯曲乳杆菌(Lactobacillus curvatus)、乳酸乳球菌乳酸亚种(Lactococcus lactis subsp.lactis)、冷明串珠球菌(Leuconostoc gelidum)、格氏乳杆菌(Lactobacillus gasseri)、詹氏乳杆菌(Lactobacillus jensenii)和嗜淀粉乳杆菌(Lactobacillus amylohilus)。进一步采用产酸能力、食盐耐受性、亚硝酸盐耐受性、生长温度以及蛋白质和脂肪降解能力等试验测定菌株发酵性能,最终优化结果表明乳酸乳球菌乳酸亚种具备优良乳酸菌发酵剂的性能。

The aim of this study is to obtain lactic acid starters with excellent fermentation properties from air-dried and fermented Megalobrama amblycephala, a fermented fish product unique to China. The fermentation capacity of lactic acid bacteria was isolated, identified, and evaluated from the fermented fish. Strains were isolated by dilution plate method and identified by colony characteristics, bacterial morphology, carbohydrate fermentation, and a series of physiological and biochemical tests. The results showed that the isolated strains belonged to the following seven species： Tetragenococcus halophilus, Lactobacillus curvatus, Lactococcus lactis subsp, lactis, Leuconostoc gelidum, Lactobacillus gasseri, Lactobacillus jensenii, and Lactobacillus amylophilus. Fermentation capacity was evaluated in terms of acidification rate, salt tolerance, nitrite tolerance, growth temperaaxres, and proteolytic and lipolytic capacities. The final optimization results showed that Lactococcus lactis subsp, lactis qualified as an excellent lactic acid starter.