东北酸菜发酵液中耐低温乳酸菌的分离及抑菌性研究

Isolation and Antibacterial Activity of Low-temperature Lactic Acid Bacteria in Fermented Broth of Northeast Sauerkraut

从东北地区低温(10～15℃)贮藏的酸菜发酵液中分离出25株乳酸菌,获得在10℃能良好生长的菌株CCT-1,经形态、生理生化和16SrDNA鉴定,该菌株为植物乳杆菌(Lactobacillus plantarum)。分别将MRS固体培养基与LB、查氏、牛肉膏蛋白胨和YPD半固体培养基组成双层平板,对大肠杆菌(Escherichia coli)、黑曲霉(Aspergillus niger)、枯草芽孢杆菌(Bacillus subtilis)及啤酒酵母(S.cerevisiae)4种指示菌进行抑菌性研究,结果显示:CCT-1对4种指示菌均有抑菌作用。利用牛津杯法研究菌液的最低抑菌浓度,测得CCT-1菌悬液稀释3倍时,细胞浓度为3.4×106cfu/mL,此时还存在抑菌作用,啤酒酵母、大肠杆菌、枯草芽孢杆菌和黑曲霉的抑菌圈直径分别为10,9.8,9,8.5mm,该研究可为冷藏食品的保藏提供生物防腐菌株。

25 strains of lactic acid bacteria are isolated from low-temperature (10~15 ℃) stored sauerkraut fermentation broth in Northeast China, and the strain CCT-1 which grows well at 10 ℃ is obtained. The strain is identified by morphology, physiology and biochemistry and 16S rDNA. The strain is Lactobacillus plantarum. MRS solid medium is combined with LB, Czapek's, beef paste peptone and YPD semi-solid medium to form a double-layer plate, and the antibacterial activity of Escherichia coli, Aspergillus niger, Bacillus subtilis and S.cerevisiae is studied. The results show that CCT-1 has antibacterial activity against the four indicator bacteria.The CCT-1 is determined by using Oxford cup method to study the minimum inhibitory concentration of bacteria liquid. When the CCT-1 bacterial suspension is diluted by 3 times, the cell concentration is 3.4×10^6 cfu/mL. At the moment, there's also bacteriostatic action. The inhibition zone diameter of S.cerevisiae, Escherichia coli, Bacillus subtilis and Aspergillus niger is 10, 9.8, 9, 8.5 mm respectively. This study has provided bio-preservative strains for the preservation of frozen foods.