腌萝卜干产气菌的分离与鉴定

Seperation and Identification of the Aerogen from Pickled Radish

为解决产气微生物引起的真空包装腌萝卜干胖袋问题,从真空包装的萧山萝卜干中分离出2种产气菌,观察它们的形态、大小以及革兰氏染色、荚膜、芽孢特性。根据革兰氏阳性菌鉴定大纲,做耐酸染色试验、内生孢子染色、过氧化氢酶试验、富葡萄糖培养试验和Loeffler血清消化试验。测定这两株产气菌的16SrDNA序列,并与基因库中其它相关细菌的16SrDNA序列进行比较。最终两种产气菌分别被鉴定为短乳杆菌和表皮葡萄球菌。短乳杆菌产气速度快,产气量大,而表皮葡萄球菌产气缓慢,产气量较少。

In order to solve a problem of the vacuum package of pickle radish swell due to aerogen. Two aerogen strains from Xiaoshan pickle radish in vacuum plastic package were isolated. The size of bacteria, characteristic of Gram stain, types of capsule and endospore were observed and analyzed. And characteristic of acid fast staining,endospore staining,the activity of catalase,nutrient agar growth, rich dextrose culture, Loeffler resum medium digest experiment were carried out according to Identification of Gram Positive Bacteria. 16S rDNA sequences of the two aerogens were sequenced and compared with other relative bacteria＇s 16S rDNA sequences from NCBI-GenBank using BlastN method. Lactobacillus brevis and Staphylococcus epidermidis were certified as the main aerogens microbes in gas accumulating pickle radish in vacuum package repectively. LactobaciUus brevis could produce gas rapid and large comparaed with Staphylococcus epidermidis only produce gas slight and slowly.