传统豆制品白干与薄百叶中优势腐败菌的分离与初步鉴定

Isolation and Preliminary Identification of Specific Spoilage Organisms from Traditional Soybean Products White Bean Curd and Bean Curd

以传统豆制品白干和薄百叶为材料,对贮藏过程中主要腐败微生物进行分离鉴定。利用纯培养的方法共筛选出菌落形态差别比较明显的菌株19株。对细菌菌株进行形态观察、革兰氏染色和生理生化鉴定,同时对细菌和酵母菌纯培养物提取DNA,分别进行16S rDNA和26S rDNA PCR扩增,PCR产物经测序后与NCBI中已知序列进行比对和鉴定,确定各细菌和酵母菌菌株的种属;霉菌纯培养物染色后观察孢子繁殖形态,最终确定这些菌株的种属。结果表明:白干和薄百叶中共有的优势腐败菌是溶酪葡萄球菌,枯草芽孢杆菌,约翰逊不动杆菌,戊糖片球菌;季也蒙毕赤酵母,皮状丝孢酵母;圆弧青霉和黄绿青霉。此外,白干中还有诞沫假丝酵母;薄百叶中有浅黄假单胞菌,芸苔丝孢酵母。

The spoilage organisms in white bean curd and bean curd during storage period were isolated and identified in this experiment.Nineteen strains obviously different in morphology were screened out,and the gram staining and their physical and chemical characteristic were identified using the method of pure culture.DNA were extracted from the pure culture of bacterium and yeast,and amplified the 16S rDNA and 26S rDNA;PCR products were sequenced and the results were identified and compared with the closest known sequences from NCBI to determine the various bacteria and yeast respective genus.The pure culture of mould were dyed to review the conidium morphology to indentify the genus of the strains.Results indicated that the common dominant spoilage organisms in the white bean curd and bean curd were Staphylococcus caseolyticus,Bacillus subtilis,Acinetobacter johnsonii,Pediococcus pentosaceus;Pichia guilliermondii,Trichosporon cutaneum;Penicillium cyclopium,Penicillium toxicarum Miyake.In addition,Candida zeylanoides was specific organism in white bean curd,and Pseudomonas luteola and Trichosporon cutaneum in bean curd.