白乌鱼胴体粘液中耐热菌的耐热性及特征菌种鉴定

Heat Resistance and Identification of Characteristic Strain of Thermophilic Bacteria from Epidermal Mucus of White Mullet Fish (Opniocepnalus argus var. kimnra)

为了进一步分析白乌鱼胴体粘液中特征微生物的耐热性,并对其中的特征菌进行鉴定,本文对白乌鱼胴体粘液进行了热处理,然后对热处理粘液中的特征菌进行了分离纯化,并对其种属进行了鉴定。通过比较热处理后白乌鱼胴体粘液的外表特征、耐热性、特征菌的形态特征、特征菌的生长曲线和特征菌S3的耐高热性,发现新鲜白乌鱼胴体粘液呈淡红色,随着处理温度的升高逐渐呈淡绿色;接种了30℃热处理粘液的培养基有三种菌落(S1、S2和S3),接种了50℃热处理粘液的培养基有S2和S3两种菌,而接种了70℃、90℃和煮沸处理粘液的培养基,只生长了S3菌,空白组中无菌落生长。进一步对S1、S2和S3菌进行分析,得出S1为革兰氏阴性菌,S2和S3为革兰氏阳性菌;菌株S3在105℃高压灭菌锅中处理20 min之后仍能存活;菌株S2、S3分别在培养14 h、16 h时达到生长高峰;通过16S rDNA序列测序,发现菌株S1属于不动杆菌属(Acinetobacter sp.),菌株S2属于嗜根考克氏菌属(Kocuriarhizophilasp.),菌株S3属于芽孢杆菌属(Bacillussp.)。因此,白乌鱼胴体粘液中的耐热菌为枯草芽孢杆菌(Bacillus subtilis)。

To deeply analyze the heat resistance of the characteristic microbes and identifying the characteristic strain in the epidermal mucus of white mullet fish,the carcass mucus of white mullet was heat treated,then the characteristic bacteria in the heat treated mucus were isolated and purified,and their species were identified.By comparing the appearance characteristics and heat resistance of the heated mucus,and morphological features of the characteristic bacteria,the growth curve of the characteristic bacteria and the heat resistance of the strainS3were investigated.Results showed that the fresh mucus was faint red.The mucus was-gradually became light green with the increase of heat temperature.Three kinds of colonies,namely S1,S2,S3,were observed in the culture medium inoculated with the30℃,andS2andS3in the culture medium inoculated with the50℃,while only S3 in the culture medium inoculated with the70℃,90℃,boiling treated mucus.No colony was found in the control medium.Further analysis ofS1,S2andS3bacteria showed that S1was gram-negative bacterial strainsS2and S3were gram-positive bacterial strains.The strainS2andS3reached the peak of growth when they were cultured for14h and16h,respectively. By analyzing16S rDNA sequence of S1,S2andS3,it was found that strain S1belonged to Acinetobacter sp.,strainS2belonged to Kocuriarhizophila sp.,and strainS3belonged to Bacillus sp.Therefore,the thermophilic bacterium inepidermal mucus of white mullet fish is Bacillus subtilis.