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为了解罗非鱼肠道乳酸菌群多样性和优势菌种,促进乳酸菌在罗非鱼养殖中的应用,采用MRS、M17、TPY、Elliker四种培养基,分别在有氧、厌氧以及30℃、37℃和45℃温度条件下分离罗非鱼肠道乳酸菌,分析不同培养基、培养温度、有氧和厌氧条件对罗非鱼肠道乳酸菌分离的影响;并对分离到的菌株进行分子鉴定和16S r RNA序列分析,构建系统发育树,比较不同分离条件下分离肠道乳酸菌的遗传多样性.结果表明,不同培养基对罗非鱼肠道乳酸菌的分离效果有一定的差异,其中MRS培养基的分离效果最好,且遗传多样性最高;37℃较30℃对乳酸菌的分离更加有利,45℃未分离到乳酸菌;有氧条件下共分离出8种33株乳酸菌,主要为杆菌;厌氧条件下得到10种24株乳酸菌,主要为球菌.共分离到植物乳杆菌(Lactobacillus plantarum)29株,可能是罗非鱼肠道优势乳酸菌种.本研究可为开发水产养殖肠道乳酸菌提供依据,并推广到其他种类的鱼肠道乳酸菌的分离和鉴定.
In order to understand the diversity and dominant species of lactic acid bacteria in tilapia, and to promote the application of lactic acid bacteria in tilapia culture, MRS, M17, TPY and Elliker four media were used respectively in aerobic, anaerobic and 30 ℃ , 37 ℃ and 45 ℃, respectively. The effects of different media, culture temperature, aerobic and anaerobic conditions on the separation of lactic acid bacteria in tilapia were analyzed. Identification and 16S rRNA sequence analysis to construct phylogenetic tree and to compare the genetic diversity of lactic acid bacteria isolated from intestinal tract under different separation conditions.The results showed that there were some differences in the isolation effect of different lactic acid bacteria in tilapia, The results showed that the culture medium had the best separation effect and the highest genetic diversity. The isolation of lactic acid bacteria was more beneficial than that of 30 ℃ at 37 ℃, but no lactic acid bacteria were isolated at 45 ℃. Eight kinds of 33 lactic acid bacteria were isolated under aerobic conditions, Twenty-four kinds of lactic acid bacteria, mainly cocci, were obtained under anaerobic conditions.A total of 29 strains of Lactobacillus plantarum were isolated, which may be the dominant lactic acid bacteria in tilapia.This study can be used to develop aquaculture intestinal milk Acid bacteria provide the basis for the promotion and identification of other types of fish intestinal lactic acid bacteria.