罗非鱼下脚料酶解液特定腐败菌的分离和鉴定
Isolation and identification of specific spoilage organism from Tilapia wastes enzymatic hydrolysates
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摘要: 采用PCR-DGGE和PCR-RFLP技术研究了罗非鱼下脚料酶解液冷藏过程中的特定腐败菌。结果表明:酶解液在冷藏条件下,在20 d左右腐败,细菌总数在012 d里逐渐增加（8.71×1028.13×107cfu/g）,12 d之后趋向稳定。16S r RNA的PCR-RFLP及序列比对分析结果显示,随机挑取的18株细菌分成三个分型,其中分型1占61%,与Genbank核酸数据库的假单胞菌（Pseudomonas sp.）有最大相似性;PCR-DGGE图谱显示酶解液的细菌菌相随时间的延长而逐渐减少,腐败终点菌相单一。DGGE主要条带测序结果表明,酶解液存在三个类群的细菌,分别是假单胞菌属、气单胞菌属（Aeromonas）和不动杆菌属（Acinetobacter）,其中在酶解液腐败终点,荧光假单胞菌（Pseudomonas fluorescens）占绝对优势,与RFLP结果相符。Abstract: Specific spoilage organism of Tilapia Wastes enzymatic hydrolysates during chilled storage was studied by PCR- DGGE and PCR- RFLP.Results indicated that Tilapia enzymatic hydrolysates spoilaged about 20 days at 4℃,and the total number of bacteria increased during 0 ~ 12 days( 8.71 × 102~ 8.13 × 107 cfu / g) gradually,became stable during 12~20 days.There were three types of bacteria by PCR- RFLP analysis of 16 S r RNA from 18 strains of bacteria selected randomly. Type one which dominated 61% of the total bacteria was highly similar with Pseudomonas.The maps of PCR- DGGE showed that the bacteria reduced gradually before spoilaged,and there was only one single band of bacteria at last.Sequencing analysis results of DGGE bands showed that there were three types of bacteria Pseudomonas sp.,Aeromonas and Acinetobacter in the Tilapia Wastes enzymatic hydrolysates,Pseudomonas fluorescens was the predominant bacteria when spoilaged,this conclusion was consistent with RFLP.
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