大黄鱼源腐败菌的腐败能力与粘附性研究

The Ability of Spoilage and Adhesion of Spoilage Bacteria Isolated from Large Yellow Croaker(Pseudosciaena crocea)

以从大黄鱼中分离得到的腐败菌为研究对象,从菌体粘附性这一角度解释希瓦氏菌成为海水鱼的优势腐败菌的原因。以细菌总数、TVB-N、TMA和K值为腐败指标,测定分离纯化自冰鲜大黄鱼体的3株希瓦氏菌(MA1-5,MA1-7,MA1-13)和3株假单胞菌(R3-1,R3-2,R3-5)的腐败能力,测定此6株腐败菌对大黄鱼体表、鱼鳃和鱼肠黏液的粘附能力,建立腐败能力与粘附能力之间的相关性。结果表明,希瓦氏菌的致腐性强于假单胞菌:希瓦氏菌的细菌总数增速显著高于假单胞菌,产TMA能力显著强于假单胞菌,K值变化快,TVB-N含量与冷藏时间呈指数增长趋势;而假单胞菌产TVB-N含量与冷藏时间呈正比趋势。希瓦氏菌对鱼体各部位黏液的粘附能力强于假单胞菌:希瓦氏菌对鱼鳃和鱼肠的粘附性高于体表,在高盐条件下时的粘附能力随氯化钠含量的升高而增强,而假单胞菌则对体表的粘附性较高。腐败能力与粘附力相关性分析表明,腐败菌的腐败能力和粘附能力呈正相关,尤其腐败菌对肠黏液的粘附能力与腐败能力呈极显著的正相关性。结果表明,希瓦氏菌在高盐浓度下对鱼鳃和鱼肠的高粘附力是其成为海水鱼优势腐败菌的原因之一。

Adhesion ability of spoilage bacteria isolated from large yellow croaker(Pseudosciaena crocea) was provided as a new direction to clarify the reason why Shewanella become the dominant spoilage bacteria in marine fish.Spoilage ability about three Shewanella and three Pseudomonas isolated and purified from iced pseudosciaena crocea were identified by total number of viable bacteria(TVC), TVB-N, TMA and K value. The adhesion ability of the six spoilage bacteria to mucus of fish were evaluated to establish the correlation with spoilage ability of spoilage bacteria. The results showed that the spoilage ability of Shewanella were stronger than Pseudomonas: the growth rate of TVC of Shewanella was significantly higher than that of Pseudomonas;the amount of TMA produced by Shewanella was significantly more than Pseudomonas, and K value increased more quickly;the increase of TVB-N prouduced by Shewanella showed exponential growth trend within cold storage days, while direct proportional trend by Pseudomonas. The adhesion ability of Shewanella to the mucus of large yellow croaker was higher than Pseudomonas. The adhesion ability to gill and intestine were higher than which to skin, and the adhesion ability of Shewanella in high concentration of NaCl was enhanced with the concentration of NaCl increased, while Pseudomonas had stronger adhesion ability to skin. Correlation analysis indicated that there was a positive correlation between the spoilage ability and the adhesion degree of spoilage bacteria. The adhesion ability of spoilage bacteria to intestinal mucus has the most significant positive correlation with spoilage ability.The results indicated that the high adhesion ability of Shewanella to gill and intestine in the high concentration of NaCl was the reason for Shewanella to be the dominant spoilage bacteria in marine fish.