生鲜肉中假单胞菌致腐机制的研究进展

Progress in Understanding the Mechanism by Which Pseudomonas spp. Causes the Spoilage of Raw Meat

生鲜肉的腐败是一个与多种特定微生物密切相关并受多种外界环境因素影响的生态现象。假单胞菌属是生鲜肉中的优势腐败菌之一;但假单胞菌属对生鲜肉的致腐机制仍然缺乏较为系统的总结,尤其是对影响肉腐败的相关基因调控及表达尚未有定论。因此本文首先概述了假单胞菌的特性、分类及种间差异,进而分析了假单胞菌的污染来源,最后从底物利用(糖代谢、氨基酸代谢、脂代谢等)角度分析了假单胞菌基因水平上的致腐原因,其中调控Entner-Doudoroff途径中相关酶类的基因、调控胞外蛋白酶的AprX基因和编码ABC转运蛋白的基因、编码脂肪酶的lipA基因在不同条件下和不同菌类中表达量的差异可能是导致假单胞菌腐败的根本原因。通过本文的总结,以期为揭示肉品中假单胞菌的腐败机制和控制腐败提供理论参考。

The spoilage of raw meat is an ecological phenomenon closely related to many specific microorganisms and is affected by many external environmental factors.Pseudomonas spp.is one of the dominant spoilage microorganisms in raw meat.However,there is still lacking a systematic review on the mechanism of action of Pseudomonas spp.in the spoilage of raw meat.Notably,there is as yet no definite conclusion on the regulation and expression of genes involved in the spoilage of meat.Therefore,this paper summarizes the characteristics,classification and interspecific difference of Pseudomonas spp.,and overviews its contamination sources.The mechanism of meat spoilage caused by Pseudomonas spp.is elucidated at the genetic level from the viewpoint of substrate utilization(including carbohydrate metabolism,amino acid metabolism and lipid metabolism).Specifically,the difference in the expression of the genes encoding enzymes regulating the Entner-Doudoroff pathway,the AprX gene regulating extracellular protease,the genes encoding ABC transporter,and the lipase encoding gene lipA under different conditions and the inter-species difference in the expression of these genes may be the fundamental cause of the spoilage of Pseudomonas spp.The information gathered here provides a theoretical basis for controlling meat spoilage.