食品中常见的微生物PPT课件.ppt

第二章 食品中常见的微生物 Common foodborne microorganisms in foods 假单胞菌属：革兰氏阴性、极生鞭毛、可运动、不生芽孢、杆状，新鲜食品中的优势菌，常存在于土壤和水中，广泛分布在食品中。另外，许多菌株是嗜冷，是导致新鲜冷冻食品腐败的重要细菌。有时腐败能产生水溶性蓝绿色素。 Pseudomonas：These gram-negative rods constitute the largest genus of bacteria that exist in fresh foods. They are typical of soil and water bacteria and are widely distributed among foods .They are , by far, the most important group of bacteria that bring about the spoilage of refrigerated fresh foods since many species and strains are psychrotrophic.Some are notable by their production of water-soluble , blue-green pigments. 产碱杆菌属：革兰氏阴性棒状杆菌，但菌体着色时有时也显现革兰氏阳性反应，周身鞭毛，无芽孢，严格好气，化能有机营养型，大多营养简单。不能发酵糖类，但能产碱（特别是在石芯乳中）。不产色素，分布在各种腐烂物质中，并大量存在于原乳、食用家禽制品以及排泄物中。 Alcaligenes:Although gram negative,these organisms sometimes stain gram positive.They are rods that do not ,as the generic name suggested,N ferment sugars but instead produce alkaline reactions especially in litmus milk. Nonpigmented,they are widely distribu-ted in nature in decomposing matter of all types. Raw milk,poultry product,and fecal matter are common source. 沙雷氏菌属 :革兰氏阴性、杆状、好氧，能分解蛋白质，有时能产生红色素，而不产色素的菌株则比较少见。液化沙雷氏菌是与食物中毒相关的最常见的菌株，能够引起冷冻蔬菜以及肉类制品的腐败。 Serratia： These gram-negative rods belong to the family Enerobacteriaceae are aerobic and proteolytic, and they generally produce red pigments on culture media and in certain foods , although nonpigmented strains are not uncommon. S.liquefaciens is the most prevalent of the foodborn species; it causes the spoilage of refrigerated vegetable and meats products. 弧菌属: 革兰氏阴性，直形或弯曲形杆菌，极生鞭毛，兼厌气性，通常需要一定浓度的盐，可污染咸鱼咸肉，有几株菌株能够引起人体肠胃疾病或其他疾病。 Vibrio: They are gram-negative straight or curved rods 。 Several species cause gastroenteritis and other human illness. 志贺氏菌属 : 杆状、不运动、无芽孢、无荚膜、革兰氏阴性，不能利用柠檬酸盐，能产酸但不产气。该属所有菌株都可存在于人体肠道中。 Shigella：All members of this genus are presumed to be enteropathogens. 气单胞菌属：典型的水生革兰氏阴性棒状杆菌，极生鞭毛，兼厌气性。能发酵糖类产生大量气体。通常出现在鱼体中。 Aeromonas: These are typically aquatic gram-negative rods .A