| 摘要: |
| 对0、5和10 ℃冷藏养殖罗非鱼货架期终点的特定腐败菌进行定性和定量研究，并建立特定腐败菌的生长动力学模型。实验结果表明，0、5和10 ℃冷藏养殖罗非鱼货架期终点时，假单胞菌占总菌数比例分别为80.7%、68.1%和575%。该类菌在营养琼脂和胰酶解大豆胨琼脂培养基上菌落圆状隆起，边缘整齐，透明，无色；菌体为革兰氏阴性杆菌，极生单鞭毛，具有运动性，大小为（0.5-0.7）μm×（1.6-3.2)μm；氧化酶反应为阳性，不能利用海藻糖、棉子醇和甘露醇等；直链、支链、环丙基和羟基脂肪酸等被检出，富含单不饱和脂肪酸（50.18%），主要脂肪酸有16∶1ω7c 、iso-15∶0、16∶0和17∶1ω8c，比例分别为26.16 %、14.83%、7.96%和3.94%；Riboprinter测试其核糖体型为56-S-7。采用修正的Gompertz方程拟合假单胞菌生长模型表明，0、5和10 ℃冷藏过程延滞时间分别为（59.63±61.88）、(7.25±24.06)和（3.95±9.83）h；最大比生长速率分别为（0.02±0.00）、（0.04±0.00）和（0.08±0.01）/h。 |
| 关键词: 养殖罗非鱼 特定腐败菌 假单胞菌 生长动力学 |
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| 基金项目:国家自然科学基金项目(30771675)和中央级公益性科研院所基本科研业务费专项资金项目(2007M05)共同资助 |
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| Identification and growth dynamics of specific spoilage organisms in chilled tilapia |
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| Abstract: |
| The specific spoilage organisms (SSO) in cultured tilapia at the end of shelf life during storage at 0, 5 and 10 ℃ were qualitatively and quantitatively investigated, and the growth model of SSO was established. The results indicated that the percentage of Pseudomonas spp. in total bacteria in the tilapia were 807%，681% and 575% at the end of shelf life of tilapia stored at 0, 5 and 10 ℃, respectively. Colonies of Pseudomonas spp. on nutrition agar and trypticase soy broth agar were circular apophysis with smooth edge, transparent and colourless; The cells were gram negative rod (0.5-0.7 μm×1.6-3.2 μm) and motile by means of polar flagellum; Positive for oxidation，but the strains could not assimilated trehalose, mannitol and raffinose, etc. A variety of acids were detected in these organisms, including branched and straight chained acids, cyclopropane, and hydroxy acids. Unsaturated fatty acids comprised a large part of all fatty acids (50.18%), and the major ones were 16∶1ω7c, iso 15∶0, 16∶0 and 17∶1ω8c, which were 26.16%, 14.83%, 7.96% and 3.94% of total fatty acids, respectively. The type of ribosome of these bacteria was 56-S-7, as tested by Riboprinter. The growth dynamic for Pseudomonas spp. was fitted by modified Gompertz equation. The results showed that lag time reached（59.63±61.88）, (7.25±24.06) and （3.95±9.83）h during storage at 0, 5 and 10 ℃, respectively. The maximum specific growth rates for Pseudomonas spp. were （0.02±000）h-1, （0.04±0.00）h-1 and （0.08±0.01）h-1 at 0, 5 and 10 ℃, respectively. |
| Key words: Identification and growth dynamics of specific spoilage organisms in chilled tilapia |
