Isolation and Identification of Acinetobacter from the Muscle of Channel Catfish (Ictalurus punctatus)
ZHAO Kui, WANG Lan, SUN Weiqing, XIONG Guangquan, QIAO Yu, WU Wenjin, LI Xin, DING Anzi
1.Key Laboratory of Agricultural Products Cold Chain Logistics, Ministry of Agriculture and Rural Affairs, Institute of Agro-Products Processing and Nuclear Agricultural Technology, Hubei Academy of Agricultural Sciences, Wuhan 430064, China; 2.College of Life Sciences, Yangtze University, Jingzhou 434025, China
Abstract：Two bacterial strains, designated by 7-2 and bs 7-3, were isolated from the back muscle of channel catfish vacuum packaged at 4 ℃ for seven days. They were identified by morphological observation and Gram staining, biochemical tests, 16S rDNA sequencing, and negative staining. Strain by 7-2 formed round, moist, white colonies on LB agar medium, and strain bs 7-3 formed round, moist, milky white colony colonies on LB agar medium. Both bacteria were Gram-negative bacteria, and strain by 7-2 was a short rod-shaped bacterium, while strain bs 7-3 was a long rod-shaped bacterium. Both strains had no flagella and were negative for nitrate reduction, arginine dihydrolase, acetamidase, xylose decomposition, maltose decomposition, mannitol decomposition, DNase and oxidase. Strain bs 7-3 was positive for citrate and O-F test, while strain by 7-2 was negative. 16S rDNA sequencing and phylogenetic tree analysis showed that by 7-2 had the closest relationship with Acinetobacter johnsonii (99.90%); bs 7-3 had the closest relationship with Acinetobacter radioresistens (99.79%). Therefore, by 7-2 was identified as Acinetobacter johnsonii, and bs 7-3 as Acinetobacter radioresistens.
2022, Vol. 36 
