Zhang Dunhua, Xu De-Hai, Qiu Junqiang, Rasmussen-Ivey Cody R, Liles Mark R, Beck Benjamin H
Aquatic Animal Health Research Unit, USDA-ARS, 990 Wire Road, Auburn, AL, 36832, USA.
College of Fisheries and Life Sciences, Shanghai Ocean University, Pudong New District, Shanghai, 201306, China.
Arch Microbiol. 2017 May;199(4):573-579. doi: 10.1007/s00203-016-1326-1. Epub 2016 Dec 28.
Virulent Aeromonas hydrophila (vAh) is one of the most important bacterial pathogens that causes persistent outbreaks of motile Aeromonas septicemia in warm-water fishes. The survivability of this pathogen in aquatic environments is of great concern. The aim of this study was to determine the capability of the vAh strain ML10-51K to degrade and utilize chitin. Genome-wide analysis revealed that ML10-51K encodes a suite of proteins for chitin metabolism. Assays in vitro showed that four chitinases, one chitobiase and one chitin-binding protein were secreted extracellularly and participated in chitin degradation. ML10-51K was shown to be able to use not only N-acetylglucosamine and colloidal chitin but also chitin flakes as sole carbon sources for growth. This study indicates that ML10-51K is a highly chitinolytic bacterium and suggests that the capability of effective chitin utilization could enable the bacterium to attain high densities when abundant chitin is available in aquatic niches.
强毒嗜水气单胞菌（vAh）是导致温水鱼类持续性运动性气单胞菌败血症暴发的最重要的细菌病原体之一。该病原体在水生环境中的生存能力备受关注。本研究的目的是确定vAh菌株ML10-51K降解和利用几丁质的能力。全基因组分析表明，ML10-51K编码一套用于几丁质代谢的蛋白质。体外试验表明，四种几丁质酶、一种壳二糖酶和一种几丁质结合蛋白分泌到细胞外并参与几丁质降解。结果表明，ML10-51K不仅能够利用N-乙酰葡糖胺和胶体几丁质，还能利用几丁质薄片作为唯一碳源进行生长。本研究表明，ML10-51K是一种高度几丁质分解细菌，并表明当水生生态位中有大量几丁质时，有效利用几丁质的能力可使该细菌达到高密度。
