Sunish K S, Sreedharan Prathapan, Daniel Sobhi, Biji Mathew, Rosamma Philip, Sukumaran Vrinda, Mohandas A, Singh I S Bright
National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Lakeside Campus, Fine Arts Avenue, Kochi, 682016, India; Department of Zoology, Maharaja's College, Ernakulam, Kochi, 682011, Kerala, India.
Department of Applied Chemistry, Cochin University of Science and Technology, Kochi, 682022, India.
Microb Pathog. 2021 Aug;157:104967. doi: 10.1016/j.micpath.2021.104967. Epub 2021 May 17.
In an attempt to screen antagonistic microorganisms from marine environment for the management of bacterial pathogens in aquaculture, an isolate of actinomycete MCCB 110 was segregated based on its comparatively higher inhibitory property on Vibrio harveyi (MCCB 111) and profound luminescent inhibition. Based on the culture characteristics, cell wall fatty acid profile and the nucleotide sequence of the 16S rRNA gene (1495 bp), the isolate was identified as Nocardiopsis alba. Solvent extraction of the fermentation broth followed by TLC and HPLC analyses resulted in the isolation of a major fraction active against luminescent Vibrio harveyi. Partial characterization of this bioactive fraction based on spectroscopic data obtained from FT-IR, UV, MS-MS and H NMR analyses identified it as a substituted derivative of sterol, and was recognized to differ from those reportedly produced by the same genus. The fraction was not toxic to VERO cell line and shrimp haemocytes up to 1000 ppm tested. The study demonstrated the potential of the putative probiotic Nocardiopsis alba (MCCB 110) and its novel extra-cellular bioactive product in the management of Vibrio harveyi in aquaculture.
为了从海洋环境中筛选拮抗微生物以管理水产养殖中的细菌病原体，基于其对哈维氏弧菌（MCCB 111）相对较高的抑制特性和显著的发光抑制作用，分离出了一株放线菌MCCB 110。根据培养特征、细胞壁脂肪酸谱和16S rRNA基因（1495 bp）的核苷酸序列，该分离株被鉴定为白色诺卡氏菌。对发酵液进行溶剂萃取，随后进行薄层层析（TLC）和高效液相色谱（HPLC）分析，分离出了对发光哈维氏弧菌有活性的主要组分。基于傅里叶变换红外光谱（FT-IR）、紫外光谱（UV）、串联质谱（MS-MS）和核磁共振氢谱（H NMR）分析获得的光谱数据对该生物活性组分进行的部分表征表明，它是一种甾醇取代衍生物，且被认为与同一属报道产生的那些物质不同。该组分在高达1000 ppm的测试浓度下对VERO细胞系和虾血细胞无毒。该研究证明了推定的益生菌白色诺卡氏菌（MCCB 110）及其新型细胞外生物活性产物在水产养殖中管理哈维氏弧菌方面的潜力。
