Department of Biotechnology, R & D Centre, Dayananda Sagar College of Engineering, Bangalore, Karnataka, India.
Lett Appl Microbiol. 2014 Mar;58(3):231-41. doi: 10.1111/lam.12178. Epub 2013 Nov 13.
Marine coastal areas of India have vast diversity of sponges which harbours many endosymbiotic bacteria which are the source of many potential antimicrobial metabolites. This study focuses the screening and characterization of drug-producing bacteria symbiotically which are associated with marine sponges collected from Gulf of Mannar, South Coast India. Six different sponges were collected and they were identified on the basis of their morphology. The drug-producing isolates were screened by agar overlay method towards various clinical strains. The secondary metabolites were characterized and were found to be quinones, alkaloids, flavanoids and flavonyl glycosides. The metabolites showed significant inhibitory properties against clinical strains that were further identified as chromophoric and fluorophoric in nature. Ethyl acetate extracts of chromophore and floureophore substances showed significant inhibitory properties against Methicillin resistant Staphylococcus aureus (MRSA) and Salmonella typhi respectively. 16S rRNA gene sequencing of theses isolates revealed that chomophore-producing strain were closely related to Pseudomonas spp. RHLB12, isolated from Callyspongia spp. and floureophore-producing bacteria was related to Bacillus licheniformis T6-1 which was isolated from Haliclona spp. Hence, our study demonstrated that antimicrobial metabolites extracted from symbiotic bacteria associated with marine sponges have high therapeutic potential against many bacterial pathogens including multidrug-resistant strains.
This is the first study demonstrating antimicrobial potential of flurophoric and chromophoric metabolites extracted from bacterial biosymbionts associated with marine sponges. Our study has significant scope as Indian coastal area especially harbours vast varieties of sponges with novel secondary metabolites-producing organisms. The natural metabolites extracted from sponge-derived bacteria pave novel therapeutic remedy against various pathogens when most of them are emerged as extreme drug resistant superbugs.
印度的海洋沿海地区拥有丰富多样的海绵，这些海绵中栖息着许多内共生细菌，这些细菌是许多潜在抗菌代谢物的来源。本研究集中于筛选和表征与从印度南海岸的马纳尔湾采集的海洋海绵共生的产药细菌。收集了六种不同的海绵，并根据它们的形态进行了鉴定。采用琼脂覆盖法对各种临床菌株进行了产药分离物的筛选。对次级代谢产物进行了表征，发现它们是醌类、生物碱、类黄酮和黄酮苷。这些代谢产物对临床菌株表现出显著的抑制作用，进一步鉴定为显色和荧光物质。显色和荧光物质的乙酸乙酯提取物对耐甲氧西林金黄色葡萄球菌（MRSA）和伤寒沙门氏菌分别表现出显著的抑制作用。这些分离物的 16S rRNA 基因测序表明，显色产生菌与假单胞菌属密切相关。RHLB12 从 Callyspongia 属中分离得到，荧光产生菌与地衣芽孢杆菌属 T6-1 有关，后者从 Haliclona 属中分离得到。因此，我们的研究表明，从与海洋海绵共生的细菌中提取的抗菌代谢物具有针对许多细菌病原体（包括多药耐药株）的高治疗潜力。
这是第一项研究，证明了从与海洋海绵共生的细菌中提取的荧光和显色代谢物的抗菌潜力。我们的研究具有重要意义，因为印度沿海地区尤其拥有丰富的海绵种类，其中蕴藏着许多产生新型次生代谢物的生物。从海绵衍生细菌中提取的天然代谢物为各种病原体提供了新的治疗方法，因为大多数病原体已经成为极端耐药的超级细菌。
