Padmanaban Vishnu Priya, Verma Pankaj, Venkatabaskaran Srividhyalakshmi, Keppayan Thirupathi, Gopal Dharani, Sekar Ashok Kumar, Ramalingam Kirubagaran
Centre for Biotechnology, Anna University, Chennai, Tamil Nadu, 600025, India.
Marine Biotechnology Division, OSTI Group, National Institute of Ocean Technology, Ministry of Earth Sciences, Government of India, Chennai, Tamil Nadu, 600100, India.
World J Microbiol Biotechnol. 2017 Feb;33(2):27. doi: 10.1007/s11274-016-2193-2. Epub 2017 Jan 2.
Microbial-derived natural products from extreme niches such as deepsea are known to possess structural and functional novelty. With this background, the present study was designed to investigate the bioprospecting potential and systematics of a deep-sea derived piezotolerant bacterial strain NIOT-Ch-40, showing affiliation to the genus Streptomyces based on 16S RNA gene similarity. Preliminary screening for the presence of biosynthetic genes like polyketide synthase I, polyketide synthase II, non ribosomal peptide synthase, 3-amino-5-hydroxybenzoic acid synthase and spiroindimicin followed by antibacterial activity testing confirmed the presence of potent bioactivity. The secondary metabolites produced during fermentation in Streptomyces broth at 28 °C for 7 days were extracted with ethyl acetate. The extract exhibited a specific inhibitory activity against Gram-positive bacteria and was significantly effective (p < 0.0001) against methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentration and minimum bactericidal concentration against MRSA was 1.5 µg/mL, which was statistically significant in comparison with erythromycin. A multifaceted analysis of the Streptomyces spp. was carried out to delineate the strain NIOT-Ch-40 at a higher resolution which includes morphological, biochemical and molecular studies. Piezotolerance studies and comparison of fatty acid profiles at high pressures revealed that it could be considered as one of the taxonomic markers, especially for the strains isolated from the deep sea environments. In conclusion, the observation of comparative studies with reference strains indicated towards the strain NIOT-Ch-40 as an indigenous marine piezotolerant Streptomyces sp. with a higher probability of obtaining novel bioactive metabolites.
已知来自深海等极端生态位的微生物源天然产物具有结构和功能上的新颖性。在此背景下，本研究旨在调查一株深海来源的耐压细菌菌株NIOT-Ch-40的生物勘探潜力和系统分类，基于16S RNA基因相似性，该菌株隶属于链霉菌属。对聚酮合酶I、聚酮合酶II、非核糖体肽合酶、3-氨基-5-羟基苯甲酸合酶和螺旋吲哚霉素等生物合成基因的存在进行初步筛选，随后进行抗菌活性测试，证实了其具有强大的生物活性。将链霉菌肉汤在28°C下发酵7天期间产生的次生代谢产物用乙酸乙酯萃取。该提取物对革兰氏阳性菌表现出特异性抑制活性，对耐甲氧西林金黄色葡萄球菌（MRSA）有显著效果（p < 0.0001）。对MRSA的最低抑菌浓度和最低杀菌浓度为1.5 μg/mL，与红霉素相比具有统计学意义。对链霉菌属进行了多方面分析，以更高分辨率描绘菌株NIOT-Ch-40，包括形态学、生物化学和分子研究。耐压性研究以及高压下脂肪酸谱的比较表明，它可被视为分类学标记之一，特别是对于从深海环境中分离的菌株。总之，与参考菌株的比较研究观察结果表明，菌株NIOT-Ch-40是一种本土海洋耐压链霉菌，具有获得新型生物活性代谢物的较高可能性。
