Department of Microbiology, School of Life Sciences, Pondicherry University, Puducherry, India.
Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Puducherry, India.
Sci Rep. 2020 Jul 14;10(1):11558. doi: 10.1038/s41598-020-67717-9.
Marine sponges are sources of various bioactive metabolites, including several anticancer drugs, produced mainly by sponge-associated microbes. Palk Bay, on the south-east coast of India, is an understudied, highly disturbed reef environment exposed to various anthropogenic and climatic stresses. In recent years, Palk Bay suffered from pollution due to the dumping of untreated domestic sewage, effluents from coastal aquaculture, tourism, salt pans, cultivation of exotic seaweeds, and geogenic heavy-metal pollution, especially arsenic, mercury, cadmium, and lead. Low microbial-abundant sponge species, such as Gelliodes pumila and Cliona lobata, were found to be ubiquitously present in this reef environment. Triplicate samples of each of these sponge species were subjected to Illumina MiSeq sequencing using V3-V4 region-specific primers. In both C. lobata and G. pumila, there was an overwhelming dominance (98 and 99%) of phylum Candidatus Saccharibacteria and Proteobacteria, respectively. The overall number of operational taxonomic units (OTUs) was 68 (40 and 13 OTUs unique to G. pumila and C. lobata, respectively; 15 shared OTUs). Alphaproteobacteria was the most abundant class in both the sponge species. Unclassified species of phylum Candidatus Saccharibacteria from C. lobata and Chelotivorans composti from G. pumila were the most abundant bacterial species. The predominance of Alphaproteobacteria also revealed the occurrence of various xenobiotic-degrading, surfactant-producing bacterial genera in both the sponge species, indirectly indicating the possible polluted reef status of Palk Bay. Studies on sponge microbiomes at various understudied geographical locations might be helpful in predicting the status of reef environments.
海洋海绵是各种生物活性代谢物的来源，包括几种抗癌药物，主要由海绵相关的微生物产生。印度东南海岸的 palk 湾是一个研究不足、高度受干扰的珊瑚礁环境，受到各种人为和气候压力的影响。近年来，由于未经处理的生活污水、沿海水产养殖、旅游、盐田、外来海藻养殖和地球成因重金属污染（尤其是砷、汞、镉和铅）的倾倒，palk 湾受到了污染。低微生物丰富的海绵物种，如 Gelliodes pumila 和 Cliona lobata，在这种珊瑚礁环境中普遍存在。对这两种海绵物种的每一种都采集了三份重复样本，使用 Illumina MiSeq 测序，使用 V3-V4 区域特异性引物。在 C. lobata 和 G. pumila 中，分别有压倒性的优势（分别为 98%和 99%）的门菌和变形菌。总的操作分类单元（OTU）数为 68 个（40 个和 13 个 OTU 分别为 G. pumila 和 C. lobata 所特有；15 个共享 OTU）。在这两个海绵物种中，α变形菌是最丰富的类群。C. lobata 中的未分类菌门候选糖菌和 G. pumila 中的 Chelotivorans composti 是最丰富的细菌物种。α变形菌的优势也揭示了这两个海绵物种中存在各种异生物质降解、表面活性剂产生细菌属，间接表明 palk 湾的珊瑚礁可能处于污染状态。在各种研究不足的地理位置对海绵微生物组的研究可能有助于预测珊瑚礁环境的状况。
