Microbial communities in the reef water at Kham Island, lower Gulf of Thailand

Naraporn Somboonna; Alisa Wilantho; Somchai Monanunsap; Suchana Chavanich; Sithichoke Tangphatsornruang; Sissades Tongsima

doi:10.7717/peerj.3625

Microbial communities in the reef water at Kham Island, lower Gulf of Thailand

PeerJ. 2017 Aug 14:5:e3625. doi: 10.7717/peerj.3625. eCollection 2017.

Authors

Naraporn Somboonna¹, Alisa Wilantho², Somchai Monanunsap³, Suchana Chavanich⁴, Sithichoke Tangphatsornruang², Sissades Tongsima²

Affiliations

¹ Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
² Genome Technology Research Unit, National Center for Genetic Engineering and Biotechnology, Pathum Thani, Thailand.
³ Marine and Coastal Resources Research Center, Lower Gulf of Thailand, Department of Marine and Coastal Resources, Ministry of Natural Resources and Environment, Songkhla, Thailand.
⁴ Department of Marine Science, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.

Abstract

Coral reefs are among the most biodiverse habitats on Earth, but knowledge of their associated marinemicrobiome remains limited. To increase the understanding of the coral reef ecosystem in the lower Gulf of Thailand, this study utilized 16S and 18S rRNA gene-based pyrosequencing to identify the prokaryotic and eukaryotic microbiota present in the reef water at Kham Island, Trat province, Thailand (N6.97 E100.86). The obtained result was then compared with the published microbiota from different coral reef water and marine sites. The coral reefs at Kham Island are of the fringe type. The reefs remain preserved and abundant. The community similarity indices (i.e., Lennon similarity index, Yue & Clayton similarity index) indicated that the prokaryotic composition of Kham was closely related to that of Kra, another fringing reef site in the lower Gulf of Thailand, followed by coral reef water microbiota at GS048b (Cooks Bay, Fr. Polynesia), Palmyra (Northern Line Islands, United States) and GS108b (Coccos Keeling, Australia), respectively. Additionally, the microbial eukaryotic populations at Kham was analyzed and compared with the available database at Kra. Both eukaryotic microbiota, in summer and winter seasons, were correlated. An abundance of Dinophysis acuminata was noted in the summer season, in accordance with its reported cause of diarrhoeatic shellfish outbreak in the summer season elsewhere. The slightly lower biodiversity in Kham than at Kra might reflect the partly habitat difference due to coastal anthropogenic activities and minor water circulation, as Kham locates close to the mainland and is surrounded by islands (e.g., Chang and Kut islands). The global marine microbiota comparison suggested relatively similar microbial structures among coral sites irrespective of geographical location, supporting the importance of coral-associated marine microbiomes, and Spearman's correlation analysis between community membership and factors of shore distance and seawater temperature indicated potential correlation of these factors (p-values < 0.05) with Kham, Kra, and some other coral and coastal sites. Together, this study provided the second marine microbial database for the coral reef of the lower Gulf of Thailand, and a comparison of the coral-associated marine microbial diversity among global ocean sites.

Keywords: 16S ribosomal RNA; Eukaryote; Fringing reef; Marine; Microbiota; Prokaryote; Pyrosequencing.

Grants and funding

This work was supported by Thailand Research Fund MRG5480120, a research fund from the Faculty of Science, Chulalongkorn University, and the Ratchadaphiseksomphot Fund, Chulalongkorn University. ST was supported in part by the Thailand Research Fund, grant number RSA58-80061. There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.