SIGNIFICANCE?
Invisible microorganisms are fundamental to the health of every life and environment, for instances the number of bacteria is estimated around 5x1030 on earth and for a man estimated around 6x1013, in which are many fold greater than the number of human body cells. The microbiota have symbiosis relationship among one another, and with the surrounding environment or the host, with many biotic and abiotic factors were reported to associate with the alteration of the microbiota composition, and many times link to the phenotypic changes of the environment and human diseases, for examples.
Traditionally, microbial diversity was discovered by culture-dependent approach that is limited by the culture nutrient and condition. Whereas only 0.1-1% has been described by cultivation, with metagenomics and next generation sequencing comes revealing of the true microbiota in each environment and the era of the BIG MICROBIOME DATABASE.
Thailand maritime zone is rich in biodiversity, both microorganisms and organisms, being recognized as part of the tropical heritage location in a so called "Indo-Burma." On the east is the Gulf of Thailand covers 320,000 km² area and the coastal length is more than 2,400 km, and is divided into: the upper, the central, and the lower. The central Gulf of Thailand is a basin where nutrients and minerals accumulate through the inflowing rivers from the South China Sea, yet the upper is situated a major oil rig site of Thailand. On the west is the Andaman Sea, part of the Indian Ocean. This is world's known highly aquatic abundance and endangered eco-region of the world.
Marine represent the major food resources on Earth, and further the underlying of every food resources and food networks are microorganisms (particularly bacteria). More importantly, Thailand contains abundant coral reefs, which represent the most productive resources of the marine food networks. However, global warming has caused coral bleaching and death periodically during the past decades.
Starting in 2012, we first pioneered the microbiota at coastal areas of Sichang island, where one side is polluted by pier (Tha Wang coast) and the other side is not (Tham Phang coast). The results indicated that the Tha Wang microbiota contain groups of microbes many with functional potentials involved high saline and high temperature, whereas the Tham Phang microbiota contain groups of microbes with functional potentials in diverse nutrient recycling and secondary metabolite syntheses (e.g. Actinobacteria) (Fig. 1: Somboonna et al. 2012). During July 2011 to January 2012, when Thailand experienced the largest flood in decades of history, coastal Tha Wang and Tham Phang coasts were also analyzed.
Fig. 1. Comparison of microbial prokaryotes (left) and eukaryotes (right) between Tha Wang and Tham Phang coasts of Sichang island
In continuation with contribution from several marine sectors of Thailand, the team started collections ranging from nature-preserved coral reef sites like Kra island and Kham island, Samae San island, the Andaman Sea, and the central Gulf of Thailand, to a different water season (wet vs. dry), and additionally all kinds of coral species and sediment habitats. The Kra and Kham reef water microbiota were compared against Global Ocean Sampling (GOS) marine databases and found close to the microbiota around Galapagos island; indicative of the fruitful microbial diversity (Fig. 2: Somboonna et al. 2014). The marine microbial diversity were found correlated by specific niche types i.e. coral reefs vs. ocean ocean, coast, etc. (Fig. 3: Somboonna et al. 2017).
Fig.2. Satellite map showing regions where microbiota are close to Kra reef water: Galapagos island, GS039, GS040 and GS045, in orderly
Fig. 3. Phylum-level taxonomic compositions of prokaryotes at Kham reef surface in summer, compared with the other global ocean sites. Each community was phylogenetic clustered based on their similarity metrics. Following information include water temperature, %GC, total number of phyla for each site, and the number of phyla that are shared and different to that at Kham. Due to limited space, tree branch does not represent evolutionary distance among communities. Different color denotes different phylum.
More details on the Thailand Marine Microbiome Database, please click here.