Discovering potential coral probiotics in Singapore

Abstract

Global climate change has caused seawater temperatures to rise, increasing the incidence of coral diseases, bleaching and mortality. Singaporean corals have a unique ‘microbiome flexibility’, which modify its bacterial community to adapt and survive against different anthropogenic- and climate change-induced stressors. I hypothesize that Singaporean corals harbor symbiotic marine bacteria that can be deemed as beneficial microorganisms for corals (BMC), containing traits that can enhance coral resilience. The Masters project aims to isolate and identify bacteria from the resilient Singaporean coral species Pachyseris speciosa and screen the isolates for BMC traits through genome mining, physiological- and biochemical based assays. Novel species of Pseudovibrio strains were discovered, containing BMC traits including anti-Vibrio activity, catalase production, and biofilm formation. These strains also encode genes involved in dimethylsulfoniopropionate (DMSP) degradation, denitrification, and production of secondary metabolites like tropodithietic acid (TDA), Pseudovibriamides and 1,6-phenazinedimethanol. These novel Pseudovibrio strains containing these BMC traits are ideal candidates as coral probiotics, to reduce the risk of coral decimation worldwide.