Changes in microbial community composition affect bioactivities of mucus isolated from coral acropora millepora

Abstract

Antibioticresistance is increasingly popular together with emerging diseases presentsan urgent requirement for more and more discovery of novel marine bioactive compounds. Paired-end reads of 16S rRNA sequenceof bacteria living in the coralAcropora milleporaobtained by the Illumina next-generation sequencing technology to be processed by DADA2 pipeline, phyloseq and ggplot2 packagesshowed thatbleached coral mucus hadan alpha diversity to be higher than healthy coral mucus.The coral surface mucuslayer (SML) of healthy coral exhibited higher growth inhibitionactivity to Vibrio parahaemolyticusteststrainthan that of bleached coral inany amount(10 –30 μL). The cytotoxicity againstthecolon cancer cell line HCT116 was also clearly observed when treated with healthy SMLand was1.5 times higher than mucuswastaken from bleached coral. The composition of the microbial community was shiftedwhen coralschangedfrom a healthy state to a bleached one,resulting in the reductionof antibacterial activity and cytotoxicity.