Mining sponge-associated microorganisms from the central coastal region of Vietnam for antimicrobial compounds

Introduction

Marine sponges are well known to harbour diverse microbes and are the source of various types of bioactive natural compounds derived from the marine environment. Many of these compounds are important for medicinal and pharmaceutical purposes. Discovery of novel antibiotics and new drugs is of increasing interest because of an rapid growth of infections by antibiotic-resistant bacteria and a lack of new products on the market. However, marine sponges produce in small quantities of bioactive compounds, leading to challenges in mining the drug-producing potential of sponges due to sustainability issues. Additionally, marine sponges are hard to culture in the laboratory. Therefore, sponge-associated microorganisms have become an important target for microbiological and pharmaceutical research. It has been reported that the true producers of many bioactive compounds are the sponge-associated microorganisms. However, sponge-associated microbes cannot easily be cultured, and only a minor fraction of the microbial community could be successfully isolated. The combination of cultivation and metagenomics will help us overcome the limitations of the different methods, and bring us a more comprehensive and clear insight in sponge-associated microorganisms and their functional genes.

Objectives

• Investigation of the diversity of sponge-associated microbes in the central coastal region of Vietnam
• Study on the diversity of genes for the synthesis of antimicrobial compounds in sponge-associated microbes
• Isolation of sponge-associated microbes producing antimicrobial compounds
• Isolation of the antimicrobial compounds from sponge-associated microbes and elucidation their chemical structures

Approach

• Phylogenetic analysis of sponge-associated microbial communities will be based on next-generation technology sequencing data of the 16S rRNA gene.
• The diversity of  relevant biosynthesis gene clusters (PKS, NRPS and halogenase) will be mined from metagenome data
• Cultivation of sponge-associated microbes and antimicrobial assays will be carried out to screen isolates with antimicrobial activity
• The highest active isolates will be subjected to isolate antimicrobial compounds. Purification and elucidation of the chemical structure of compounds will be done using a semi-preparative HPLC, followed by structure elucidation using NMR and mass spectrometry.