LC-MS-based metabolomics study of marine bacterial secondary metabolite and antibiotic production in Salinispora arenicola.

Utpal Bose,Paul Shaw,Mark Hodson,John Fuerst,Amitha Hewavitharana,Yi Ng

doi:10.3390/md13010249

Abstract

An LC-MS-based metabolomics approach was used to characterise the variation in secondary metabolite production due to changes in the salt content of the growth media as well as across different growth periods (incubation times). We used metabolomics as a tool to investigate the production of rifamycins (antibiotics) and other secondary metabolites in the obligate marine actinobacterial species Salinispora arenicola, isolated from Great Barrier Reef (GBR) sponges, at two defined salt concentrations and over three different incubation periods. The results indicated that a 14 day incubation period is optimal for the maximum production of rifamycin B, whereas rifamycin S and W achieve their maximum concentration at 29 days. A “chemical profile” link between the days of incubation and the salt concentration of the growth medium was shown to exist and reliably represents a critical point for selection of growth medium and harvest time.

Highlights

The marine environment presents a unique combination of environmental factors such as salinity, pressure, low temperatures and issues of nutrition availability
Results showed that the production of rifamycin W increased to a maximal level in 1% w/v NaCl medium after 14 days for two strains (M413 and SW15), while all three strains generated a minimal rifamycin W level at the same time point in
Metabolomics was used as a tool to begin to understand how the pattern of secondary metabolite production in the obligate marine S. arenicola species might be affected by salt concentration

Summary

Introduction

The marine environment presents a unique combination of environmental factors such as salinity, pressure, low temperatures and issues of nutrition availability. When compared with their terrestrial counterparts, marine organisms require distinctive metabolic capabilities in order to adapt and thrive in such an environment. It is important to optimise the salt concentration while culturing marine bacteria to understand how marine organisms respond to different salinity conditions and produce secondary metabolites. Production has been optimised for anticancer compounds in Salinispora [5], the metabolic response to changed conditions during anti-bacterial rifamycin antibiotic production in this organism remains unexplored The identification of salinosporamide A, an antitumor agent derived from obligate marine actinobacteria, has been shown to be correlated with different growth patterns on a number of salt-based media such as sodium sulphate-, sodium chloride- and potassium chloride-based formulations [4,5].

Results

Discussion

Conclusion