Phenotypic responses to interspecies competition and commensalism in a naturally derived microbial co-culture

Authors

Nymul Khan, Pacific Northwest National Laboratory
Yukari Maezato, Pacific Northwest National Laboratory
Ryan S. McClure, Pacific Northwest National Laboratory
Colin J. Brislawn, Pacific Northwest National Laboratory
Jennifer M. Mobberley, Pacific Northwest National Laboratory
Nancy Isern, Pacific Northwest National Laboratory
William B. Chrisler, Pacific Northwest National Laboratory
Lye Meng Markillie, Pacific Northwest National Laboratory
Brett M. Barney, University of Minnesota, St Paul
Hyun-Seob Song, Pacific Northwest National LaboratoryFollow
William C. Nelson, Pacific Northwest National Laboratory
Hans C. Bernstein, Pacific Northwest National LaboratoryFollow

ORCID IDs

Hyun-Seob Song

William C. Nelson

Hans C. Bernstein

Date of this Version

2018

Citation

Scientific Reports | (2018) 8:297

Comments

© The Author(s) 2017

Open access

DOI:10.1038/s41598-017-18630-1

Abstract

The fundamental question of whether different microbial species will co-exist or compete in a given environment depends on context, composition and environmental constraints. Model microbial systems can yield some general principles related to this question. In this study we employed a naturally occurring co-culture composed of heterotrophic bacteria, Halomonas sp. HL-48 and Marinobacter sp. HL- 58, to ask two fundamental scientific questions: 1) how do the phenotypes of two naturally co-existing species respond to partnership as compared to axenic growth? and 2) how do growth and molecular phenotypes of these species change with respect to competitive and commensal interactions? We hypothesized – and confirmed – that co-cultivation under glucose as the sole carbon source would result in competitive interactions. Similarly, when glucose was swapped with xylose, the interactions became commensal because Marinobacter HL-58 was supported by metabolites derived from Halomonas HL- 48. Each species responded to partnership by changing both its growth and molecular phenotype as assayed via batch growth kinetics and global transcriptomics. These phenotypic responses depended on nutrient availability and so the environment ultimately controlled how they responded to each other. This simplified model community revealed that microbial interactions are context-specific and different environmental conditions dictate how interspecies partnerships will unfold.