Format

Send to

Choose Destination
ISME J. 2014 Feb;8(2):369-82. doi: 10.1038/ismej.2013.145. Epub 2013 Aug 29.

The (d)evolution of methanotrophy in the Beijerinckiaceae--a comparative genomics analysis.

Author information

1
Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.
2
1] Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada [2] Department of Bioengineering, School of Minerals Processing and Bioengineering, Central South University, Changsha, Hunan, China.

Abstract

The alphaproteobacterial family Beijerinckiaceae contains generalists that grow on a wide range of substrates, and specialists that grow only on methane and methanol. We investigated the evolution of this family by comparing the genomes of the generalist organotroph Beijerinckia indica, the facultative methanotroph Methylocella silvestris and the obligate methanotroph Methylocapsa acidiphila. Highly resolved phylogenetic construction based on universally conserved genes demonstrated that the Beijerinckiaceae forms a monophyletic cluster with the Methylocystaceae, the only other family of alphaproteobacterial methanotrophs. Phylogenetic analyses also demonstrated a vertical inheritance pattern of methanotrophy and methylotrophy genes within these families. Conversely, many lateral gene transfer (LGT) events were detected for genes encoding carbohydrate transport and metabolism, energy production and conversion, and transcriptional regulation in the genome of B. indica, suggesting that it has recently acquired these genes. A key difference between the generalist B. indica and its specialist methanotrophic relatives was an abundance of transporter elements, particularly periplasmic-binding proteins and major facilitator transporters. The most parsimonious scenario for the evolution of methanotrophy in the Alphaproteobacteria is that it occurred only once, when a methylotroph acquired methane monooxygenases (MMOs) via LGT. This was supported by a compositional analysis suggesting that all MMOs in Alphaproteobacteria methanotrophs are foreign in origin. Some members of the Beijerinckiaceae subsequently lost methanotrophic functions and regained the ability to grow on multicarbon energy substrates. We conclude that B. indica is a recidivist multitroph, the only known example of a bacterium having completely abandoned an evolved lifestyle of specialized methanotrophy.

PMID:
23985741
PMCID:
PMC3906808
DOI:
10.1038/ismej.2013.145
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Nature Publishing Group Icon for PubMed Central
Loading ...
Support Center