Myxobacteria in high moor and fen: An astonishing diversity in a neglected extreme habitat.

Kathrin I Mohr,Marc Stadler,Joachim Wink,Elke Wilharm,Tanja Zindler

doi:10.1002/mbo3.464

Abstract

Increasing antibiotic resistances of numerous pathogens mean that myxobacteria, well known producers of new antibiotics, are becoming more and more interesting. More than 100 secondary metabolites, most of them with bioactivity, were described from the order Myxococcales. Especially new myxobacterial genera and species turned out to be reliable sources for novel antibiotics and can be isolated from uncommon neglected habitats like, for example, acidic soils. Almost nothing is known about the diversity of myxobacteria in moors, except some information from cultivation studies of the 1970s. Therefore, we evaluated the myxobacterial community composition of acidic high moor and fen both with cultivation‐independent 16S rRNA clone bank analysis and with cultivation. Phylogenetic analyses of clone sequences revealed a great potential of undescribed myxobacteria in high moor and fen, whereby all sequences represent unknown taxa and were detected exclusively by cultivation‐independent analyses. However, many clones were assigned to sequences from other cultivation‐independent studies of eubacterial diversity in acidic habitats. Cultivation revealed different strains exclusively from the genus Corallococcus. Our study shows that the neglected habitat moor is a promising source and of high interest with regard to the cultivation of prospective new bioactive secondary metabolite producing myxobacteria.

Highlights

Myxobacteria are soil inhabiting, Gram-negative Deltaproteobacteria and are distributed all over the world (Dawid, 2000). Due to their nutritional requirements, they can be divided in predators and cellulose-degraders. Beside their interesting life-style expressed by the development of often colorful fruiting bodies and dry resistant myxospores (Reichenbach & Dworkin, 1992), myxobacteria are extremely interesting with regard to their great potential to produce a high diversity of bioactive secondary metabolites (Weissman & Müller, 2010)
3.1 | Myxobacterial diversity in high moor and fen detected with cultivation independent clone bank analyses
From a total of 38 collected samples which were all used for cultivation approaches, cost-intensive clone banks were established from four representative sampling sites, two from high moor (B4, B9) and two from fen (C1, C2). 16S rRNA genes were amplified in a first PCR with eubacterial primers (F27/R1525), whereby total genomic soil DNA was used as template

Summary

Introduction

Myxobacteria are soil inhabiting, Gram-negative Deltaproteobacteria and are distributed all over the world (Dawid, 2000). We investigated high moor and fen samples due to their myxobacterial diversity with cultivation- independent methods, based on PCR amplification and sequencing of 16S rRNA genes, as well as with cultivation.

Results

Conclusion