Genetic Diversity and Association Characters of Bacteria Isolated from Arbuscular Mycorrhizal Fungal Spore Walls

PLoS One. 2016 Aug 1;11(8):e0160356. doi: 10.1371/journal.pone.0160356. eCollection 2016.

Abstract

Association between arbuscular mycorrhizal fungi (AMF) and bacteria has long been studied. However, the factors influencing their association in the natural environment is still unknown. This study aimed to isolate bacteria associated with spore walls of AMF and identify their potential characters for association. Spores collected from coastal reclamation land were differentiated based on their morphology and identified by 18S rDNA sequencing as Funneliformis caledonium, Racocetra alborosea and Funneliformis mosseae. Bacteria associated with AMF spore walls were isolated after treating them with disinfection solution at different time intervals. After 0, 10 and 20 min of spore disinfection, 86, 24 and 10 spore associated bacteria (SAB) were isolated, respectively. BOX-PCR fingerprinting analysis showed that diverse bacterial communities were associated to AMF spores. Bacteria belonging to the same genera could associate with different AMF spores. Gram positive bacteria were more closely associated with AMF spores. Isolated SAB were characterized and tested for spore association characters such as chitinase, protease, cellulase enzymes and exopolysaccharide production (EPS). Among the 120 SAB, 113 SAB were able to show one or more characters for association and seven SAB did not show any association characters. The 16S rDNA sequence of SAB revealed that bacteria belonging to the phyla Firmicutes, Proteobacteria, Actinobacteria and Bactereiodes were associated with AMF spore walls.

MeSH terms

  • Bacteria / classification
  • Bacteria / enzymology
  • Bacteria / genetics*
  • Bacteria / isolation & purification
  • Cell Wall / microbiology
  • Cellulase / genetics
  • Cellulase / metabolism
  • Chitinases / genetics
  • Chitinases / metabolism
  • Cluster Analysis
  • Genetic Variation*
  • Gram-Positive Bacteria / classification
  • Gram-Positive Bacteria / genetics
  • Gram-Positive Bacteria / isolation & purification
  • Mycorrhizae / physiology*
  • Peptide Hydrolases / genetics
  • Peptide Hydrolases / metabolism
  • Phylogeny
  • Polymerase Chain Reaction
  • RNA, Ribosomal, 18S / genetics
  • RNA, Ribosomal, 18S / metabolism
  • Sequence Analysis, DNA
  • Spores, Fungal / growth & development

Substances

  • RNA, Ribosomal, 18S
  • Chitinases
  • Cellulase
  • Peptide Hydrolases

Grants and funding

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2015R1A2A1A05001885). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.