Culturable bacteria from an Alpine coniferous forest site: biodegradation potential of organic polymers and pollutants

Folia Microbiol (Praha). 2021 Feb;66(1):87-98. doi: 10.1007/s12223-020-00825-1. Epub 2020 Sep 25.

Abstract

The potential of the culturable bacterial community from an Alpine coniferous forest site for the degradation of organic polymers and pollutants at low (5 °C) and moderate (20 °C) temperatures was evaluated. The majority of the 68 strains belonged to the phylum Proteobacteria (77%). Other strains were related to Bacteroidetes (12%), Alphaproteobacteria (4%), Actinobacteria (3%), and Firmicutes (3%). The strains were grouped into 42 different OTUs. The highest bacterial diversity was found within the phylum Bacteroidetes. All strains, except one, could grow at temperatures from 5 to 25 °C. The production of enzyme activities involved in the degradation of organic polymers present in plant litter (carboxymethyl cellulose, microgranular cellulose, xylan, polygalacturonic acid) was almost comparable at 5 °C (68%) and 20 °C (63%). Utilizers of lignin compounds (lignosulfonic acid, lignin alkali) as sole carbon source were found to a higher extent at 20 °C (57%) than at 5 °C (24%), but the relative fractions among positively tested strains utilizing these compounds were almost identical at the two temperatures. Similar results were noted for utilizers of organic pollutants (n-hexadecane, diesel oil, phenol, glyphosate) as sole carbon source. More than two-thirds showed constitutively expressed catechol-1,2-dioxygenase activity both at 5 °C (74%) and 20 °C (66%). Complete phenol (2.5 mmol/L) degradation by strain Paraburkholderia aromaticivorans AR20-38 was demonstrated at 0-30 °C, amounts up to 7.5 mmol/L phenol were fully degraded at 10-30 °C. These results are useful to better understand the effect of changing temperatures on microorganisms involved in litter degradation and nutrient turnover in Alpine forest soils.

MeSH terms

  • Bacteria / classification
  • Bacteria / genetics
  • Bacteria / isolation & purification
  • Bacteria / metabolism*
  • Bacterial Proteins / metabolism
  • Biodegradation, Environmental
  • Biodiversity
  • Biopolymers / metabolism
  • Environmental Pollutants / metabolism*
  • Forests*
  • Lignin / metabolism
  • Phenol / metabolism
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics
  • Soil Microbiology
  • Temperature
  • Tracheophyta / microbiology*

Substances

  • Bacterial Proteins
  • Biopolymers
  • Environmental Pollutants
  • RNA, Ribosomal, 16S
  • Phenol
  • Lignin