TITLE:
A Culture-Independent and Culture-Dependent Study of the Bacterial Community from the Bedrock Soil Interface
AUTHORS:
Karen Olsson-Francis, Carl P. Boardman, Victoria K. Pearson, Paul F. Schofield, Anna Oliver, Stephen Summers
KEYWORDS:
Mineral Weathering, Soil Microbial Communities, Basalt Dissolution
JOURNAL NAME:
Advances in Microbiology,
Vol.5 No.13,
December
15,
2015
ABSTRACT: In
nutrient limited soils, minerals constitute a major reservoir of bio-essential
elements. Consequently, the release of nutritive elements during weathering is
crucial. Bacteria have been shown to enhance weathering rates; however, there
has been limited work that has focused on the bacterial weathering of bedrock
or parent rock, which are the major sources of minerals, in nutrient limiting
soils. In this study, both a culture-independent and culture-dependent approach
was used to study the bacterial community at the interface between basaltic
bedrock and nutrient limiting soil in Cadiar Idris region of Snowdonia National
Park, United Kingdom. High throughput sequencing method, Ion Torrent, was used
to characterise the bacterial community, which generated over 250,000 sequences. Taxonomical assignment
demonstrated that approximately 50% (125,000 sequences) of the community
consisted of the orders Actinomycetales, Burkholderiales, Clostridales, Bacillales, Rhizobiales and Acidobacterium, with unclassified sequences representing 44% ± 1.46%
(110,000 ± 3650). Bacteria belonging to the genera Serratia, Pseudomonas, Bacillus, Paenibacillus, Chromobacterium, Janthinobacterium, Burkholderia and Arthrobacter, were isolated from the sample site. All of the
isolates were able to grow in a minimal growth medium, which contained glucose,
ammonium chloride with basalt as the sole source of bio-essential elements. Seventy
percent of the isolates significantly enhanced basalt dissolution (p