Tropical soil bacterial diversity in Sabah, Malaysia

Abstract

Bacteria are an essential biological component of soil function that plays fundamental roles in biogeochemical cycling, soil quality improvement, habitat-shaping, and ecosystem conservation. It is therefore important to have a good record of soil bacteria in the tropics in order to monitor future changes that may occur due to global warming and other factors. However, extremely limited data are available on the diversity of bacteria in soils in some tropical Borneo regions such as Sabah, Malaysia. This research, therefore, was undertaken to determine the bacterial diversity of soils from various locations in Sabah, Malaysia. Ten soil samples (n=10) were collected around Sabah. 16S rDNA of bacterial DNA extracted from soils were amplified and analysed using the Denaturing Gradient Gel Electrophoresis (DGGE). A total of 100 dominant and well-defined DNA fragments observed in the DGGE gel were extracted, sequenced, and aligned. The results indicated that 93 different bacterial operational taxonomic units (OTUs) representing bacteria from 8 different phyla were present. The most abundant phyla in the analysed Sabah soils were Proteobacteria followed by Acidobacteria, Firmicutes, Actinobacteria, Planctomycetes, Verrucomicrobia, Chloroflexi, and Bacteroidetes. The examined soils of Sabah and Peninsular Malaysia had similar dominant phyla in general, except that the most dominant phylum in Peninsular Malaysia soils is the Acidobacteria instead of Proteobacteria. These baseline data generated from this work are important and can be used to track bacterial diversity shifts due to soil or environmental changes in the future.