The potential of bacterial key species as a tool for monitoring peatland quality

Abstract

Bacterial key species (BKS) is unique and found only in peat secondary forest, but not in converted peat areas. Its presence helps in biomonitoring of peatland quality. BKS candidates were detected based on the 16S rRNA gene sequence using the Next Generation Sequencing method. The 16S rRNA gene sequencing data were obtained from DNA isolated from peat soil of the secondary forest (SF), acacia plantations (AP), and rubber plantations (RP) in the Giam Siak Kecil - Bukit Batu (GSK-BB) Biosphere Reserve, Riau. The natural vegetation of peat swamp forest dominates the SF, which was relatively heterogeneous with anaerobic conditions and water level at 60-120 cm. The RP locations were planted with 6-7 year old rubber, water level was 20 cm, and the garden was not maintained. The AP locations were planted with A. crassicarpa and peat thickness was 9 m. The peat soil was sampled in August 2019. BKS candidates were selected based on a phylogenetic tree using MEGA 6.06 by observing the grouping of DNA sequences obtained only from secondary forests. Furthermore, the selection was also conducted using BLASTn: Align Two or More Sequence analysis to determine the similarity between selected BKS candidates. Based on the detected BKS candidate, a specific primer was designed to amplify the BKS sequence, and the specificity was tested in silico with FastPCR to detect that the primer was only for the amplification of the BKS target. Two BKS candidates with the same sequence length of 455 bp were discovered in the secondary forests and there were successfully amplified by 2 pairs of specific primers. The 16S rRNA gene sequences of the two BKS candidates could be used to monitor the peat quality that has been converted into plantation areas molecularly.