DNA microarray for detection and identification of sulfur oxidizing bacteria in Biogas Clean-up System

Abstract

Knowledge of gene function and coexistence in the sulfur oxidizing bacteria (SOB) communities plays a significant role in driving the sulfide oxidation process in biogas clean-up process, including the stability and balance within the system. Microarray techniques can be responding to achieve as specific-detection, quantitative-identification, and high-throughput tools for microbial characterization in various environments. This research designed the microarray for monitoring SOB bacteria based on the entire genome and functional genes: soxAXBYZ and fccAB, using genome sequencing of non-SOB as a negative control, and then SOB microarray used to detect and identify SOB species-strain in the starch industry. The design of the DNA microarray revealed 61,788 probes which covered 722 strains of SOB and 35 strains of non-SOB. The quality test results demonstrated the DNA concentration, specific activity (28-36 pmol/μg), and yield (6-7 μg) of the genomic DNA had high-quality and could be repeated in the future with little noise signal. The expression level of recirculating sludge has increased in level of expression than the starting sludge. Thiothrix, Syntrophomonas, Paracoccus Magnetospirillum, Arcobacter, Sulfuricurvum, Acinetobacter, and Hydrogenophaga gained the gene expression level that involved with sulfide oxidation. The overexpression could be due to the biotrickling filter have more nutrients and optimal conditions for SOB growth to synthesize the necessary proteins for cell adaptation, such as SoxXA, SoxYZ, SoxB, and FccAB related to bacterial activity that oxidized the H2S in biogas.