Profile of sulfur oxidizing bacteria in full-scale Biotrickling filter to remove H2S in biogas from in cassava starch industry

Abstract

The success of Next generation sequencing (NGS) technology over the past decades has led to a better understanding of complex microbial communities in such environment. Here, we employed NGS to monitor sulfur oxidizing bacteria (SOB) community from cassava starch industry (BPT), which can oxidize H2S into sulfate or elemental sulfur under aerobic conditions. Microbial sludge was collected from two sampling points comprising starting sludge (BPT1) and recirculating sludge (BPT2) of the biotrickling filter. gDNA was extracted from BPT1 and BPT2 samples and removed other contaminations by using the GenepHarM Gel/PCR Kit (Geneaid). DNA concentrations and DNA purity were analyzed by using gel electrophoresis and NanoDrop™ 1000 Spectrophotometer, respectively. Analysis of SOB species using NGS technique was based on the hypervariable regions V4 on the 16S rRNA gene. The comparative genomic hybridization (CGH) microarray probes for detection and identification of SOB species-strain that high expression of soxAXBYZ and fccAB genes in the cassava starch industry. For the recirculating sludge (BPT2), the bacterial communities were dominated by Sulfurimonas (13.7%) followed by Synechococcus (9.4%), Hydrogenophaga (6.5%), Methanosaeta (2.4%), and Acidithiobacillus (2.1%), the same dominant genera were also found in the starting sludge (BPT1), but with slightly different abundancy. The heatmap revealed that Acidithiobacillus caldus species (33.9%–49.9%) could play a vital role in eliminating H2S in biogas from the cassava starch industry. The CGH microarray indicated that Thiothrix, Paracoccus, Sulfurimonas, Hydrogenophaga, Magnetospirillum, Rhodoplanes, Syntrophomonas, Pseudomonas, Sulfuricurvum, and Arcobacter were dominant genus, that has a high expression of sulfur oxidation genes in biotrickling filter.