Cloning and characterization of bgl6111 gene encoding β‐glucosidase from bagasse metagenome

β‐Glucosidase (BGL) is an essential enzyme for the hydrolysis of cellulose in industrial processes, but natural BGL enzymes are poorly understood. Metagenomics is a robust tool for bioprospecting in the search for novel enzymes from the entire community’s genomic DNA present in nature. The metagenomics approach simplifies the process of searching for new BGL enzymes by extracting DNA and retrieving its gene information through a series of bioinformatic analyses. In this study, we report the gene cloning, heterologous expression of the bgl6111 gene (accession number MW221260) in Pichia pastoris KM71, and the biochemical characterization of the recombinant enzyme. We successfully identified the bgl6111 sequence of 2,520 bp and 839 amino acids with a molecular size of 89.4 kDa. The amino acid sequence of the bgl6111 gene showed 67.61% similarity to BGL from an uncultured bacterium (ABB51613.1). The BGL product has the highest activity on the third day at 1.210 U/mL, categorized as low production. The enzymatic activity could enhance up to 539.8% of 7.742 U/mL by using the ultrafiltration method. Our findings provide insightful information that bgl6111 obtained from bagasse metagenome could be an alternative candidate for industrial applications in the future

Comparative analysis of bacterial communities associated with healthy and diseased corals in the Indonesian sea

Coral reef ecosystems are impacted by climate change and human activities, such as increasing coastal development, overfishing, sewage and other pollutant discharge, and consequent eutrophication, which triggers increasing incidents of diseases and deterioration of corals worldwide. In this study, bacterial communities associated with four species of corals: Acropora aspera, Acropora formosa, Cyphastrea sp., and Isopora sp. in the healthy and disease stages with different diseases were compared using tagged 16S rRNA sequencing. In total, 59 bacterial phyla, 190 orders, and 307 genera were assigned in coral metagenomes where Proteobacteria and Firmicutes were predominated followed by Bacteroidetes together with Actinobacteria, Fusobacteria, and Lentisphaerae as minor taxa. Principal Coordinates Analysis (PCoA) showed separated clustering of bacterial diversity in healthy and infected groups for individual coral species. Fusibacter was found as the major bacterial genus across all corals. The lower number of Fusibacter was found in A. aspera infected with white band disease and Isopora sp. with white plaque disease, but marked increases of Vibrio and Acrobacter, respectively, were observed. This was in contrast to A. formosa infected by a black band and Cyphastrea sp. infected by yellow blotch diseases which showed an increasing abundance of Fusibacter but a decrease in WH1-8 bacteria. Overall, infection was shown to result in disturbance in the complexity and structure of the associated bacterial microbiomes which can be relevant to the pathogenicity of the microbes associated with infected corals