Mangrove health shapes lignocellulolytic bacterial communities.

Abstract

The process of lignocellulosic biofuel production needs enzymes that are resistant to high temperatures and low pH. The mangrove sediments, which are typified by variable conditions, can contain bacteria that synthesize intrinsically steady enzymes. We selected 193 bacterial isolates of 12 mangrove sites in Goa, India and tested them to produce lignocellulolytic enzymes (cellulase, laccase, xylanase, xylose isomerase) under the conditions of neutral (37°C, pH 7), acidic (37°C, pH 5), thermophilic (50°C, pH 7), and combined stress (50°C, pH 5). Bacillus and Vibrio dominated, with 22 genera identified. There were no significant differences in alpha diversity following Benjamini-Hochberg FDR correction (all P_adj = 1.00, Cohen d < 0.5) but significant compositional differentiation in beta diversity (PERMANOVA: R² = 0.243, P = 0.017). Salinity (R² = 0.903, P_adj = 0.003) and temperature (R² = 0.722, P_adj = 0.006) were major structuring factors. Site-type differentiation was the most significant factor in xylanase-producing communities (R² = 0.272, P = 0.013). Although there was limited replication of dead sites (n = 3), the results confirmed that candidates undergo biochemical characterization and that ecosystem degradation does not decrease diversity but alters community composition.