Phylogenetic Identification and Enzyme Activities of Indigenous Bacteria from a Landfill Stabilization Pond

Abstract

Although several experimental works have been focused on landfill waste/wastewater treatment, no research has been carried out to evaluate the major enzyme activities expressed by indigenous microbiota. In this work, a total of 30 bacterial strains were isolated from a recent operating landfill stabilization pond and were identified by 16S rRNA gene sequencing. The majority of the isolates were phylogenetically related to different species of the genera Paracoccus, Pseudomonas and Aquamicrobium, whereas two bacterial isolates were distantly related to the species Gemmobacter aquatilis and Paenirhodobacter enshiensis (95.1 and 96.3 % similarity, respectively). All the bacterial isolates obtained from the stabilization pond were further examined for their endo- and exocellular β-glucosidase, lipase and protease activities. Protease activities were either undetected or extremely low (below 10 U g−1 protein), while lipase activities were exhibited by only certain bacterial strains. However, almost all bacterial isolates exhibited β-glucosidase activities (half of the isolates exerting activities above 100 U g−1 protein), indicating their β-glycosidic nature. Indeed, the presence of an important cellulose fraction in the effluent may explain the high β-glucosidase activities expressed by the majority of the bacterial strains.