Characterization of culturable bacteria from pulp and paper industry wastewater, with the potential for degradation of cellulose, starch, and lipids

Abstract

The search for microbial enzymatic activities applied to wastewater treatment is an important task in environmental biotechnology. Microbial enzymes have been previously explored in hostile habitats. They are increasingly important in extreme habitats; biological wastewater from the pulp and paper mill industry can harbor microorganisms with valuable enzymatic capabilities that can improve the efficiency for the same process of depuration. This study was performed to characterize and evaluate cellulolytic, amylolytic, and lipolytic activities of bacteria isolated from a pulp and paper effluent. The enzymatic activities were evaluated by the formation of a clear halo around the colonies in defined substrate media. By the use of a sequence analysis of 16S rDNA libraries, isolates were identified. The 16S rDNA libraries belong to the Bacillus subtilis, B. megaterium, B. licheniformis, B. pumilus, B. thuringiensis, B. cereus, Chryseobacterium daecheongense, and Microbacterium sediminis (an alkali-tolerant bacteria which has only been isolated from deep-sea sediment). B. cereus was the best strain for cellulose and lipase activities; moreover, C. daecheongense was best for amylase activity. The present study shows that the aerated lagoons from the pulp and paper industry are a promising source of bacterial with different enzyme activities. This data is relevant for industrial applications.