Bacterial Diversity in Two Aerated Lagoons of a Pulp and Paper Effluent and their Interaction with a Commercial Inoculum using PCR-DGGE

Abstract

Aerated lagoons are a main unit operation for wastewater treatment in the paper industry. Many such operations involve inoculation with bacterial formulations in which in situ effectiveness has not been proven; this can be translated into low efficiency in treatment and unnecessary investments. Lack of knowledge of bacterial biodiversity present in a lagoon limits the capacity to exploit the maximum degradation. To overcome such problems, various methods to identify and study these microorganisms have been developed. In this study, a PCR-DGGE analysis was performed to estimate the bacterial diversity and to verify the presence of bacteria present in a commercial inoculum in two aerated lagoons of a pulp and paper effluent. Phylogenetic affiliation of predominant member's correspondent to γ-and β-proteobacteria and Firmicutes were found. The dominant bacteria present in lagoon 2 belonged to the following genus Microbacterium sp. Rhodocyclaceae sp., Eubacterium sp. and B. subtilis. In lagoon 1 the dominant genus included Microbacterium sp., Rhodocyclaceae sp. Tepidimonas sp., Acetanaerobacterium sp., and Flavobacteria sp. The two characterized lagoons were not similar to the commercial inoculum. In addition, nondominant bacteria (less relative intensity) were composed mostly of bacteria of the commercial inoculum.

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

“…The amplification reactions were performed in a total volume of 50 μL containing 300 ng of DNA, 5 μL of PCR buffer, 2.5 U of polymerase, 1 μL (100 pmol) of each primer, 3 μL MgCl2 (1.5 mM), 1 μL of dNTP mixture (200 µM), and H2O Milli-Q. The amplification reactions were performed in a thermal cycler (BioRad® T100, Hercules, CA, USA) using the conditions reported by Bailón-Salas et al (2017). All amplicons were analyzed on 1% agarose gels to confirm the fragment size; PCR products were purified with the (Promega, Fitchburg, WI, USA).…”