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Microbial diversity in tanning wastewaters treatment reactors
Author(s) -
Mlaik Najoua,
Bakonyi Jozef,
Borsodi Andrea,
Woodward Steve,
Belbahri Lassaad,
Mechichi Tahar
Publication year - 2014
Publication title -
environmental progress and sustainable energy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.495
H-Index - 66
eISSN - 1944-7450
pISSN - 1944-7442
DOI - 10.1002/ep.12000
Subject(s) - activated sludge , biomass (ecology) , biology , library , proteobacteria , microorganism , 16s ribosomal rna , bacteria , microbiology and biotechnology , bacilli , diversity index , sewage treatment , food science , ecology , environmental science , environmental engineering , species richness , genetics
Diversity of the microbial consortia involved in biodegradation of unhairing wastewater from tanneries was assessed. Both culture‐dependent and culture‐independent approaches were applied to identify bacteria in the activated sludge and endogenous biomass systems. Conventional culturing using dilution and planting techniques yielded eighteen pure bacterial isolates from endogenous biomass and activated sludge reactors. Isolates were identified using sequence analysis of PCR‐amplified 16S rRNA sequences. Most of these bacteria belonged to the genus Bacillus . Culture‐independent molecular studies of bacterial diversity in both reactors, however, revealed a wide diversity of microorganisms, including members of the Proteobacteria group. Therefore, the alpha Proteobacteria group in the endogenous biomass was characterized by the genus Pseudochrobactrum , which was absent from the activated sludge biomass. The 77 and 88 bacterial clone sequences recovered from the activated sludge reactor and the endogenous biomass reactor, respectively, were grouped into 23 Operational Taxonomic Units (OTUs). The Proteobacteria division represented the predominant phylogenetic group within the clone library, encompassing 52.17% and 60.75% of the total OTUs obtained from the activated sludge and endogenous biomass tanks, respectively. The diversity in both tanks was also determined. The rarefaction curves and Shannon index indicated that bacterial populations were equally diverse in both reactors. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 401–410, 2015