Phenotypic and phylogenic groups to evaluate the diversity of Citrobacter isolates from activated biomass of effluent treatment plants
ABSTRACT The diversity of Citrobacter isolated from effluent treatment plants (ETPs) was studied using three different parameters. Thirty Citrobacter strains were isolated from different ETPs treating wastewaters generated at various industries. All the isolates were characterized based on biochemical tests, antibiotic assay/functional analysis, and phylogenetic analysis. Results demonstrated that the pattern of grouping varied based on the selected criteria for analysis. Species that clustered together by biochemical analysis were found to vary by functional and 16S rDNA analysis and vice versa. This suggests that multiple methods approach needs to be carried out to understand the microbial diversity. Bacteria in effluent treatment plants are exposed to diverse categories of pollutants. Salicylate is a key intermediate formed during biodegradation of several aromatic compounds, a scenario expected in ETPs. Hence, the Citrobacter isolates were screened for their capability to utilize salicylate. In future studies, these isolates can be incorporated in a bioremediation program.
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- "However, there are differences in metabolic capacities within a single species as can be seen in different strains of C. amalonaticus (Table 1). Bacteria in the Citrobacter genus are typical inhabitants of industrial wastewaters and able to degrade aromatic compounds with different efficiency (Selvakumaran et al., 2008). "
ABSTRACT: The wastewater originating from simultaneous production of styrene and propylene oxide (SPO) is classified as highly polluted with chemical oxygen demand level in the range 5965 to 9137mgL(-1)-as well as highly toxic. The dilution factor providing for a 10 percent toxic effect of wastewater samples in a test with Paramecium caudatum was 8.0-9.5. Biological approach for pretreatment and detoxification of the wastewater under full-scale bioreactor conditions was investigated. The number of suspended microorganisms and the clean up efficiency were increased up to 5.5-6.58×10(8)CFUmL(-1) and 88 percent, respectively during the bioreactor's operation. Isolates in the Citrobacter, Burkholderia, Pseudomonas, and Paracoccus genera were dominant in the mature suspended, as well as the immobilized microbial community of the bioreactor. The most dominant representatives were tested for their ability to biodegrade the major components of the SPO wastewater and evidence of their role in the treatment process was demonstrated. The investigated pretreatment process allowed the wastewater to be detoxified for conventional treatment with activated sludge and was closely related to the maturation of the bioreactor's microbial community.Ecotoxicology and Environmental Safety 07/2014; 108C:195-202. DOI:10.1016/j.ecoenv.2014.07.012 · 2.76 Impact Factor
Conference Paper: A maximum likelihood approach to harmonics measurements in power systems[Show abstract] [Hide abstract]
ABSTRACT: Estimating the amplitudes and phases of the harmonic components of one or three-phase currents (and voltages) is required for efficient active power filtering. In this paper, we propose a new approach based on the maximum likelihood principle. This estimation is unbiased and reaches the lowest statistical variance. Moreover, its computational burden is shown to be weaker than for any other method. Two algorithms are also derived to track slowly-varying nonstationary harmonic signalsComputers in Power Electronics, 1994., IEEE 4th Workshop on; 09/1994