Isolation and Characterization of Paracoccus

A potential bacterial strain GSM2, capable of degrading an azo dye Reactive Violet 5 as a sole source of carbon, was isolated from textile mill effluent from Solapur, India. The 16S rDNA sequence and phenotypic characteristics indicated an isolated organism as Paracoccus sp. GSM2. This strain exhibited complete decolorization of Reactive Violet 5 (100 mg/L) within 16 h, while maximally it could decolorize 800 mg/L of dye within 38 h with 73% decolorization under static condition. For color removal, the most suitable pH and temperature were pH 6.0–9.0 and 25–40°C, respectively. The isolate was able to decolorize more than 70% of five structurally different azo dyes within 38 h. The isolate is salt tolerant as it can bring out more than 90% decolorization up to a salt concentration of 2% (w/v). UV-Visible absorption spectra before and after decolorization suggested that decolorization was due to biodegradation and was further confirmed by FT-IR spectroscopy. Overall results indicate the effectiveness of the strain GSM2 explored for the treatment of textile industry effluents containing various azo dyes. To our knowledge, this could be the first report on biodegradation of Reactive Violet 5 by Paracoccus sp. GSM2

Drug susceptibility profiles of Mycobacterium tuberculosis isolates from Gulbarga, South India

Aim of the work: Drug resistance surveillance is a useful tool to assess the effective functioning of tuberculosis (TB) control program. This study was undertaken to know the first line anti tuberculosis drug susceptibility profile of Mycobacterium tuberculosis clinical isolates from the Gulbarga district of South India. Methods: Drug susceptibility test was performed for 102 clinical isolates of M. tuberculosis belonging to new (n = 62), treated (n = 22) and unknown treatment category (n = 18) of TB. All the isolates were tested for susceptibility to first line anti-tuberculosis drugs by minimum inhibitory concentration (MIC) and resistance ratio method (for streptomycin). Results: The susceptibility profile of M. tuberculosis to all five first line anti-tubercular drugs was found to be 60.78% (62/102). Overall, multi drug resistance (resistance to at least isoniazid and rifampicin) was observed in 8.82% (9/102) isolates and was found to be higher for treated cases (18.18%). Conclusions: High level of drug resistance observed in new cases for isoniazid, rifampicin and ethambutol suggests need for the implementation of drug resistance surveillance studies in order to document the success of the tuberculosis control program in reducing the level of drug resistance