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

ISOLATION, SCREENING AND CHARACTERIZATION OF L-ASPARAGINASE PRODUCING FUNGI FROM MEDICINAL PLANTS

Objective: To isolate and characterize of L-asparaginase producing fungi from medicinal plants.Methods: Fungal strains were isolated on standard media, characterized and were screened for their ability to produce L-asparginase, used in the treatment of certain types of cancers, using modified Czapek-Dox medium supplemented with L-asparagine.Results: A total of 10 fungal isolates were obtained from 3 plant leaf samples and two isolates exhibited significant L-aspargniase production. Fusarium sp. (SMGR-F1) isolated from the papaya leaves showed the maximum activity. The organism was grown under submerged fermentation conditions at 30 °C produced 111.07±1.53 IU/ml of L-asparaginase at 120 h.Conclusion: L-asparaginase is being effectively used for the treatment of acute lymphoblastic leukemia and tumor cells. Fusarium sp. was isolated from the papaya plant leaves showing significant L-asparaginase activity and thus can be further exploited for the commercial production of L-asparaginase.Â

Bioleaching of copper from chalcopyrite ore by fungi

319-324Microorganisms have been geologically active in mineral formation, mineral diagenesis and sedimentation via direct action of their enzymes or indirectly through chemical action of their metabolic products. This property of microorganisms is being harnessed during the recent years for extraction of metals from their ores, especially from low-grade ores. In the present study bioleaching of copper from its low-grade chalcopyrite ore using 26 isolates of acidophilic fungi is reported. Most of these fungal strains belonged to the genera Aspergillus, Penicillium and Rhizopus. The leaching experiments were conducted in Czepek Dox minimal medium containing 1% (100 mesh) ore with shaking at room temperature for 20 days. Out of these, 4 isolates exhibited significant bioleaching activities. Maximum leaching of copper (78 mg/L) was observed with Aspergillus flavus (DSF-8) and Aspergillus niger (DOF-1). Nutritional and environmental conditions for optimum bioleaching were standardized. Present study indicates the usefulness of acidophilic fungi in bioleaching of copper from its low-grade ores.</span

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