Shripad N. Surwase

Ecofriendly degradation, decolorization and detoxification of textile effluent by a developed bacterial consortium

Present study illustrates the effectual decolorization and degradation of the textile effluent using a developed bacterial consortium SDS, consisted of bacterial species Providencia sp. SDS and Pseudomonas aeuroginosa strain BCH, originally isolated from dye contaminated soil. The intensive metabolic activity of the consortium SDS led to complete decolorization of textile effluent within 20 h at pH 7 and temperature 30°C. Significant induction in the activities of veratryl alcohol oxidase, laccase, azoreductase and DCIP reductase were observed during decolorization, which indicates their involvement in decolorization and degradation process. The decolorization and biodegradation was monitored using UV-vis spectroscopy, IR spectroscopy, HPLC and HPTLC analysis. Toxicological analysis of effluent before and after treatment was performed using classical Allium cepa test. Investigations of various toxicological parameters viz, oxidative stress response, cytotoxicity, genotoxicity and phytotoxicity, collectively concludes that, the toxicity of effluent reduces significantly after treatment with consortium SDS.

Optimization of l‐DOPA production by Brevundimonas sp. SGJ using response surface methodology

l‐DOPA (3,4‐dihydroxyphenyl‐l‐alanine) is an extensively used drug for the treatment of Parkinsons disease. In the present study, optimization of nutritional parameters influencing l‐DOPA production was attempted using the response surface methodology (RSM) from Brevundimonas sp. SGJ. A Plackett–Burman design was used for screening of critical components, while further optimization was carried out using the Box–Behnken design. The optimized levels of factors predicted by the model were pH 5.02, 1.549 g l−1 tryptone, 4.207 g l−1 l‐tyrosine and 0.0369 g l−1 CuSO4, which resulted in highest l‐DOPA yield of 3.359 g l−1. The optimization of medium using RSM resulted in a 8.355‐fold increase in the yield of l‐DOPA. The anova showed a significant R2 value (0.9667), model F‐value (29.068) and probability (0.001), with insignificant lack of fit. The highest tyrosinase activity observed was 2471 U mg−1 at the 18th hour of the incubation period with dry cell weight of 0.711 g l−1. l‐DOPA production was confirmed by HPTLC, HPLC and GC‐MS analysis. Thus, Brevundimonas sp. SGJ has the potential to be a new source for the production of l‐DOPA.

Bioremediation Perspective of Navy Blue Rx–Containing Textile Effluent by Bacterial Isolate

ABSTRACT The aim of the present study was to investigate the textile effluent degrading potential of an isolated bacterium, Proteus sp. SUK7. The strain had the capacity to decolorize Navy Blue Rx–containing textile effluent up to 83% within 96 h. The maximum decolorization was observed under static conditions at pH 7.0 and 30°C. Reduction in the chemical oxygen demand (COD) and biological oxygen demand (BOD) of textile effluent was observed after treatment with Proteus sp. SUK7. Induction in the activities of laccase and aminopyrine N-demethylase was observed after decolorization, which indicates involvement of these enzymes in the decolorization process. The presence of various inducers was also found to have a modulatory effect on enzyme activities and the decolorization process. Biodegradation was confirmed using various analytical techniques, such as ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR), gas chromatography–mass spectrometry (GC-MS), and high-performance liquid chromatography (HPLC). A phytotoxicity study was performed to confirm the nontoxic nature of the degradation metabolites.