Research Journal of Engineering and Technology

M. Alamelumangai ¹, J. Dhanalakshmi ¹, M. Mathumitha ¹, R. Saranya Renganayaki ¹, N. Rajalakshmi ²

Affiliations
1 Department of Biotechnology, Kumaraguru College of Technology, Coimbatore - 641 049, IN
2 T. Stanes and Company Limited, Coimbatore – 641 018, IN

Abstract

Polyphenol oxidase or tyrosinase which is universally present in plants, animals, fungi and bacteria, catalyses two different oxidative reactions combining with molecular oxygen. It causes the hydroxylation of monophenols into odiphenols and further oxidation of o- diphenols into o- quinones. Subsequent polymerisation of o- quinones results in the discoloration of tissues and loss of nutrients from fruits and vegetables. In the present study, PPO (E.C number 1.14.18.1) was extracted from banana (Musa paradisiaca) and partially purified by acetone precipitation. The enzyme was found to have high affinity towards its substrate, catechol and the Michaelis Menten constant was observed as 1mM. The optimum pH and temperature of the enzyme were determined to be 5.0 and 50°C respectively. In this study, various plant extracts like Glycyrrhiza glabra, Rubia cordifolia, Hesperethusa crenulata and oil from the seeds of Hydnocarpus laurifolia and purified compounds like Curcumin, Psoralenwere observed to modulate the activity of PPO. These compounds can be used in skin care cosmetics and in the treatment of skin diseases like vitiligo, leucoderma etc.

Keywords

Polyphenol Oxidase, Characterization, Enzyme Activity.

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P. M. Muthukumaran ¹, Alamelumangai ¹, M. Mathumitha ¹

Affiliations
1 Department of Biotechnology, Kumaraguru College of Technology, Coimbatore, Tamil Nadu - 641 049, IN

Abstract

Environmental pollution is one of the major problems of the modern world. Synthetic dyes are extensively used in textile dyeing, paper printing, colour photography, pharmaceutical, food, cosmetics and other industries. Conventional wastewater treatment plants are unable to perform a complete dye removal, 90% of reactive textile dyes persist after activated sludge treatment. Currently, various chemical, physical and biological treatment methods are used to remove color. This study focuses on the biological decolourization of textile effluents through microbial isolates obtained from contaminated sites. The dye effluent samples and soil sample from the dye contaminated sites were collected from CETP, Perundurai. Totally 3 different effluent and soil samples were collected. The isolation of fungal colony from these samples was then carried out and identified as Aspergillus niger. For decolorization studies, three synthetic dyes namely Reactive Red 120 and Reactive Black 5 used and these dyes were prepared at a concentration of 50 mg/100 ml and the decolorization assay mixture consists of 10% of dye. The optimization of the decolorization efficiency was then carried out for the screened fugal isolates. The effect of pH, Temperature, C: N ratio and shaking conditions were studied and these parameters are optimized to obtain maximum decolorization of the commercial dyes using the fungal colonies.

Keywords

Decolorization, Degradation, Reactive Dyes, Aspergillus niger.

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