Bioremedation of Industrial Effluent using Immobilized Cells of Halotolerant Marine Bacterium

M. Jayaprakashvel^1,3*, R. Divyalakshmi², M. Venkatramani¹, S. Vinothini¹, R. Muthezhilan¹ and A. Jaffar Hussain^1,3

¹Department of Marine Biotechnology, AMET University 135, East Coast Road, Kanathur, Chennai - 603112, India ²Department of Microbiology, AVC College of Arts and Science, Mannampandal, Mayiladuthurai - 609305, India ³Centre for Marine Bioprospecting, AMET University 135, East Coast Road, Kanathur, Chennai - 603112, India.

DOI : http://dx.doi.org/10.13005/bbra/1393

ABSTRACT: Dyes are the major toxic substances in all industrial wastewater and are highly carcinogenic to human beings and other soil and water living things. In this present study, 52 halophilic bacterial strains were isolated from water and sediments samples collected from Kelambakkam and Marakkanam salterns, nearby East Coast of Tamil Nadu, India and they were designated with unique codes as AMETH101 to AMETH152. They were screened for their ability to produce hydrolytic enzymes such as protease, lipase and tannase enzymes. On comparison, three strains namely, AMETH111, AMETH132 and AMETH148 have exhibited all of the enzyme activities tested and they were chosen to test their ability in decolorization of five different textile dyes namely Black’B’ , Yellow MR , Red BSID , Blue M2R and Torque Blue ‘G’. Among the three halophilic bacterial strains, AMETH148 exhibited 93.61% decolorization in Black-B, 68.74% decolorization in Yellow-MR, 72.84% in Torque Blue ‘G’, 91.27% Red BSID and 92.26% in Blue M2R compared to other two isolates and hence chosen for immobilization and further study. The halotolerant strain AMETH148 was immobilized with calcium alginate and dye decolorization experiments were conducted. After immobilization, there was a good improvement in decolorization percentage by the strain, as compared to their free cell counterparts and it was concluded that AMETH148 was the most efficient of all the bacterial strains in decolorizing all the five textile dyes. Decolorized dye solutions were subjected to plant growth promotion studies to determine to understand the level of bioremediation or detoxification. All the decolorized dye solutions were found to enhance the seed germination and seedling growth parameters of four different crop plants such as, Green gram (Vigna radiata), Black gram (Vigna mungo), Wheat (Triticum aestivum) and Paddy (Oryza sativa). This confirms that the treated dyes had no phytotoxic effect on crop plant seedlings. This study concluded the potential of halotolerant marine bacterium AMETH148 as a suitable candidate for the decolorization and bioremediation of textile dyes.

KEYWORDS: Hypersaline environment; Halotolerant bacteria; bioremediation; immobilization; plant growth promotion

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