European Journal of Applied Sciences 7 (1): 01-08, 2015 ISSN 2079-2077 © IDOSI Publications, 2015 DOI: 10.5829/idosi.ejas.2015.7.1.9296 Corresponding Author: S. Viswanathan, Department of Microbiology (Government-Aided), India. 1 Studies on the Role of Bacteria in Self Purification of the River Tamirabarani S. Viswanathan, M. Anitha, M. Amuthan, R. Rajesh, P. Veilumuthu and K.R. Narayanan 1 1 1 1 1 2 Department of Microbiology (Government-Aided), India 1 Department of Zoology Sri Paramakalyani College, Alwarkurichi- 627 412, Tamil Nadu, India 2 Abstract: Tamirabarani – A perennial river in South India satisfy the water demand of more than three southern districts in Tamil Nadu. The quality of the river is degraded by diverse pollutants including oil contaminants. Bio surfactants are amphiphillic compounds produced by microbes used for degrading oils. Investigating the ability of surfactant production in microbes help us to understand its self-purification nature. The total viable count in the water sample collected from the river at Kokkirakulam, Tirunelveli was found to be 5.5×10 CFU/ 4 ml. Initial screening methods indicated us that 40 % of the total bacterial isolates were found to be bio surfactant producers. Bacterial identification studies conducted on the positive surfactant producers through basic microbiological and biochemical tests indicated the presence of Pseudomonas aeruginosa and Bacillus subtilis. The efficacy of bio surfactant produced by the two bacterial isolates was checked against commonly used oils such as coconut oil, gingili oil and palm oil and also against glycerol by three methods such as oil displacement method, emulsification index and drop collapse method. Results of the methods employed revealed positive action of the bio surfactant against all the tested samples but more activity was observed on gingili oil followed by coconut oil. Effect of physicochemical parameters such as pH, temperature and carbon and nitrogen source was also investigated on the growth of bio surfactant producing bacteria. Comparative analysis between P. aeruginosa and B. subtilis declared more production of bio surfactant in the initial organism. Thin Layer Chromatography studies exposed a variation in the chemistry of surface active molecules. The biochemistry of the surface active molecules were found to be glycolipid in Pseudomonas sp and lipopeptide in Bacillus sp. Antimicrobial studies of the surface active molecules indicated the presence of bio controlling potential against human bacterial pathogens. The current study helped us to understand the role of microbes in pollution management of the river on its own. Key words: Tamirabarnai River Bio Surfactant Pseudomonas aeruginosa Bacillus subtilis Submerged Fermentation INTRODUCTION Literature survey revealed, no work has been done Water is an important natural resource of earth and distribution in the river so far. plays a vital role in our life. Surface water and groundwater are the major sources of water. Bio Surfactants Are Biological Amphipathic: The surface water qualities of major river basins are Compounds produced by various bacteria, fungi and contaminated by the municipal and industrial discharges moulds [6-7]. They are capable of reducing surface and [1]. River Tamirabarani is well known for its historical and interfacial tension and forming micro emulsion where cultural values is not an exception from quality hydrocarbon can be solubilized in water or where water degradation by pollution. This perennial river satisfy the can solubilize in hydrocarbons [8]. Even though water demand of domestic, agricultural and industries in surfactants of microbial origin find applications in three districts in south Tamil Nadu. Plenty of research different sectors such as cosmetics, food, pharma works have been carried out on determining the physico industries etc. and its role in oil pollution management is and chemical aspects in the water of this river [2-5]. something amazing [9-12]. explaining the bio surfactant producing microbe’s