*Corresponding Author: P.Saranraj, Email: microsaranraj@gmail.com, Phone No: +91-9994146964 ISSN 0976 – 3333 ORIGINAL RESEARCH ARTICLE Available Online at www.ijpba.info International Journal of Pharmaceutical & Biological Archives 2012; 3(5):1077-1084 Effect of Bacterial Isolates on Reduction of Physico – Chemical Characteristics in Sugar Mill Effluent P.Saranraj* and D.Stella Department of Microbiology, Annamalai University, Chidambaram – 608 002, Tamil Nadu, India Received 10 Jun 2012; Revised 28 Sep 2012; Accepted 08 Oct 2012 ABSTRACT Environmental pollution has been recognized as one of the major problems of the modern world. Sugar industry is one of the most important agro based industries in India and is highly responsible for creating significant impact on rural economy in particular and countries economy in general. The sugar industry is playing an important role in the economic development of the Indian sub continent, but the effluents released produce a high degree of organic pollution in both aquatic and terrestrial ecosystems. They also alter the physico-chemical characteristics of the receiving aquatic bodies and affect aquatic flora and fauna. In the present study, the effect of bacterial isolates on the reduction of physico – chemical characteristics in sugar mill effluent was investigated. The sugar mill effluent was bioremediated by using the bacteria isolated from sugar mill effluent. Maximum reduction of physico – chemical characteristics was observed in the Bacillus subtilis followed by Serratia marcescens, Enterobacter asburiae, Pseudomonas fluorescens, Bacillus weihenstephanensis, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Brevibacterium halotolerance whereas Proteus mirabilis showed least reduction of physico - chemical characteristics in sugar mill effluent. Key words: Sugar mill effluent, Physico-chemical properties, Bioremediation and Bacterial. 1. INTRODUCTION Sugar industry is backbone of rural, agricultural and socioeconomic development in India. Many industries are directly or indirectly dependent on sugar industry which in turn is responsible for overall development of state in this context sugarcane production is of vital importance for its products and by-products. Disposal of industrial waste is the major cause of soil pollution. Number of chemical industries, mainly tannery, paper, textiles, atomic and electric power plants discharge pollutants. They content organic and inorganic as well as non biodegradable material touch toxic chemicals affect the soil parameters and there by the soil fertility. Sugar factory effluent has an obnoxious odour and unpleasant colour when released into the environment without proper treatment. Farmers have been using these effluents for irrigation, and found that the growth, yield and soil health were reduced. Contaminants, such as chloride, sulphate, phosphate, magnesium and nitrate, are discharged with the effluent of various industries, which create a nuisance due to physical appearance, odour and taste. Such harmful water is injurious to plants, animals and human beings. The effects of various industrial effluents on seed germination, growth and yield of crop plants have captivated the attention of many workers [1, 2] Diverse sugar industry effluents disposed of in soil and water cause major pollution problems. The sugar industry plays an important role in the economic development of India, but the effluents released produce a high degree of organic pollution in both aquatic and terrestrial ecosystems . [3] . The effluents also alter the physico-chemical characteristics, and flora and fauna of receiving aquatic bodies. In addition, sugar factory effluent discharged in the environment poses a serious health hazard to the rural and semi-urban populations that use stream and river water for agriculture and domestic purposes. Fish mortality and damage to paddy crops due to sugar industry waste-waters entering agricultural land have been reported [4] . Sugar factory effluent that has not been treated properly has an unpleasant odor when released into the