AGRICULTURAL RESEARCH COMMUNICATION CENTRE www.arccjournals.com/www.ijarjournal.com *Corresponding author’s e-mail: prabhatjatav.94@gmail.com Indian J. Agric. Res., 52(5) 2018: 497-504 Print ISSN:0367-8245 / Online ISSN:0976-058X Antagonistic activity of cellulase enzyme produced by Trichoderma Viride against Xanthomonas Citri Prabhat Jatav, Sonu Singh Ahirwar, Abhishek Gupta*, Kirti Kushwaha and Sadhna Jatav Center for Microbiology and Biotechnology Research and Training Institute, Bhopal-462 003, Madhya Pradesh, India. Received: 23-02-2018 Accepted: 20-08-2018 DOI: 10.18805/IJARe.A-4999 ABSTRACT Citrus canker is a bacterial disease which occurs in citrus (lemon) species produce by Xanthomonas especially X. citri. The infection occurs on the lesions of leaves, stems, and fruits of citrus trees, it also occurs in other plants such as orange, grapes. The main goal of this study was to prevent the lemon (citrus) disease such as citrus canker by using some cellulase enzymes produces by soil fungi. In the present study, we isolated soil fungi Trichoderma viride, which produces cellulase enzyme these have higher antibacterial activities against plant pathogen such as X. citri. This enzyme produced by T. viride by using fermentation method, quantified by DNAS method and used as a bio-control agent against X. citri. They also isolated and characterized X. citri. In the last step of the study they have checked antibacterial activity of cellulase enzyme against X. citri. The present study concluded that cellulase enzyme produced by T. viride shows higher antibacterial activity against X. citri when treated it at 100C. Key words: Antimicrobial activity, Cellulase enzyme, Characterization, Fermentation, Quantification, TLC, Trichoderma, Xanthomonas. INTRODUCTION Lemon has an important value as fruit crop and economically good for farmers. In the 21 st century lemon is delectable, juicy, and has great nutritional significance (Khan et al., 1992). Lemon is a member of citrus family and grown in changeable densities in countries with tropical or subtropical climates. It is used as best source of ascorbic acid (vitamin C), sugars, amino acids and other nutrients (Ahmed and Khan, 1999). Citrus canker is one of the most destructive and predominant disease of acid lime in the world as well as India. In the central region of India citrus canker is one of the most predominant disease which occurs in lemons. In the Sehore district of Madhya Pradesh (India) the disease affects most of the crops of lemon. Citrus canker is a bacterial disease that causes lesions on the leaves, stems, and fruit of plants including citrus and other plants like orange, grapes in the Rutaceae family. The disease does not affects human, this is plant disease mainly affect the crops of lemon. The symptoms of the disease consist of brown spots on leaves, often with an oily or water-soaked appearance. Disease of lemon is usually spotted on fruit peel and leaf surface but when the atmosphere is very favorable for contamination, the infections spread in whole plant parts. The citrus canker caused by the bacteria X. Citri, this is a gram’s negative, rod-shaped bacteria with polar flagella. The bacterium has a genome length of around 5 mega-base pairs. The growth of this bacterium is obligatorily aerobic, and the optimum temperature for growth is 35C to 39C (Mehrotra, 1980; Whiteside, et al 1988). They have capability to form a biofilm for connection on the host; the biofilm ensures the virulence and epiphytic survival of X. citri earlier to the increase of citrus canker. They have the capability to form a biofilm to makes the connection on the host; the biofilm ensures the virulence and epiphytic survival of X. citri earlier to the increase of citrus canker. The effecter interacts through host machinery to make transcription used for genes that control plant hormones such as auxin and gibberellin (Pereira et al., 2014). The species of Trichoderma is a hyper-parasitic pathogenic fungi which have highly efficient antagonist activity (Barnett and Binder, 1973; Durrell et al., 1968). Trichoderma is commonly present in the soil, especially waterlogged soil, dung and decaying plant materials, and familiar because of its antagonistic action and involvement in food processing and biodegradation. To get rid of citrus canker disease they have used T. viride as a bio-control agent and produced cellulase enzyme by T. viride, it is a green mold which is commonly fungi found in soil. It can produce a variety of enzymes, inclu ding cellulase and chitinase which can degrade cellulose and chitin respectively. Cellulase enzyme has become the important biocatalysts due to their complex nature and large spread industrial applications. Cellulase is composed of separately folding, structurally and functionally discrete units called domains or modules, production cellulase module (Henrissat et al., 1998). Cellulase enzyme is inducible enzymes synthesized by a large diversity of