~ 194 ~ ISSN Print: 2617-4693 ISSN Online: 2617-4707 IJABR 2024; SP-8(1): 194-197 www.biochemjournal.com Received: 08-11-2023 Accepted: 16-12-2023 Chaitra Lakkannavar Department of Agricultural Microbiology, UAS Raichur, Karnataka, India Mahadeva Swamy Department of Agricultural Microbiology, UAS Raichur, Karnataka, India Nagraj Naik Department of Agricultural Microbiology, UAS Raichur, Karnataka, India Ramesh YM Department of Agronomy, ARS Dhadesugur, UAS Raichur, Karnataka, India Gundappagol Department of Agricultural Microbiology, UAS Raichur, Karnataka, India Corresponding Author: Chaitra Lakkannavar Department of Agricultural Microbiology, UAS Raichur, Karnataka, India Screening of Bacillus spp. for its plant growth promoting potential Chaitra Lakkannavar, Mahadeva Swamy, Nagraj Naik, Ramesh YM and Gundappagol DOI: https://doi.org/10.33545/26174693.2024.v8.i1Sd.306 Abstract Bacillus spp. are known to influence the crop plants by variety of direct and indirect mechanisms. A total of 20 bacteria were isolated from rhizosphere region of Raichur and Gulbarga districts and characterized morphologically and biochemically. Further, the isolates were screened for the plant growth promoting activities like Indole Acetic Acid production, P solubilization, Siderophore production. By the production of these traits the result shows that rhizosphere Bacillus spp are promising source for the plant growth promotion. Keywords: Bacillus, Rhizosphere, IAA, Siderophore, P solubilizaton Introduction Intensive agriculture has not benefited from the use of inorganic fertilizer since it is frequently linked to decreased crop yield, acidic soil, and nutrient imbalance. Repeated application of inorganic fertilizers contributes to soil degradation caused by the loss of organic matter that comes with continuous cropping. It has been proven that inoculating various crop plants with phosphate-solubilizing microorganisms increases their P-uptake and yield (Asea et al., 1988) [2] . It is reported that the addition of organic matter increases the efficacy of phosphate solubilizers (Banik and Dey, 1985) [6] . Therefore, we need to create microbial consortia that will improve nutrient uptake and enhance Ragi's growth and yield in order to reduce our dependence on chemical fertilizers. Plant Growth Promoting Rhizobacteria (PGPR) are a diverse group of soil bacteria that invade plant roots and, via various mechanisms, increase the activity of plant growth promotion. Direct and indirect mechanisms can be used to categorize these various mechanisms. PGPR either directly affect plant growth by promoting nutrient cycling processes like biological nitrogen fixation, siderophore production, phosphorus solubilization, and phytohormone synthesis, or indirectly by producing biocontrol compounds that inhibit phytopathogens. Bacillus species promote plant growth and control plant pathogens through a combination of strategies including antibiosis, competition, mycoparasitism, and systemic resistance in the host plant. Due to their involvement in the synthesis of defense-related enzymes like peroxidase, polyphenol oxidase, and phenylalanine ammonia lyase, which promote systemic resistance, these mechanisms may function alone or in combination (Bais et al., 2004) [5] . Furthermore, it is known that they secrete extracellular lytic enzymes, such as β1, 3 glucanase, chitinase, amylase, protease, lipase, and Xylanase, which exhibit antagonistic properties due to the breakdown of bacterial and fungal cell walls (Aliye et al., 2008) [1] . Although Bacillus species are widely distributed in nature, they can be found more in soil, water, and plant-based food products. Bacillus strains make excellent candidates for usage as probiotics. Bacillus species are highly metabolically active, and past studies have found that they produce a wide range of useful enzymes as well as antibiotics. Because Bacillus can form endospores, they stay stable in probiotic products for a longer period of time than conventional probiotics. This is in addition to their secreted products. International Journal of Advanced Biochemistry Research 2024; SP-8(1): 194-197