ISOLATION AND IDENTIFICATION OF ANTIBIOTIC PRODUCING MICROORGANISMS FROM WHEAT RHIZOSPHERIC SOIL

Multidrug resistance of bacteria is the major global healthcare problem in the post-golden era of antibiotics. Initially, the multidrug resistance (MDR) of the bacteria was associated with hospitalized patients, specifically immunosuppressed and ICU patients. But, now a days MDR has become a common problem in most patients and it is difficult to identify and cure. The molecular mechanism of multidrug resistance is very complex and it is mostly associated with the presence of resistant plasmid or transposon, or due to the action of multidrug efflux pump activated by increased expression of genes or enzymatic inactivation of drug, etc. To overcome these scenarios there is a need to search for novel antibiotics. In the present investigation, the antibiotic-producing microorganisms were isolated from wheat rhizospheric soil by using the crowded plate method and screened further against pathogens by the Giant plate technique. Among the five soil samples screened, only one soil sample from the wheat rhizospheric region has shown the zone of inhibition. The organism was then purified and checked for antagonistic activity by cross streak method using pathogens such as Escherichia coli, Pseudomonas, Salmonella typhi, Klebsiella, and Staphylococcus aureus. The molecular identification of the isolate was done by using 16s rRNA sequence analysis. The outcome demonstrated that the isolated organism belonged to the genus Bacillus spizizenii NRRL B-23049(T), which was its 100% closest neighbor. The detected organism’s nucleotide sequence was submitted to GenBank under accession number PP911443. Thus, in the present investigation, we tried to find a new antimicrobial compound-producing microorganism from wheat rhizospheric soil.