Antagonistic and Antibiotic Effects of Endophytic and Rhizobacteria of Sugarcane Plant at Wonji Sugar Estate, Ethiopia
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Date
2013-06-06
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Addis Ababa University
Abstract
The thesis targeted to identify the endophytic, (leaf and root) and rhizobacteria of three sugarcane sample plants taken from different sites of Wonji sugar estates plantation. Accordingly, leaf and root samples cleared of surface bacteria by chemical sterilization, crushed using sterile mortar and pestle and the extract plated on nutrient agar media. The soil samples were also sieved and serially diluted from 10-1 -10-6 and 100µl of the solution spread plated on nutrient agar media. A total of 40 representative isolates were identified based on standard morphological characterization. These isolates were sub cultured for purity and preserved on nutrient agar slant for future use in different testes: Antagonism, Antibiotic effect and development of serological methods of screening of the isolates. The identification of the isolates was done in two steps. First, grouping of the isolates by morphological, physiological and Biochemical tests and second, sorting of the groups that had more than one genera in to the specific genus was done by Busnson’s method. The result showed 11 genera, the dominant of which were Shigella, Bacillus and Klebsiella. Antagonstic interactions between all the isolates revealed 22 of them were susceptible to 18 isolates that had inhibitory effects. The test for antibiotic effect of isolates against four human pathogenic bacteria: E. coli, Salmonella thyphimurium, Staphylococcus aureus and Streptococcus pneumonae showed 18 isolates with anti-biotic effects ranging from 10-17mm clear zone diameter. This was less sensitive compared to the positive control antibiotics, chloranphenicol and ampicillin. The serological method development for screening of the isolates was started by SDS-PAGE fractionation of the proteins and induction of antibodies in swiss albino mice shall be tested as soon as the conjugated antibodies arrive. The potential use of the identified isolates; in sustainable agriculture, environmental protection and animal and human benefits are discussed in detail.
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Sugarcane, Biofertilizer, Endophytes, PGPB, Root Exudates, Rhizosphere and Bacteria in the Rhizosphere