Antimicrobial Properties of Actinomycetes Isolated from Menengai Crater in Kenya

作     者：Paul Njenga Waithaka Francis B. Mwaura John M. Wagacha Eliud M. Gathuru Benson M. Githaiga 

作者机构：School of Biological Sciences University of Nairobi Nairobi Kenya Department of Biological Sciences Egerton University Njoro Kenya 

出 版 物：《CellBio》 (细胞生物学（英文）)

年 卷 期：2017年第6卷第2期

页      面：13-26页

学科分类：1002[医学-临床医学] 100214[医学-肿瘤学] 10[医学] 

主　　题：Actinomycetes Antimicrobials Crater Menengai Metabolites Sensitivity 

摘      要：A study was carried out to isolate and screen actinomycetes for antimicrobials from Menengai Crater in Kenya. The actinomycetes were isolated using starch casein agar, Luria Bertani agar and starch nitrate agar. Primary screening for antagonism was carried out using perpendicular method while secondary screening was done using agar disk technique. Extraction of the antimicrobials was carried out using ethyl acetate. Sensitivity testing of the crude extracts against Staphylococcus aureus, Bacillus subtilis, Escherichia faecalis, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Xanthomonas campestris, Erwinia carotovora, Candida albicans, Alternaria alternate and Fusarium oxysporum was carried out using agar well technique. Biochemical tests and carbon source requirements were used in characterization of the selected antimicrobial producers. M1 was the best agar medium for isolation of actinomycetes. The number of actinomycetes from regions A, B, C, and D in the crater varied significantly (F = 27.50 P = 0.000). Out of the 156 actinomycetes isolates, 20 isolates were positive for both primary and secondary screening for antimicrobials. There was no significant difference in the zones of inhibition in primary screening of the actinomycetes for antagonistic properties against the test pathogens (F = 1.6957 P = 0.0838). The zones of inhibition after secondary screening varied significantly (F = 2.4473 P = 0.0089). Likewise, there was a significant difference (F = 6.6046 P = 0.001338) in the zones of inhibition after exposing the pathogens to ethyl extracts of the selected antagonistic actinomycetes. There is need to purify and characterize the antimicrobials obtained from the present study.