Elias Firew, Muddada Sudhamani, Muleta Diriba, Tefera Belachew
Department of Biotechnology, Koneru Lakshmaiah Education Foundation, Vaddesswaram, AP, India.
Animal Products Veterinary Drugs and Feed Quality Control Centre, Addis Ababa, Ethiopia.
Adv Pharmacol Pharm Sci. 2022 Jun 13;2022:1724906. doi: 10.1155/2022/1724906. eCollection 2022.
The study was undertaken to isolate, screen, and identify actinomycetes with antimicrobial metabolites. Twenty-one composite soil samples were randomly collected from various unique agroecological niches in the Rift Valley of Ethiopia. The soil samples were serially diluted and spread on starch casein agar medium supplemented with 50 g/ml cycloheximide and 25 g/ml nalidixic acid. Two hundred and forty-nine (249) actinomycetes cultures were isolated and screened by cross streaking against various human pathogens. Twenty-four isolates with pronounced antimicrobial activity were selected for identification and further screening. Among the isolates, 172 (69.1%) showed antimicrobial activities against tested pathogens. The inhibition zone of the isolates ranged from 5 ± 0.31 to >40 mm during primary screening. The antimicrobial activity of the crude extracts of promising isolates showed a statistically significant difference ( < 0.05) between them and the control. The isolates RVE129 and RVE217 showed the maximum zone of inhibition at 27 ± 0.6 mm and 26 ± 0.6 mm, respectively, against . , and the results were higher than the standard drug streptomycin (25 ± 0.58 mm). The inhibition zone of crude extracts from RVE129 was at the maximum of 22 ± 0.0 mm against . , almost comparable to the standard drug streptomycin (24 ± 0.58 mm). Crude extract from the isolates RVE129 and RVE187 showed higher inhibition zones of 22 ± 0.6 mm and 16 ± 0.33 mm against . ATCC10535, which, however, were smaller than those obtained with the standard drug amphotericin B (29 ± 0.6 mm). Twenty-four actinomycete strains with remarkable bioactivity were characterized using various cultural, morphological, physiological, and biochemical characteristics and assigned under the genus . The finding of the current study indicates that sp. isolated from the Rift Valley of Ethiopia was found to possess a broad spectrum of bioactivity against a range of human pathogens.
本研究旨在分离、筛选和鉴定具有抗菌代谢产物的放线菌。从埃塞俄比亚裂谷不同独特的农业生态位随机采集了21份复合土壤样本。将土壤样本进行系列稀释，然后涂布在添加了50μg/ml放线菌酮和25μg/ml萘啶酸的淀粉酪蛋白琼脂培养基上。分离并筛选了249株放线菌培养物，通过与各种人类病原体交叉划线进行筛选。选择了24株具有显著抗菌活性的分离株进行鉴定和进一步筛选。在这些分离株中，172株（69.1%）对测试病原体表现出抗菌活性。在初次筛选期间，分离株的抑菌圈范围为5±0.31至>40mm。有前景的分离株粗提物的抗菌活性与对照之间存在统计学显著差异（P<0.05）。分离株RVE129和RVE217分别对……显示出最大抑菌圈，分别为27±0.6mm和26±0.6mm，结果高于标准药物链霉素（25±0.58mm）。RVE129粗提物对……的抑菌圈最大为22±0.0mm，几乎与标准药物链霉素（24±0.58mm）相当。分离株RVE129和RVE187的粗提物对……ATCC10535显示出较高的抑菌圈，分别为22±0.6mm和16±0.33mm，然而，这些抑菌圈小于标准药物两性霉素B（29±0.6mm）所获得的抑菌圈。利用各种培养、形态、生理和生化特征对24株具有显著生物活性的放线菌菌株进行了鉴定，并归入……属。本研究结果表明，从埃塞俄比亚裂谷分离的……种对一系列人类病原体具有广泛的生物活性。
