KHẢO SÁT HOẠT TÍNH KHÁNG VI KHUẨN GRAM ÂM CỦA CAO CHIẾT TỪ XẠ KHUẨN STREPTOMYCES ALBUS 4VH4

Abstract

Objectives: To investigate the anti-gram-negative bacteria activity of fractionated extracts derived from the cultivation of actinomycete strain Streptomyces albus 4VH4. Methods: The S. albus 4VH4 strain was cultivated in a modified ISP medium. Fractions obtained from the crude extract of the bacterial culture were evaluated for antibacterial activity using diffusion and microdilution techniques, and the chemical composition of these extracts was analyzed using LC-MS. Results: The antibacterial agent identified in fraction F6 of the dichloromethane extract from S. albus 4VH4 fermentation had a molecular weight of 506.15 Da. This compound showed antibacterial activity against Gram-negative bacteria Klebsiella pneumoniae, Escherichia coli, particularly K. pneumoniae, with a MIC of 0.25 µg/ml, equivalent to gentamicin. Conclusion: The fractionated extracts from the fermentation broth of S. albus 4VH4 containing a compound having a molecular weight of 506.15 Da, exhibited activity against Gram-negative bacteria.