Antibiotic Producing Potentials of Three Freshwater Actinomycetes Isolated from the Eastern Cape Province of South Africa

International Journal of Molecular Sciences

Timothy Sibanda²  Leonard V. Mabinya²  Ntsikelelo Mazomba²  David A. Akinpelu⁴  Kim Bernard³  Ademola O. Olaniran¹ 

[1] Division of Microbiology, University of KwaZulu Natal, Durban Westville, South Africa; E-Mail:;Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, South Africa; E-Mails:;South African Environmental Observation Network (SAEON), Elwandle Node, Grahamstown, South Africa; E-Mail:;Department of Microbiology, Obafemi Awolowo University, Ile-Ife, Nigeria; E-Mail:

关键词: actinomycetes;    crude extract;    antibacterial activity;    time-kill;   

DOI  :  10.3390/ijms11072612

来源: mdpi

【 摘 要 】

Crude extracts of three actinomycetes species belonging to Saccharopolyspora (TR 046 and TR 039) and Actinosynnema (TR 024) genera were screened for antibacterial activities against a panel of several bacterial strains. The extracts showed antibacterial activities against both gram-negative and gram-positive test bacteria with inhibition zones ranging from 8 to 28 mm (TR 046); 8 to15 mm (TR 039); and 10 to 13 mm (TR 024). The minimum inhibitory concentrations ranged from 0.078 to 10 mg/mL (TR 046); 5 to >10 mg/mL (TR 039); and 1.25 to 5 mg/mL (TR 024). Time-kill studies revealed that crude extract of TR 046 showed strong bactericidal activity against Bacillus pumilus (ATCC14884), reducing the bacterial load by 10⁴ cfu/mL and 10² cfu/mL at 4× MIC and 2× MIC, respectively, after 6 h of exposure. Similarly, against Proteus vulgaris (CSIR 0030), crude extract of TR 046 achieved a 0.9log₁₀ and 0.13log₁₀ cfu/mL reduction at 5 mg/mL (4× MIC) and 1.25 mg/mL (2× MIC) after 12 h of exposure. The extract was however weakly bactericidal against two environmental bacterial strains (Klebsiella pneumoniae and Staphylococcus epidermidis); and against Pseudomonas aeruginosa (ATCC 19582): the extract showed bacteriostatic activities at all concentrations tested. These freshwater actinomycetes appear to have immense potential as a source of new antibacterial compound(s).

【 授权许可】

CC BY   
© 2010 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.