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Antifungal and
antibacterial compounds from Streptomyces strains
Mustafa
Oskay
Biology Department, Faculty of Sciences and Arts, Celal
Bayar University, Manisa, Turkey. E-mail:
mustafa.oskay@bayar.edu.tr.
Accepted 15 May, 2009 |
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Sixteen
antibiotic-producing Streptomyces sp. isolated from
the North Cyprus soils were evaluated for their ability to
inhibit in vitro against six filamentous fungi
including human and plant pathogens. One promising strain,
designed as KEH23 with strong antifungal activity, was
selected for further studies. This isolate was identified as
Streptomyces sp. based on a great variety of
morphological, cultural, physiological and biochemical
characteristics. Its antifungal activity was confirmed in
batch culture. In order to standardize the antibiotic
production some cultural conditions like different
incubation temperatures (20.0, 25.0, 30.0 and 37.0°C),
carbon sources (glucose, glycerol, starch and sucrose), pH
(6.0, 7.0, 7.5, 8.0 and 9.0) and incubation time in hours
(24, 48, 72, 96 and 120) were determined. During
fermentation, growth, pH and antibiotic production were
monitored at 12 h intervals. Penicillium sp. was most
sensitive to the produced compound(s) followed by Candida
albicans, Cladosporium oxysporum and
Alternaria alternata with an inhibition zone 28.0, 20.0,
16.0 and 15.0 mm, respectively. In addition, antibacterial
activity of this strain was determined against human
pathogenic bacteria such as Staphylococcus aureus,
Klebsiella pneumoniae, Kocuria rhizophila,
Escherichia coli, Salmonella typhimurium and
methicillin-resistant Staphylococcus aureus (MRSA).
The present results indicate that isolate KEH23 is a
potential antibiotic producer agent for the biocontrol of
plant and human pathogens.
Key
words:
Antifungal
activity, biocontrol, characterization, fermentation,
isolation, North Cyprus, pathogenic fungi, Streptomyces,
soil. |
