Mycobiology.  2006 Sep;34(3):138-142. 10.4489/MYCO.2006.34.3.138.

Screening of Cyanobacteria (Blue-Green algae) from Rice Paddy Soil for Antifungal Activity against Plant Pathogenic Fungi

• Kim JD

• KMID: 1598819
• DOI: http://doi.org/10.4489/MYCO.2006.34.3.138

Abstract

Soil cyanobacteria isolated from the rice paddy fields of 10 different locations across Korea were evaluated by agar plate diffusion test for antifungal activity. Aqueous, petroleum ether, and methanol extracts from one hundred and forty two cyanobacterial strains belonging to the 14 genera were examined for antifungal properties against seven phytopathogenic fungi causing diseases in hot pepper (Capsicum annuum L). Of total cyanobacteria, nine cyanobacteria (6.34%) exhibited antifungal effects. The nine cyanobacteria selected with positive antifungal activities were two species of Oscillatoria, two of Anabaena, three of Nostoc, one of Nodularia, and one of Calothrix. Alternaria alternata and Botrytis cinerea were inhibited by nine and eight species of cyanobacteria, respectively. Rhizopus stolonifer was suppressed by only methanol extract of Nostoc commune FK-103. In particular, Nostoc commune FK-103 and Oscillatoria tenuis FK-109 showed strong antifungal activities against Phytophthora capsici. Their antifungal activity at the late exponential growth phase is related to the growth temperature and not associated with the growth parameters such as cell biomass and chlorophyll-alpha concentration. The high inhibition levels of antibiotics were 22.5 and 31.8 mm for N. commune FK-103 and O. tenuis FK-109, respectively. The optimal temperature for antibiotic productivity was 35degrees C.

Keyword

Antibiotics; Antifungal activity; Cyanobacteria; Rice paddy filed; Soil

MeSH Terms

Agar
Alternaria
Anabaena
Anti-Bacterial Agents
Biomass
Botrytis
Cyanobacteria*
Diffusion
Efficiency
Ether
Fungi*
Korea
Mass Screening*
Methanol
Nodularia
Nostoc
Nostoc commune
Oscillatoria
Petroleum
Phytophthora
Plants*
Rhizopus
Soil*
Agar
Anti-Bacterial Agents
Ether
Methanol
Petroleum
Soil