Isolation and antifungal and antioomycete activity of Streptomyces scabiei strain PK-A41, the causal agent of common scab disease

Abstract

The actinomycete strain PK-A41 was isolated from a soil sample from pepper fields in Ko-yang, Korea. The strain PK-A41 inhibited the mycelial growth of some plant pathogenic fungi and oomycete, Altemaria mali, Colletotrichum orbiculare, Fusarium oxysporum f.sp. lycopersici, Magnaporthe grisea, Rhizoctonia solani, and Phytophthora capsici. The presence of LL-diaminopi- melic acid in the cell wall extract and the nucleotide sequence of the 16S rDNA region of the strain PK-A41 was assigned to Streptomyces scabiei. Further morphological, biochemical, and pathological analyses also confirmed the strain PK-A41 to be S. scabiei, which is pathogenic to potato tubers. The maximum antibiotic production of the strain PK-A41 was achieved when grown on the glycerol peptone broth (GPB) medium for 9 days.