Antagonistic effect of multifunctional actinomycete strain Act12 on soil-borne pathogenic fungi and its identification

Antagonistic effects of multifunctional actinomycete strain Act12 on six soil-borne pathogenic fungi were determined using agar block method and inhibitory test. The strain Act12 was identified by analyses on its morphological character, physiological and biochemical characteristics, as well as 16 S rDNA sequence. The results showed varying degrees of Act12 antagonism against all tested six soil-borne pathogenic fungi. The widths of inhibitory zones against Fusarium equiseti and F. oxysporum f. sp. niveum were 20.5 mm and 18.4 mm, respectively. The rate of bacteriostasis of Act12 axenic fermentation filtrate against F. equiseti after 48 h cultivation was 83.2%. Based on micro-morphology, and cultural, physiological and biochemical characteristics, as well as 16 S rDNA sequence analysis, Act12 strain was identified as Streptomyces pactum.