OPTIMAL CONDITIONS TO ENHANCE BIOCONTROL ACTIVITY OF Penicillium chrysogenum

ABSTRACT

Phytopathogens cause devastating effect on agricultural products, thereby leading to great economic loss. Several methods have been employed in controlling phytopathogens, of which the biocontrol approach seems to be environmentally friendly. The present study was carried out to investigate the optimal conditions for enhancing the biocontrol activity of Penicillium chrysogenum against Aspergillus niger. Agricultural soil samples were collected from three different locations in Benin City and fungi were isolated. The fungal isolates obtained were purified on fresh potato dextrose agar (PDA). The isolates were identified using cultural, microscopic and morphological methods. The identity of the biocontrol agent and the pathogenic fungus were confirmed using molecular technique. The effects of different amount of dextrose in the culture medium, different media pH, and different incubation temperatures on the biocontrol potential of the agent were investigated using the antagonistic dual culture method. The results of the phenotypic characterization revealed the fungal isolates as species Penicillum and Aspergillus for the biocontrol agent and phytopathogen, respectively. The molecular characterization indicated both isolates as Penicillium chrysogenum and Aspergillus niger, respectively. The highest biocontrol activity was obtained when 20g of dextrose were used for media supplementation with a pH of 9.2 and incubated at 37oC. The findings of this study reveal that the biocontrol activity of Penicillium chrysogenum could be greatly enhanced by manipulating the growth condition.