Determination of desirable attributes of an indigenous burkholderia isolate towards biological control of plant pathogenic fungi and its microbial enzyme production

Abstract

Purpose: Microorganisms are proven bio-resources for the environmentally-friendly and sustainable biological control of plant diseases and microbial enzyme production. The present study confirms the identity of an indigenous Burkholderia isolate, determines its desirable features as a biological control agent of plant pathogenic fungi and an enzyme producer and analyzes molecular relationships with selected environmental isolates of Burkholderia. Research Method: In vitro antagonism of Burkholderia isolate on colony growth and spore germination of five fungal pathogens causing field and postharvest diseases were tested. Antifungal ability of cell-free filtrate and effect of temperature on antifungal ability were determined. Extracellular enzyme production of Burkholderia isolate was screened and phylogenetic relationships were elucidated. Findings: Burkholderia isolate inhibited colony growth of the five fungal pathogens by a range of 45-59 %, reduced the spore germination ability forming spores of a typical morphology. Antifungal ability was lost beyond 57 oC and cell-free filtrates did not show antagonism against the tested fungi. The bacterial isolate gave the best match with Burkholderia A45 strain and it was; catalase, gelatinase, lipase and casein hydrolysis positive. The indigenous bacterial isolate grouped together with Burkholderia strains, having biodegradation ability of environmental pollutants. Research Limitations: Absence of a comprehensive image on extracellular enzyme producing ability and information on biodegradation ability of the bacterial isolate. Originality/value: Findings will be useful to exploit the potential of the bacterium in integrated management of pre-and postharvest fungal diseases and in microbial enzyme production.