Fungistatic and fungicidal properties of Candida pyralidae Y1117, Pichia kluyveri Y1125 and Pichia kluyveri Y1164 on the biocontrol of Botrytis cinerea

Abstract

The agro-processing industry is currently facing losses due to microbial spoilage of agricultural produce and associated value-added products such as beverages. To address this, synthetic chemicals that have potential human health and environmental effects have been widely used to control microbial spoilage. As a result, a bioprospecting approach that uses biological systems e.g. yeast as biocontrol agents is increasingly being considered in the food industry. The aim of the current study was to investigate the effect of varying inoculum dose (ID) of Candida pyralidae strain Y1117, Pichia kluyveri Y1125 and Pichia kluyveri Y1164 for the biocontrol of Botrytis cinerea. The headspace of the growth medium was contaminated with a fungal plug subsequent to biotreatment with different initial inoculum dose of the respective biocontrol agents. The results obtained showed that the fungistatic and fungicidal effects on the fungal pathogen was dose dependent. The fungistatic characteristics against Botrytis cinerea were displayed after 7 days when 102 -105 cells mL-1 of Candida pyralidae Y1117, Pichia kluyveri Y1125 and Pichia kluyveri Y1164 were independently used in-vitro and in-vivo. However, 106 -108 cells mL-1 inoculum doses displayed fungicidal characteristics. Additionally, the fungicidal property of yeasts studied was also confirmed on table grape (in vivo studies) using closed jars.