Impact of cultivation conditions and nitrogen source on Bacillus velezensis AG growth and production of fengycin and surfactin

Abstract

The occurrence of basal stem rot (BSR) in oil palms, identified to be predominantly caused by Ganoderma boninense, is one of the most destructive diseases plaguing the oil palm industry. Biological control agents (BCA) such as Bacillus velezensis (B. velezensis) capable of producing the cyclic lipopeptide (CLP) fengycin and surfactin, has been put forth as more effective and environmentally friendlier alternatives to currently employed strategies for BSR control. While there have been multiple studies conducted on the viability of B. velezensis as a biocontrol agent, studies concerning its growth and CLP production are lacking. In this study, the effects of varying cultivation conditions on the growth of B. velezensis as well as its fengycin and surfactin production was investigated. To achieve this, the impacts of various growth conditions such as the molar ratio of carbon to nitrogen (C:N) , type of carbon and nitrogen sources and initial inoculating pH were studied. Results attained from this study aims to identify the optimal conditions for B. velezensis growth and CLP production, so as to give an insight on its viability as a BCA for BSR control in an agricultural setting.