Studies On Microbial Spoilage

Abstract

Pour microorganisms were isolated from rotted onion bulbs, purple variety, purchased from markets in the Lagos State of Nigeria. Three of them were pathogenic they produced soft rot when wound-inoculated into healthy onion bulbs. The microorganisms were identified as Pseudomonas cepacia Buckholder, Candida utilis (Henneberg) Lodder and Kreger-Van Rig and Pseudomonas fluorescens Migula; the last being the most pathogenic of the three.

A study of the effect of infection 10 of the nutritional quality of bulbs by the bacterial pathogens revealed a loss in total sugars and no appreciable change in amino acid and 11pid contents of the bulbs. Infection by Candida utilts, however, resulted in an increase in total amino acids but an appreciable amount loss of sugars and lipids.

Growth studies of R. fluoresens showed that It grew well on a variety of solid and liquid media at 298 2°c. It utilised glucose, fructose, sucrose, maltose, lactose, galactose, saccharose and mannitol; growth was best with glucose.