Characterisation of Pseudomonas spp. isolated from foods

Abstract

Putative Pseudomonas spp. (102 isolates) from different foods were first characterised by API 20NE and then tested for some enzymatic activities (lipase and lecithinase production, starch hydrolysis and proteolytic activity). However subsequent molecular tests did not always confirm the results obtained, thus highlighting the limits of API 20NE. Instead RFLPITS1 and the sequencing of 16S rRNA gene grouped the isolates into 6 clusters: Pseudomonas fluorescens (cluster I), Pseudomonas fragi (cluster II and V) Pseudomonas migulae (cluster III), Pseudomonas aeruginosa (cluster IV) and Pseudomonas chicorii (cluster VI). The pectinolytic activity was typical of species isolated from vegetable products, especially Pseudomonas fluorescens. Instead Pseudomonas fragi, predominantly isolated from meat was characterised by proteolytic and lipolytic activities.