Fungal Contamination Of Meat And Its Environment With Special Reference To The Strains Producing Aflatoxins, Ochratoxins, Proteinase And Lipase Enzymes

Abstract

A total of 337 isolates were recovered from 200 samples of meat. The rate was higher in meat obtained during slaughter (2.3) in comparison to that obtained from butcher shops (1.0). On the other hand,790 fungal isolates were recovered from 120 environmental samples. The highest rate of isolation was from floors (11.6 isolates per sample) and the lowest was from workers hands (1.6 isolates / sample).The most commonly isolated fungi belonged to the genera Aspergillus, Penicillium, Candida and Rhodotorula. Aspergillus niger was by far the most common, followed by Aspergillus flavus, Aspergillus fumigatus and Aspergillus terreus. The most common Penicillium species were Penicillium chrysogenum, Penicillium expansum, Penicillium oxalicum and Penicillium citrinum.Of the 27 Aspergillus flavus isolates tested for the production of aflatoxins, 21 isolates (77.7%) were found toxigenic. They produced aflatoxins B1, B2 or G1, either singly or combined. On the other hand, 15 out of 26 isolates of Aspergillus ochraceus produced ochratoxins.The rate of proteolytic activity was slightly higher in buffalo meat isolates, than in cattle meat, where 80% of Aspergillus isolates and 100% of Penicillium isolates were proteolytic. Corresponding figures for cattle isolates were 74% and 86.6%.The least proteolytic activity was demonstrated by Candida albicans recovered from both types of meat. However, 70%-80% of Rhodotorula isolates produced proteases. All tested mould and yeast isolates showed lipolytic activity.

New Egyptian Journal of Microbiology Vol. 17 (2) 2007: pp. 1-14