Isolation and Screening of Antifungal Producing Lactic Acid Bacteria From Pro-Vitamin A Cassava

摘要

Lactic Acid Bacteria (LAB) are non-pathogenic bacteria reported to play essential role in preservation, fermentation and contribute to organoleptic and textural profile of food items. This study investigated antifungal producing LAB during fermentation of Pro-vitamin A and white cassava variety which were used against spoilage mould of cassava products ( garri, lafun and fufu) . One white cassava variety (IITA TMS IBA 30572 (ITI3)) and one yellow variety (IITA TMS IBA 011368 (ITI0)) were fermented for 96 hours. The pH and Total Titratable Acidity (TTA) of the fermenting medium and LAB counts of the supernatant and cassava mash were determined using standard procedures. The LAB were screened with Aspergillus niger to detect their antifungal ability. The LAB were identified as different species which are Lactobacillu s plantarum, Lactobacillus fermentum , Lactobacillus mesenteroides , Lactobacillus casei and Lactobacillus acidophilus . These LAB isolates posses the potential to inhibit most of the isolated moulds used in this study. Quantities of lactic acid, diacetyl and hydrogen peroxide produced by the LAB were also determined using standard procedures. It was also observed that the pH and temperature of the growth medium have significant effect on the production of these antifungal metabolites by the isolated lactic acid bacteria. The proliferation of LAB at low pH and their inhibition against some moulds indicate their potential as bio-protective agents in cassava food products.