Journal of Food: Microbiology, Safety & Hygiene
Open Access
ISSN: 2476-2059
+44 1478 350008
ISSN: 2476-2059
+44 1478 350008
Lilia R Cavaglieri, Maria L Gonzalez Pereyra and Maria P Martonez
Universidad Nacional de R�?o Cuarto, Argentina
Posters & Accepted Abstracts: J Food Microbiol Saf Hyg
Microbial degradation of Aflatoxins (AFs) is an alternative to the use of mycotoxin binders. The lactone ring is a possible target for microbial enzymes, since its cleavage would result in less toxic derivatives. The aim of this study was to isolate and identify Bacillus strains able to degrade Aflatoxin B1 (AFB1) to less toxic metabolites, to identify aiiA genes encoding for N-acyl-homoserine lactone (AHL) lactonase and to possibly correlate detoxification with the production of this enzyme. Eleven Bacillus strains were isolated from soil, pond sediment and identified by MALDI-TOF MS. Ability of the strains and their cell free culture supernatants (CFCS) and cell lysates to degrade AFB1 was tested. Toxicity of degradation products was tested using the Artemia salina acute toxicity test. The presence of the aiiA gene was studied by PCR amplification using specific primers. The cleavage of the lactone ring was confirmed by Thin-Layer Chromatography (TLC). Strains were identified as B. mojavensis, B. subtilis, B. cereus and B. mycoides. Ten out of 11 cultures and eight CFCS were able to significantly degrade (P<0.05) AFB1. Degradation percentages ranged from 27.78% to 79.78%. Cell lysates were also able to reduce AFB1 (P<0.05). Exposure to high temperatures (70 and 80�?°C for 20 min) did not affect enzyme activity. All strains degraded AFB1 to less toxic metabolites. B. subtilis RC1B, B. cereus RC1C and B. mojavensis RC3B, amplified a fragment of 753 pb corresponding to the aiiA gene encoding for AHL lactonase. CFCS and cell lysates these strains were able to cleave the lactone ring. In conclusion, the degradation activity of these Bacillus strains is due to extracellular and intracellular enzymes. If demonstrated to be safe, they have potential to be used as biological control agents to detoxify AFB1 in contaminated food or feed. lcavaglieri@exa.unrc.edu.ar