Purpose: Considering the adverse effects associated with this toxin, there is need for strategies to reduce or at best, eliminate their occurrence in food commodities. This study thus investigated the AFB1 biodegradation ability of liquid cultures and cell lysates of Pseudomonas anguilliseptica and Pseudomonas fluorescens and the cytotoxicity of the degraded products thereof.
Methods: Liquid cultures and cell lysates (disrupted in the presence or absence of protease inhibitors to obtain lysates) were respectively incubated with 2.5 µg/ml AFB1 for 3, 6, 12, 24 and 48 h. Aflatoxin B1 degradation was subsequently monitored on high performance liquid chromatography (HPLC), while cytotoxicity of the bio-transformed extracts were investigated against human lymphocytes using the MTT assay.
Results: After 48 h of incubation, liquid cultures of P. anguilliseptica demonstrated significantly (P˂0.05) higher % AFB1 degradation of 64.9% as compared to P. fluorescens of 59.9%. Conversely, in 6 h of incubation, 83.5 and 79.1% AFB1 degradation was observed for the protease inhibited lysates of P. anguilliseptica and P. fluorescens, respectively, while in 12 h, a 100% AFB1 degradation was recorded. The uninhibited lysates however recorded a significantly (P˂0.05) lower percentage AFB1 degradation. Results obtained from the cytotoxicity studies showed that the AFB1 bio-transformed products exhibited a significantly (P 0.05) lower cytotoxic effect when compared to the parent AFB1.
Significance: This study demonstrated the efficacy of crude bacterial lysates to degrade and detoxify AFB1. The potential of these lysates in decontaminating AFB1 could be an important bio-control measure with a huge potential for industrial applications.