Aflatoxin B1 degradation by liquid cultures and lysates of three bacterial strains.
Aflatoxin contamination remains a daunting issue to address in food safety. In spite of the efforts geared towards prevention and elimination of this toxin, it still persists in agricultural commodities. This has necessitated the search for other measures such as microbial degradation to combat this hazard. In this study, we investigated the biodegradation of aflatoxin B1 (AFB1), using lysates of three bacterial strains (Pseudomonas anguilliseptica VGF1, Pseudomonas fluorescens and Staphylococcus sp. VGF2) isolated from a gold mine aquifer. The bacterial cells were intermittently lysed in the presence and absence of protease inhibitors to obtain protease free lysates, subsequently incubated with AFB1 for 3, 6, 12, 24, and 48h to investigate whether any possible AFB1 degradation occurred using high performance liquid chromatography (HPLC) for detection. Results obtained revealed that after 6h of incubation, protease inhibited lysates of Staphylococcus sp. VGF2 demonstrated the highest degradation capacity of 100%, whereas P. anguilliseptica VGF1 and P. fluorescens lysates degraded AFB1 by 66.5 and 63%, respectively. After further incubation to 12h, no residual AFB1 was detected for all the lysates. Lower degrading ability was however observed for liquid cultures and uninhibited lysates. Data on cytotoxicity studies against human lymphocytes showed that the degraded products were less toxic than the parent AFB1. From this study, it can thus be deduced that the mechanism of degradation by these bacterial lysates is enzymatic. This study shows the efficacy of crude bacterial lysates for detoxifying AFB1 indicating potential for application in the food and feed industry.
Department of Biotechnology and Food Technology, Faculty of Science, University of Johannesburg, P. O. Box 17011, Doornfontein 2028, Gauteng, South Africa. Electronic address: oluwafemiadebo@yahoo.com.
Oluwafemi Ayodeji
OA
Adebo
Department of Biotechnology and Food Technology, Faculty of Science, University of Johannesburg, P. O. Box 17011, Doornfontein 2028, Gauteng, South Africa.
Patrick Berka
PB
Njobeh
Gold One International Limited, Corner Cloverfield Ave & Auteniqua Road, Eastvale, Springs, South Africa.
Sibusiso
S
Sidu
Department of Biochemistry, Faculty of Science, University of Johannesburg, P.O. Box 254, Auckland Park 2006, Gauteng, South Africa.
Matsobane Godfrey
MG
Tlou
Department of Biotechnology and Food Technology, Faculty of Science, University of Johannesburg, P. O. Box 17011, Doornfontein 2028, Gauteng, South Africa.
Vuyo
V
Mavumengwana
D016604:Aflatoxin B1 / Q000378:metabolism* / Q000633:toxicity; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media / Q000378:metabolism; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects; D011549:Pseudomonas / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000378:metabolism*; D013210:Staphylococcus / Q000378:metabolism*
D003470:Culture Media; D016604:Aflatoxin B1
Aflatoxin B(1); Bacterial lysate; Biodegradation; Cytotoxicity