Microbial Detoxification of AFLATOXIN Presented by Mr. SANJAY KUMAR BHARIYA Assistant Professor Plant Molecular Biology and Biotechnology

CONTAMINATED COTTON SEED AND MAIZE

Mycotoxin These compounds are highly toxic, carcinogenic, mutagenic, and immunosupressor Aspergillus FLAvus TOXIN (AFLATOXIN) Secondary metabolites Filamentous fungi Aspergillus flavus, A. parasiticus and rarely A. nomius Especially in corn, various nuts, oilseeds Aflatoxins B2α and G2α appear to be relatively non-toxic

Aflatoxin can cause:- Liver damage Liver cancer Pulmonary edema Coma Death Vomiting Mental impairment

Classification of Aflatoxin 1. Aflatoxin B Aflatoxin B 1 Aflatoxin B 2 2. Aflatoxin G Aflatoxin G 1 Aflatoxin G 2 3. Aflatoxin M Aflatoxin M 1 Aflatoxin M 2

Aflatoxin B and Aflatoxin G

Aflatoxin M

Non toxic Aflatoxin

CHEMICAL INACTIVATION Ozonization Effectively destroyed aflatoxins B1and G1 but comparatively ineffective against B2 Attack was the double bond on the terminal furan Decreased the nutritive value Hydrogen Peroxide At 80 C for 0.5 hr with hydrogen peroxide at pH 9.5 Did not affect the protein efficiency ratio (PER) No toxicity

Methylamine 2% concentration and 15% moisture for 30 min at 100 C Reduction in the PER in peanut meal but not cottonseed meal Sodium Hypochlorite At pH 8, 0.4% NaOCl Ammonia Moistened to 9.6% and 14.6% at 200 F for 60 min at 20 psg anhydrous amonia

BIOLOGICAL INACTIVATION Biodegredation Removed aflatoxin from solution The amount of toxin removed was small Biotransformation Conversion of aflatoxin e.g. B l and G l to B2α and G2α

INTRODUCTION Aflatoxin B1 is considered the most potent carcinogen of all the aflatoxins Aflatoxin B1 is carcinogenic to many organs and primary liver Very strong correlation exists between the daily dietary intake of aflatoxin B1 There are combined actions of aflatoxins and hepatitis B virus infection leading to hepatocellular carcinoma Physical, chemical or biological methods are presently used to reduce aflatoxin content in food Physical and chemical methods for the detoxification is restricted due to limited efficacy, losses of nutritional value and high cost They concluded that Flavobacterium aurantiacum NRRL B-184 was the only bacterium capable of removing aflatoxins irreversibly from test substrates

RESULTS AND DISCUSSION

Palumbo et al. reported that a number of Bacillus, Pseudomonas, Ralstonia and Burkholderia strains could completely inhibit A. flavus growth. B. subtilis and P. solanacearum strains isolated from maize soil were also able to inhibit aflatoxin accumulation. El-Nezami et al. reported the ability of lactic acid bacteria to remove AFB1 from artificially contaminated liquid media. Munimbazi and Bullerman reported that more than 98% inhibition in aflatoxin production by A. parasiticus was caused by B. pumilus. Biological degradation of AFB1 by R. erythopolis and Mycobacterium fluoranthenivorans was greater than 90% within 4 hours at 300C, while after 8 hours AFB1 was practically undetectable. The degradation was enzymatic and the enzymes responsible for the degradation of AFB1.

CONCLUSION The development of safer, rapid and cost-effective degradation methods is essential The contaminated product can be discarded or the toxin can be degradated into less toxic or non-toxic products The ability of N. corynebacteriodes to detoxify aflatoxin without the need for exogenous sources A better understanding of the AFB1 degradative pathway is necessary for the practical application of this biological method Researches should be continued to detect the degradation mechanism of AFB1

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