ABSTRACT
Inactivation of aflatoxin B1 was studied by using gamma radiation and hydrogen peroxide. A 100-krad dose of gamma radiation was sufficient to inactivate 50 micrograms of aflatoxin B1 in the presence of 5% hydrogen peroxide, and 400 krad was required for total degradation of 100 micrograms of aflatoxin in the same system. Degradation of aflatoxin B1 was confirmed by high-pressure liquid chromatographic and thin-layer chromatographic analysis. Ames microsomal mutagenicity test showed loss of aflatoxin activity. This method of detoxification also reduces the toxin levels effectively in artificially contaminated groundnuts.
Subject(s)
Aflatoxins/radiation effects , Hydrogen Peroxide/pharmacology , Aflatoxin B1 , Aflatoxins/antagonists & inhibitors , Aflatoxins/pharmacology , Animals , Dose-Response Relationship, Radiation , Gamma Rays , Microsomes, Liver/metabolism , Mutagenicity Tests , Salmonella typhimurium/drug effectsABSTRACT
Lactobacillus acidophilus AC1 was found to produce a proteinic inhibitor having a molecular weight of 5.4 kd, active against both Gram-positive and Gram-negative bacteria. Some of the sensitive bacteria were found to be resistant to most of the commonly employed drugs and antibiotics. Sodium dodecyl sulphate polyacrylamide gel electrophoresis of the purified inhibitor showed the presence of a single polypeptide. The inhibitor was active over a wide pH range from 4.0 to 7.5. It was heat sensitive, and complete inactivation occurred within 20 min at 50 degrees C. The purified inhibitor lost 50% of its activity within 24 h at room temperature and after 5 days at 4 degrees-8 degrees C. The inhibitory protein was readily distinguished from other inhibitors in lactic cultures by its immunological cross-reactivity.
Subject(s)
Anti-Bacterial Agents/isolation & purification , Bacterial Proteins/isolation & purification , Lactobacillus acidophilus/analysis , Bacterial Proteins/immunology , Hot Temperature , Molecular WeightABSTRACT
Studies on kappa phage inactivation with isolated pigments from Serratia marcescens were carried out. Kappa phage is sensitive to inactivation with diethyl ether, petroleum ether, acetone and methanol, but is quite stable in chloroform and dimethyl sulphoxide. The pigment extract dissolved in chloroform inactivates about 50% of the total suspended phages. The pigment dissolved in acetone and dimethyl sulphoxide inactivates about 96.50% and 64.10% of the phages, respectively. High inactivation values with acetone were partially due to direct inactivation rather than the pigment itself.
