ABSTRACT
Aflatoxin M1 (AFM1) in milk from 100 different herds of free-grazing cows in Abeokuta, Nigeria, was analysed by immunoaffinity column cleanup and HPLC with fluorescence detection. AFM1 was found in 75% of the samples, the toxin levels in positive samples ranged from 9.0 to 456.0 ng/l. The mean AFM1 level in positive samples was 108.15 ng/l, exceeding, for example, the European Union maximum level by a factor of two. These results indicated that there is an urgent need to more closely control the milk of free-grazing cows for AFM1 in order to protect the health of humans consuming milk and milk products.
Subject(s)
Aflatoxin M1/analysis , Milk/chemistry , Animals , Cattle , Chromatography, Affinity , Chromatography, High Pressure Liquid , Fluorometry , NigeriaABSTRACT
The potential of activated charcoal in the purification of fungal glucoamylase was investigated. Various concentrations of activated charcoal (1-4% w/v) were used to concentrate crude glucoamylase from Rhizopus oligosporus at different temperature values (30-50°C). Effects of pH (3.0-6.0) and contact time (0-60 min) on enzyme purification were also monitored. Activated charcoal (3% w/v) gave a 16-fold purification in a single-step purification at 50°C for 20 min and pH 5.5. The result of SDS-PAGE analysis of purified glucoamylase showed two major protein bands with corresponding molecular weight of 36 kDa and 50 kDa. The method is inexpensive, rapid, and simple which could facilitate downstream processing of industrial enzyme.
ABSTRACT
A simple method based on precipitation with Calotropis procera latex was developed for the purification of crude enzyme from fermentation broth. C. procera latex (10(-2) dilution) clarified and concentrated the crude amylase of Aspergillus oryzae 4-fold with 97% recovery of the initial amylase activity in the filtrate in a single step operation. The latex was stable at pH < or = 4.5 and there was no significant difference (P < or = 0.05) in the purification potential of the latex at 4 and 28 degrees C. This method could prove useful to developing economies of the tropics where ambient temperature is around 28 degrees C.
