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Two media (mCP medium and Tryptose Sulphite Cycloserine (TSC) agar) were evaluated for recovery of Clostridium perfringens in environmental and part‐treated drinking water. For laboratory strains of Clostridium, mCP was more selective and specific for Cl. perfringens than TSC, but was markedly less efficient for the enumeration of both vegetative cells and spores. For samples of river water and part‐treated drinking water, TSC recovered significantly greater numbers of Cl. perfringens than mCP. In contrast to previous reports, there was a significant number of false presumptive positive and negative isolates on mCP. TSC is a more suitable medium for the routine monitoring of water supplies for the presence of Cl. perfringens.

The thermal stability of P-lactoglobulin was studied using differential scanning calorimetry (DSC) as part of a larger investigation into milk and whey fouling. Measurement of kinetics using DSC is very difficult as the resultant trace is the sum of simultaneous denaturation and aggregational enthalpies; the two processes were demonstrated by measurements at different heating rates. P-lactoglobulin denaturation proceeds via an intramolecular disulphide stabilized intermediate and is irreversible even before the denaturation temperature is reached. Denaturation and aggregational processes can be partially separated by measurements over a range of pH. The literature shows that the rate of fouling decreases as solution pH increases. However, DSC shows that the thermal stability of P-lactoglobulin decreases as pH increases, particularly above pH 6. It is hypothesised that aggregation rather than denaturation might be the critical step in the formation of fouling deposit.

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