The filtration efficiency of the hydroxyapatite powder cake filtration method, which was developed as a concentration method for protozoa, such as Cryptosporidium, was evaluated as an Escherichia coli concentration method. When pond water was used as a sample, this method could filtrate 2 to 2.5 times more water than a ∅47 ㎜ cellulose-mixed ester filter(pore size 0.22 or 0.45 µm)or a polycarbonate filter(0.2 µm)alone. Additionally, there was a high recovery rate of E. coli from the concentrate. In E. coli enumeration using actual river water, sewage, and effluents, E. coli concentrations equal to or higher than the conventional membrane filter method were achieved. This method enables the easy processing of volumes exceeding 100 mL and applies in liquid media, such as the Colilert method, for which no appropriate concentration methods were present previously.
To prevent fungal deterioration of house mandarin during storage and transportation, a bacterium, Bacillus pumilus TM-R, producing volatile antifungal organic compounds (VAOCs) with strong activity was applied as a biological control agent, which was an alternative to chemical fungicidal treatment. The surface of house mandarin was contaminated with conidiospores of Cladosporium cladosporioides, and the fruits were incubated with a culture of B. pumilus TM-R in a sealed container at 30℃ for 7 days. Deterioration was significantly reduced by the presence of the bacterium. VAOCs produced by the bacterium inhibited the germination of conidiospores and mycelium elongation. Among 208 bacterial isolates newly obtained from soil and manure, 6 isolates showed a stronger and wider antifungal activity. B. pumilus TM-R was, however, still the strongest in the production of VAOCs for suppressing fungal growth.