Journal of Environmental Conservation Engineering
Online ISSN : 1882-8590
Print ISSN : 0388-9459
ISSN-L : 0388-9459
Volume 49 , Issue 2
Showing 1-2 articles out of 2 articles from the selected issue
  • Atsushi HASHIMOTO, Kana NAKAMOTO, Hiroyuki SUZUKI, Hiroaki TSUCHIOKA, ...
    2020 Volume 49 Issue 2 Pages 91-97
    Published: March 20, 2020
    Released: April 02, 2020
    JOURNALS FREE ACCESS

    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.

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  • Toshiyuki MORITA, Noriko RYUDA, Nobuya TASHIRO, Daisuke UENO, Takashi ...
    2020 Volume 49 Issue 2 Pages 98-106
    Published: March 20, 2020
    Released: April 02, 2020
    JOURNALS FREE ACCESS

    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.

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