Mycopathologia. 2004 Apr;157(3):349-57.
Penitrem and thomitrem formation by Penicillium crustosum.
Rundberget T, Skaar I, O'Brien O, Flåøyen A.
National Veterinary Institute, PO Box 8156 Dep., 0033 Oslo,
Norway.
thomas.rundberget@vetinst.no
The levels of penitrems A, B, C, D, E, F, roquefortine C and
thomitrem A and E recovered from extracts of 36 Norwegian, 2
American and one each of Japanese, German, South African, Danish
and Fijian isolates of Penicillum crustosum Thom were
quantitatively determined using high performance liquid
chromatography-mass spectrometry (HPLC-MS). Forty-two of the 44
isolates of penitrem-producing isolates grown on rice, afforded
levels of thomitrem A and E comparable to that of penitrem A.
Thomitrems A and E were also found, but at lower levels, when
cultures were grown on barley. No thomitrems were found when the
isolates were grown on liquid media. The effects of time and
temperature on mycotoxin formation were studied on rice over a 4
week period at 10, 15 and 25 degrees C, respectively. No
mycotoxins could be detected after 1 week at 10 degrees C, but
after 2 weeks at 10 degrees C levels were similar to those
produced at 15 and 25 degrees C. Higher levels of thomitrems A
and E were detected when media were maintained at lower pH. The
possibility that thomitrems A and E might be derived by acid
promoted conversion of penitrems A and E was explored in
stability trials performed at pH 2, 3, 4, 5 and 7 in the
presence and absence of media. Thomitrems were formed at pH 2, 3
and 4 but not at pH 5 and 7.
PMID: 15180164 |
