Twenty samples of maize collected from healthy growing crops and at harvest time and during storage were screened for four Fusarium toxins (deoxynivalenol, diacetoxyscirpenol, T-2 toxin and zearalenone) by gas chromatography-mass spectrometry and thin-layer chromatography. Seventeen samples (85%) contained one or more of these toxins. Zearalenone was present in 15 samples at levels ranging between 0.1 and 16 ppm. Deoxynivalenol, diacetoxyscirpenol and T-2 toxin were found in 11, 6 and 13 samples respectively, all at levels below 1 ppm. This work documents the first reported natural occurrence of Fusarium toxins in New Zealand maize, and it is concluded that all four of the mycotoxins studied are prevalent in apparently healthy standing crops as well as in stored maize.

Chromatography, Thin Layer↗

PubMedDate not supplied

Partial characterization of proteolytic enzymes of Microsporum canis and Microsporum cookei.

Characterization by proteinase inhibitors of the enzymes produced by Microsporum spp. revealed that Microsporum canis and Microsporum cookei produce serine proteinase(s), but only M. canis expresses aspartic and cysteine proteinases and probably a metalloproteinase. Both M. canis and M. cookei expressed metalloelastinolytic proteinases. All the proteinase types have been implicated in the pathogenicity of a wide range of microorganisms.

Endopeptidases↗

PubMedDate not supplied

Multiple proteinases from two Microsporum species.

Enzyme expression of 67 isolates of two Microsporum species, M. canis and M. cookei, were compared in both shake and stationary cultures using substrate copolymerized SDS-PAGE. Most M. canis isolates expressed more proteolytic bands in shake culture, while M. cookei isolates expressed more in stationary culture. M. canis isolates expressed up to six proteinases of different relative mobilities (122, 64, 62, 45, 31 and 25 kDa). M. cookei expressed up to seven proteinases in stationary culture (67, 66, 64, 62, 45, 42 and 39 kDa). Those of 67 and 66 kDa were not expressed in shake culture. The proteinases expressed by M. cookei were similar to those expressed by M. canis except for 122 and 25 kDa. With the exception of isolates from non-infected cats, 25 kDa was also commonly expressed by isolates from infected hosts in the shake culture treatment. The differences in enzyme expression obtained may reflect differences in the contrasting ecological roles of the two species.

Animals↗