Aspergilli as ochratoxin producers
1972
Hesseltine, C.W. | Vandegraft, E.E. | Fennell, D.I. | Smith, M.L. | Shotwell, O.L.
To determine whether ochratoxin is produced by species of Aspergillus other than Asp. ochraceus, 44 strains representative of the 9 spp. composing the Asp. ochraceus group were grown on both pearled wheat and cracked corn in duplicate shaken flasks at 28°C for 5 days. Rice was a poor substrate for ochratoxin production. Moulded substrates were extracted with acetonitrile-water; partially purified extracts were assayed for ochratoxins by TLC. All positive samples were confirmed by solubility in sodium bicarbonate and preparation of methyl esters. Ochratoxins A and B were found in some strains of Asp. sulphureus, Asp. sclerotiorum, Asp. alliaceus, Asp. melleus, Asp. ochraceus, Asp. ostianus, and Asp. petrakii. No ochratoxin was produced by the one strain of Asp. elegans or any of 6 strains of Asp. auricomus. 5 of 9 strains of Asp. sclerotiorum and 5 of 11 strains of Asp. ochraceus were negative. All 7 strains of Asp. alliaceus were positive, but one was at a very low level. Generally, yields of ochratoxin were higher in wheat than in corn. Occasionally, as much ochratoxin B was produced as A. Highest yields of ochratoxins A and B were obtained from respective strains of Asp. ochraceus NRRL 3174 and NRRL 3519. Some strains of most species of the Asp. ochraceus group produce this mycotoxin as a secondary metabolite.
显示更多 [+] 显示较少 [-]