Ogundero V W, Adebajo L O
Department of Botany and Microbiology, University of Ibadan, Nigeria.
Nahrung. 1987;31(10):993-1000. doi: 10.1002/food.19870311013.
The factors responsible for the production and activities of polysaccharide degrading enzymes of a toxigenic strain of Aspergillus clavatus (ASC - IB 202) on an oat meal chaff (OMC) medium were studied. The enzymes assayed for were amylases, CM-cellulases, filter paper (FP)-cellulases, xylanases and dextranases. Amylase production by A. clavatus (ASC - IB 202) reached a peak within 48 h of incubation at 30 degrees C while optimal production of CM-cellulases occurred on day 6. The FP-cellulase and xylanase production did not reach a peak within the 10 day incubation period. Determination of dextranase activity showed optimal production and activity between days 6 and 8. When grown on varying sources of carbon at 30 degrees C, CM-cellulase production was only recorded on cellobiose, CM-cellulose and on the OMC medium. FP-cellulase production occurred on the microcrystalline cellulose and on the OMC medium. The other enzymes were produced to various extents on the carbon sources used. The best mycelial growth was recorded at 30 degrees C and pH 6.0. So also were the peak production of CM-cellulases and FP-cellulases. The xylanase and dextranase activity of the culture filtrate were optimally produced at 30 degrees C and pH 5.4. The potential health hazards which the presence of this toxigenic strain of Aspergillus clavatus on poultry feeds poses to farm animals including man are discussed.
研究了棒曲霉产毒菌株（ASC - IB 202）在燕麦麸皮（OMC）培养基上产生多糖降解酶及其活性的相关因素。所测定的酶包括淀粉酶、CM - 纤维素酶、滤纸（FP） - 纤维素酶、木聚糖酶和葡聚糖酶。棒曲霉（ASC - IB 202）产生的淀粉酶在30℃培养48小时内达到峰值，而CM - 纤维素酶的最佳产量出现在第6天。在10天的培养期内，FP - 纤维素酶和木聚糖酶的产量未达到峰值。葡聚糖酶活性测定表明，在第6天至第8天产量和活性最佳。当在30℃下于不同碳源上生长时，仅在纤维二糖、CM - 纤维素和OMC培养基上记录到CM - 纤维素酶的产生。FP - 纤维素酶在微晶纤维素和OMC培养基上产生。在所使用的碳源上，其他酶也有不同程度的产生。在30℃和pH 6.0时记录到最佳的菌丝体生长。CM - 纤维素酶和FP - 纤维素酶的产量峰值也是如此。培养滤液的木聚糖酶和葡聚糖酶活性在30℃和pH 5.4时最佳产生。文中讨论了家禽饲料中存在的这种棒曲霉产毒菌株对包括人类在内的农场动物所造成的潜在健康危害。
