Peixoto Simone C, Jorge João A, Terenzi Héctor F, Polizeli Maria de Lourdes T M
Departamento de Biologia, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, 14040-901, Ribeirão Preto SP, Brazil.
Int Microbiol. 2003 Dec;6(4):269-73. doi: 10.1007/s10123-003-0140-1. Epub 2003 Aug 15.
The effect of several nutritional and environmental parameters on growth and amylase production from Rhizopus microsporus var. rhizopodiformis was analysed. This fungus was isolated from soil of the Brazilian "cerrado" and produced high levels of amylolytic activity at 45 degrees C in liquid medium supplemented with starch, sugar cane bagasse, oat meal or cassava flour. Glucose in the culture medium drastically repressed the amylolytic activity. The products of hydrolysis were analysed by thin layer chromatography, and glucose was detected as the main component. The amylolytic activity hydrolysed several substrates, such as amylopectin, amylase, glycogen, pullulan, starch, and maltose. Glucose was always the main end product detected by high-pressure liquid chromatography analysis. These results indicated that the amylolytic activity studied is a glucoamylase, but there were also low levels of alpha-amylase. As compared to other fungi, R. microsporus var. rhizopodiformis can be considered an efficient producer of thermostable amylases, using raw residues of low cost as substrates. This information is of technological value, considering the importance of amylases for industrial hydrolysis.
分析了几种营养和环境参数对微小根霉根状变种生长及淀粉酶产生的影响。该真菌从巴西“塞拉多”的土壤中分离得到，在添加淀粉、甘蔗渣、燕麦粉或木薯粉的液体培养基中，于45℃时产生高水平的淀粉酶活性。培养基中的葡萄糖显著抑制淀粉酶活性。通过薄层色谱法分析水解产物，检测到葡萄糖是主要成分。该淀粉酶活性可水解多种底物，如支链淀粉、淀粉酶、糖原、普鲁兰多糖、淀粉和麦芽糖。通过高压液相色谱分析，葡萄糖始终是检测到的主要终产物。这些结果表明所研究的淀粉酶活性是一种葡糖淀粉酶，但也存在低水平的α-淀粉酶。与其他真菌相比，微小根霉根状变种可被视为利用低成本原料残渣作为底物的耐热淀粉酶高效生产者。考虑到淀粉酶对工业水解的重要性，这一信息具有技术价值。
