Saito K, Kawamura Y, Oda Y
Department of Upland Agriculture, National Agricultural Research Center for the Hokkaido Region, Memuro, 082-0071 Hokkaido, Japan.
J Ind Microbiol Biotechnol. 2003 Jul;30(7):440-4. doi: 10.1007/s10295-003-0071-z. Epub 2003 Jul 3.
Rhizopus oryzae strain NBRC 4707 produced lactic acid and ethanol more efficiently than strain NRRL 395 in potato pulp, an agricultural by-product of the starch industry. The two strains developed comparable activities of xylanase, cellulase, alpha-amylase, and glucoamylase, while the polygalacturonase activity of strain NBRC 4707 was double that of strain NRRL 395. The addition of commercial pectinase enhanced the formation of metabolites, suggesting that the degradation of pectic substances determines the fermentation of potato pulp by R. oryzae. Orange and apple peel were more effective in the induction of polygalacturonase activity than potato pulp, sugarbeet pulp, or wheat bran when used as a principal carbon source for fungal growth in a solid-state culture. The fungal cells in both types of fruit peel stimulated the fermentation of potato pulp and increased the quantity of lactic acid and ethanol to higher levels than those in other agricultural by-products.
米根霉NBRC 4707菌株在淀粉工业的农业副产品马铃薯浆中比NRRL 395菌株更有效地产生乳酸和乙醇。这两种菌株的木聚糖酶、纤维素酶、α-淀粉酶和葡糖淀粉酶活性相当，而NBRC 4707菌株的聚半乳糖醛酸酶活性是NRRL 395菌株的两倍。添加商业果胶酶可增强代谢产物的形成，这表明果胶物质的降解决定了米根霉对马铃薯浆的发酵。当用作固态培养中真菌生长的主要碳源时，橙皮和苹果皮在诱导聚半乳糖醛酸酶活性方面比马铃薯浆、甜菜浆或麦麸更有效。两种果皮中的真菌细胞都刺激了马铃薯浆的发酵，并使乳酸和乙醇的产量比其他农业副产品中的更高。
