Peleg Y, Rokem J S, Goldberg I
Department of Applied Microbiology, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
FEMS Microbiol Lett. 1990 Feb;55(3):233-6. doi: 10.1016/0378-1097(90)90001-7.
A simple plate-assay has been developed to screen microorganisms for L-malic acid production. Acid producing organisms were identified, after microbial colony growth on media containing glucose or fumaric acid as sole carbons sources, by formation of a dark halo of formazan. The halo was observed when the plate was covered with a soft agar overlay containing NAD(+)-malate dehydrogenase, NAD+, phenazine methosulfate (PMS) and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT). The assay developed is simple, specific for L-malic acid and therefore can be used to identify L-malic acid producing filamentous fungi using glucose as carbon source (e.g. Aspergillus strains). The assay is also applicable for screening bacteria with high fumarase activity, able to convert fumaric acid to L-malic acid.
已开发出一种简单的平板测定法，用于筛选产L-苹果酸的微生物。在以葡萄糖或富马酸作为唯一碳源的培养基上微生物菌落生长后，通过形成暗蓝色的甲臜环来鉴定产酸微生物。当平板覆盖有含有NAD(+)-苹果酸脱氢酶、NAD+、硫酸吩嗪甲酯（PMS）和3-[4,5-二甲基噻唑-2-基]-2,5-二苯基溴化四唑（MTT）的软琼脂覆盖层时，可观察到该光环。所开发的测定法简单，对L-苹果酸具有特异性，因此可用于鉴定以葡萄糖为碳源产L-苹果酸的丝状真菌（例如曲霉属菌株）。该测定法也适用于筛选具有高延胡索酸酶活性、能够将富马酸转化为L-苹果酸的细菌。
