Smit B A, Engels W J M, Wouters J T M, Smit G
Department of Flavour, Nutrition and Ingredients, NIZO food research, P.O. Box 20, 6710 BA Ede, The Netherlands.
Appl Microbiol Biotechnol. 2004 Apr;64(3):396-402. doi: 10.1007/s00253-003-1447-8. Epub 2003 Nov 18.
Various microorganisms, belonging to the genera Lactococcus, Lactobacillus, Streptococcus, Leuconostoc, Bifidobacterium, Propionibacterium, Brevibacterium, Corynebacterium and Arthrobacter, used in dairy fermentations such as cheese making, were analysed for their potential to convert leucine into flavour components, most notably 3-methylbutanal. A large variation between and within species was observed for various enzyme activities involved in the conversion pathway, e.g. transaminases, alpha-hydroxy acid dehydrogenase and alpha-keto acid decarboxylase. In particular, alpha-keto acid decarboxylase activity-leading to 3-methylbutanal-was found to be present in only two of the strains tested. It is proposed that this activity is rate-controlling in the conversion pathway leading to the flavour compound 3-methylbutanal.
对各种用于奶酪制作等乳制品发酵的微生物进行了分析，这些微生物属于乳球菌属、乳杆菌属、链球菌属、明串珠菌属、双歧杆菌属、丙酸杆菌属、短杆菌属、棒状杆菌属和节杆菌属，分析它们将亮氨酸转化为风味成分（最显著的是3-甲基丁醛）的潜力。在所测试的菌株中，观察到参与转化途径的各种酶活性（如转氨酶、α-羟基酸脱氢酶和α-酮酸脱羧酶）在种间和种内存在很大差异。特别是，导致3-甲基丁醛的α-酮酸脱羧酶活性仅在两个测试菌株中存在。有人提出，这种活性在导致风味化合物3-甲基丁醛的转化途径中起速率控制作用。
