Taniguchi M, Nakazawa H, Takeda O, Kaneko T, Hoshino K, Tanaka T
Department of Materials Science and Technology, Faculty of Engineering, Niigata University, Japan.
Biosci Biotechnol Biochem. 1998 Aug;62(8):1522-7. doi: 10.1271/bbb.62.1522.
The antimicrobial activities of standard solutions of three organic acids (lactic, acetic, and propionic acids) were compared using Micrococcus luteus, Pseudomonas sp. and Staphylococcus aureus as test microorganisms. At the same concentrations of the undissociated form, the antimicrobial activities of acetic and propionic acids were higher than that of lactic acid, irrespective of test microorganisms. In a single cultivation of Bifidobacterium longum, a mixture of lactic (17 g/l) and acetic (20 g/l) acids was produced from 50 g/l lactose and its antimicrobial activities against M. luteus, Pseudomonas sp., and S. aureus correspond to that of 32, 19, and 25 g/l of acetic acid, respectively. To increase the total antimicrobial activity, a co-culture of B. longum and Propionibacterium freudenreichii, in which lactic acid produced once from lactose by B. longum was converted to acetic and propionic acids by P. freudenreichii, was done using TPY medium containing commercially available peptones as a nitrogen source. By the sequential conversion of lactose using the two microorganisms, the culture supernatant containing a mixture of acetic (27 g/l) and propionic (13 g/l) acids without lactic acid was produced. The antimicrobial activities of the mixture against M. luteus, Pseudomonas sp., and S. aureus were 35, 30, and 26 g/l as a concentration of acetic acid, respectively, higher than that obtained in the cultivation of B. longum alone. When the medium containing an enzymatic hydrolyzate of whey proteins with a protease was used in the co-culture of B. longum and P. freudenreichii, the culture supernatant containing the mixture of organic acids was also obtained in the same manner as the co-culture using TPY medium and the activities were 43, 29, and 29 g/l as a concentration of acetic acid for M. luteus, Pseudomonas sp. and S. aureus, respectively.
以藤黄微球菌、假单胞菌属和金黄色葡萄球菌作为测试微生物，比较了三种有机酸（乳酸、乙酸和丙酸）标准溶液的抗菌活性。在未解离形式浓度相同的情况下，无论测试微生物如何，乙酸和丙酸的抗菌活性均高于乳酸。在长双歧杆菌的单一培养中，由50 g/l乳糖产生了乳酸（17 g/l）和乙酸（20 g/l）的混合物，其对藤黄微球菌、假单胞菌属和金黄色葡萄球菌的抗菌活性分别相当于32、19和25 g/l乙酸的抗菌活性。为了提高总抗菌活性，使用含有市售蛋白胨作为氮源的TPY培养基，对长双歧杆菌和费氏丙酸杆菌进行共培养，其中长双歧杆菌由乳糖产生的乳酸被费氏丙酸杆菌转化为乙酸和丙酸。通过两种微生物对乳糖的顺序转化，产生了不含乳酸的乙酸（27 g/l）和丙酸（13 g/l）混合物的培养上清液。该混合物对藤黄微球菌、假单胞菌属和金黄色葡萄球菌的抗菌活性分别为35、30和26 g/l乙酸浓度，高于单独培养长双歧杆菌时获得的抗菌活性。当在长双歧杆菌和费氏丙酸杆菌的共培养中使用含有蛋白酶水解乳清蛋白的培养基时，也以与使用TPY培养基共培养相同的方式获得了含有有机酸混合物的培养上清液，其对藤黄微球菌、假单胞菌属和金黄色葡萄球菌的活性分别为43、29和29 g/l乙酸浓度。
