van Laack R L, Schillinger U, Holzapfel W H
Department of The Science of Food of Animal Origin, Faculty of Veterinary Medicine, University of Utrecht, The Netherlands.
Int J Food Microbiol. 1992 Jul;16(3):183-95. doi: 10.1016/0168-1605(92)90079-i.
Twenty Leuconostoc strains isolated from vacuum packaged Vienna-type sausages were screened for antagonistic activity against various Gram-positive organisms (including Listeria spp.). One of the three strains exhibiting inhibitory activity was chosen for further investigation. This strain was identified as Leuc. carnosum and the inhibitory substance produced was named carnosin. Carnosin was inactivated by trypsin but not by catalase or other non-proteolytic enzymes tested. Carnosin retained activity after heating at 100 degrees C for 20 min, whereas heating at 121 degrees C for 15 min resulted in complete loss of activity. Carnosin was active at pH values ranging from 2 to 9. Carnosin activity was not detectable until cells were in the late log-phase of growth. At low temperatures (4 degrees C), higher cell densities were required before carnosin activity could be detected. Carnosin was active against various lactic acid bacteria, Enterococcus faecalis and Enterococcus faecium and against Listeria spp. Difficulties in purification were reduced by growing Leuc. carnosum in a modified MRS medium, having 50% of the normal peptone concentration and no Tween or meat extract. Sodium dodecyl sulphate polyacrylamide gel electrophoresis of partially purified carnosin indicated that it has a molecular mass between 2510 and 6000 Da. Yet, retention of activity after exhaustive dialysis suggested a molecular mass > 14kDa. It is hypothesized that carnosin forms large active complexes which can be dissociated to small (active) components.
从真空包装的维也纳型香肠中分离出20株明串珠菌菌株，筛选它们对各种革兰氏阳性菌（包括李斯特菌属）的拮抗活性。在表现出抑制活性的三株菌株中选择了一株进行进一步研究。该菌株被鉴定为肉明串珠菌，所产生的抑制物质被命名为肌肽。肌肽可被胰蛋白酶灭活，但不能被过氧化氢酶或其他测试的非蛋白水解酶灭活。肌肽在100℃加热20分钟后仍保留活性，而在121℃加热15分钟则导致活性完全丧失。肌肽在pH值为2至9的范围内具有活性。直到细胞处于生长对数后期才能检测到肌肽活性。在低温（4℃）下，需要更高的细胞密度才能检测到肌肽活性。肌肽对各种乳酸菌、粪肠球菌和屎肠球菌以及李斯特菌属具有活性。通过在改良的MRS培养基中培养肉明串珠菌来减少纯化的困难，该培养基的蛋白胨浓度为正常浓度的50%，且不含吐温或肉提取物。对部分纯化的肌肽进行十二烷基硫酸钠聚丙烯酰胺凝胶电泳表明，其分子量在2510至6000 Da之间。然而，经过彻底透析后仍保留活性表明分子量>14 kDa。据推测，肌肽形成了大的活性复合物，这些复合物可以解离成小的（活性）成分。
