Cutter C N, Siragusa G R
United States Department of Agriculture, Agricultural Research Service, Roman L. Hruska US Meat Animal Research Center, Clay Center, NE 68933, USA.
Lett Appl Microbiol. 1996 Jul;23(1):9-12. doi: 10.1111/j.1472-765x.1996.tb00018.x.
Lean and adipose beef carcass tissues inoculated with Brochothrix thermosphacta (BT) (approx. 4.50 log10 cfu cm-2) were left untreated (U) or treated with 100 micrograms ml-1 nisin (N), calcium alginate (A) or 100 micrograms ml-1 nisin immobilized in a calcium alginate gel (AN). Tissue samples were refrigerated after treatments and bacterial populations and nisin activity were determined at 0, 1, 2 and 7 d. U, A and N treatments of lean and adipose tissues did not suppress bacterial growth ( > 6 log10 cfu cm-2 by day 7) while treatments of lean and adipose tissues with AN suppressed bacteria ( > 2.42 log10 cfu cm-2 by day 7). Bacteriocin titres from both tissues were higher in AN vs N samples after the 7 d incubation. This study demonstrates that immobilization of nisin in a gel may be a more effective delivery system of a bacteriocin to the carcass surface than direct application.
用嗜热栖热丝菌（BT）（约4.50 log10 cfu cm-2）接种的瘦肉和脂肪牛肉胴体组织，一部分不做处理（U），另一部分分别用100微克/毫升的乳酸链球菌素（N）、海藻酸钙（A）或固定在海藻酸钙凝胶中的100微克/毫升乳酸链球菌素（AN）进行处理。处理后将组织样本冷藏，并在0、1、2和7天测定细菌数量和乳酸链球菌素活性。瘦肉和脂肪组织的U、A和N处理均未抑制细菌生长（到第7天>6 log10 cfu cm-2），而瘦肉和脂肪组织用AN处理则抑制了细菌生长（到第7天>2.42 log10 cfu cm-2）。孵育7天后，两种组织的AN样本中的细菌素滴度均高于N样本。这项研究表明，将乳酸链球菌素固定在凝胶中可能是一种比直接应用更有效的将细菌素递送至胴体表面的系统。
