Abstract：
Chinese traditional fermented meat products in Guizhou province harbor a unique microbial community owing to particular geographical, environmental, and climatic conditions. In this study, coagulase-negative staphylococci (CNS) with high protease activity were isolated from a Guizhou traditional naturally fermented meat product, i.e., Qianwufu sausages. In addition, the potential of isolated CNS strains to be used as starter cultures in sausage fermentation was evaluated. Culture- and molecular-biology-based methods were employed to isolate and identify CNS. A total of 40 CNS strains could hydrolyze pork meat proteins. In particular, strain QB7 identified as Staphylococcus simulans had the highest proteolytic activity, was resistant to growth in the presence of 6.5 % NaCl and 150 mg/kg of nitrites, and lacked virulence genes, hemolytic, decarboxylase, DNase, and biofilm-forming activities. Subsequently, S. simulans QB7 was used as a starter in sausage fermentation, which led to an increase in competitiveness of dominant bacteria, reduced growth of undesirable bacteria, higher content of total free fatty acids and free amino acids, and lower pH and water activity values. Thus, S. simulans QB7 can potentially be used as a starter to improve the quality and nutritional properties of fermented meat products.
摘要：
中国传统的发酵肉制品在贵州省具有独特的微生物群落,环境,和气候条件。在这项研究中,从贵州传统的自然发酵肉制品中分离出具有高蛋白酶活性的凝固酶阴性葡萄球菌（CNS），即，千伏香肠。此外,评估了分离的CNS菌株在香肠发酵中用作发酵剂培养物的潜力。采用基于培养和分子生物学的方法来分离和鉴定CNS。总共40个CNS菌株可以水解猪肉蛋白质。特别是,被鉴定为模拟葡萄球菌的菌株QB7具有最高的蛋白水解活性，在6.5%NaCl和150mg/kg亚硝酸盐存在下对生长具有抗性，缺乏毒力基因，溶血,脱羧酶,DNase,和生物膜形成活性。随后，美国模拟物QB7被用作香肠发酵的发酵剂，这导致优势细菌的竞争力增加，减少不良细菌的生长，总游离脂肪酸和游离氨基酸含量较高，和较低的pH和水活度值。因此，S.simulansQB7可以用作发酵剂，以提高发酵肉制品的质量和营养特性。
