Table_1_Technological and Safety Characterization of Kocuria rhizophila Isolates From Traditional Ethnic Dry-Cured Ham of Nuodeng, Southwest China.DOCX

Nuodeng ham is known for its unique processing techniques and flavor. In the present study, proteolytic microorganisms from cured artisanal Nuodeng ham were investigated in order to identify and select potential starter cultures for its faster and safer fermentation. Eight isolates, accounting for 57% of proteolytic microorganisms, were found to be related to Kocuria rhizophila. Relevant properties of K. rhizophila as potential starter culture were evaluated in vitro for the first time. Intra-species diversities were found in phylogenetic and physiological properties of K. rhizophila isolates. Nevertheless, desirable attributes, such as halo-tolerance, nitrate reductase and protease activity, as well as the absence of antimicrobial resistance and amino acid decarboxylase activity, were observed in selected isolates. Moreover, genome analysis of isolates K24 and K45 confirmed their lack of typical genes for virulence, antimicrobial resistance and amino acid decarboxylase. K. rhizophila may thus represent a novel starter candidate of coagulase-negative cocci group and contribute to color and flavor development of fermented meats.

诺邓火腿凭借独特的加工技艺与风味著称。本研究针对手工腌制诺邓火腿中的蛋白水解微生物展开探究，旨在筛选并鉴定可用于该火腿快速、安全发酵的潜在发酵剂菌株。本次研究共分离得到8株菌，占所检测蛋白水解微生物总数的57%，经确认与嗜根库特菌（Kocuria rhizophila）具有密切亲缘关系。本研究首次在体外水平评估了嗜根库特菌作为潜在发酵剂菌株的相关特性。研究发现，不同分离株的嗜根库特菌在系统发育与生理特性层面存在种内多样性。不过，经筛选的分离株仍具备诸多优良特性：如耐盐性、硝酸还原酶活性与蛋白酶活性，且未检测出抗菌耐药性及氨基酸脱羧酶活性。此外，对分离株K24与K45的全基因组分析证实，二者均不携带致病性、抗菌耐药性及氨基酸脱羧酶相关的典型功能基因。由此可见，嗜根库特菌可作为凝固酶阴性球菌（coagulase-negative cocci）类群中的新型发酵剂候选菌株，同时有助于发酵肉制品的色泽与风味形成。