Abstract: Longxi bacon is a traditional fermented meat products. Using Longxi bacon as the raw material, the dominant lactic acid bacteria (LAB) during the processing were isolated and identified by the methods of classic morphological classification, physiological and biochemical identification. Then the strains with excellent fermentation performance were screened by a series of tests, including acid-producing ability, growth characteristics, tolerance to sodium chloride and sodium nitrite, capability of producing gas, mucus, protease and lipase. Whereafter, raw meat was fermented by artificially inoculating the superior strain in order to analyze its effect on the sensory quality of bacon. The results showed that seven strains of LAB screened from Longxi bacon were identified as Lactobacillus plantarum, L. sake, Lactococcus lactis, Pediococcus pentosaceus, Leuconostoc mesenteroides, L. alimentarius and L. curvatus, respectively. Among them, the strain R-1 which was identified as Lactobacillus plantarum had strong acid-producing ability, fast growth rate and good tolerance to sodium chloride and sodium nitrite. The simulating fermentation test of bacon revealed that the flavor of Longxi bacon had been improved after inoculating strain R-1, and it showed better sensory acceptance. The research indicated that Lactobacillus plantarum R-1 had good fermentation performance，and it could be used as a source of strain for the modernization of traditional fermented bacon.

Key words: Longxi bacon, lactic acid bacteria, isolation, identification, fermentation performance

摘要： 陇西腊肉是一种传统发酵风味肉制品。以陇西腊肉为材料，通过经典形态学分类和生理生化鉴定，对其加工过程中的优势乳酸菌（lactic acid bacteria，LAB）进行分离、鉴定。通过测定菌株的产酸能力、生长特性、耐氯化钠和亚硝酸钠能力以及产气、产黏液、产蛋白酶和脂肪酶的能力等，筛选具有优良发酵性能的菌株。随后，开展人工接种优良菌株的模拟腊肉加工试验，分析其对腊肉感官品质的影响。结果表明，从陇西腊肉中筛选获得7株乳酸菌，根据菌种形态学分类，初步鉴定分别为植物乳杆菌（Lactobacillus plantarum）、米酒乳杆菌（L. sake）、乳酸乳球菌（Lactococcus lactis）、戊糖片球菌（Pediococcus pentosaceus）、肠膜明串珠菌（Leuconostoc mesenteroides）、食品乳杆菌（L. alimentarius）和弯曲乳杆菌（L. curvatus），其中，菌株R-1（植物乳杆菌）产酸能力强、生长速度快，对氯化钠和亚硝酸钠均具有较好的耐受性。经模拟腊肉发酵试验发现，添加菌株R-1后，陇西腊肉的风味得到了较大改善，表现出更好的感官可接受性。研究表明，植物乳杆菌R-1具有优良的发酵性能，可作为传统陇西腊肉工艺现代化改造的菌株来源。

关键词: 陇西腊肉, 乳酸菌, 分离, 鉴定, 发酵性能