新疆传统香肠中抗李斯特菌乳酸菌的分离

香肠在贮藏末期,乳酸菌检出量很高,其中还有一些具有抑制其他微生物的乳酸菌。在北疆市场上抽到8批样品,真空包装后,将其贮藏在4℃条件下,分别在贮藏前后检测其理化指标。各样品的pH值、水分活度和盐分基本一致;香肠中微生物的生长也比较一致,初期乳酸菌水平比较低(102CFU/g),贮藏末期,乳杆菌占多数(107CFU/g),肠杆菌相对较低(105CFU/g)。这表明,乳酸菌具有相对的竞争优势。其中,贮藏前后,样品中均没有检出李斯特菌。抑菌圈试验发现,分离出的乳酸菌中有41%对李斯特菌有抑菌特性,经过进一步试验,发现大部分的乳酸菌不具有产细菌素能力,但这些乳酸菌仍然具有竞争优势,对于香肠的贮藏仍有积极的作用。

Anti-listerial Inhibitory Lactic Acid Bacteria Isolated from Sausage in Xinjiang

The natural microflora of sausage at the end of shelf-life are lactic acid bacteria.Some of these bacteria display an ability to inhibit other pathogenic micro-organisms.Eight batches of sausage from shihezi,Karamay and tacheng were collected at retail.Packs were stored at 4℃ and examined for chemical and microbiological characteristics at purchase date and at expiration date.pH,water activity and salt content were similar among all these products.There was a consistent pattern in the development of the microflora on sausage.The initial level of LAB was low on freshly produced sausage(102 CFU/g).At the end of the stated shelf-life,these micro-organisms represented mainly by Lactobacillus spp.attained 107 CFU/g while Enterobacteriaceae counts were consistently lower(105 CFU/g),which indicated that lactic acid bacteria had relatively competitive advantage.L.monocytogenes was not found in any sample.Forty-one percent of isolated LAB strains exhibited inhibitory ability against Listeria innocua in a plate assay.A majority of the inhibitory effects were non-bacteriocinogenic,but these lactic acid bacteria still had a competitive advantage for the storage of the sausage.