四川香肠中产香葡萄球菌的分离与鉴定

从四川自然发酵香肠中共分离得到242株微球菌和葡萄球菌,采用快速半定量平板方法从中筛选出了硝酸盐还原酶活性较大的株菌80株,并对这些菌株进行发酵基本实验和产香基本要求实验,筛选得到了2株过氧化氢酶阳性葡萄球菌S15和S25。通过GC-MS分析发现,在实验条件下只有S25具有代谢亮氨酸生成3-甲基丁醛的能力。生化鉴定以及菌株的16S rDNA测序结果表明,S25为腐生葡萄球菌。     

发酵肉用耐高温产香葡萄球菌优质菌株的筛选

为了开发发酵肉制品高温加工新工艺,首先需要获得新型耐高温肉用发酵剂。因此,从湘西腊肉中取样,通过耐盐性、耐酸性、产酶活性、硝酸盐还原能力等指标筛选出4株耐高温葡萄球菌S5、S9、S10和S20,鉴定为1株表皮葡萄球菌,2株华纳氏葡萄球菌,1株木糖葡萄球菌。该些菌株的耐盐、耐亚硝酸盐、耐高温和产香能力较强,有望在发酵肉制品生产中使用。     

肉品发酵剂葡萄球菌和微球菌的分离筛选及其与乳酸菌混合培养的研究

本试验采用MSA培养基从二十多种传统发酵肉制品中分离菌株198株，通过对分离菌株发酵特性试验，筛选出两株过氧化氢酶阳性球菌，经过初步鉴定为肉糖葡萄球菌(Staphylococcus carnosus)S15和S113，并研究了戊糖片球菌(Pediococcus pentosaceus)P20、米酒乳杆菌(Lactobacillus sake)J17分别同两株葡萄球菌在模拟肉汤中混合培养的相互关系，初步确定了肉品混合发酵剂P20 S15。     

肉品混合发酵剂的筛选及应用研究

研究了戊糖片球菌(Pediococcuspentosaceus)P20、米酒乳杆菌(Lactobacillussake)J17分别同两株肉糖葡萄球菌(Staphylococcuscarnosus)S15和S113在模拟肉汤培养基中混合培养的相互关系,初步筛选出没有拮抗作用的混合发酵剂P20 S15应用于发酵香肠,测定并分析了发酵和成熟过程中理化和微生物指标的变化,认为可以作为混合发酵剂用于香肠的生产。     

优良“老酸奶”发酵剂组合的筛选

为了筛选出优良的酸奶发酵剂,根据菌株的稳定性、发酵活力、凝乳时间等指标对23菌株(其中有13株球菌与10株杆菌)进行初步筛选,获得13株具有优良发酵特性的菌株(其中有7株球菌与6株杆菌)。根据单菌株发酵实验结果,按菌种性能互补原则将各球菌与杆菌复配,进行28个组合发酵实验,测定发酵速度、质构、乳清析出以及后酸化等指标。最终筛选出球菌S1、S4与杆菌L2,此组合与目前商业化直投发酵剂比具有发酵前期产酸速度快、发酵时间短的优点,而且具有天然的发酵香气,乳清析出量很少,适用于直投式发酵剂的生产。     

发酵香肠菌种的筛选及鉴定

本文从混合发酵剂中筛选菌株,确定用于发酵香肠生产的菌株名称,并对其筛选出的菌种进行生化鉴定,结果如下:RFx1为植物乳杆菌,RF261为德氏乳杆菌,AFx1为变异微球菌,ALx3为肉糖葡萄球菌。     

自然发酵腊肉中细菌的分离鉴定及其发酵特性

为探究适合发酵肉制品的细菌性发酵菌株,以信阳腊肉、四川腊肉、云南腊肉和湖南腊肉为材料,以菌株的安全性、生产适应性、发酵性能等为指标,通过菌株的分离筛选、16S rDNA测序、基础发酵特性研究,确定自然发酵腊肉中的细菌种类,以及各菌株作为发酵剂的适宜性。结果表明,分离、鉴定出5株具有较高耐盐性、耐亚硝盐性、耐酸性且发酵性能优良的菌株,分别为乳链球菌、腐生葡萄球菌、木糖葡萄球菌、马葡萄球菌和肠膜明串珠菌。筛选的5株菌株有望作为腊肉生产中的发酵菌种。     

发酵香肠菌种的筛选及鉴定

本文从混合发酵剂中筛选菌株,确定用于发酵香肠生产的菌株名称,并对其筛选出的菌种进行生化鉴定,结果如下:RFx1为植物乳杆菌,RF261为德氏乳杆菌,AFx1为变异微球菌,ALx3为肉糖葡萄球菌.     

发酵香肠菌种的筛选及鉴定

从混合发酵剂中筛选菌株，确定用于发酵香肠生产的菌株名称，并对其筛选出的菌种进行生化鉴定，结果如下：RFx1为植物乳杆菌，RF261为德氏乳杆菌，AFx1为变异微球菌，ALx3为肉糖葡萄球菌。     

中式发酵香肠用发酵剂混合菌种的研究

将玫瑰色微球菌、干酪乳杆菌、植物乳杆菌、戊糖片球菌、嗜酸乳杆菌、木糖葡萄球菌采用正交试验法组合为 9组发酵剂 ,考察了发酵肠的 pH值、水分含量、乳酸菌活菌数、感官品质等的变化规律。结果表明 ,混合球菌更适合于作为发酵肠的发酵剂。经优化组合 ,筛选出了由葡萄球菌、干酪乳杆菌、玫瑰色微球菌、嗜酸乳杆菌、戊糖片球菌等混合菌制备的发酵剂 ,是符合发酵肠GMP要求的快速发酵剂 ,且经济合理 ,并赋予产品良好的风味。发酵条件 :37℃ ,RH >80 % ,2 0h。     

鲊肉粉中乳酸菌和葡萄球菌的筛选及鉴定

从传统发酵鲊肉粉中分离、筛选发酵性能优良的乳酸菌和葡萄球菌,为鲊肉粉接种发酵提供理论依据。按照肉制品发酵菌株的筛选标准,利用形态学特征和16S rDNA序列分析鉴定菌株,筛选出2株乳酸菌A1、C7和2株葡萄球菌S6、S7。结果表明:乳酸菌菌株A1、C7均为植物乳杆菌(Lactobacillus plantarum),能快速产酸,具有较好抑菌特性;葡萄球菌菌株S6为沃氏葡萄球菌(Staphylococcus warneri),S7为巴氏葡萄球菌(Staphylococcus pasteuri),能产蛋白酶和脂肪酶,具有良好的耐盐性和耐亚硝酸盐性,对不同抗生素有不同的敏感性。筛选得到的4株菌株具有良好的发酵特性,乳酸菌和葡萄球菌之间无拮抗作用,复配后用可于鲊肉粉接种发酵。     

Isolation and technological properties of coagulase negative staphylococci from fermented sausages of Southern Italy

The aims of this study were to characterize the population of Micrococcaceae in different types of fermented sausages of Southern Italy and to determine the technological properties of Staphylococcus strains in order to evaluate the suitability of selected strains as starter cultures in the processing of dry fermented pork sausages. Ninety-six strains were studied to evaluate nitrate reductase, proteolytic, lipolytic and antioxidant activities as well as growth ability at different temperatures, pH's and NaCl concentrations. All the strains were classified as Staphylococcus except for one isolate assigned to Kocuria spp. The species most often isolated were S. saprophyticus, S. xylosus and S. equorum, although they were not equally distributed within the different sausages. Other species isolated were, in descending order of abundance, S. succinus, S. warneri, S. lentus, S. vitulus, S. pasteuri, S. epidermidis, and S. haemolyticus. In general, the S. xylosus strains exhibited the best technological properties that would make them eligible as good starter cultures for fermented meat products. However, strains belonging to other species also showed good technological properties. Finally, all strains grew at 10, 15 and 20 °C, in the presence of 10% and 15% of NaCl and at pH 5.0 and 5.5. The results showed that it is possible to formulate a broad variety of staphylococcal starter cultures, adaptable to different technological conditions and sausage manufacture practices.     

发酵肉制品中葡萄球菌的分离、鉴定及其对肉蛋白的降解能力

为在筛选用于肉制品发酵的有益葡萄球菌,通过划线分离,从发酵肉制品中筛选出54株菌,根据菌株耐盐性及16S DNA测序结果,选择8株耐盐葡萄球菌做血浆凝固酶试验。经鉴定,其中6株呈凝固酶阴性。将凝固酶阴性葡萄球菌胞外蛋白酶与肌肉蛋白孵育20 h,分析其对肌肉蛋白的降解性能。试验结果表明,6株葡萄球菌胞外蛋白酶对肌浆蛋白250 ku处的蛋白条带有一定的降解能力,然而对肌原纤维蛋白无明显降解作用。     

发酵肉制品常见乳酸菌的发酵性能研究

选择发酵肉制品中常见的6株乳酸菌,对其发酵性能进行研究,结果表明:6株菌均有较强的耐亚硝酸盐能力,其中植物乳杆菌、干酪乳杆菌、清酒乳杆菌、发酵乳杆菌能够耐受6%食盐,且无蛋白和脂肪分解能力。发酵乳杆菌产酸能力弱,不能有效控制致病菌的生长,不适合单独作为发酵剂使用。清酒乳杆菌、植物乳杆菌和干酪乳杆菌能够有效降低pH值,抑制致病菌的生长,适合发酵肉制品的生产。     

腌腊肉制品中乳酸菌的筛选鉴定及其在腊肠中的应用

为筛选适合传统腌腊肉制品的优良乳酸菌菌株,从多种农家自制传统腌腊肉制品中分离纯化出9株优势乳酸菌。通过发酵特性筛选,得到一株性状优良菌株10M-7,并制备该菌株的干粉发酵剂,以未接种发酵剂腊肠为对照,分析此发酵剂对腊肠感官品质和微生物变化的影响。结果表明,10M-7菌株具有良好的产酸特性和抑菌性能。根据形态学、生理生化特征和16S rRNA序列分析,鉴定其为植物乳杆菌,采用冷冻干燥法制备纯种发酵剂,并制作人工发酵腊肠。发酵剂组pH值在初期便迅速下降,且始终低于对照组;发酵剂组乳酸菌迅速生长繁殖,且葡萄球菌和大肠杆菌数量与对照组相比明显降低。感官评价表明,当添加量为10~4CFU/g原料肉时,能够很好地保持和改善产品风味,使产品整体感觉更好。     

Streptococcus parauberis associated with modified atmosphere packaged broiler meat products and air samples from a poultry meat processing plant

Lactic acid bacteria (LAB) isolated from marinated or non-marinated, modified atmosphere packaged (MAP) broiler leg products and air samples of a large-scale broiler meat processing plant were identified and analyzed for their phenotypic properties. Previously, these strains had been found to be coccal LAB. However, the use of a 16 and 23S rRNA gene RFLP database had not resulted in species identification because none of the typically meat-associated LAB type strains had clustered together with these strains in the numerical analysis of the RFLP patterns. To establish the taxonomic position of these isolates, 16S rRNA gene sequence analysis, numerical analysis of ribopatterns, and DNA-DNA hybridization experiments were done. The 16S rRNA gene sequences of three isolates possessed the highest similarities (over 99%) with the sequence of S. parauberis type strain. However, in the numerical analysis of HindIII ribopatterns, the type strain did not cluster together with these isolates. Reassociation values between S. parauberis type or reference strain and the strains studied varied from 82 to 97%, confirming that these strains belong to S. parauberis. Unexpectedly, most of the broiler meat-originating strains studied for their phenotypical properties did not utilize lactose at all and the same strains fermented also galactose very weakly, properties considered atypical for S. parauberis. This is, to our knowledge, the first report of lactose negative S. parauberis strains and also the first report associating S. parauberis with broiler slaughter and meat products.     

Protective cultures inhibit growth of Listeria monocytogenes and Escherichia coli O157:H7 in cooked, sliced, vacuum- and gas-packaged meat

Contamination of cooked meat products with Listeria monocytogenes poses a constant threat to the meat industry. The aim of this study was therefore to investigate the use of indigenous lactic acid bacteria (LAB) as protective cultures in cooked meat products. Cooked, sliced, vacuum- or gas-packaged ham and servelat sausage from nine meat factories in Norway were inoculated with 10(3) cfu/g of a mixture of three rifampicin resistant (rif-mutant) strains of L. monocytogenes and stored at 8 degrees C for four weeks. Growth of L. monocytogenes and indigenous lactic acid flora was followed throughout the storage period. LAB were isolated from samples where L. monocytogenes failed to grow. Five different strains growing well at 3 degrees C. pH 6.2, with 3% NaCl, and producing moderate amounts of acid were selected for challenge experiments with the rif-resistant strains of L. monocytogenes. a nalidixic acid/streptomycin sulphate-resistant strain of Escherichia coli O157:H7 and a mixture of three rif-resistant strains of Yersinia enterocolitica O:3. All five LAB strains inhibited growth of both L. monocytogenes and E. coli O157:H7. No inhibition of Y. enterocolitica O:3 was observed. A professional taste panel evaluated cooked, sliced, vacuum-packaged ham inoculated with each of the five test strains after storage for 21 days at 8 degrees C. All samples had acceptable sensory properties. The five LAB strains hybridised to a 23S rRNA oligonucleotide probe specific for Lactobacillus sakei. These indigenous LAB may be used as protective cultures to inhibit growth of L. monocytogenes and E. coli O157:H7 in cooked meat products.     

乳酸菌在肉制品中的生物防腐作用

<正> 肉制品是人们喜爱的食物,并具备丰富的营养。它不但能补充人体所需,促进人体健康,亦是各种自然细菌滋长的良好基质,能提供理想的细菌繁殖和生长条件,导致产品易腐败,甚至使人生病。所以,肉制品的质量在很大程度上受细菌群落的种类影响;至于肉制品中细菌群落的种类,则取决于原料肉的质量、加工过程中原料肉的处理方法,以及运输和贮存时的温度。 在中国,目前经加工处理后出售的肉制品,只占肉类总产量的5～10％。