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。     

盐干带鱼中葡萄球菌的分离鉴定及其特性研究

研究了盐干带鱼加工过程中各种微生物类群数量的变化,并对产品中葡萄球菌进行了分离鉴定和生物学特性研究。结果表明,整个加工过程中细菌总数、酵母、乳酸菌、葡萄球菌和微球菌均呈现逐步增加趋势,葡萄球菌是盐干带鱼中重要微生物类群之一。从产品中分离得到葡萄球菌疑似菌株20株,经鉴定初步确定为木糖葡萄球菌(7株)、松鼠葡萄球菌(3株)、马胃葡萄球菌(3株)、腐生葡萄球菌(3株)和耳氏葡萄球菌(2株),其余2株未能鉴定种类,其中木糖葡萄球菌为优势葡萄球菌。与耳氏葡萄球菌相比,木糖葡萄球菌和松鼠葡萄球菌具有良好的生长性能和耐盐性;酶活性实验表明,松鼠葡萄球菌具有弱蛋白酶活性,木糖葡萄球菌具有弱脂肪酶活性。     

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。     

肉品发酵剂葡萄球菌和微球菌的筛选

应用一种快速半定量平板方法初步筛选可作为肉品发酵剂的葡萄球菌和微球菌。从中式传统肉制品中分离、纯化了 1 0 0多株葡萄球菌和微球菌 ,将菌株点种在加有KNO3的琼脂平板 ,据菌落周围显示的红圈大小挑选出硝酸盐还原酶活性较高的菌株 ,同时具有一定蛋白酶和脂肪酶活性的菌株进行发酵适应性试验。筛选出 1株过氧化氢酶阳性球菌 ,经初步鉴定为肉糖葡萄球菌S1 5。通过在模拟肉汤培养基中和乳酸菌混合培养确定了一种复配方案P2 0 +S1 5。将混合发酵剂用于发酵香肠的制作 ,测定微生物和理化指标 ,并用仪器测定标准化部分感官指标     

低盐发酵香肠用优良菌株的分离筛选及鉴定

从10 种我国自然发酵制品中分离纯化得到52 株乳酸菌及56 株过氧化氢酶阳性球菌,首先通过菌株耐受性、发酵特性等指标对菌株进行初步筛选,然后利用抑菌特性和风味特性对菌株进行复筛,选择可能改善低盐发酵香肠安全性和风味的优良菌株,最终筛选得到3 株葡萄球菌Z9、L2和R2,以及4 株乳酸菌P6、P12、X和SN1-3。经由形态学特征、生理生化特征及16S rDNA序列分析对筛选得到的菌株进行鉴定,结果表明,葡萄球菌菌株Z9、L2为腐生葡萄球菌,R2为肉葡萄球菌;乳酸菌菌株P6、P12均为植物乳杆菌,X为干酪乳杆菌,SN1-3为戊糖片球菌。最后测定菌株的生长特性及产酸能力,研究菌株间的拮抗特性,最终筛选得到戊糖片球菌SN1-3与肉葡萄球菌R2作为制作发酵香肠的复配菌株。     

火腿中葡萄球菌的分离、筛选及其生物学特性的研究

以产香、产鲜作为菌株筛选的第一指标，筛得符合要求的菌株5株，并研究了它们的生理生化特性．试验结果表明，它们的最适生长温度在30℃-35℃，都具有较强的食盐、亚硝酸盐的耐受力，C141、C231既具有蛋白酶活性又具有脂肪酶活性，C131、C155、C156只具有脂肪酶活性，无蛋白酶活性。     

易门豆豉中芽孢杆菌分离筛选及产酶特性研究

该研究从云南传统发酵豆制品易门豆豉中分离筛选获得产淀粉酶、蛋白酶、脂肪酶和纤维素酶的芽孢杆菌,利用水解圈法初筛、摇瓶发酵复筛得到产酶菌株,并对产酶较高的菌株进行生长性能分析和分子生物学鉴定。结果表明,从易门豆豉中分离纯化得到64株菌,筛选得到1株产淀粉酶和蛋白酶能力均较好菌株NB-13,其淀粉酶和蛋白酶活力分别为100.64 U/m L和34.30 U/m L;1株产脂肪酶能力较好的菌株ND-21,其脂肪酶活力为39.95 U/m L;2株产纤维素酶能力较好的菌株,菌株ND-38、NB-55,其纤维素酶活力分别为1.65 U/m L和1.72 U/m L;由生长状况结果可知,菌株ND-21和NB-13富集的菌量最多,生长能力最强;菌株NB-13和NB-55分别被鉴定为枯草芽孢杆菌（Bacillus subtilis）和解淀粉芽孢杆菌（Bacillus amyloliquefaciens）,菌株ND-21、ND-38被鉴定为地衣芽孢杆菌（Bacillus licheniformis）。     

浏阳豆豉发酵中高产酶活菌株的分离鉴定及酶活性分析

从浏阳豆豉发酵过程中分离产高酶活菌株,通过形态观察结合分子生物学技术进行鉴定,并对其产蛋白酶、脂肪酶及纤维素酶的活性进行分析。结果表明,分离得到3株菌（编号为000、5132、621）均被鉴定为溜曲霉菌（Aspergillus tamarri）。3株菌的蛋白酶、脂肪酶及纤维素酶的活性测定结果表明,菌株621蛋白酶活性最强,为（207.98±3.20）U/mL;菌株5132的纤维素酶活性最强,为（3.40±1.40）U/mL;菌株000的脂肪酶活性最高,为（90.7±0.64）U/mL。     

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。     

广式腊肠中高产脂肪酶葡萄球菌的选育

从广式腊肠中的28株葡萄球菌中,经初筛和复筛,获得产脂肪酶活力较高的菌种M1和M14.以M1和M14为起始菌株,经过微波和紫外单独诱变、微波复合紫外和紫外叠加诱变,选育一株产脂肪酶活力高、酶活的遗传性稳定的菌株M14-W-UV-Ⅰ,酶活为5.26 U/mL,是初始菌株M14的8倍.产酶培养基的初步优化结果表明,M14-W-UV-Ⅰ产酶最适的碳源和氮源分别是1%可溶性淀粉和1%蛋白胨,最适的诱导剂是1%橄榄油,优化后获得的最高酶活为17.54 U/mL.     

Characterization and technological properties of Staphylococcus xylosus strains isolated from a Tunisian traditional salted meat

The technological properties of strains of Staphylococcus xylosus were studied to select the most suitable for use as starter cultures for the production of dried fermented meat products. Strains of S. xylosus were isolated from traditional salted Tunisian meat and were identified by biochemical and molecular methods. Thirty strains of S. xylosus were studied to evaluate their catalase, nitrate reductase, lipolytic, proteolytic and antibacterial activities as well as growth ability at different temperatures, pH's and NaCl concentrations. All strains of S. xylosus had catalase activity and were able to reduce nitrates to nitrites. The nitrate reductase activity increased when the strains were kept under anaerobic conditions. Proteolytic activity on milk and on gelatin agar was demonstrated for 100% and 83.3% of the S. xylosus isolates, respectively. However extracellular proteolytic activity as assessed by the azocasein method was poor in all the strains. Lipolytic activity as assessed by the agar method showed that 76.6% of strains of S. xylosus could hydrolyze Tween 20 against 33.3% that could hydrolyze tributyrin. Tween 80 was hydrolyzed by only 10% of strains. Strains of S. xylosus hydrolyzed pork fat better than beef and lamb fat. The majority of strains had antibacterial activity against Salmonella arizonae, Staphylococcus aureus, Pseudomonas aeuroginosa, Escherichia coli and Enterococcus faecalis.     

传统鱼制品中优良葡萄球菌的筛选与鉴定

从盐干鱼及糟腌鱼中分离纯化得到158株葡萄球菌,按照肉制品发酵剂筛选标准,获得3株优良葡萄球菌S8、S61和S92,其具有良好的生长特性及耐盐性。经梅里埃VITEK-2全自动微生物系统鉴定及16SrDNA序列分析,优良葡萄球菌S8、S61和S92分别为沃氏葡萄球菌(Staphylococcus warneri)、松鼠葡萄球菌(Staphylococcus sciuri)和木糖葡萄球菌(Staphylococcus xylosus)。     

Characterisation of Micrococcaceae isolated from different varieties of chorizo

A total of 426 strains of Micrococcaceae bacteria isolated from chorizo (a traditional Spanish fermented sausage) were identified. The chorizos were sampled from three regions of Castilla and León in Spain: Burgos, Segovia and Salamanca. Two factories were chosen in each region and the samples were taken at three stages of ripening. Staphylococcus xylosus was the most predominant species isolated (95%). Twelve strain types of S. xylosus were established according to their fermentation patterns, and two of them, S. xylosus type 2 and S. xylosus type 5, made up the majority of the strains of S. xylosus isolated (27 and 52%). Production of acetoin, nitrate reductase, urease activity, proteolytic and lipolytic activity were determined for all isolates. The percentage of strains of S. xylosus producing acetoin depends on the manufacturing location. In general, the proteolytic and lipolytic activities of the S. xylosus isolated from chorizo from Castilla and León were low and moderate; 97% of the strains showed nitrate reductase and urease activity. According to our results and to previous investigations, it seems that S. xylosus type 5, showing nitrate reductase and urease activity, low-moderate proteolytic and lipolytic activities and not producing acetoin would be suitable as a starter culture. Of the strains isolated in this study, 38% comply with these requirements.     

Biochemical and sensory characteristics of traditional fermented sausages of Vallo di Diano (Southern Italy) as affected by the use of starter cultures

In this study, two strains of Staphylococcus xylosus isolated from traditional fermented sausages of Vallo di Diano (Southern Italy) were used in combination with an acidifying strain of Lactobacillus curvatus as starter culture for the production of fermented sausages. Two starter formulation were developed combining the proteolytic but not lipolytic (prt(+), lip(-)) S. xylosus CVS11 with the L. curvatus AVL3 (starter S1) and the S. xylosus FVS21 (prt(-), lip(+)) with the same strain of L. curvatus (starter S2). Proteolysis and lipolysis were observed during ripening by the increase in total free amino acids (FAA) and free fatty acids (FFA), respectively. Such activities were observed in both started and non started sausages (control). Moreover, the proteolytic and lipolytic activities were detected in products started by both formulations irrespective of the presence of such activities in the strains used. Therefore, it was not possible to conclude whether the effect of proteolysis and lipolysis during ripening of the started fermented sausages was due to the activity of the starter cultures or to the action of meat endogenous enzymes.     

传统湖南腊肉中产香葡萄球菌的筛选及鉴定

从传统湖南腊肉中共分离到289株葡萄球菌,按照肉用发酵剂筛选的基本原则进行初筛,再以产3-甲基丁醛的能力为依据,测定初筛获得的菌株产香能力,然后以产硝酸还原酶、过氧化氢酶和抑制脂肪酸氧化的能力为指标进行复筛,得到1株安全的,产香性能优良,适用于肉制品发酵的葡萄球菌S52。生化鉴定和16S rRNA鉴定的结果表明,S52为模仿葡萄球菌。     

Technological activities of Staphylococcus carnosus and Staphylococcus simulans strains isolated from fermented sausages

The aim of this study was to determine the technological properties of 2 strains of Staphylococcus simulans (Ssm12, Ssm21) and 4 strains of S. carnosus (SC28, SC31, SC54 and SC55) for the selection of a potential starter cultures to employ in the processing of dry fermented sausages. The strains were studied to evaluate nitrate reductase, proteolytic, lipolytic, decarboxylase and antioxidant activities as well as growth ability at different temperatures, pH and NaCl concentrations. Nitrate reductase activity was determined at 15, 20 and 30 °C. By spectrophotometric method all the strains were able to reduce nitrate to nitrite at the different temperatures but these results were not confirmed by the agar plate method. Antioxidant and lipolytic activities were evaluated by spectrophotometric assay. All the strains showed antioxidative enzymes superoxide dismutase (SOD) and catalase whereas all appeared unable to hydrolyse pork fat. Proteolytic activity was determined by agar plate method, spectrophotometric assay (OPA) and sodium dodecyl sulphate gel-electrophoresis (SDS–PAGE) and all strains appeared to be able to hydrolyse sarcoplasmic proteins but not myofibrillar proteins. Finally, all the strains grew at 15 and 20 °C, in presence of 10%, 15% and 20% of NaCl and at pH 5.0 and 5.5 and were unable to produce histamine, cadaverine and putrescine. The results showed that all strains studied possess useful technological activities that would make them eligible as a good starter cultures for fermented sausages.     

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.     

Technological and safety characterization of coagulase-negative staphylococci from traditionally fermented sausages of Basilicata region (Southern Italy)

Thirty-seven strains of coagulase-negative staphylococci, isolated from traditional fermented sausages of Basilicata region, were screened on the basis of their technological properties (nitrate reductase, proteolytic, lipolytic, amino acid-decarboxylase and antimicrobial activities) and for their ability to grow in the presence of different salt concentrations, temperatures and pH values, to elucidate their possible role during meat fermentation process.     

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。