黑果枸杞酵素中乳酸菌和酵母菌的分离鉴定和安全性评价

为得到适合黑果枸杞发酵的菌株，采用形态学观察、16s rDNA、26S rDNA与ITS全序列分析分离鉴定自然发酵黑果枸杞酵素中的乳酸菌和酵母菌，并对其安全性进行评价，包括药敏试验、溶血试验和急性毒性试验。结果表明：从酵素中分离得到了三株菌株分别为类食品乳杆菌（Lactobacillus paralimentarius）（M4），植物乳杆菌（Lactobacillus plantarum）（M6）和库德里阿兹威毕赤氏酵母菌（Pichia kudriavzevii）（Y5）。2株乳酸菌对青霉素类、头孢类、β-内酰胺类、大环内酯类及四环素类等大多数常见抗生素无耐药性；酵母菌Y5除了对氟康唑表现为耐药外，对其余抗真菌类抗生素均未表现出耐药性。3株菌均无急性毒性，也未发现有溶血现象。试验初步验证了菌株的安全性，为三株菌在黑果枸杞酵素产品的研发与生产中的应用提供了基础研究数据。     

具有抗氧化功能的副干酪乳杆菌FM-LP-4和干酪乳杆菌FM-M9-1的安全性初步评价

对具有优良抗氧化性能的副干酪乳杆菌FM-LP-4和干酪乳杆菌FM-M9-1的安全性进行初步研究,为菌株的工业化应用提供理论依据。通过急性毒理实验、有害代谢产物测定、生物膜形成实验、溶血实验,耐药性测定及质粒提取实验,评价副干酪乳杆菌FM-LP-4和干酪乳杆菌FM-M9-1的安全性。结果表明急性毒理实验结果显示动物的体重变化正常而且主要脏器无异常;耐药性测定结果显示FM-LP-4和FM-M9-1菌株对8种抗生素没有耐药性,对万古霉素、庆大霉素和多粘菌素具有抗性;质粒提取结果显示FM-LP-4和FM-M9-1菌株不含有可转移的质粒;吲哚实验、硝酸盐还原酶实验和氨基脱羧酶实验结果均为阴性,说明在代谢活动中不产生有害代谢产物;菌株的溶血型是γ-型,不具有溶血活性;FM-LP-4和FM-M9-1菌株的无成膜能力。副干酪乳杆菌FMLP-4和干酪乳杆菌FM-M9-1安全性初步评价结果显示,两菌株具有良好的安全性,可以作为开发抗氧化功能食品和微生态制剂的备选优良益生菌菌株。     

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。     

R362菌株产黑色素的安全性研究

利用小鼠急性毒性试验、小鼠骨髓嗜多染红细胞微核试验、Ames试验和小鼠精子畸形试验对R362菌株产黑色素的食用安全性进行研究。急性毒性试验表明R362菌株产黑色素LD50为6.2 g/kg bw,为实际无毒级物质;而且毒理学试验检测表明均呈阴性,无致突变性,可以作为天然食用色素使用。     

两株干酪乳杆菌的安全性评价

干酪乳杆菌X-29和X-15是两株分离于黄酒浸米浆水中的乳酸菌,这两株菌均具有高的水解淀粉活性。本实验主要是评价这两株菌的安全性,为其应用于发酵米制品提供安全性保障。通过急性毒性实验、耐药性实验、有害代谢产物和溶血实验,确定这两株菌株是否具备安全性。结果表明该两株菌株不会引起急性毒性和易位现象;不产生有害代谢产物;对大部分常见抗生素没有耐药性;不会产生溶血现象。通过对这两株菌的安全性评价可知干酪乳杆菌X-29和X-15是安全的。     

五株有机高分子化合物降解菌的生物安全性分析

以分离自环洞庭湖水系的3个淡水湖渔场表层底泥样品中的2株产几丁质酶菌株及3株产胶原蛋白酶菌株为研究对象,对其进行酶活分析及分子生物学鉴定,并通过药敏性、溶血性、氨基酸脱羧酶活性及硝酸还原酶活性实验对其安全性进行评价。结果表明,2株产几丁质酶菌株AL1、BM1分别被鉴定为芽孢杆菌（Bacillus sp.）和假单胞菌（Pseudomonas sp.）;3株产胶原蛋白酶菌株ALJ1、BMJ1及DJ2分别被鉴定为Pseudomonas sp.、Pseudomonas sp.和微小杆菌（Exiguobacterium sp.）。安全性试验结果表明,菌株DJ2、BMJ1分别对6种和4种抗生素高度敏感,其余菌株仅对1种抗生素高度敏感;除菌株AL1外,其余4株菌均无溶血性;除菌株DJ2外,其余4株菌均有氨基酸脱羧酶活性;5株菌均无硝酸还原酶活性。综上,菌株BM1和DJ2是降解有机高分子化合物的较安全菌株,可将其应用于有机高分子化合物的降解。     

动物双歧杆菌乳亚种BZ25的安全性评价

从贵州特色香猪里筛选出耐酸、耐胆盐和降胆固醇能力较高的动物双歧杆菌乳亚种BZ25,对其进行安全性评价,包括急性毒性试验、药物敏感性试验、质粒提取、氨基酸脱羧酶活性检测和溶血试验。结果表明,该菌株无急性毒性,无质粒,对青霉素类抗生素普遍敏感,氨基糖苷类抗生素除新霉素外,均表现耐药,对四环素抗生素、大环内酯类抗生素和头孢类抗生素均表现敏感,不产生物胺,没有溶血现象。初步确定了菌株的安全性,对开发相应益生菌产品具有一定参考价值。     

灰树花菌丝体β-葡聚糖的毒理学实验

目的：对灰树花菌株GF-932 发酵菌丝体β- 葡聚糖的食用安全性进行初步研究及评价。方法：采用最大限量法进行急性毒性实验;通过微生物回复突变实验(Ames 实验)和小鼠骨髓嗜多染红细胞微核实验考察其致突变性;通过小鼠精原细胞染色体畸变实验和小鼠精子畸形实验考察其生殖毒性;通过大鼠30d 喂养实验进行体质量、进食量、血液和生化等指标测定。结果：灰树花菌丝体β- 葡聚糖小鼠急性毒性实验LD50 大于20g/kg bw;灰树花菌丝体β- 葡聚糖对鼠伤寒沙门氏菌组氨酸缺陷型菌株的回复突变实验结果为阴性;无致小鼠骨髓嗜多染红细胞微核作用,无致小鼠精原细胞染色体畸变作用,也无致小鼠精子畸形作用;大鼠30d 喂养实验期内,与对照组相比,体质量、食物利用率、血常规、血液生化、脏器系数等各项指标均无显著差异(P ＞ 0.05),各实验组大鼠生长发育良好。结论：灰树花菌株GF-932 发酵菌丝体β- 葡聚糖属实际无毒物质,无遗传毒性作用,对动物的生长发育无不良影响。     

自然发酵五彩椒中具有益生特性乳酸菌的筛选及鉴定

为获得具有益生功效的乳酸菌，采用钙溶圈法从自然发酵五彩椒发酵液中分离纯化乳酸菌，测定其耐酸能力，并对耐酸能力较强的菌株进行鉴定。结果表明，分离得到32株疑似乳酸菌，其中5株菌（编号为CA1-1,CA1-4,CA3-4,CA4-2,CA6-2）具有较强的耐酸能力。根据16S r RNA测序结果，菌株CA1-1、CA3-4、CA6-2分别被鉴定为发酵乳杆菌（Lactobacillus fermentum）、类肠膜魏斯氏菌（Weissella paramesenteroides）、嗜酸乳杆菌（Lactobacillus acidophilus），菌株CA1-4、CA4-2被鉴定为植物乳杆菌（Lactobacillus plantarum）。菌株CA1-1和CA4-2的产酸量（9.43 g/L和9.86 g/L）和胆盐处理4 h后的存活率（108.1%和96.51%）均高于其余菌株。此外，菌株CA1-1和CA4-2的耐胃肠道消化能力（胃液处理3 h后的存活率分别为82.4%和88.89%，肠液处理3 h后的存活率分别为38.4%和41.88%）、抗氧化能力（DPPH自由基清除率分别为46.84...     

胡桃楸种仁壳黄酮的急性毒性和Ames试验的结果分析

通过急性毒性试验和Ames试验,研究胡桃楸种仁壳黄酮的安全性。急性毒性试验表明胡桃楸种仁壳黄酮无急性毒性作用(LD5016 g/kg);Ames试验中胡桃楸种仁壳黄酮不诱发鼠伤寒沙门氏菌组氨酸缺陷型菌株TA98和TA100的回复突变。表明胡桃楸种仁壳黄酮无致突变性,为安全无毒物。     

传统乳制品中潜在益生植物乳杆菌的体外筛选

对从内蒙古牧区乳制品中分离到的29株植物乳杆菌的耐酸性（pH=3．0）、耐胆汁性（质量浓度3g／L牛胆酸钠）、抗菌活性进行了系统性研究。结果表明，有10株菌具有较好的耐酸耐胆盐特性，结合抗菌特性及黏附性试验结果，菌株WZ47-1，WZ32-2-1和WH13-2有可能成为潜在益生菌菌株。     

益生菌发酵剂发酵特性研究

选择干酪乳杆菌(Lactobacillu casei,Lc),嗜酸乳杆菌(Lactobacillus acdophilus,La),保加利亚乳杆菌(Lactobacillus bulgaricus,Lb)三种益生菌作为发酵肉发酵剂,对其发酵特性进行研究。结果表明:三种菌均有较强的耐亚硝酸盐、食盐能力,能够耐受150 mg/kg亚硝酸盐和6%食盐。所选菌种无蛋白和脂肪分解能力,能够有效降低pH,抑制致病菌的生长,适合发酵肉制品的生产。     

药食两用天麻的安全性评价研究进展

天麻是我国的名贵中药材,作为药食同源物质被广泛食用及药用。国家相关部门已经批准,将天麻按照传统既是食品又是中药材的物质进行试点管理。随着天麻药食同源在现代食品领域的广泛应用,有关天麻食品、功能性食品、活性物质、复方制剂等天麻制品的研究开发会越来越多。天麻制品的毒理学研究还不够深入,多为急性、遗传毒性试验,而亚急性、长期毒性试验的数据较少;天麻素、天麻复方制剂的临床安全性评估多为联合用药评价分析,缺乏单独使用的安全性数据。因此,探讨天麻的食用安全性对天麻制品开发具有一定的参考意义。本文概述了天麻制品的毒理学研究、临床安全性评价及环境污染风险评估研究现状,为未来天麻制品的安全性评价研究提供了新方向和思路。     

益生菌的安全性评价

过去几十年，益生菌被广泛应用于食品和医药等领域.选择和应用益生菌时，不仅要考虑益生菌的功能特性，安全性也是必须要考虑的方面.随着科学的不断发展，对益生菌的安全性认识也在发生变化，传统益生菌的安全性需要重新评价，新的益生菌菌种也不断地开发， 这些新菌种在使用前也应进行安全性评价.目前我国需要完善对这些新菌种进行系统的安全性评价的程序.本文综述了益生菌潜在的危险因素、转基因益生菌的安全性，安全性评价程序和国外如美国、欧盟、德国等国对益生菌的评价体系。     

一株微生态制剂菌株的筛选、鉴定及其对南美白对虾的生长影响研究

从南美白对虾体内筛选到一株微生态制剂菌株,探讨微生态制剂菌株对提高养殖对虾的免疫力的作用,并对其安全性进行评价.在注射感染试验中,用高剂量的菌液注射,对照组有65%以上的死亡率,而试验组未发生死亡现象,表明细菌JK-1对对虾是安全的.为对虾养殖进一步开发利用微生态制剂提供实践依据.     

Safety evaluation of probiotics

The market for functional products, such as probiotics, is undoubtedly the fastest growing area of new food product development. This market introduces a new paradigm for food safety professionals: beneficial physiological effects beyond those of good nutrition without adverse effects. This specificity generates a need for new approaches in food safety evaluation. Conventional toxicology and safety evaluation alone is of limited value in the safety evaluation of probiotic microorganisms. Instead, a multidisciplinary approach is necessary, involving the contributions of pathologists, geneticists, toxicologists, immunologists, gastroenterologists, and microbiologists. In the case of new products, the objective is to produce products that are at least as safe as conventional counterparts regardless of potential health benefits. In the case of existing strains, the history of safe use criterion is very much associated with being able to detect, enumerate and characterize strains to ensure consumers have been ingesting the same organism throughout the claimed exposure period.     

Enterococci as probiotics and their implications in food safety

Enterococci belong to the lactic acid bacteria (LAB) and they are of importance in foods due to their involvement in food spoilage and fermentations, as well as their utilisation as probiotics in humans and slaughter animals. However, they are also important nosocomial pathogens that cause bacteraemia, endocarditis and other infections. Some strains are resistant to many antibiotics and possess virulence factors such as adhesins, invasins, pili and haemolysin. The role of enterococci in disease has raised questions on their safety for use in foods or as probiotics. Studies on the incidence of virulence traits among enterococcal strains isolated from food showed that some can harbour virulence traits, but it is also thought that virulence is not the result of the presence of specific virulence determinants alone, but is rather a more intricate process. Specific genetic lineages of hospital-adapted strains have emerged, such as E. faecium clonal complex (CC) 17 and E. faecalis CC2, CC9, CC28 and CC40, which are high risk enterococcal clonal complexes. These are characterised by the presence of antibiotic resistance determinants and/or virulence factors, often located on pathogenicity islands or plasmids. Mobile genetic elements thus are considered to play a major role in the establishment of problematic lineages. Although enterococci occur in high numbers in certain types of fermented cheeses and sausages, they are not deliberately added as starter cultures. Some E. faecium and E. faecalis strains are used as probiotics and are ingested in high numbers, generally in the form of pharmaceutical preparations. Such probiotics are administered to treat diarrhoea, antibiotic-associated diarrhoea or irritable bowel syndrome, to lower cholesterol levels or to improve host immunity. In animals, enterococcal probiotics are mainly used to treat or prevent diarrhoea, for immune stimulation or to improve growth. From a food microbiological point of view, the safety of the bacteria used as probiotics must be assured, and data on the major strains in use so far indicate that they are safe. The advantage of use of probiotics in slaughter animals, from a food microbiological point of view, lies in the reduction of zoonotic pathogens in the gastrointestinal tract of animals which prevents the transmission of these pathogens via food. The use of enterococcal probiotics should, in view of the development of problematic lineages and the potential for gene transfer in the gastrointestinal tract of both humans and animals, be carefully monitored, and the advantages of using these and new strains should be considered in a well contemplated risk/benefit analysis.     

Safety assessment of Lactobacillus strains: presence of putative risk factors in faecal, blood and probiotic isolates

The widespread use of immunosuppressive therapy and antimicrobial agents as well as novel probiotics without a long history of safe use has increased requirements for safety assessment of probiotic lactobacilli. In this study 44 faecal, 52 blood and 15 probiotic isolates (including 3 dairy strains) of Lactobacillus were assayed for their adhesion properties to extracellular matrix proteins and mucus, hemolysis, ability to avoid the induction of respiratory burst in peripheral blood mononucleocytes (PMN) and resistance to human serum. Among tested strains adhesion to collagen, fibrinogen and mucus was isolate-specific and no statistically significant differences were obtained between faecal, blood and probiotic isolates. However, blood isolates showed a trend for higher adhesion to mucus than probiotic strains (P=0.07). Probiotic strains induced lower respiratory burst in PMN when compared to the blood isolates (P<0.05). Moreover, there was a positive correlation between adhesion to collagen and induction of respiratory burst for faecal isolates (P<0.05). In the determination of serum resistance, probiotic strains showed a trend for lower sensitivity to human serum-mediated killing when compared to the faecal isolates (P=0.07). None of the measurable virulence factors were found to be present at statistically higher level in clinical blood isolates when compared to faecal and/or probiotic isolates indicating that these factors do not cause risk when safety of probiotics is considered. However, the significance of adhesion to mucus, low induction of respiratory burst in PMN and resistance to human serum-mediated killing may need further evaluation in experimental animal models and in epidemiological data.     

Safety aspects and implications of regulation of probiotic bacteria in food and food supplements

The application of living bacteria as probiotics in food or food supplements requires a careful safety assessment. This review summarizes key issues concerning the safety aspects of bacteria added to particular products marketed for improvement of general health or treatment of (post)infectious symptoms. The bacteria used in such products should be completely safe; however, it can be challenging to provide evidence for absence of all virulence properties. In some cases, virulence factors have been detected in probiotic bacterial strains, and the implications of these traits for safety assessments are discussed. Horizontal gene transfer can result in acquisition of virulence genes or antimicrobial resistance in probiotic bacteria. Antimicrobial resistance in these bacteria can possibly aid the spread of undesired resistance in intestinal bacterial populations. The relative risk of such gene transfers is considered. The generation of complete bacterial genome sequences can both resolve and create safety issues. Current practices of safety assessment procedures in the United States and the European Union are briefly reviewed and a future outlook is provided.     

紫甘薯废渣的食用安全性评价

评价水提紫甘薯色素废渣的食用安全性,为其研究开发提供理论依据.按GB15193.1-2003<食品安全性毒理学评价程序>进行评价,包括:急性毒性试验、小鼠骨髓微核试睑和小鼠精子畸形试验.结果表明:大、小鼠急性经口LD50>10 g/kg·bw,属无毒级;小鼠骨髓微核试验和小鼠精子畸形试验结果均为阴性;受试物对各剂量组动...