乳酸菌细菌素抑菌特性及在食品中的应用研究进展

乳酸菌细菌素是细菌在核糖体上合成的具有抗菌活性的多肽类物质,这些细菌素能杀灭或抑制引起食品腐败的细菌的繁殖,可作为天然的食品防腐剂在食品中应用。该文综述了乳酸菌细菌素的分类、国内外研究现状、抑菌特性及应用等方面的最新研究进展,并对乳酸菌细菌素未来研究趋势进行简要分析,对乳酸菌细菌素在食品中的应用有一定参考价值。     

乳酸菌作为生物保护菌的抑菌机理及其在食品中应用的研究进展

食品在加工和贮藏过程中易受到有害微生物污染,导致食品腐败变质,造成食用安全隐患。而现在常用的物理或化学保鲜方法虽然可以有效延长食品货架期,但应用范围有限、存在安全隐患且容易造成资源浪费。乳酸菌因其天然、安全、高效的抑菌活性被作为生物保护菌应用于食品中。本文主要从乳酸菌产生的抑菌活性物质、微生物群体感应以及竞争作用等角度综述了乳酸菌的抑菌机制;同时介绍了近年来乳酸菌作为生物保护菌在乳制品、肉制品、水产品和果蔬产品中的最新应用进展,为今后食品高效保鲜提供新思路。     

果胶酶解液抑菌性能的研究

对果胶酶解液的抑菌性能进行了研究。结果表明,果胶在酶解到一定程度后具有明显的抑菌活性,可显著抑制食品中常见细菌,特别是乳酸菌的生长,是一种极有开发价值的新型天然食品防腐剂。     

乳酸菌中抗李斯特细菌素的筛选及理化性质分析

从鱼肉丸中分离筛选到1株具有抑菌活性的乳酸菌菌株Y153,对单核细胞增生李斯特菌ATCC54003的生长具有良好的抑制作用。16SrRNA序列同源性分析鉴定乳酸菌Y153为乳酸链球菌属（Streptococcus）。在排除有机酸、过氧化氢的干扰后,确定该抑菌物质为蛋白类物质,即细菌素,命名为细菌素Y153。理化性质分析表明,细菌素Y153具有较好的热稳定性、酸碱稳定性可被人体内蛋白酶降解的特性。由此对乳酸链球菌所产细菌素Y153有了初步的研究,为开发天然的食品防腐剂奠定理论基础。     

乳酸菌细菌素研究进展及其在水产养殖和加工中的应用

乳酸菌细菌素是一种由乳酸菌在核糖体内合成、具有抑菌活性的多肽或蛋白质。由于乳酸菌通常被认为是安全的微生物,因此由它产生的细菌素受到了广泛地关注。目前由于大部分乳酸菌细菌素抑菌机理研究还不够深入,在一定程度上限制了它的发展和应用。本文对现有乳酸菌细菌素研究成果进行总结,并对细菌素进行了系统分类,阐述了各类乳酸菌细菌素对革兰氏阳性菌的作用机理,最后介绍了乳酸菌细菌素在水产养殖、水产品加工贮藏过程中的应用,旨在为乳酸菌细菌素的应用提供新的探索和基础理论依据。     

乳酸菌细菌素分类与作用机制

乳酸菌细菌素作为天然的食品防腐剂,可抑制或杀灭食品中致病微生物和腐败微生物从而保护食品的安全。文中介绍了乳酸菌细菌素传统分类方法和新提出的分类方法,并且综述了乳酸菌细菌素的作用机制。     

提高乳酸菌细菌素合成量方法的研究进展

细菌素是某些细菌通过核糖体合成机制产生的蛋白质或多肽,能够抑制与其亲源关系相同或相近的微生物,某些细菌素在食品加工和发酵过程中能抑制致病菌和腐败菌。乳酸菌被认为是一般公认安全,其细菌素具有安全性高、稳定性好、抑菌谱广等优点,作为一种新型食品防腐剂备受关注,但商品化的乳酸菌细菌素十分有限,仅限于Nisin和Pediocin PA-1等少数几种,合成量低是细菌素在食品中应用受限的主要原因之一。从不同原料中筛选高产菌株、发酵培养基和发酵条件优化、诱变育种、原生质体融合、基因工程方法、群体感应系统调控六个方面,论述了增加乳酸菌细菌素合成量的方法,以期为实现乳酸菌细菌素的工业化生产提供一定的借鉴。     

产细菌素乳酸菌菌株的来源及所产细菌素的分类研究进展

乳酸菌产生的细菌素对很多导致食源性疾病的致病菌和腐败菌均具有抑制作用,近年来引起了诸多研究者的关注,在食品 储存和保鲜中也有应用。为了便于科研工作者更好的开发抑菌谱广、抑菌效果好的细菌素,该文对产细菌素乳酸菌菌株的来源食品、 菌株的所属种属、细菌素的分类以及分离纯化方法等做一评价,为相关的研究提供基础材料和参考,促进天然防腐剂的开发工作更 好更快地开展。     

南京板鸭中产细菌素乳酸菌菌株的筛选鉴定及理化特性研究

试验从5种发酵肉中筛选出1株产细菌素类似物的乳酸菌。这株乳酸菌经16SrRNA鉴定与Weissella hellenica的相似度达99.4%。这株菌产生的细菌素类似物对胰蛋白酶敏感证明其蛋白特性,在121℃加热20min抑菌活性降低26.6%,在p H值2~12均有较好的抑菌效果,对革兰氏阳性菌有明显的抑制作用。经过以上实验表明,这株菌株有作为生物防腐剂的潜力加入到低温杀菌食品中抑制有害微生物生长。     

植物源抑菌剂的研究进展

植物源抑菌剂是通过物理或化学分离提取方法从天然植物中获得的具有抑菌作用的生物活性物质,具有安全、高效、毒副作用小等优点,在抑制病原菌及有害微生物生长繁殖、保障食品安全方面有较高的开发潜力和研究价值。植物源抑菌剂种类丰富,主要包括多酚、多糖、黄酮、挥发油、生物碱、萜类化合物等。本文分析总结了常见植物源抑菌剂的提取及纯化方法,讨论了提取方法选择过程中存在的问题,探究了不同种类植物源抑菌剂的作用机理及在食品保藏、加工中的应用现状。植物源抑菌剂在抑菌防腐领域具有较广阔的应用前景,未来可在提取工艺优化、有效成分分析及抑菌基因表达等方面进行深入研究,以期为植物源抑菌剂的综合利用提供一定的理论依据。     

乳酸菌对发酵肉制品抑菌作用及风味特征的影响研究进展

发酵肉制品因生产周期较长、营养物质丰富,极易受到微生物的污染,从而影响产品品质并对人体健康带来不利的影响。由于消费者对发酵肉制品风味以及安全性的关注日益增加,因此对肉制品的安全性以及风味特征的研究非常重要。乳酸菌是最早从发酵肉制品中分离出来的微生物,是传统发酵肉制品中重要的优势菌群,与产品品质密切相关。在发酵肉制品中,乳酸菌不仅可以产生具有抑菌作用的物质抑制有害微生物生长,提高肉制品的安全性;还可以通过影响碳水化合物代谢、蛋白质以及脂质的分解氧化,从而改善发酵肉制品的风味。本文主要从乳酸菌影响发酵肉制品中有害微生物的生长、提高产品安全性及其对风味形成的影响方面进行综述,以期为今后发酵肉制品的研究提供新思路。     

Characterisation of anti-Listeria monocytogenes bacteriocins from Enterococcus faecium strains isolated from dairy products

Bacteriocin-producing lactic acid bacteria were isolated from 34 samples of dairy products. Nine bacteriocin producers were phenotypically and genotypically identified as Enterococcus faecium . By means of PCR-techniques, enterocin A was characterised in all of the nine bacteriocin-producing Enterococcus isolates. Enterocin-producing lactic acid bacteria were the most abundant in dairy products collected from different areas in Iran. Maximum bacteriocin production by Enterococcus faecium strains was detected in the stationary phase of growth. Bacteriocins produced by all isolates were found to have anti-listerial activity in sterile milk. The purified bacteriocins were identified as <6.5 kDa peptide by sodium dodecyl sulphate-polyacrylamide gel (SDS-PAGE). The molecular weights of bacteriocins were found to be the same in all strains. This bacteriocin might be useful as a natural preservative.     

群体感应调控下的乳酸菌细菌素合成

细菌素是一种在新陈代谢过程中由核糖体合成的具有抑菌作用的抗菌肽,因此被作为天然、无毒抗菌剂并广泛应用到食品行业中。群体感应是细菌细胞间通过对自诱导物浓度的感知,从而对基因表达进行调控的行为,现已证明乳酸菌的群体感应是细菌素合成的关键调控机制。作者主要综述了目前乳酸菌细菌素的研究现状、细菌素的系统分类、群体感应信号的转导机制及其对乳酸菌细菌素合成的调节,以促进对细菌素的研究及应用。     

菱角壳黄酮提取物抑菌活性评价及对冷鲜鸭肉中假单胞菌生长特性的影响

为探究菱角壳黄酮提取物的抑菌能力及其对冷鲜鸭肉中假单胞菌生长特性的影响,采用抑菌圈法、MIC值测定和液体中生长曲线来评价其对食品中常见微生物生长的抑制作用,建立假单胞菌经浓度为2.5 mg/mL的黄酮纯化物处理后的鸭肉基质中的一级生长预测模型。结果表明:菱角壳黄酮提取物对假单胞菌、金黄色葡萄球菌有明显的抑制作用,其中黄酮纯化物对假单胞菌和金黄色葡萄球菌的抑菌效果更好,抑菌圈直径分别为(47.01±0.43)、(45.06±0.35) mm;菱角壳黄酮提取物对热杀索丝菌有一定的抑制效果,对大肠杆菌、乳酸菌和酵母菌无抑菌效果。菱角壳黄酮粗提物和纯化物对假单胞菌的MIC值均为3.125 mg/mL,对金黄色葡萄球菌的MIC值分别为12.000和3.125 mg/mL。采用对供试菌抑菌效果最好的菱角壳黄酮纯化物浓度(2.5 mg/mL)处理鸭肉,在不同温度下储藏,发现与10、15和20 ℃相比,0和5 ℃可将冷鲜鸭肉的货架期延长至8 d以上,并且通过建立假单胞菌在经浓度为2.5 mg/mL的菱角壳黄酮纯化物处理后的鸭肉基质中的一级模型可知,在0~15 ℃储藏时,菱角壳黄酮提取物作为保鲜剂的抑菌效果较好,能够有效延长食品保质期,但随温度升高,其抑菌能力逐渐减弱,这为菱角壳开发为天然抑菌剂提供了理论基础。     

Nisin as a Food Preservative: Part 1: Physicochemical Properties,Antimicrobial Activity,and Main Uses

Nisin is a natural preservative for many food products. This bacteriocin is mainly used in dairy and meat products. Nisin inhibits pathogenic food borne bacteria such as Listeria monocytogenes and many other Gram-positive food spoilage microorganisms. Nisin can be used alone or in combination with other preservatives or also with several physical treatments. This paper reviews physicochemical and biological properties of nisin, the main factors affecting its antimicrobial effectiveness, and its food applications as an additive directly incorporated into food matrices.     

Effect of Extrinsic Parameters on the Production of a Bacteriocin by Lactobacillus buchneri,Isolated from Mexican Raw Sausages

Bacteriocins are antimicrobial peptides acting on certain pathogens and spoilage microorganisms. They have recently been considered as natural alternative to food preservatives. The objective of this work was to study the inhibition spectrum of a bacteriocin produced by Lactobacillus buchneri, isolated from a Mexican sausage, against Listeria monocytogenes and several lactic acid bacteria, and the influence of several extrinsic parameters on bacteriocin activity. Culture media (MRS or APT) had no significant effect on bacteriocin production (p < 0.060) although higher activity was observed in MRS (220 AU/mL). Conversely, temperature significant affected production (p > 0.001). Bacteriocin activity was also increased by 100% nitrogen atmosphere (180 AU/mL) as compared to N₂/CO₂ (50:50) (150 AU/mL) and 100% CO₂ (60 AU/mL). Maximum activity occurred at the end of the exponential growth phase. This bacteriocin inhibited some Listeria monocytogens strains and several lactic acid bacteria, mainly Lactobacillus sp.     

Microbial and Physicochemical Characterization of the Horse Meat in Fermented Sausage

In this study, 150 lactic acid bacterial strains, originating from horse meat, were subjected to a step-by-step screening and characterization to search for potential protective cultures to be used in the meat industry. Strains were first tested for their homofermentation and salt tolerance. Second, the antibacterial capacities towards Listeria monocytogenes were determined in an agar spot test. In total, 50% of the tested strains were inhibitory towards Listeria monocytogenes. However, only 12 strains produced a bacteriocin. Finally, three strains with strong bacteriocin activity were competitively evaluated by comparing their growth rate, acidifying character and lactic acid production at 15°C under anaerobic conditions in a liquid broth. All three strains had a fast growth rate with rapid acidification caused by the production of high levels of lactic acid. Based on this Lactobacillus sakei was used as starter culture for producing sausage horse meat. In this study, fermentations were followed analyzing the microbiological and physicochemical aspects of this product. The sausages were characterized based on microbial activity of lactic acid bacteria that resulted in a product with a final pH of about 4.56. No Listeria monocytogenes, Salmonella spp. nor Sulfite reducing clostridia were ever isolated from the raw materials or the fermented sausages during the maturation, reflecting the safety of this product. The final water activity of the product was 0.85. Lactobacillus sakei was efficient in reducing amine production since this strain caused a quick pH drop during sausage fermentation.     

环境胁迫调控植物乳杆菌细菌素合成的研究进展

植物乳杆菌作为具有重要经济价值的乳酸菌被广泛应用于食品发酵与保鲜领域,由于其代谢过程中会产生具有广谱抑菌特性、对热稳定且易被蛋白酶水解的细菌素,因此有作为天然食品生物防腐剂的较大应用潜力。研究表明,在发酵过程中菌体的生长和细菌素的合成受多种环境因素如盐胁迫、酸胁迫、氧胁迫及低高温胁迫的影响,但目前环境因素调节信号分子产生以及调控相关基因合成细菌素的具体机制仍然有待研究,另一方面,通用的调控通路还未被发现。因此,本文介绍了植物乳杆菌抵御胁迫的反应机制并详细阐述了环境胁迫下与细菌素合成密切相关的调控基因和重要调控蛋白,为食品发酵加工过程中合理控制发酵条件,促进细菌素合成从而延长食品货架期提供理论依据。