共查询到18条相似文献,搜索用时 28 毫秒
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乳酸乳球菌镉抗性菌株的鉴定及质粒消除的研究 总被引:1,自引:1,他引:0
为构建乳酸菌食品级载体/受体系统.从分离自内蒙古传统乳制品103株乳源性乳酸菌中筛选出7株高浓度镉抗性菌株.特异性16SrDNA PCR扩增产物的序列测定结果表明.其中两株为乳酸乳球菌.PCR扩增镉抗性基因部分序列证实了这两株乳酸乳球菌含有镉抗性基因,为镉抗性阳性菌株.通过物理和化学方法消除乳酸乳球菌内源质粒,确定了镉抗性质粒,并获得一系列衍生菌株,包括无质粒菌株.为进一步研究各种质粒的功能及基因表达提供了理想的宿主,也为乳酸菌食品级载体/受体系统的构建奠定了基础. 相似文献
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乳酸菌是对人和动物具有多种益生功能的食品级微生物,被广泛地应用于食品、医药、生物技术等领域。乳酸菌的安全益生特性及乳酸菌基因表达系统研究取得的重大进展,使得重组乳酸菌黏膜疫苗成为研究的热点。乳酸菌作为黏膜免疫的蛋白呈递载体,可诱导机体产生有效的免疫反应和免疫耐受,具有巨大的发展潜力。 相似文献
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不同来源食品级乳酸菌及双歧杆菌对乳酸链球菌素敏感性的研究 总被引:1,自引:0,他引:1
目的:研究不同来源的食品级乳酸菌和双歧杆菌对乳酸链球菌素(nisin)的敏感性,为构建以nisin作为食品级筛选标记的受体乳酸菌表达系统以及筛选食品发酵、保鲜与贮藏过程中的nisin抗性乳酸菌提供科学依据.方法:采用试管稀释法研究不同来源的食品级的18株乳酸球菌、15株乳酸杆菌和5株双歧杆菌对nisin的敏感性.结果:大部分乳球菌和部分乳杆菌对nisin不敏感,但乳酸乳球菌(Lactococcus lactis)ML0230、99210,肠膜明串珠菌葡聚糖亚种(Leuconostoc mesenteroides subsp dextranicum)AS 1.2141T,嗜酸乳杆菌(Lactobacillus acidophilus)La1,德氏乳杆菌保加利亚亚种(Lactobacillus delbrueckii subsp bulgaricus)S-1、DR、LD、AS 1.2625T,长双歧杆菌(Bifidobacterium longum)Blm对nisin非常敏感.在nisin质量浓度为5 μg/mL(IU/mL)时即可抑制其生长.结论:初步筛选出17株以nisin作为食品级筛选标记的受体乳酸菌,同时筛选出21株食品发酵、保鲜与贮藏过程中的nisin抗性乳酸菌. 相似文献
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乳酸菌是一类广泛使用的工业菌.近几十年来,乳酸菌作为同源和异源蛋白表达的宿主菌的潜在应用已得到深入研究,在此基础上建立和发展了乳酸菌食品级基因表达系统.首先介绍了乳酸菌食品级表达系统的一些基本条件,表达和标记系统的适用原则,然后追踪其前沿应用进展情况,对乳酸菌食品级基因表达系统的最新应用进行了归纳,根据此表达系统在当前食品经济中的位置,对其在食品工业、医药和保健品等领域的应用前景进行了展望. 相似文献
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Folate: A Functional Food Constituent 总被引:1,自引:0,他引:1
ABSTRACT: Folate, a water-soluble vitamin, includes naturally occurring food folate and synthetic folic acid in supplements and fortified foods. Mammalian cells cannot synthesize folate and its deficiency has been implicated in a wide variety of disorders. A number of reviews have dwelt up on the health benefits associated with increased folate intakes and many countries possess mandatory folate enrichment programs. Lately, a number of studies have shown that high intakes of folic acid, the chemically synthesized form, but not natural folates, can cause adverse effects in some individuals such as the masking of the hematological manifestations of vitamin B12 deficiency, leukemia, arthritis, bowel cancer, and ectopic pregnancies. As fermented milk products are reported to contain even higher amounts of folate produced by the food-grade bacteria, primarily lactic acid bacteria (LAB), the focus has primarily shifted toward the natural folate, that is, folate produced by LAB and levels of folate present in foods fermented by/or containing these valuable microorganisms. The proper selection and use of folate-producing microorganisms is an interesting strategy to increase "natural" folate levels in foods. An attempt has been made through this review to share information available in the literature on wide ranging aspects of folate, namely, bioavailability, analysis, deficiency, dietary requirements, and health effects of synthetic and natural folate, dairy and nondairy products as a potential source of folate, microorganisms with special reference to Streptococcus thermophilus as prolific folate producer, and recent insight on modulation of folate production levels in LAB by metabolic engineering. 相似文献
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Lara Gorissen Frédéric Leroy Luc De Vuyst Stefaan De Smet 《Critical reviews in food science and nutrition》2015,55(11):1561-1574
Conjugated linoleic acid (CLA) and conjugated linolenic acid (CLNA) isomers are present in foods derived from ruminants as a result of the respective linoleic acid (LA) and α-linolenic acid (LNA) metabolism by ruminal microorganisms and in animals’ tissues. CLA and CLNA have isomer-specific, health-promoting properties, including anticarcinogenic, antiatherogenic, anti-inflammatory, and antidiabetic activity, as well as the ability to reduce body fat. Besides ruminal microorganisms, such as Butyrivibrio fibrisolvens, many food-grade bacteria, such as bifidobacteria, lactic acid bacteria (LAB), and propionibacteria, are able to convert LA and LNA to CLA and CLNA, respectively. Linoleate isomerase activity, responsible for this conversion, is strain-dependent and probably related to the ability of the producer strain to tolerate the toxic effects of LA and LNA. Since natural concentrations of CLA and CLNA in ruminal food products are relatively low to exert their health benefits, food-grade bacteria with linoleate isomerase activity could be used as starter or adjunct cultures to develop functional fermented dairy and meat products with increased levels of CLA and CLNA or included in fermented products as probiotic cultures. However, results obtained so far are below expectations due to technological bottlenecks. More research is needed to assess if bacterial production kinetics can be increased and can match food processing requirements. 相似文献
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植物基食品泛指用植物来源的原料制成的食品。进入大健康时代,植物基食品具有较大的增长空间。乳酸菌发酵技术在多元化的植物基食品开发方面具有明显潜力,可实现植物基食品风味口感和营养健康功效的多元化。因此,植物基乳酸菌发酵食品产业面临良好的发展机遇。作者对国内外植物基乳酸菌发酵食品的类型、相关基础理论和关键技术研究以及产业化现状等进行了综述,并分别从基础理论、关键技术、产品开发等方面简要讨论了植物基乳酸菌发酵食品产业未来发展趋势,旨在为新型植物基乳酸菌发酵食品研发提供参考。 相似文献
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Lactic acid bacteria (LAB) are naturally associated with many foods or their raw ingredients and are popularly used in food fermentation to enhance the sensory, aromatic, and textural properties of food. These microorganisms are well recognized for their biopreservative properties, which are achieved through the production of antimicrobial compounds such as lactic acid, diacetyl, bacteriocins, and other metabolites. The antifungal activity of certain LAB is less well characterized, but organic acids, as yet uncharacterized proteinaceous compounds, and cyclic dipeptides can inhibit the growth of some fungi. A variety of microbes are carried on raw materials used in beer brewing, rendering the process susceptible to contamination and often resulting in spoilage or inferior quality of the finished product. The application of antimicrobial-producing LAB at various points in the malting and brewing process could help to negate this problem, providing an added hurdle for spoilage organisms to overcome and leading to the production of a higher quality beer. This review outlines the bioprotective potential of LAB and its application with specific reference to the brewing industry. 相似文献
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乳酸菌(LAB)被广泛应用于农业食品工业中,有些乳酸菌还是人和动物体内的菌群的组成部分。在基因组研究热潮的推动下,乳酸菌蛋白质组学研究近年来也取得令人鼓舞的进展,将会给细菌在工业、人类健康和与细菌病原体作斗争中的应用带来新的认识。本文将对乳酸菌蛋白质组学研究及其意义作一简要概述. 相似文献
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Lactic acid bacteria (LAB) are applied in the food industry as fermentation agents for a variety of products. Cheese whey (CW) and second cheese whey (SCW) are the two main by-products of cheese production, and can be reused for biotechnological purposes. In this context, this review aims to summarise literature on the use of CW and SCW as culture media for the growth of LAB, as cryoprotectants for freeze-drying and as encapsulating agents for the spray-drying of these microorganisms. CW contains several nutrients that are reported to enhance the growth of LAB. As for SCW, research shows that it has potential to be applied as culture medium, although bacterial growth remains at least one or two log orders lower than CW. Regarding freeze-drying and spray-drying, reports indicate that whey-based cryoprotectants and CW as encapsulating agent offer significant protection from the stressful conditions employed in these processes. 相似文献
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Heterologous production of bacteriocins by lactic acid bacteria 总被引:8,自引:0,他引:8
Rodríguez JM Martínez MI Horn N Dodd HM 《International journal of food microbiology》2003,80(2):101-116
Over the last two decades, bacteriocins produced by lactic acid bacteria (LAB) have been the subject of considerable research and industrial interest due to their potential as food biopreservatives. The development of heterologous expression systems for such antimicrobial compounds may offer a number of advantages over native systems, such as facilitating the control of bacteriocin gene expression or achieving higher production levels. In addition, the heterologous production by food-grade LAB offers an attractive method for overcoming some of the adverse situations that may affect the effectiveness of some bacteriocins in food systems. Construction of multibacteriocinogenic strains or acquisition of antimicrobial properties by industrial strains are further objectives that can be achieved through the use of heterologous gene expression systems. The development of new biotechnological tools and recent advances in LAB genetics account for the escalating number of studies dealing with heterologous production of bacteriocins by such hosts. This paper reviews the literature published on the subject and compares the different experimental strategies that have been used up to the present for this purpose. 相似文献