免疫乳对肠道菌群的调节作用

以24种人肠道病原茵作为抗原对乳牛进行免疫，制得的免疫乳中乳抗体的凝集价为非免疫乳的64倍。以免疫乳作为原料制备的免疫乳粉具有调节肠道茵群的作用。结果表明免疫乳粉较普通乳粉可显著增加小鼠肠道中双歧杆茵和乳杆茵的数量以及肠道中乳酸和已酸的含量，同时可显著降低小鼠肠道中肠球茵、大肠杆茵及产气荚膜梭茵的数量。     

Phenotypic and technological diversity of lactic acid bacteria and staphylococci isolated from traditionally fermented sausages in southern Greece

The physicochemical and microbiological characteristics of spontaneously fermented sausages made by two medium-sized enterprises (MSE) located in southern Greece have been studied. A total of 300 lactic acid bacteria and 300 staphylococcal strains have been isolated and identified by their physiological characteristics. Lactobacillus plantarum strains were found to dominate the lactic acid bacteria microbiota in most of the cases with L. sakei strains prevailing in some of them and L. rhamnosus strains occasionally accompanying the dominant lactic acid bacteria microbiota. On the other hand, S. saprophyticus strains were found to dominate the staphylococcal microbiota in all spontaneously fermented sausages with of S. simulans, S. xylosus, S. gallinarum and S. cohnii cohnii strains being sporadically present. Following the identification, an evaluation of their technological properties, namely proteolytic and lipolytic capacities as well as production of biogenic amines and antimicrobial compounds, took place. None of the lactic acid bacteria and staphylococci was found to possess lipolytic activity whereas a total of 6 lactic acid bacteria and 51 staphylococci strains were found to be able to hydrolyse either the sarcoplasic, myofibrillar or both protein fractions. Furthermore, only one L. sakei strain and 185 staphylococci strains were found to possess decarboxylase activity against lysine, tyrosine, ornithine or histidine. Finally none of the staphylococcal microbiota and 3 lactic acid bacteria strains were found to be able to produce antimicrobial compounds of proteinaceous nature against Listeria monocytogenes.     

乳汁中的寡糖及在乳品工业中的应用

母乳中的寡糖大约占总糖的10％，根据其核心结构不同可分为12类，其寡糖组分随哺乳期的变化而改变。母乳中的寡糖具有独特的生理功能，对于婴儿的神经系统发育、预防感染和促进正常的肠道微生物生态形成等非常重要，是保证婴儿健康成长的关键因素．目前用于婴儿乳添加剂的寡糖主要有寡聚果糖和寡聚半乳糖。本文讨论了母乳寡糖的结构、消化吸收、生理作用和在乳品工业中的应用。     

肠道菌群与婴幼儿食物过敏相关性的研究进展

随着婴幼儿食物过敏的发病率逐年上升,食物过敏逐渐成为了全球性公共卫生问题。大量研究表明人体内肠道菌群与食物过敏有着密切的关系,在受到外界因素的干扰后,肠道菌群多样性和数量发生改变,进而引发机体对某些正常抗原的免疫耐受度降低,导致过敏反应。本文介绍了食物过敏婴幼儿和健康婴幼儿肠道菌群的差别,对肠道菌群在食物过敏中的调节机制(影响肠道细胞功能和调节屏障保护特性、产生信号分子进行免疫调控以及促进和维护机体口服耐受)进行综述,并对肠道菌群调节婴幼儿食物过敏的策略进行展望。     

绿原酸在肝微粒体和肠道菌群中的体外代谢研究

摘 要：目的 研究绿原酸在大鼠肝微粒体和肠道菌群中的代谢产物及代谢途径。方法 运用大鼠肝微粒体体外温孵法和大鼠离体粪便温孵法,采用超高效液相色谱串联四极杆飞行时间质谱(UPLC-Q-TOF/MS),色谱柱为Waters ACQUITY UPLC BEH C18 (1.7 μm, 2.1 mm×100 mm),流动相为乙腈和0.1%甲酸水溶液梯度洗脱系统,流速为0.35 mL/min,离子源为电喷雾离子源(ESI),以负离子模式进行检测。采用Masslynx软件通过保留时间与一、二级质谱信息,进行成分分析。结果 大鼠肝微粒体温孵样品中有绿原酸原型成分和奎宁酸、咖啡酸2个代谢产物;粪便温孵样品中有绿原酸原型成分和奎宁酸、3-羟基苯丙酸、二氢咖啡酸、二氢阿魏酸、咖啡酸、O-甲基绿原酸6种代谢产物。结论 UPLC-Q-TOF/MS技术鉴定绿原酸及其代谢产物,操作便捷高效,结果准确全面,绿原酸在体外代谢的主要途径为氢化、甲基化、水解、去羟基化等。     

Characterization of Habitat of Rhamnus alaternus L. at the Jebel Tessala （North-Western Algeria）

In this study, the authors were interested to the evaluation of biodiversity in the Jebel Tessala. Ten stations were selected based on altitudinal gradient, inside each station, identified flora has been conducted and a soil sample was taken from. A floristic inventory was carried out from all stations characterizing habitat of our studied taxon which is Rhamnus alaternus L. The authors established a list of plants represented by 94 species, distributed in 46 botanical families that are dominated by Asteraceae. The biological spectrum of these species reveals the dominance of hemicryptophytes and therophytes. The biogeographical element which predominates the vegetation is the Mediterranean-type. Statistical processing PCA （principal component analysis） from the pedological analysis of the examined stations reveals the formation of three groups defining a set of station that are marked by the presence of some components of the soil. Data processing obtained by FCA （factorial correspondence analysis） and the ascending hierarchical classification had underscored the existence of two groups of strata according to the soil substrate.     

肉桂精油对小鼠肝肠组织抗氧化能力以及肠道菌群结构的调节作用

目的：探究肉桂精油对小鼠肝脏代谢相关酶活性,肝、十二指肠、结肠组织抗氧化能力及肠道菌群的影响,评价肉桂精油的摄入对机体健康的潜在影响。方法：将8 周龄C57雄性小鼠随机分为3 组：对照组和肉桂精油低、高剂量（100、300 mg/（kg·d））组;饲养4 周后测定小鼠体质量、肝脏代谢相关酶活性以及肝、十二指肠、结肠组织抗氧化能力,运用Illumina高通量测序技术测定小鼠肠道菌群的变化情况,利用气相色谱-质谱联用仪检测小鼠粪便中短链脂肪酸含量变化情况。结果：肉桂精油的摄入能够显著降低小鼠腹脂指数,使肝脏丙氨酸氨基转移酶活力、肠道抗氧化能力显著提高（P＜0.05）;摄入肉桂精油后,在门水平上小鼠粪便中软壁菌门（Tenericutes）相对丰度显著降低（P＜0.05）,在属水平上布劳特氏菌属（Blautia）、真杆菌属（[Eubacterium]_fissicatena_group）等条件致病菌相对丰度显著降低（P＜0.05）,罗氏菌属（Roseburia）、粪芽孢菌属（Coprobacillus）等有益菌相对丰度显著上升（P＜0.05）;肉桂精油高剂量组小鼠粪便中乙酸、丙酸、总酸的含量显著降低（P＜0.05）。结论：肉桂精油的摄入能够调节肠道氧化还原状态平衡和肠道菌群结构,抑制致病菌群生长,促进有益菌群增殖,具有潜在促进机体健康的作用。     

Effects of different ripening procedures on the final characteristics of Picante cheese

 Picante da Beira Baixa (or Picante) cheese is a hard, piquant, salted traditional cheese manufactured in Portugal from raw sheep's and goat's milks. The purpose of this work was to quantitatively assess the influence of various ripening procedures on the final characteristics of Picante cheese. Two alternative ripening protocols were considered, the traditional one and another with controlled environmental conditions via use of maturation chambers set at different preselected temperatures. The experimental cheeses were characterised in terms of microbiological, physicochemical, biochemical, sensorial and textural properties. Ripening time and temperature were statistically significant parameters for all microflora. The two ripening methods led to statistically significant differences in all physicochemical and biochemical parameters, especially the moisture content and the soluble nitrogen fractions (i.e. water loss was slower and proteolysis was faster in cheeses ripened via the traditional method). Differences in microbiological, physicochemical and biochemical properties were probables implicated in differences in textural and sensorial properties, especially cheese hardness and flavour. It was concluded that the standard ripening method was closest to the traditional one in terms of final cheese characteristics when the ripening temperature was above 11.5  °C. Received: 3 February 1998     

干酪中生物活性肽的研究进展

文章阐述了干酪中生物活性肽的产生,归纳了干酪中常见的几种生物活性肽的类型及研究进展,综述了干酪中生物活性肽在生物利用度以及对肠道菌群影响方面的研究进展,并对干酪中生物活性肽的研究前景进行了总结与展望。     

湛江地区养殖南美白对虾冷藏期间的菌相分析及优势腐败菌的初步鉴定

将湛江地区养殖的南美白对虾在(4±1)℃条件下进行冷藏保鲜,通过细菌形态观察和生理生化实验对冷藏不同时期的细菌组成进行了定性和定量研究,并对优势腐败菌进行了初步鉴定。结果表明:湛江地区养殖的南美白对虾冷藏初期的细菌总数为2.8×104CFU/g,由10个属的细菌组成,其中有6个属为G-,且它们的数量占细菌总数的80%,其中以黄杆菌和气单胞菌的数量最多,分别占细菌总数的33.3%和13.3%;冷藏的第2天为高品质期,细菌总数为5.1×104CFU/g,黄杆菌(30%)和不动杆菌(16.7%)的数量最多,G-的数量增长到86.7%;随着冷藏时间的延长,细菌种类逐渐减少,货架期终点时细菌总数为3.0×106CFU/g,但只分离到8个属的细菌,其中G-占93.4%,气单胞菌和假单胞菌的数量均增加到16.7%,而黄杆菌减少为26.7%,其他种类的G-均有不同程度的增长。冷藏至第6天,细菌总数高达2.4×107CFU/g,虾肉完全腐败变质,从中分离获得的4个属的优势腐败菌均为G-,它们分别是黄杆菌、希瓦氏菌、假单胞菌和气单胞菌,各自所占比例为28.74%、26.44%、21.84%和16.09%。