Anti-obesity Action of Fermented Barley Extracts with Lactobacillus plantarum dy-1 and Associated Micro RNA Expression in High-fat Diet-induced Obese Rats

Objective To further explore associated effects of Lactobacillus plantarum dy-1(LFBE) on obesity and lipid metabolism at the gene expression level, the expression of micro RNAs(mi RNAs) was investigated in the liver of high-fat diet(HFD) induced obese rats.Methods Three groups of animal models were established. Changes in mi RNA expression in the liver of each group were analyzed by microarray and RT-q PCR, complemented by bioinformatics. Palmitateinduced hepatocellular carcinoma(Hep G2) cells were used as a model to validate the test.Results LFBE treatment groups and HFD groups were observed to be distinctly different with respect to rates of increase in body weight and body fat percentage and triglyceride(TG) and total cholesterol(TC) levels in serum and liver. In addition, the LFBE group showed upregulation of ten mi RNAs and downregulation of five mi RNAs in the liver. Downregulation of mi R-34 a and mi R-212 was observed in the livers of the LFBE group. Gene ontology and kyoto encyelopedia of geues and genomes(KEGG)pathway analysis showed that possible target genes of the deregulated mi RNAs were significantly enriched in the adrenergic and HIF-1 signaling pathways.Conclusion These results demonstrate that LFBE might regulate the expression of mi RNAs in order to inhibit obesity and fatty liver.

Nuclear assembly of purified Crythecodinium cohnii chromosomes in cell-free extracts of Xenopus laevis eggs

Incubation of dinoflagellate Crythecodinium cohnii chromosomes in cytoplasmic extracts of unfertilized Xenopus laevis eggs resulted in chromosomes decondensation and recondensation, nuclear envelope assembly, and nuclear reconstitution.Dinoflagellate Crythecodinium cohnii is a kind of primitive eukaryote which possesses numerous permanently condensed chromosomes and discontinuous double-layered nuclear membrane throughout the cell cycle. The assembled nuclei, being surrounded by a continuous double membrane containing nuclear pores and the uniformly dispersed chromatin fibers are morphologically distinguishable from that of Dinoflagellate Crythecodinium cohnii. However, incubation of dinoflagellate Crythecodinium cohnii chromosomes in the extracts from dinoflagellate Crythecodinillm cohnii cells does not induce nuclear reconstitution.

鼠李糖乳酸杆菌Lactobacillus rhamnosus GG胞外多糖合成与提取优化研究

试验旨在对鼠李糖乳杆菌(Lactobacillus rhamnosus GG,LGG)胞外多糖的提取工艺和合成条件进行优化。采用单因素试验分别研究三氯乙酸浓度、乙醇添加量和乙醇沉淀时间对胞外多糖提取量的影响,利用单因素结合正交试验对碳源、葡萄糖浓度、培养基初始pH值、接种量、培养温度、培养时间等影响胞外多糖合成的条件进行优化。结果表明,胞外多糖合成的最佳条件为:培养基中添加20 g/l的葡萄糖,调节其pH值为6.5,在30℃培养20 h,在此条件下,胞外多糖的产量为230.2 mg/l。胞外多糖最佳提取条件为:用11%的三氯乙酸除蛋白,4倍体积95%的乙醇沉淀24 h,胞外多糖提取效果较佳。

In vitro reassembly of nuclear envelopes and organelles in Xenopus egg extracts

We reconstituted bilayer nuclear membranes, multilayer membranes, and organelles from mixtures ofXenopus laevis egg extracts and demembranatedXenopus sperm nuclei. Varying proportions of the cytosolic and vesicular fractions from the eggs were used in the reconstitution mixtures. A cytosol：vesicle ratio of 10：1 promoted reassembly of the normal bilayer nuclear membrane with inserted nuclear pore complexes around the decondensed Xenopus sperm chromatin. A cytosol： vesicle ratio of 5：1 caused decondensed and dispersed sperm chromatin to be either surrounded by or divided by unusual multilayer membrane structures with inlaid pore complexes. A cytosol：vesicle ratio of 2.5：1 promoted reconstitution of mitochondria, endoplasmic reticulum networks, and Golgi apparatus. During reassembly of the endoplasmic reticulum and Golgi apparatus, vesicular fragments of the corresponding organelles fused together and changed their shape to form flattened cistemae, which were then stacked one on top of another.

川崎病小鼠模型的超声心动图评估

目的建立干酪乳杆菌细胞壁成分(LCWE)诱导的川崎病(KD)小鼠模型,利用连续高分辨率小动物心脏超声观察该模型冠状动脉成像及心功能变化,为KD小鼠动物模型的制备及其功能评价提供依据。方法将50只小鼠随机分为两组:模型组(使用LCWE诱导KD小鼠模型,n=30)及对照组(无任何干预,n=20)。两组分别于造模后第15,21,30天使用小动物超声诊断仪测量冠状动脉内径,M型超声记录左心室舒张末期内径(LVEDD)、左心室收缩末期内径(LVESD)、左心室射血分数(LVEF)及左心室短轴缩短率(LVFS)。对照组及造模后第15,21,30天模型组分别处死1只小鼠并取出心脏标本进行病理检查。结果造模后第15,21天模型组超声心动图显示冠状动脉管壁与其周围出现高回声;造模后第30天模型组冠状动脉管壁弥漫性增厚。造模后第21天模型组左右冠状动脉内径均大于对照组(P<0.05);造模后第15和30天模型组左右冠状动脉内径与对照组比较无统计学差异(P<0.05)。造模后第15天模型组LVEDD、LVESD、LVEF及LVFS均低于对照组(P<0.05);造模后第21天模型组LVEF及LVFS低于对照组(P<0.05);造模后第30天模型组LVEDD、LVEF、LVFS低于对照组(P<0.05)。病理结果显示,造模后第15天小鼠心外膜间质水肿,少量淋巴细胞浸润及纤维结缔组织弥漫轻度增生,局部心肌纤维结缔组织增生并伴有固体钙盐沉着;造模后第21天小鼠心外膜局部可见多量淋巴细胞、嗜酸粒细胞、单核细胞浸润;造模后第30天小鼠冠状动脉管壁增厚,弹力纤维不连续,内膜轻度增厚,局部玻璃样变性。结论LCWE诱导KD冠脉损伤与自然病程状态的患儿损伤情况相似,可以用来模拟KD冠状动脉损伤及心功能的变化过程。

干酪乳杆菌发酵人参茎叶提取物对锦鲫免疫及抗氧化功能的影响

为了研究干酪乳杆菌发酵人参茎叶提取物对锦鲫的免疫及抗氧化功能的影响,实验先用3%、4%、5%、6%(记为L3、L4、L5、L6)的干酪乳杆菌菌液发酵人参茎叶提取物,再分别添加到基础饲料(记为L0)中,对初始平均体重为(25.00±0.05)g的锦鲫进行为期5周的饲喂实验。周期性取样,采集锦鲫血清、肝胰脏、中肾、脾脏和全肠,以检测相关免疫指标的变化。在饲喂实验结束后进行嗜水气单胞菌攻毒保护性实验。结果显示,与L0组相比,L5组碱性磷酸酶(AKP)、免疫球蛋白M(IgM)、溶菌酶(LZM)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)含量显著升高,L5组丙二醛(MDA)含量显著低于L0组。各组织中IL-10、TNF-α、TGF-β、IFN-γ、IL-1β基因表达水平均有不同程度的升高,表现出时空差异,其中IL-10的基因水平表达升高更为敏感。在攻毒保护性实验中,L5组的存活率达到30%,相较于其他组而言存活率最高。研究表明,本实验条件下,当干酪乳杆菌的接种量为5%时,人参茎叶提取物发酵对锦鲫的应用效果最好,能够提高锦鲫抗氧化能力及免疫相关基因的表达,并对降低嗜水气单胞菌的感染有较好的预防作用。

植物乳杆菌发酵提取未成熟琯溪蜜柚果实果胶工艺优化

目的:利用植物乳杆菌发酵未成熟琯溪蜜柚果实提取果胶,并分析植物乳杆菌发酵提取果胶的性质。方法:以果胶提取率为指标,采用正交试验优化植物乳杆菌发酵未成熟琯溪蜜柚果实提取果胶的工艺条件,并测定果胶的半乳糖醛酸含量、酯化度、蛋白质、持水性、持油性、乳化活性以及乳化稳定性。结果:植物乳杆菌发酵未成熟琯溪蜜柚果实提取果胶的最佳工艺条件为发酵温度37℃、植物乳杆菌发酵接种量14%、液料比25∶1 (mL/g)、发酵时间12 h。此条件下未成熟琯溪蜜柚果胶提取率为11.60%;果胶的半乳糖醛酸含量、酯化度、蛋白质、持水性、持油性、乳化活性以及乳化稳定性分别为26.13%、68.58%、1.57%、0.53 g/g、7.01 g/g、14.33%和33%。结论:植物乳杆菌发酵提取的果胶提取率与酸法工艺的相似,所得果胶为高酯化度果胶,且应用性质良好。

猕猴桃酵素的乳酸菌和酵母菌发酵特性及成分变化

酵素中含有丰富的维生素、酶、矿物质和次生代谢产物等营养成分,是一种具有潜在保健功效的新型食品。将6种乳酸菌和2种酵母菌接种到华特猕猴桃原浆中发酵,检测益生菌发酵原浆过程中的成分变化。通过光谱学、色谱学技术分析发酵过程中的生物活性物质,结果表明:不同乳酸菌和酵母菌菌株对华特猕猴桃酵素的微生物菌数、理化特性及生物活性发挥重要作用,乳酸菌和酵母菌菌数在发酵第5天达到峰值,分别为(7.89~9.30)lg(CFU/mL)和(7.05~8.18)lg(CFU/mL),其中鼠李糖乳杆菌LG0262菌数达9.30 lg(CFU/mL)。发酵结束后乳酸菌发酵组酸度比酵母菌发酵组高,乳酸菌发酵组pH值在3.25~3.45之间,酵母菌发酵组pH在3.51~3.70之间。华特猕猴桃酵素中可溶性固形物含量与乙醇质量浓度分别为(10.3~30.6)。Brix和(13.55~50.82)mg/mL,二者呈正相关性(R2=0.963,P<0.01);GABA、多糖和有机酸的种类和浓度均有所增加,发酵第60天时,瑞士乳杆菌LG4316、乳酸乳球菌LG0827、植物乳杆菌LG1034酵素中多糖含量分别达到0.30%,0.30%和0.29%。乳酸、酒石酸、琥珀酸在植物乳杆菌LG1034酵素、鼠李糖乳杆菌LG0262酵素、酿酒酵母J2861酵素中浓度最高,分别达到2482.03,1842.18μg/mL和168.78μg/mL。

Acaricidal activities of whole cell suspension,cell-free supernatant,and crude cell extract of Xenorhabdus stokiae against mushroom mite (Luciaphorus sp.)

Xenorhabdus bacterium has been used as a biological control agent against Luciaphorus sp., a mushroom mite endemic in Thailand. To develop an effective formulation ofXenorhabdus stokiae, treatments using different parts of X. stokiae isolate PB09 culture, including whole cell suspension, cell-free supernatant, and crude cell extract, were performed. The results show that different parts ofX. stokiae isolate PB09 culture could induce variable effects on mite mortality and fecundity. Application with cell-free supernatant of X. stokiae culture resulted in both the highest mite mortality rate [（89.00＋3.60）%] and the lowest mite fecundity [（41.33_＋23.69） eggs/gravid female]. Whole cell suspen- sion of X. stokiae isolate PB09 culture was found to be slightly less effective than its cell-free supernatant, suggesting that X. stokiae was more likely to release its metabolites with acaricidal activities to the surrounding culture media. Crude cell extract of X. stokiae was not effective against mites. Cell-free supematant of X. stokiae isolate PB09 was the most effective biological control agent and it could be conveniently used in future formulations instead of live bacteria.

Methodologies for preparation of prokaryotic extracts for cell-free expression systems

Cell-free systems that mimic essential cell functions,such as gene expression,have dramatically expanded in recent years,both in terms of applications and widespread adoption.Here we provide a review of cell-extract methods,with a specific focus on prokaryotic systems.Firstly,we describe the diversity of Escherichia coli genetic strains available and their corresponding utility.We then trace the history of cell-extract methodology over the past 20 years,showing key improvements that lower the entry level for new researchers.Next,we survey the rise of new prokaryotic cell-free systems,with associated methods,and the opportunities provided.Finally,we use this historical perspective to comment on the role of methodology improvements and highlight where further improvements may be possible.

杜仲叶水提取物对植物乳杆菌体外益生特性影响

为明确杜仲叶水提取物对植物乳杆菌体外益生特性的影响,采用活菌计数、扫描电镜和气相色谱等方法探究不同浓度ELWE对植物乳杆菌生长曲线、产酸性能、形态和耐受性等的影响。结果表明,培养24 h后,试验组的活菌数均显著高于对照组;ELWE(80,320 mg/mL)使植物乳杆菌菌体更加饱满,且能显著提高其产乳酸能力,36 h时乳酸含量分别提高42.07%和111.64%。在胃液环境的胁迫下,80 mg/mL ELWE组的对数存活率达到87.77%(3 h),显著高于对照组(0%);80 mg/mL ELWE可显著提高植物乳杆菌在热、NaCl、胆盐和真空冷冻干燥胁迫环境下的活菌数,分别保持在5.67,8.16,7.65,7.78 lg CFU/mL。80 mg/mL ELWE对植物乳杆菌体外益生特性有积极影响。研究为ELWE在益生菌行业的应用提供理论参考。

NUCLEAR RECONSTITUTION IN THE Xenopus laevis EGG EXTRACTS CELL-FREE SYSTEM

Ⅰ. INTRODUCTIONNuclear reconstitution (nuclear assembly )was reported by several laboratories in recent years and regarded as an important advance in cell biology. In vitro nuclear assembly system provides a good model to study the organization and function of nucleus, chromatin, nuclear envelope and nuclear matrix. Although it is too early to evaluate its significance in theory and in bioengineering, there is no doubt that the prospect in this field is inspiring.

Nicotiana ovule extracts induce nuclear reconstitution of demembranated Xenopus sperm in cell-free system

Nicotiana tabaccum ovule extracts induced nuclear reconstitution of demembranated Xenopus leavis sperm in a cell-free system. Demembranated Xenopus sperm began to swell after 15 min of incubation with Nicotiana ovule extracts. Accompanying the process of incubation, Xenopus sperm decondensed and their shapes changed gradually from long and ellipse to round. The completely decondensed chromatin was surrounded with membrane structure, which was a mixture envelope of a double membrane and a single membrane. Nucleosome assembly was verified by means of micrococcal nuclease digestion to re-constituted nuclei and DNA electrophoresis. Nicotiana ovule extracts supplied one more experimental model and system. The new system could promote powerfully the research on mechanisms of cell division and cell cycle regulation.

嗜酸乳杆菌和艾叶提取物对肉鸡生长性能、屠宰性能及肉品质的影响

本试验主要研究在肉鸡饲粮中添加嗜酸乳杆菌和艾叶提取物对肉鸡生长性能、屠宰性能及肉品质的影响,为寻找抗生素替代品和开发利用艾叶资源提供依据。试验选取1日龄、健康AA肉鸡240只,随机分成4个组,每组5个重复,每个重复12只。对照组不添加艾叶提取物和嗜酸乳杆菌制剂,饲喂基础饲粮;A组饲喂基础饲粮,添加0.2%艾叶提取物;B组饲喂基础饲粮,添加4.2×108 cfu/g嗜酸乳杆菌制剂;C组饲喂基础饲粮,添加0.2%艾叶提取物和4.2×108 cfu/g嗜酸乳杆菌制剂。试验进行84 d后结果显示,C组终末体重、平均日采食量显著高于对照组、A、B组(P<0.05)。B、C组料重比显著低于对照组、A组(P<0.05)。A、B、C组全净膛率显著高于对照组(P<0.05),腹脂率显著低于对照组(P<0.05),其中C组腹脂率显著低于A、B组(P<0.05)。A、B、C组肉色红度值显著高于对照组(P<0.05)。C组失水率显著低于对照组、A组(P<0.05)。综上可知,添加嗜酸乳杆菌和艾叶提取物可以提高肉鸡生长性能、屠宰性能及改善胴体品质,两者混合添加效果优于单独添加。

广谱抗菌乳酸菌的分离鉴定及细菌素的提取和纯化

本研究从黑龙江传统自制酸菜中分离到1株产抑菌活性物质的乳酸菌HLJ-174,其发酵产物排除有机酸、H2O2等干扰因素后对大肠杆菌、荧光假单胞菌、蜡样芽孢杆菌和藤黄微球菌等食品中常见的致病菌有广谱抑菌活性。通过形态学、生理生化和16S r RNA序列分析鉴定该菌株为植物乳杆菌(Lactobacillus plantarum),命名为Lactobacillus plantarum HLJ-174。研究了利用有机溶剂萃取的方法提取细菌素,发现正丁醇、乙酸乙酯萃取效果较好,正己烷、二氯甲烷、三氯甲烷、四氯化碳、丙酮、乙醇等没有效果。使用不同体积的正丁醇和乙酸乙酯(0.5、1.0、1.5、2.0、2.5、3.0倍发酵液体积)萃取,发现1.5倍发酵液体积的正丁醇效果最好。利用Sephadex LH-20对萃取产物进行了进一步分离,得到的活性物质对大肠杆菌和蜡样芽孢杆菌等具有较强的抑菌活性。

嗜酸乳杆菌细胞壁肽聚糖的分离提取

分别采用超声波法、溶菌酶法、三氯乙酸法对嗜酸乳杆菌细胞壁肽聚糖进行分离提取。结果表明超声波法的最优组合为超声功率400W,超声时间30min,水浴温度40℃,肽聚糖得率10.2%;溶菌酶法的最优组合为溶菌酶添加量4mg/mL,水浴温度55℃,作用时间5h,pH7,肽聚糖得率10.0%;三氯乙酸法肽聚糖得率15.8%。通过多重比较,最终确定采用三氯乙酸法提取嗜酸乳杆菌细胞壁肽聚糖。

副干酪乳杆菌HD1.7产生抗菌物质的初步研究

对从乳酸菌酸菜发酵液中分离到的能产生抑菌物质的菌株进行了鉴定,并对该菌的发酵产物进行了提取和性质研究。经形态学、生理生化与16SrDNA序列分析鉴定该菌株为副干酪乳杆菌(Lactobacillus paracasei)。抑菌谱试验表明:除酵母菌外,该抑菌物质对革兰氏阳性、阴性菌和多种致病菌均有较强的抑制作用。经有机溶剂萃取法获得了抑菌物质的粗提物,胰蛋白酶水解证明抑菌物质具有蛋白质性质,尿素-SDS-PAGE不连续凝胶电泳法测得抑菌物质的分子量为14000左右。

干酪乳杆菌与银杏叶提取物对肥胖小鼠血脂及抗氧化功能的影响

【目的】研究干酪乳杆菌与银杏叶提取物协同的降血脂及抗氧化作用。【方法】将体质量为(20±1.0)g/只的60只健康雌性小鼠随机分成5组,即空白对照组、高脂对照组、干酪乳杆菌组、银杏叶提取物组及干酪乳杆菌与银杏叶提取物混合组,除空白对照组外,其余4组均给予高脂饲料,建立肥胖模型,试验期为30d。试验结束后测定各组小鼠体质量,血清中的总胆固醇(TC)、甘油三脂(TG)、高密度脂蛋白胆固醇(HDL-C)、丙二醛(MDA)浓度及谷胱甘肽过氧化物酶(GSH-Px)和过氧化氢酶(CAT)等的活性。【结果】干酪乳杆菌与银杏叶提取物协同作用,能明显降低肥胖小鼠体质量、TC、TG和MDA,与高脂对照组相比,小鼠体质量降低13.22%,TC和TG降解率分别达到24.48%和20.93%,差异极显著(P<0.01);小鼠血清中HDL-C增加167.85%,差异极显著(P<0.01);小鼠血清中GSH-Px活性提高了13.14%(P<0.05),CAT活性降低了49.01%(P<0.01)。【结论】干酪乳杆菌与银杏叶提取物协同使用,具有控制小鼠体质量、降血脂、促进胆固醇代谢的作用,可用于预防和治疗高脂血症。

植物乳杆菌细胞壁肽聚糖的分离及鉴定

采用三氯乙酸法提取了植物乳杆菌细胞壁肽聚糖,对提取物进行了成分分析和结构验证。结果表明:经氨基酸组分分析,溶菌酶实验,糖类、脂肪、蛋白质含量测定证明了该物质主要成分确系肽聚糖,其得率为(15.29±1.28)%,其中总糖含量为(39.10±1.95)%,脂肪含量为(1.41±0.04)%,蛋白质含量为(58.00±2.16)%,组成植物乳杆菌肽聚糖的四种氨基酸(丙氨酸、谷氨酸、天冬氨酸、赖氨酸)含量明显高于菌粉中同种氨基酸含量。红外光谱分析显示提取物具有肽聚糖特征性结构。

嗜酸乳杆菌胞外多糖提取工艺优化

微生物的胞外多糖是微生物在生长代谢过程中分泌到细胞壁外的黏液多糖或荚膜多糖,是具有增稠和胶体性质并能溶解或分散在水中的长链、高分子聚合物。试验以嗜酸乳杆菌胞外多糖为研究对象,对提取时间、提取的乙醇体积分数和提取的料液比进行单因素实验,并利用sas软件对其提取工艺进行优化,得到在80%体积分数的乙醇下,以1∶1.8(体积比)的料液比抽提12 h,得到的多糖的产量为1.91 g/L。