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1.
【目的】利用微生物发酵植物可以提高多糖的产量,并且能够将原有的植物多糖转化成活性更高的新型发酵多糖,本研究围绕天山雪莲的粗多糖,基于发酵后的活菌数、多糖产量和护肤功效进行发酵菌种筛选,旨在获得适宜发酵天山雪莲粗多糖的优良菌株。【方法】利用不同菌株发酵天山雪莲粗多糖,通过平板菌落计数法测定活菌数,采用蒽酮比色法测定发酵液的多糖含量;采用细胞屏障损伤和抗炎模型,利用噻唑蓝(MTT)法检测细胞活率,利用格里斯法检测NO含量,评价发酵多糖在细胞模型中的护肤功效;利用特应性皮炎小鼠模型,分析发酵多糖对皮肤组织表观及经皮失水率、皮肤组织病理及表皮厚度变化和皮肤组织屏障蛋白-丝聚合蛋白的影响,评价发酵多糖在动物模型中的功效。【结果】不同菌株发酵天山雪莲粗多糖后的活菌数和多糖产量差异较大,其中枯草芽孢杆菌(Bacillus subtilis) CCFM1162和165-M1、干酪乳杆菌(Lactobacillus casei) CCFM1073、罗伊氏乳杆菌(L. reuteri) CCFM8631、清酒乳杆菌(L. sakei) GD17-9的活菌数较高,均不低于2.0×108 CFU/mL;而酿酒...  相似文献   

2.
A monoclonal antibody giving a dominant reaction with the group-specific polysaccharide of streptococcus group B in an ELISA test has been developed. The purified polysaccharide exhibited a high positivity with reference anti B streptococcal antiserum in the ELISA test. Cross-tests of antibodies with other groups of streptococci provided a minimum cross-reaction only in the case of G streptococci. Monoclonal antibodies were prepared usingStreptococcus agalactiœ S 589 MT strain isolated from a case of bovine mastitis which does not express Ia, Ib, II, III, IV and V type antigens, nor C, R and X protein antigens.  相似文献   

3.
The mechanism of resistance toB toxicity in barley and wheat was studied in a solution culture experiment using several cultivars displaying a large range of sensitivity to excessB supply. Plants were cultured for 35 d atB concentrations ranging from normal to excessive (15 to 5000 M, respectively) then examined for dry matter production and theB distribution between roots and shoots.In both species, increasedB supply was accompanied by increased tissueB concentrations, development ofB toxicity symptoms and depressed growth. At each level ofB supply, however, resistant cultivars accumulated considerably lessB than did sensitive cultivars, in both roots and shoots. Even at the lowestB supply, at which noB toxicity symptoms developed and growth was not affected, resistant cultivars maintained relatively low tissueB concentrations. No cultivar displayed an ability to tolerate high tissueB concentrations.These results indicate that sensitivity toB toxicity in barley and wheat is governed by the ability of cultivars to excludeB. If theB concentrations of tissues is used to indicate resistance toB toxicity, then cultivars have the same ranking whether cultured at a normal or excessB supply.  相似文献   

4.
Sonicated lysates of 5 N. meningitidis strains, serogroup B, obtained from two solid serum-free culture media (a medium with casamino acids and a medium with Hottinger's hydrolysate) were studied with the aim of comparing the capacity of different group B meningococcal strains for the accumulation of group-specific polysaccharide. In the lysates obtained after 7-hour growth no sialic acid was found. After 20-hour cultivation, group-specific polysaccharide was detected in the lysates obtained from 4 out of 5 strains. All sonicated lysates obtained in these experiments were serologically active. The lysates obtained from the medium containing casamino acid had a higher content of group-specific polysaccharide. N. meningitidis strain 125, obtained at the Mechnikov Central Research Institute for Vaccines and Sera (Moscow) by selection, showed the highest content of capsular polysaccharide in microbial cells and the stable yield of biomass.  相似文献   

5.
Abstract

Crude glycerol is becoming a financial and environmental liability due to its surplus production from biodiesel industry, and its utilization as a fermentation feedstock for value-added chemicals production has been widely studied. In present work, the capacity of an endophytic fungus, Chaetomium globosum CGMCC 6882, using glycerol and crude glycerol for polysaccharide production was investigated. Results showed that the polysaccharide titers from glucose and glycerol were 1.85 and 3.8?g/L, respectively. Moreover, spore morphology of C. globosum CGMCC 6882 was favorable for polysaccharide production. Meanwhile, impurities in crude glycerol have no effect on polysaccharide production by C. globosum CGMCC 6882. Finally, characteristic results of polysaccharides produced from glucose, glycerol, and crude glycerol have suggested that metabolic flux might be a determinant factor on polysaccharide structure. Taken together, this research provided an innovative approach of utilizing crude glycerol produced from the biodiesel production process.  相似文献   

6.
Substances which restore impaired cell division in UV-irradiated E. coli B were surveyed among various bacteria. The active substance was found only in several genera of Gram-negative bacteria, i.e., Escherichia, Enterobacter, Salmonella and some species of Pseudomonas. The activity in the dialyzed cell extract of E. coli B/r was observed in the presence of β-NAD and was enhanced by Mg2 + and Mn2+. The active substance was very labile, but the activity was protected by 1 mM dithiothreitol in the process of purification. The activity of a fraction recovered through DEAE-cellulose column chromatography was stimulated by the presence of membrane fraction. Upon treatment with lipid-degrading enzymes and proteases, the division-stimulating activity was lost or reduced. It appears that the inactivation by lipase and phospholipase A2 was due to the formation of lysophospholipids and that a proteinous substance participated in the recovery of impaired cell division of UV-irradiated E. coli B.  相似文献   

7.
【背景】目前犬布鲁氏菌病诊断存在一定的困难。【目的】筛选并研究犬种布鲁氏菌单克隆抗体4H3株的特异性抗原表位。【方法】利用噬菌体肽库展示技术,以犬种布鲁氏菌单克隆抗体4H3株作为靶分子,包被酶标板,用12肽随机肽库经过3轮生物淘洗程序进行筛选。经过3轮筛选后,噬菌体产出率从5.00×10-7增加到9.84×10-6,假阳性率逐轮降低。从第3轮筛选的阳性克隆中随机挑取14个进行增殖,提取基因组DNA,进行测序分析;并通过iELISA和cELISA检测阳性克隆的亲和性和特异性。【结果】14株阳性单克隆噬菌体共出现3种不同的短肽序列,分别是KMSIRHPIRLPI、ILRRRRKRIIQI和QRIHMRLTTQS;iELISA结果表明3种短肽序列与单克隆抗体的亲和性依次为KMSIRHPIRLPI>ILRRRRKRIIQI>QRIHMRLTTQS;cELISA结果显示短肽KMSIRHPIRLPI和ILRRRRKRIIQI特异性较强。对亲和性较强、特异性较高的2条短肽KMSIRHPIRLPI和ILRRRRKRIIQI展开具体分析,比对分析表...  相似文献   

8.
Abstract

A number of viruses are known to infect chrysanthemum plants, however in the present study a previously unknown potyvirus was detected using techniques such as ELISA, RT-PCR and hybridization. The ELISA-positive samples were amplified using a potyvirus group-specific primer which gave an amplification of ~850 bp. The amplified product was cloned and sequenced, and shows 72 – 73% homology with known potyviruses that infect chrysanthemums such as Potato virus Y potyvirus, Soyabean mosaic virus and Turnip mosaic potyvirus when compared to the sequence available in the database. However, present potyvirus isolates show 93% homology with Chilli veinal mottle virus and Pepper vein banding virus. The results were further confirmed by Northern hybridization. This is the first report of a potyvirus similar to Chilli veinal mottle virus, and Pepper vein banding virus infecting chrysanthemums.  相似文献   

9.
The candidate archaeal division Korarchaeota is known primarily from deeply branching sequences of 16S rRNA genes PCR-amplified from hydrothermal springs. Parallels between the phylogeny of these genes and the geographic locations where they were identified suggested that Korarchaeota exhibit a high level of endemism. In this study, the influence of geographic isolation and select environmental factors on the diversification of the Korarchaeota was investigated. Fourteen hot springs from three different regions of Kamchatka, Russia were screened by PCR using Korarchaeota-specific and general Archaea 16S rRNA gene-targeting primers, cloning, and sequencing. Phylogenetic analyses of these sequences with Korarchaeota 16S rRNA sequences previously identified from around the world suggested that all Kamchatka sequences cluster together in a unique clade that subdivides by region within the peninsula. Consistent with endemism, 16S rRNA gene group-specific quantitative PCR of all Kamchatka samples detected only the single clade of Korarchaeota that was found by the non-quantitative PCR screening. In addition, their genes were measured in only low numbers; small Korarchaeota populations would present fewer chances for dispersal to and colonization of other sites. Across the entire division of Korarchaeota, common geographic locations, temperatures, or salinities of identification sites united sequence clusters at different phylogenetic levels, suggesting varied roles of these factors in the diversification of Korarchaeota.  相似文献   

10.
The macrophages from peripheral blood of normal healthy individuals respond to live or killedMycobacterium leprae by producing superoxide. On the other hand, the macrophages from bacteriologically positive (B +LL) or long term treated bacteriologically negative (B -LL) and tuberculoid leprosy patients are unable to produce superoxide when stimulated with liveMycobacterium leprae. While killedMycobacterium leprae induce superoxide with the cells from tuberculoid andB(-)LL patients, cells fromB(+)LL patients fail to respond. The deficiency inB(-)LL patients to produce superoxide appears to be specific withMycobacterium leprae and the defect can be counteracted by the addition of colchicine. These observations indicate a preexisting membrane disposition which does not favour superoxide production. A similar situation is seen in the cells from tuberculoid leprosy patients. Thus it appears that both cured and active lepromatous leprosy patients have defective macrophages, unable to respond to liveMycobacterium leprae to produce superoxide anion, in contrast to the situation with the cells from normal healthy individuals.  相似文献   

11.
【背景】海洋环境中分离到的微泡菌属菌株具有多糖降解能力,在环境中可以作为糖类代谢的重要执行者参与海洋碳循环过程。【目的】测定2株微泡菌属菌株的多糖降解活性,通过与微泡菌属其他菌株基因组比较分析2株菌的多糖降解基因特征。【方法】通过3,5-dinitrosalicylicacid(DNS)定糖法测定多糖降解活性,同时利用高通量测序技术对菌株基因组序列进行测定与组装,并与其他基因组注释结果进行比较分析。【结果】分离得到2株微泡菌属菌株YPW1和YPW16,二者均为潜在新种。结果表明,菌株YPW1能够降解琼胶、褐藻胶、果胶、几丁质、木聚糖、淀粉、普鲁兰等7种多糖,而菌株YPW16仅可降解淀粉和普鲁兰。基因组分析表明,YPW1具有上述7种多糖的降解酶基因,但菌株YPW16只具有淀粉酶与普鲁兰酶降解基因。相较于其他微泡菌属菌株,菌株YPW1多糖降解范围、多糖降解酶基因种类与丰度较高,但菌株YPW16多糖降解范围却较为狭窄。由此可知,多糖降解酶基因在微泡菌属基因组中的分布差异性较大。【结论】本研究为微泡菌属提供了2株潜在的新型菌株资源,为生物多糖降解提供了生化工具,也为研究微泡菌属菌株中多糖降解基...  相似文献   

12.
In culture fluid, Klebsiella pneumoniae type 1 Kasuya strain produces polysaccharide exhibiting a strong adjuvant effect. The active substance responsible for the strong adjuvant effect of the polysaccharide is not its acidic polysaccharide fraction (the type-specific capsular antigen) but the neutral polysaccharide fraction. In the present study, a mutant which did not produce the type-specific capsular polysaccharide was isolated from ultraviolet-irradiated cells of K. pneumoniae type 1 Kasuya strain which had been labeled with leucine-requiring marker by selecting unagglutinable cells with the antiserum to the type-specific capsular polysaccharide. Serological tests showed that the type-specific acidic capsular polysaccharide was present neither on the cells surface nor in the culture fluid of the mutant. Electron microscopically, the mutant did not possess any capsular material. On the other hand, nearly an equal amount of neutral polysaccharide antigen was produced in culture fluids of the noncapsulated mutant and the parent strain. The neutral polysaccharide antigen produced by the noncapsulated mutant exhibited the same degree of strong adjuvant effect on antibody response to bovine gammaglobulin in mice as that produced by the parent strain. The relationship between the neutral polysaccharide antigen in culture fluid and the O antigen of K. pneumoniae was discussed.  相似文献   

13.
李俊  曹珺  唐鑫  张灏  陈卫  陈海琴 《微生物学通报》2021,48(12):4600-4611
[背景] 高山被孢霉(Mortierella alpina)是一种可积累大量花生四烯酸(Arachidonic Acid,AA)的产油丝状真菌,其所产脂肪酸主要被组装到甘油骨架上以三酰甘油(Triacylglycerol,TAG)形式存在。二酰甘油酰基转移酶(Diacylglycerol Acyltransferase,DGAT)是TAG生物合成途径的关键酶,对于高山被孢霉TAG的生产具有重要意义。[目的] 通过探究高山被孢霉DGAT2在TAG生物合成方面的功能特点,以期为提高产油真菌的TAG产量及改善TAG的脂肪酸组成提供参考。[方法] 利用序列比对在高山被孢霉ATCC32222基因组中筛选出2个编码DGAT2的候选基因MaDGAT2A/2B,在酿酒酵母(Saccharomyces cerevisiae)中异源表达后进行功能分析,并在外源添加AA条件下通过检测TAG产量进一步分析MaDGAT2A/2B的活性,最后在高山被孢霉中同源过表达MaDGAT2A/2B,通过检测重组菌总脂肪酸产量及组分以分析MaDGAT2A/2B的体内活性。[结果] MaDGAT2AS. cerevisiae中异源表达时,重组酵母菌TAG的产量达到细胞干重的3.06%,为对照组的4.91倍;而MaDGAT2B未明显提高重组酵母菌TAG的产量。在外源添加AA时,MaDGAT2A/2B均可显著促进重组酵母菌中TAG合成,表达MaDGAT2A的重组酵母菌TAG含量为对照组的3.67倍,表达MaDGAT2B的重组酵母菌TAG含量为对照组的2.61倍。MaDGAT2A/2B在高山被孢霉中过表达对其总脂肪酸产量无显著影响,但可显著提高总脂肪酸中AA的含量,AA占总脂肪酸比例最高达到39.15%,相比对照组提高16.14%。[结论] MaDGAT2A/2B可以参与TAG的生物合成,表明2个候选基因编码的蛋白具有DGAT活性,并且可提高高山被孢霉脂肪酸中AA的含量,对于改善产油真菌的脂肪酸组成从而提高其应用价值具有重要意义。  相似文献   

14.
15.
《Chronobiology international》2012,29(12):1772-1781
ABSTRACT

The phase of entrainment (chronotype) is known to be associated with time perspective (TP), suggesting that the state of circadian system is involved in the long-term planning of human life. However, little is known regarding the influence of circadian misalignment on long-term planning ability. The aim of this study was to investigate the association between social jetlag (SJL) and TP. A total of 1064 schoolchildren and university students (mean age ± standard deviation, 19.2 ± 2.9 years; range, 15–25 years; females, 71.7%) from four cities in the Russian Federation located between 56.9 and 61.7 degrees North completed the Munich ChronoType Questionnaire, the Pittsburgh Sleep Quality Index, the Seasonal Pattern Assessment Questionnaire, and Zimbardo Time Perspective Inventory. Study participants also indicated personal data (age, sex, height weight, place of residence, and achievements). A multiple regression analysis with stepwise inclusion of predictors in the model was performed to evaluate associations between time perspective characteristics (dependent variables) and predictor variables. The change in R2 was used as the measure of effect size. Chronotype was found to be a moderate predictor of future TP (B = 0.034; ΔR2 = 0.037). In addition, sleep quality was found to be a moderate predictor of past negative (B = 0.043; ΔR2 = 0.074), present fatalistic (B = 0.021; ΔR2 = 0.035), and deviation from balanced TP (B = 0.034; ΔR2 = 0.066). Mood seasonality was a moderate predictor of present hedonistic TP (B = 0.016; ΔR2 = 0.038), and social jetlag was a weak predictor of present fatalistic (B = 0.052; ΔR2 = 0.019), future (B = ?0.033; ΔR2 = 0.004), and deviation from balanced TP (B = 0.047; ΔR2 = 0.012). In conclusion, this study found a weak but significant association between social jetlag and TP in adolescents and young adults.  相似文献   

16.
傅文博  杜海  徐岩 《微生物学通报》2022,49(9):3567-3580
【背景】噬菌体是微生物群落的重要组成部分,但传统白酒发酵中噬菌体的分类和存在尚不清楚。【目的】通过检测公共数据库和酱香型白酒发酵中地衣芽孢杆菌(Bacillus licheniformis)基因组中的前噬菌体整合区域,探究传统酱香型白酒发酵中关键功能菌株的前噬菌体分类和侵染情况。【方法】使用未培养(细菌全基因组分析)和可培养(菌株筛选和特异性PCR反应)技术对不同环境来源和来自酱香型白酒发酵的地衣芽孢杆菌前噬菌体的分类和存在进行解析。【结果】细菌全基因组分析显示,30株来自不同环境的地衣芽孢杆菌基因组中共注释到165个前噬菌体,其中63.6%(105/165)为完整前噬菌体序列。97.1%感染地衣芽孢杆菌的噬菌体属于长尾噬菌体科(Siphoviridae),2.9%属于肌尾噬菌体科(Myoviridae),53.0%完整前噬菌体的基因功能未知。在来自酱香型白酒发酵的B. licheniformis MT-B06中检测到7个前噬菌体整合序列,其中57.1%(4/7)为完整前噬菌体序列,来自酱香型白酒发酵的地衣芽孢杆菌存在多种不同前噬菌体的共感染。来自酱香型白酒发酵的地衣芽孢杆菌前噬菌体存在来自细菌基因组上相邻CotD孢子外壳蛋白(CotD family spore coat protein)基因的水平基因转移。在26株来自酱香型白酒发酵的地衣芽孢杆菌中,69.2%(18/26)存在噬菌体编码主要衣壳蛋白的基因,100.0%(26/26)存在噬菌体编码CotD孢子外壳蛋白的基因。【结论】来自不同环境的地衣芽孢杆菌和酱香型白酒发酵的地衣芽孢杆菌中存在高水平的前噬菌体整合,来自酱香型白酒发酵的地衣芽孢杆菌前噬菌体中广泛存在来源于宿主的CotD孢子外壳蛋白基因的水平基因转移。本研究为首次对传统发酵白酒中噬菌体的分类和存在进行探究,有助于对发酵微生物群落中噬菌体-细菌相互作用加深理解。  相似文献   

17.
SYNOPSIS. Antigenic constitution of 5 Trichomonas gallinae strains and substrains was analyzed by gel diffusion technics. Fresh isolates of the very virulent JB and of an avirulent SG strain as well as avirulent substrains JBC and SGC, derived from JB and SG respectively by prolonged in vitro cultivation, were used in the experiments. An originally avirulent AG strain that was attenuated still further and lost its infectivity for pigeons during many years of serial transfers in nonliving media also was analyzed. Two major groups of antigens, A and B, were differentiated on the basis of precipitin line patterns formed in gel diffusion reactions involving the 5 strains and substrains and antisera prepared in rabbits against each of these trichomonad stocks. Group A was subdivided further into subgroups [A] and (A). JB, JBC, AG, and SGC trichomonads appeared to share all or nearly all antigens of both these subgroups, but AG strain contained some unique [A] and (A) antigens in addition to those which it had in common with the remaining 4 strains and substrains. Group B antigens were divided into 5 subgroups, B1 to B5. The complete B1 antigenic complex was found in JB and JBC trichomonads and part of this complex was present also in SG strain and SGC substrain. In all instances, subgroup B1 antigens stimulated production of specific antibodies in rabbits and combined with these antibodies present in immune sera. The complete B2 antigenic complex was found only in JBC substrain. Some subgroup B2 antigens were present also in JB trichomonads. Very few of these, however, were capable of stimulating antibody production in rabbits. The more numerous B2 elements of JB strain that did not stimulate immunologic responses in rabbits, might be in the form of incomplete hapten-like antigens. All subgroup B2 antigens found in JB strain represented only a portion of the B2 complex associated with JBC substrain. Subgroup B2 was characteristic of SG and SGC trichomonads, the latter substrain differing from the parental SG strain in the levels of both B2 and B1 antigens; these differences, however, were purely quantitative. JB strain reacted with some of subgroup B3 antibodies present in SG and SGC antisera, but failed to stimulate antibody formation against any of these antigens in rabbits. The B3 elements of JB trichomonads might be incomplete antigens. AG strain was characterized by having B4 and B5 antigenic complexes. The very small part of subgroup B4, represented by a weak precipitin line in reactions between JB strain or JBC substrain and anti-AG serum, suggested the presence of some incomplete B4 antigens in these trichomonads. Irrespective of whether freshly isolated avirulent strains or substrains attenuated by prolonged in vitro cultivation are examined by gel diffusion, such organisms are found richer in subgroup B antigens than the fully virulent JB trichomonads. All the results suggest that there may be a direct relationship between antigenic constitution and virulence of T. gallinae strains.  相似文献   

18.
目的 新型冠状病毒(SARS-CoV-2)变体往往具有更强的感染力与免疫逃逸能力,目前出现的SARS-CoV-2变体种类繁多,疫情评估与防控形势严峻。本文希望通过建立模拟病毒传染的理论模型,对SARS-CoV-2及其变体引起的疫情进行追踪与预测,并对它们的综合传染性进行评估。方法 根据方格传染病模型,对传染持续时间和群体免疫作用的相互关系进行推导,并在此基础上建立了新型冠状病毒肺炎(COVID-19)疫情感染传播的普遍理论模型,提出感染力参数A和免疫作用参数B,将传染时间与感染人数的复杂关系公式化,用于预测感染日变曲线。还引入了突变株综合传染性参数,用以定量比较各突变株的综合传染能力,并对感染参数AB不与地域因素相关的猜想进行了验证。结果 通过COVID-19疫情传播的理论模型,对病毒步行次数与传染时间做出了较为精准的预测。通过对突变株感染能力与电性变化的分析,指出了突变株传染性和突变残基电性变化的内在联系。分析了突变株的参数变化,定量比较了各突变株的综合传染能力,得出了综合传染性排行。还验证了参数AB只与病毒自身性质、病毒与人体共存的性质相关,而与地域无关的猜想,并对各爆发地域的防疫水平进行了评估与比较。结论 本文建立了COVID-19疫情传播的理论模型,在预测疫情持续时间、每日新增感染人数与评估病毒感染力、免疫逃逸能力、综合传染性、地域防疫水平方面具有一定作用,还根据病毒变异可能导致的参数变化给出了防疫注意事项与相关对策的建议。  相似文献   

19.
The pneumococcal serotype 14 polysaccharide was produced in Lactococcus lactis by coexpressing pneumococcal polysaccharide type 14-specific genes (cpsFGHIJKL14) with the lactococcal regulatory and priming glucosyltransferase-encoding genes specific for B40 polysaccharide (epsABCDB40). The polysaccharide produced by Lactococcus was secreted in the medium, simplifying downstream processing and polysaccharide isolation from culture broth.  相似文献   

20.
Liang Xia  Wenzhu Zhang 《Biomarkers》2013,18(7):700-711
Abstract

Background: Promoter methylation of tumour suppressor genes (TSGs) CDKN2A, CDKN2B and CDH13 has been reported in ovarian cancer. However, the clinicopathological characteristics and prognostic role of CDKN2A, CDKN2B and CDH13 promoter methylation in ovarian carcinoma remained unclear.

Methods: The pooled odds ratio (OR) or hazard ratios (HRs) with their 95% confidence intervals (95% CIs) were calculated in this meta-analysis. The Cancer Genome Atlas data were obtained to confirm the role of CDKN2A, CDKN2B and CDH13 methylation in ovarian cancer.

Results: CDKN2A, CDKN2B and CDH13 promoter methylation was higher in ovarian cancer than in normal ovarian tissues. CDH13 promoter methylation was correlated with tumour histology (serous vs. non-serous type: OR?=?0.33, p?=?0.031). CDKN2A promoter methylation was not linked to overall survival (OS), but it was correlated with a poor prognosis in progression-free survival (HR?=?1.55, p?=?0.004). TCGA data showed no correlation between CDKN2A, CDKN2B and CDH13 methylation and OS as well as disease-free survival (DFS).

Conclusions: CDKN2A, CDKN2B and CDH13 promoter methylation may correlate with the increased risk of ovarian cancer. CDKN2A promoter methylation may be an independent prognostic biomarker for predicting progression-free survival.  相似文献   

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