oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 735 )

2019 ( 4093 )

2018 ( 20672 )

2017 ( 21513 )

Custom range...

Search Results: 1 - 10 of 350139 matches for " 花椒 内生菌 鉴定 耐寒短杆菌 L-酪氨酸</br>Zanthoxylum bungeanum endophyte identification Brevibacterium frigoritolerans L-tyrosine "
All listed articles are free for downloading (OA Articles)
Page 1 /350139
Display every page Item
产L-酪氨酸花椒内生菌的分离鉴定
陈冲
- , 2016, DOI: 10.13982/j.mfst.1673-9078.2016.2.011
Abstract: 采用研磨法从汉源产红花椒果实中分离筛选出了6株内生菌,包括4株内生细菌和2株内生真菌。本文以其中一株内生细菌Z2为研究对象,对其进行了形态特征、生理生化特征及分子生物学特征鉴定。实验结果发现,Z2菌体短杆状,大小约为0.6~0.7 μm×1.5~2.5 μm,革兰氏阳性菌,无芽孢,无鞭毛。生理生化特征、16S rDNA基因序列及进化树的结果均表明,Z2为耐寒短杆菌(Brevibacterium frigoritolerans)。经过摇瓶液体发酵后,利用高效液相色谱法对其发酵液及未发酵培养基进行了对比分析,发现其中有新物质产生。通过Sephadex LH-20层析柱初步分离发酵液后,利用半制备型高效液相色谱仪对该物质所在组分进行进一步分离纯化,采用电喷雾电离质谱和核磁共振等方法对该物质进行结构解析,结果表明该物质为L-酪氨酸,得率为12.90 mg/L发酵液。
Six endophytic strains were isolated from the fruits of Zanthoxylum Bungeanum by grinding, and these included four strains of bacteria and two strains of fungi. The endophytic bacteria, Z2, was used as the research object in the present study, and its morphological, physiological, biochemical, and molecular biological characteristics were investigated. It was found that the strain Z2 was Gram-positive without spores and flagella, and was observed as a short rod of about 1.5~2.5 μm in length and 0.6~0.7 μm in width. According to the results on the physiological and biochemical characteristics, 16S rDNA gene sequence, and the phylogenetic tree, Z2 was identified as Brevibacterium frigoritolerans. During comparative analysis of the broth fermentated with Z2 and the broth without fermentation using high-performance liquid chromatography (HPLC), a new substance was found in the fermentation broth. This new substance was further purified by Sephadex LH-20 column chromatography and by semipreparative HPLC. Based on of the data from electrospray ionisation tandem mass spectrometry and nuclear magnetic resonance imaging, this substance was identified as L-tyrosine and its content was 12.90 mg/L in the fermented broth.
Isolation, Screening and Identification of an Antagonistic Bacterial Against Fusarium oxysporum f. sp. niveum from Pistia stratiotes L.
水浮莲中一株西瓜枯萎病拮抗菌的分离、筛选及鉴定

于蘋蘋,艾山江·阿不都拉,赵国玉,卡米力·克热木,吾甫尔·米吉提
微生物学通报 , 2008,
Abstract: One endophytic bacteria named XJPL-YB-26 had obvious antagonistic action against Fusarium oxysporum f. sp. niveum was isolated from leaves of Pistia stratiotes L., the absorption peak of its metabolizable production is 280 nm. The part 16S rDNA was PCR using the primer designed by Primer 6.0 and sequenced. The accession of GenBank is EU251191. The 16S rDNA phylogenetic tree was constructed by comparing with published 16S rDNA sequences of the relative bacteria species. XJPL-YB-26 and AB271744 was the closest relative with 99% sequence similarity. According to the phylogenetic analysis, it was identified as Bacillus subtilis.
The Activated Charcoal Filtration Chromatography and Its Use in Recovering L-Tyrosine from L-Cystine Waste
活性炭过滤色谱及其在酪氨酸分离中的应用

Shi Yuefeng,
施跃峰

色谱 , 1994,
Abstract: he basic principles of activated charcoal filtration chromatography and its use in recovering L-tyrosinefrom L-cystine waste were presented in ths paper.
氯化钠和酪氨酸增强PVP抑制水合物的性能
王杰,艾志久
- , 2017, DOI: 10.13543/j.bhxbzr.2017.03.007
Abstract: 油气输送管道在一定条件下会形成水合物,可能导致灾难性的后果,通过注入动力学抑制剂,可以延迟水合物的形成。在11.7 MPa和293.1 K条件下,向高压反应釜内注入混合气体(甲烷、乙烷和丙烷),实验研究NaCl和酪氨酸(L-tyrosine)对聚乙烯吡咯烷酮(PVP)抑制水合物性能的影响。通过测量水合物的成核温度、诱导时间和耗气量,评判NaCl和L-tyrosine对PVP抑制水合物的效果。实验结果表明:添加1%(质量分数,下同)的PVP后,水合物的成核温度为282.7 K,诱导时间为45 min,耗气量为5.96×10-2 mol;然而,添加0.25%NaCl、0.25%L-tyrosine与0.5%PVP组合抑制剂后,水合物的成核温度为281.7 K,诱导时间为65 min,耗气量为5.19×10-2 mol,比蒸馏水系统的气体消耗量减少了约27%。因此,NaCl和L-tyrosine能明显提高PVP抑制水合物的效果。
Abstract:Gas hydrates can be formed under certain conditions in oil and gas transmission pipelines, which may have disastrous consequences. Hydrate formation can be delayed by adding kinetic hydrate inhibitors. In a high-pressure reactor with methane, ethane and propane gas mixture under a pressure of 11.7 MPa at 293.1 K, the effect of adding NaCl and L-tyrosine on polyvinylpyrrolidone (PVP) as a kinetic inhibitor of the formation of hydrates has been studied. By measuring the temperature of hydrate nucleation, induction time and gas consumption, the effect of NaCl, L-tyrosine and PVP on the inhibition of hydrate formation were studied. The experimental results show that when adding 1%PVP, the temperature of hydrate nucleation is about 282.7 K, the induction time is 45 minutes and the total consumption of gas mixture is 5.96×10-2 mol. However, when adding 0.25% NaCl, 0.25% L-tyrosine and 0.5% PVP, the temperature of hydrate nucleation is about 281.7K, the induction time is 65 minutes and the total consumption of gas mixtureis 5.19×10-2 mol. The gas consumption is reduced by about 27% compared to the pure water system. Therefore, NaCl and L-tyrosine can significantly improve the inhibition performance of PVP.
Isolation and Antimicrobial Activity of Endophytic Fungi from Ginkgo biloba L.
古银杏内生真菌的分离及其抑菌活性

LIU Xiao-Li,ZHOU Jian-Zhong,ZHOU Jian-Zhong,DONG Ming-Sheng,
刘小莉
,周剑忠,黄开红,董明盛

微生物学通报 , 2009,
Abstract: Endophytic fungi inhabited in Ginkgo biloba L. were isolated, and 55 endophyte strains were obtained. Among the strains, 28 produced sterile mycelia on PDA plates, accounting for 50.9% of the total fungi. In addition, there were ten Penicillium spp., six Aspergillus spp., four Alternaria spp. and three Chromosporium spp., and one yeast, Mucor, Acremoniella, and Fusarium, respectively. Antimicrobial activity of fermentation cultures of these 55 strains were investigated against seven tested microorganisms. Twenty-three strains with antimicrobial activity were obtained, among which eleven produced sterile myce-lia, accounting for 47.83% of the fungi with antimicrobial activity. The strain with the highest antimicrobial activity was determined to be Xylaria venosula Speg., according to its morphological features and molecular analysis. As a novel antimicrobial resource, endophytic fungi in G. biloba have a potential prospect.
一株小飞蓬内生毒死蜱降解菌的分离鉴定及其降解特性初探
Isolation and identification of a chlorpyrifos degrading endophyte from Conyza canadensis(L.) Cronq and its degradation characteristics

冯发运,朱宏,李俊领,陈安良,余向阳
- , 2015,
Abstract: 为分离筛选具有毒死蜱降解特性的植物内生菌,从农药厂废液池旁采集小飞蓬植物样本,经表面消毒后研磨提取植物汁液,通过以毒死蜱作为单一碳源的机盐培养基(MSM)进行连续5代培养筛选,获得一株植物内生细菌XFP-gy,经生理生化试验及16SrDNA同源性比对分析,初步鉴定该菌属阪崎克罗诺杆菌属(Cronobacter sp.)。将菌株XFP-gy在以毒死蜱(初始质量浓度为20 mg/L)为单一碳源的MSM中培养,至第6 天时达生长高峰,第9天时毒死蜱的降解率为77.28%。在MSM培养基中补充牛肉膏和蛋白胨(加富培养基)可以促进菌株XFP-gy的生长,并将其对毒死蜱第5 天的降解率由69.59%提高到98.0%。菌株XFP-gy降解毒死蜱的最佳培养条件为30 ℃和pH 7.0,在此条件下,增加培养液中原始接菌量,降低底物毒死蜱的初始质量浓度,可明显提高XFP-gy对毒死蜱的降解效率,当毒死蜱初始质量浓度为10 mg/L,原始接菌量为2%时,至第9 天时在培养液中未检出毒死蜱残留。
In order to isolate and screen plant endophytes capable of degrading chlorpyrifos, horseweed herb(Conyza canadensis(L.) Cronq) collected near the waste pool of a pesticide factory was used as target plant. After surface sterilization, the plant tissues were triturated to obtain plant juice. The plant edophytes were screended by plating the plant juice on minimal salts media(MSM) modified with chlorpyrifos as the sole carbon. After 5 times successive screening, a strain named as XFP-gy capable of degrading chlorpyrifos was isolated. It was identified as Cronobacter sp. based on its physiological-biochemical characteristics and 16SrDNA sequence. The growth of strain XFP-gy reached the maximum at the 6th day in liquid MSM with initial chlorpyrifos concentration of 20 mg/L, and 77.28% chlorpyrifos was degraded after 9 days' inoculation. The degradation rate could be enhanced up to 98.0% at the 5th day by adding beef extract and peptone in MSM. The optimal temperature for XFP-gy degrading chlorpyrifos is 30 ℃, and the optimal pH value is 7.0. Under optimal incubation condition, the chlorpyrifos degradation efficiency increased with the increasing initial bacterium inoculum amount, and the decreasing substrate(chlorpyrifos) concentration in the media. No chlorpyrifos was detected at the 9th day when the initial inoculum of XFP-gy was 2% and concentration of chlorpyrifos was 10 mg/L.
Pathway analysis for production of L-leucine by Brevibacterium flavum TK0303
黄色短杆菌TK0303的L-亮氨酸生物合成途径分析

LIU Hui,CHEN Ning,WEN Ting-yi,
刘辉
,陈宁,温廷益

微生物学报 , 2007,
Abstract: Brevibacterium flavum is used for the production of a number of amino acids in the biotechnology industry. The yield of producing a metabolite is ultimately limited by the ability of the central metabolism and the desired biosynthesis pathway. Pathway analysis is a very useful tool for metabolic engineering, which can be applied to increase the yield of a metabolite or channeling a metabolite into desired pathways. It does not require any kinetic parameters and only uses the Stoichiometric equations. Pathway analysis for production of L-leucine by Brevibacterium flavum TK0303 at steady state was conducted in this paper. Theoretical yield and flux distribution for optimal pathway were determined.It is also concluded that pyruvate and acetyl-coenzyme A are the key nodes of the L-leucine biosynthesis pathway by analyzing the flux distributions of different modes. According to the pathway analysis, the production of L-leucine is expected to be raised by strengthening the flux of the key nodes (pyruvate and acetyl-coenzyme A) through changing the environmental factors. Because the flux of TCA cycle in Brevibacterium flavum TK0303 is weak, the production of L-leucine must be provided enough amido by adding glutamic acid to the fermentation medium. NH_4Ac is both a carbon source and a nitrogen source, which could be helpful to the production of L-leucine. The effects of glutamic acid and NH_4Ac on the production of L-leucine were further studied. The production of L-leucine increased 56% by adding glutamic acid. By improving the concentration of NH_4Ac, the biosynthesis of L-leucine was greatly strengthened too. The results indicate that the flux of L-leucine can be largely increased by changing the chemical regulatory factors such as NH_4Ac and glutamic acid and the modes established by pathway analysis prove to be efficient to describe the metabolic network of L-leucine production by Brevibacterium flavum TK0303.
苦苣菜内生菌的筛选及其次级代谢产物分析
Screening of Endophytes in Sonchus oleraceus L.and Analysis of Its Secondary Metabolite

邓振山,孔召玉,席建鑫,张宝成
- , 2018, DOI: 10.7606/j.issn.1004-1389.2018.06.016
Abstract: 为开发陕北野生苦苣菜内生菌资源,发现潜在药用活性成分和新的医药先导化合物。以苦苣菜健康植株的根、茎、叶为材料,采用平板对峙培养法测定其对11株供试指示菌的抑菌活性,以苦苣菜提取液为对照,对各拮抗菌株的发酵液进行薄层层析、硅胶柱层析和高效液相色谱分析。从中共筛选出95株内生菌,通过抑菌试验发现其中20株对1种或多种指示菌具有抑菌活性,占分离菌株数的21.05%,其中UG-004、UG-036、UY-085、CY-009、CJ-014、 CG-033和CG-035 7株具有较强谱抑菌活性。薄层层析检测结果表明,菌株CG-035的发酵产物在Rf为0.35处有与苦苣菜提取液的层析带迁移率相当的显色带。并通过高效液相色谱分析确定其主要成分为黄酮类物质。菌株CG-035能发酵产生黄酮类或其类似化合物,表明苦苣菜内生菌在次级代谢产物方面具有研究潜力,这为内生菌在微生物药物研究方面提供了理论依据。
In order to explore new potential active pharmaceutical ingredients and discover drug lead compounds,the experiment was conducted to develop endophyte resource from Sonchus oleraceus L.in North Shaanxi.Under conditions of 11 strains of microbes as indicators for inhibitory test,endophytic bacteria were isolated from root,stem and leaves of Sonchus oleraceus by using the antagonism experimented with confrontation culturing on PDA media.Moreover,the antagonistic strain fermentation was detected by thin layer chromatography analysis(TLC) column chromatography(CC) and high performance liquid chromatography(HPLC) with the extracts of Sonchus oleraceus L.as the control.The results indicated that a total number of 95 strains of endophytes were isolated from Sonchus oleraceus,20 strains were screened in vitro against plant pathogens which have obvious antagonistic activity,accounting for 21.05% of the number of isolates.The antimicrobial spectrum test showed that 7 strains(UG-004,UG-036,UY-085,CY-009,CJ-014,CG-033,CG-035) expressed antibiotic activity on 9 strains of tested microbes,The TLC and HPLC results showed that CG-035 strain fermentation liquor possessed similar Rf value 0.35 to flavonoids extractive of Sonchus oleraceus.The strain CG-035 could secrete flavonoids or its similar compounds,it showed that the endophytes had the potential of the secondary metabolites and provided a theoretical basis in the research of microbial drugs.
Overexpression of Corynebacterium glutamicum NAD kinase improves L-isoleucine biosynthesis
谷氨酸棒杆菌NAD激酶的过表达对L-异亮氨酸合成的促进作用

Xiaojing Huan,Kun Li,Feng Shi,Xiaoyuan Wang,
还晓静
,李坤,史锋,王小元

生物工程学报 , 2012,
Abstract: NAD激酶催化辅酶ⅠNAD(H)]发生磷酸化,转变成辅酶ⅡNADP(H)],而还原态辅酶Ⅱ (NADPH) 是L-异亮氨酸合成的必要辅因子。为了提高NADPH的供应,首先克隆了谷氨酸棒杆菌NAD激酶基因ppnK,并利用大肠杆菌-棒状杆菌诱导型穿梭表达载体pDXW-8和组成型穿梭表达载体pDXW-9在L-异亮氨酸合成菌——乳糖发酵短杆菌JHI3-156中进行表达。摇瓶发酵后,ppnK诱导表达菌JHI3-156/pDXW-8-ppnK的NAD激酶酶活 (4.33±0.74 U/g) 比pDXW-8空载菌提高了83.5%,辅酶Ⅱ与辅酶Ⅰ的比例提高了63.8%,L-异亮氨酸产量 (3.86±0.12 g/L) 提高了82.9%;ppnK组成表达菌JHI3-156/pDXW-9-ppnK的NAD激酶酶活 (7.67±0. 65 U/g) 比pDXW-9空载菌提高了2.20倍,辅酶Ⅱ与辅酶Ⅰ的比例提高了1.34倍,NADPH含量提高了21.7%,L-异亮氨酸产量 (2.99±0.18 g/L) 提高了41.7%。这说明NAD激酶有助于辅酶Ⅱ的供应和L-异亮氨酸的生物合成,这对于其他氨基酸的生产也有一定的参考依据。
Study of L-Isoleucine fermentation oxygen controlling on the basis of Pathway analysis
基于途径分析的L-异亮氨酸发酵溶氧控制研究

YANG Ning,WANG Jian,XU Qing-yang,CHEN Ning,WEN Ting-yi,
杨宁
,王健,徐庆阳,陈宁,温廷益

中国生物工程杂志 , 2007,
Abstract: Pathway analysis,the theoretical basis for gene operation and elementary method for metabolic network analysis,was conducted for production of L-isoleucine by Brevibacterium flavum TC-21.Metrology mode and some professional program were used in pathway analysis to establish the best metabolic mode of L-isoleucine.Metabolic engineering is used to restructure the metabolic flux in some pathways or to redirect the flux distributions in different pathways,and its target is to trim the primary metabolism to introduce the metabolic flux into the flux of end product.By analyzing the characteristic and process of L-isoleucine fermentation based on 5L autocontrol fermentor,it was proved that metabolic pathways could be changed by the environmental factors such as dissolved oxygen.According to experimental result and metrology analysis,the metabolic flux is related to the dissolved oxygen,so dissolved oxygen can influence the yield of L-isoleucine by changing the the metabolic flux.In contrast to stable oxygen supply,grading oxygen supply is more superior.L-isoleucine of 25.5g/L is accumulated by grading oxygen supply,and it is 15.77% higher than that of 20.26g/L by stable oxygen supply.On different stage of L-isoleucine fermentation,we can control oxygen supply to fulfill the different need of biomass growth and specific rate of L-isoleucine.The experimental conclusion is that oxygen supply on the basis of pathway analysis can be used in L-isoleucine fermentation.
Page 1 /350139
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.