Research progress and application of microbial origin naringinase

柚皮苷是影响柚子汁品味的最主要因素,柚苷酶具有将柚皮苷分解为普鲁宁、鼠李糖、葡萄糖和柚皮素等物质的功能,并且这些物质已广泛用于制药和饮料行业。本文介绍了近年来国内外微生物来源的柚苷酶的研究、酶学特性、酶活测定、结构与功能等,表明细菌来源的柚苷酶最适温度为37~70℃,最始PH值为4.5~8.0;真菌来源的柚苷酶最适温度为30~75℃,最始PH值为4.0~11.0。介绍了柚苷酶及其相关产物在食品、饮料和制药工业中的应用进展,发现柚苷酶不仅具有脱苦的作用,还对人类的身体健康具有重要作用。展望了今后的研究方向,应该从柚苷酶高产菌株的选育、发酵产酶的工艺优化和酶的应用等方面开展工作,大幅度提高柚苷酶的产酶水平。Naringin is the principal factor which bitters the taste of grapefruit juice.Naringin could be hydrolyzed by naringinase into prunin,rhamnose,glucose,and naringenin,which have wide applications in the pharmaceutical and beverage industry.This paper provides an overview of the studies on microbial origin naringinase,purification,characterization and determination of enzyme activity as well as protein structure and function.The optimum temperature of naringinase from bacteria is from 37 ℃ to 70 ℃ while the optimal pH is in the range of 4.5 to 8.0;the optimum temperature of naringinase from fungal is from 30 ℃ to 75 ℃ while the optimal pH is in the range of 4.0 to 11.0.The applications of naringinase and its various products in food,beverage,and pharmaceutical are also presented,showing that naringinase could not only debitter the fruit juice but also play an important role in human health.In addition,the development trends and potential applications of naringinase are also prospected.The research emphasis should be placed on screening ideal microbe strains and fermentation process optimization to enhance naringinase

Construction and application of the auto-finding errors platform named CUDer for Codon Usage Database

密码子用法数据库(Cud)是密码子用法与密码子优化研究领域的一个重要的在线服务,为了找出该数据库中潜在的两种不再适用的记录,即已过期的陈旧记录和在遗传密码类型上实际无法有效支持的记录(简称不支持记录),本文通过结合前期自主研发的两个软件bESTCOdOn与CudASSIST,组建了Cud自动寻错平台CudEr,并应用于上述问题的研究。结果发现,Cud中存在317条陈旧记录与4条不支持记录。对于陈旧记录,这些记录的物种分类号在nCbI中已发生变更,研究者应该避免使用这些记录的相关数据;对于不支持记录,本文借助CudEr计算得到这些记录正确的密码子用法表(CuT),弥补了当前Cud的不足。此外,该平台也为面向Cud的自动化数据处理,提供了一个新的软件框架,具有一定的借鉴意义。Codon Usage Database(CUD) is an important online server for researching the codon usage and codon optimization.This study aimed to locate two kinds of inapplicable records from the database,including both expired time-out records and unsupportable records,genetic code types of which were not supportable for CUD.The above work was accomplished by the auto-finding errors platform named CUDer,which mainly consisted of earlier developed softwares BestCodon and CUDassist.As a result,there were 317 time-out records and 4 unsupportable records in CUD.For the time-out records,compared with related data in NCBI,their Taxonomy ID had been changed were in the database,so researchers should be careful to use these records.For the unsupportable records,their codon usage tables(CUTs) were accurately available in this paper.In addition,the new software framework of CUDer could be referred to CUD-oriented automatic data processing.国家自然科学基金资助项目(21076172);国家自然科学基金资助项目(30770059);高等学校博士学科点专项科研基金(20070385001);福建省高校产学合作科技重大项目(2010H6023

酶定向进化技术及其在化学品生物转化中的应用

定向进化可有目的地按照需要改造蛋白质分子中的氨基酸残基或结构域,从而定向改造蛋白质的性质,使其成为具有人们预期功能的新型蛋白质,应用于不同化学品生物转化反应中。本文简要的介绍了酶定向进化技术及其在化学品生物转化中的应用。国家自然科学基金资助项目(20676048);国家“863”计划项目(2006AA020103

Development and application of BestAT tool for optimizing AT content of the initiation codon downstream region

基因的表达水平受到起始密码子下游区域AT含量的影响,从巨大的序列集中筛选出具有特定AT含量和密码子用法特征的同义序列是一个繁琐的工作。本文研发AT含量优化工具“bESTAT“,初步解决了自动获取海量同义序列和充分展示同义序列的密码子用法特性两个关键问题,并且实现了与密码子用法数据库(Cud)的无缝结合,采用了密码子参数的原位标示和AT含量曲线等直观方式展示序列特性,为这类实验设计提供有力的支持。AT content of the initiation codon downstream region affects the expression level of a gene.Picking up synonymous sequences that have specific AT content and codon usage features from tremendous sequence set is a burdensome work.In this paper,the tool named BestAT for AT content optimization had been developed.The tool resolved two key issues,(i) auto-generating mass synonymous sequences and(ii) revealing their codon usage features in details.Moreover,the tool was closely incorporated to the Codon Usage Database(CUD),and supported marking in situ codon parameters and showing visualized AT curve.All of those help to experimental design for AT content optimization powerfully.国家自然科学基金资助项目(21076172;30770059);高等学校博士学科点专项科研基金(20070385001);福建省高校产学合作科技重大项目(2010H6023

Advances in biomolecular machine: methane monooxygenases

甲烷氧化菌中的甲烷单加氧酶能够在生理条件下选择性地以甲烷和氧气为底物生成甲醇,麻省理工学院的lIPPArd教授称它为“神奇的生物分子机器“。本文重点对生物分子机器甲烷单加氧酶的结构、编码基因及调控机制、催化反应机理等进行了综述,此外也简要介绍了甲烷单加氧酶的产生菌甲烷氧化菌的研究历史及分类。生物分子机器甲烷单加氧酶可催化甲烷氧化成甲醇,不仅为甲醇的生产提供了一种新颖的生产方法,而且对生物分子机器的设计也有借鉴意义。Methane monooxygenases(MMO), regarded as "an amazing biomolecular machine", catalyze the oxidation of methane to methanol under aerobic conditions.MMO catalyze the oxidation of methane elaborately, which is a novel way to catalyze methane to methanol.Furthermore, MMO can inspire the biomolecular machine design.In this review, we introduced MMO including structure, gene and catalytic mechanism.The history and the taxonomy of MMO were also introduced.国家自然科学基金(Nos.21336009;41176111;41306124); 中央高校基本科研业务费专项资金(No.2013121029)资助~

Studies on structures and properties of glycerol and 3-hydroxypropionaldehyde by density function theory method

采用密度泛函理论(dfT)广义梯度近似(ggA)-VWnbP水平和dnd基组研究了甘油和3-羟基丙醛的全优化几何构型、电子结构、福井前线轨道和热力学性质,为研究该类化合物的结构与性质关系提供理论依据,为甘油脱水酶结构改造和分子设计提供配体数据.In this paper,the glycerol and 3-hydroxypropionaldehyde structures is modeled by using density function theory(DFT) method at the level of(GGA)-VWNBP and the DND basis set.Then their geometrical structures,electronic structures,Fukui frontier orbital and thermodynamics properties have been computed providing theoretical basis for the study of the structure and activity relationship of these compounds.国家自然科学基金资助项目(21076172);福建省高校产学合作科技重大项目(2010H6023);福建省大学生创新基金资助项目(2008cxsy01);泉州市技术研究与开发基金资助项目(2010G6

Fermentation of Brewers' Spent Grain Pretreated by Acid or Alkali with Dilute Concentration and Two-Hydrolases to Produce Alcohol

研究综合利用木质纤维三大组分的生物转化过程。将麦糟的醇不溶物按料液比1:8(W/V)加入0.1 MOl·l-1nAOH,浸泡24 H,264 W微波处理20 MIn后,调PH 5.0、45℃,加50 u·Ml-1的木聚糖酶粗酶液反应12 H后,再加入40 Mu·Ml-1的阿魏酸酯酶粗酶液反应12 H,将沉淀洗至中性,烘干,乙醇抽提,得到酶降解后麦糟的醇不溶物残渣。此残渣在料液比1:40(W/V),纤维素酶量200 u/g(麦糟的醇不溶物),反应时间36 H,初始PH值为4.5,50℃条件下进行水解,此残渣的纤维素酶解糖化率为78.5%。将残渣的水解液进行乙醇发酵,其乙醇的产量为0.27 g g 1(麦糟的醇不溶物),对应的转化率为48.72%,为理论纤维素的糖转化率的86.06%。实验结果表明经低浓度的酸碱及双酶解预处理的麦糟,经纤维素酶酶解,发酵乙醇是可行的,此研究为木质纤维的综合利用提供应用研究基础。This paper deals with the biological transformation process of the three main ingredients in lignocellulose.Alcohol-insoluble residue(AIR) of brewers’ spent grain(BSG) was put into the 0.1 mol·L-1 NaOH solution at the ratio of 1:8(W/V) and soaked for 24 h.After being treated with 264 W microwave for 20 min,the sample reacts with crude enzyme solution of xylanase(50 U·mL-1) at pH 5.0 and 45℃ for 12 h.Then the crude enzyme solution of feruloyl esterase(40 mU·mL-1) was added and reacts with the sample for another 12 h.The enzyme-treated BSG-AIR was obtained by eluting,drying,and ethanol extracting the precipitate obtained by above-mentioned process.The obtained sample was hydrolyzed with cellulose(200 U per g AIR-BSG) at the ratio of 1:40(W/V),pH 4.5 and 50℃ for 36 h,and its saccharification ratio is 78.5%.The hydrolyzate of AIR-BSG was fermented and the ethanol product of 0.27 g g 1AIR-BSG) was obtained,the corresponding conversion ratio is 48.72%,which is 86.06% of the theoretical one.Our results show that it is feasible for BSG fermentation to produce alcohol via pretreating the BSG with dilute concentration of acid or alkaline and two kinds of enzymatic hydrolyses.It may provide foundation for research on the multipurpose use of the lignocellulose.福建省科技重点项目(2011N0020); 华侨大学人才启动基金(11BS221); 华侨大学校基金(09X0289

Utilization of feruloyl esterase and xylanase for the degradation of brewers' spent grain

橘青霉以麦糟为唯一碳源培养时,阿魏酸酯酶的最佳发酵时间为60 H,其酶活力可达40.8 Mu/Ml。在PH值为5.0、45℃、料液比1∶30(g∶Ml)条件下,取47.5 u/Ml的木聚糖酶粗酶液15 Ml,加入1.0 g麦糟的乙醇不溶物,反应12 H后,加入40.8 u/Ml的阿魏酸酯酶粗酶液15 Ml再反应12 H,阿魏酸和低聚木糖释放率分别为54.1%和161 Mg/g(麦糟的乙醇不溶物)。实验结果还表明,阿魏酸酯酶与木聚糖酶存在协同作用,能极大提高麦糟中阿魏酸及低聚木糖的释放率,有利于麦糟的降解。The optimal fermentation time of Penicillium citrinum feruloyl esterase(PcFAE)was 60 h and its activity was 40.8 mU/mL when the Brewers' Spent Grain(BSG)was used as the sole carbon source for Penicillium citrinum.One gram of alcohol-insoluble residue(AIR)of Brewers'spent grain(BSG)was processed by the solution of crude xylanase(XG180)(47.5 U/mL,15 mL)for 12 hours at the condition of the material-liquid ratio 1∶30(W/V),pH 5.0 and 45 ℃,respectively.And then the solution of crude PcFAE(40.8 mU/mL)was added and the sample was processed for another 12 h.The maximum release rate of Ferulic acid(FA)was 54.1% and the release amount of xylooligosaccharide(XOS)was 161 mg/g(BSG-AIR),respectively.The results of our experiments showed that the release rate of FA and XOS from BSG-AIR increased significantly as the PcFAE could coordinate with the xylanase and enzymolysis process was also conducive to the degradation of BSG.华侨大学人才启动基金(11BS221);福建省科技重点项目(2011N0020

Effects of Spartina alterniflora on Mangrove Kandelia candel Seedlings Regeneration

以裸露的光滩为对照,在福建漳江口红树林国家级自然保护区互花米草入侵地进行秋茄胚轴插植试验,探究互花米草入侵对秋茄幼苗更新的影响。结果表明:由于互花米草遮荫的影响,秋茄幼苗生长缓慢,茎杆纤细且叶片出现脱落现象,最终由于互花米草的倒伏覆盖使得秋茄幼苗完全失去光照而全部死亡。The study was conducted in Zhangjiangkou Mangrove National Nature Reserve.Study sited with Kandelia candel hypocotyls were separately set in the places invaded by Spartina alterniflora with the control of places of bare tidal flat.The growth and survival of K.candel hypocotyls in the scopes of S.alterniflora communities were surveyed to evaluate the effects of the invasion on the regeneration of K.candel seedlings.The results showed that K.candel seedlings poorly grew because of the Spartina alterniflora shading, stalks were slender and leaves abscised,at last,because of the lodging of S.alterniflora,K.candel seedlings losed sunlight and died.国家自然科学基金项目(30600077)资

Progress of operation of NADPH metabolism in industrial strains

还原型辅酶Ⅱ(nAdPH)主要参与细胞合成代谢,是微生物代谢网络中含量最丰富的氧化还原辅酶之一。辅酶工程作为代谢工程的重要分支,通过改变微生物胞内辅酶再生途径,进而改变细胞内代谢产物构成。本文在归纳nAdPH产生途径和调控的基础上,分析和评述了工业微生物基于辅酶工程的nAdPH代谢调控研究进展,包括过量表达nAdPH代谢相关酶、敲除nAdPH代谢相关基因及引入特定代谢途径等策略,指出今后的研究重点在于深入理解nAdPH调控与中心碳代谢网络的相互作用,为利用代谢工程进行细胞工厂改造提供基础。Nicotinamide adenine dinucleotide phosphate(NADPH),a hemoprotein reductase,or in older notation,triphosphopyridine nucleotide is one of the most abundant redox cofactors in the metabolic network.It is the main electron donor in anabolism and is mainly used in the biosynthesis of biomass precursors.As an important branch of metabolism engineering,cofactor engineering changes the NADPH regeneration pathways and rebuilds the components of metabolic products.In this paper,we introduce the pathways in which NADPH is generated and reviewed the strategies to operate NADPH,including overexpression of enzymes,deletion of genes associated with NADPH metabolism or introduction of heterogeneous NADPH metabolic pathways.More attention should be focused on deeper understanding of the interplay between the operation of NADPH and central carbon metabolic networks in the future.国家自然科学基金(41176111);教育部留学回国人员科研启动基金(2010);福建省高等学校新世纪优秀人才支持计划(07FJRC03);中央高校基本科研业务费(JB-ZR1112);华侨大学科研基金(12BS132)项