检索结果-南通市图书馆

Yield penalty of maize(Zea mays L.) under heat stress in different growth stages: A review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2022年第9期21卷 2465-2476页

作者： LI Teng ZHANG Xue-peng LIU Qing LIU Jin CHEN Yuan-quan SUI Peng key laboratory of Farming systems Ministry of Agriculture and Rural Affairs/College of Agronomy and BiotechnologyChina Agricultural UniversityBeijing 100193P.R.China

Maize(Zea mays L.) can exhibit yield penalties as a result of unfavorable changes to growing conditions. The main threat to current and future global maize production is heat stress. Maize may suffer from heat stress in all of the growth stages, either continuously or separately. In order to manage the impact of climate driven heat stress on the different growth stages of maize, there is an urgent need to understand the similarities and differences in how heat stress affects maize growth and yield in the different growth stages. For the purposes of this review, the maize growth cycle was divided into seven growth stages, namely the germination and seedling stage, early ear expansion stage, late vegetative growth stage before flowering, flowering stage, lag phase, effective grain-filling stage, and late grain-filling stage. The main focus of this review is on the yield penalty and the potential physiological changes caused by heat stress in these seven different stages. The commonalities and differences in heat stress related impacts on various physiological processes in the different growth stages are also compared and discussed. Finally, a framework is proposed to describe the main influences on yield components in different stages, which can serve as a useful guide for identifying management interventions to mitigate heat stress related declines in maize yield.

关键词： growth stage heat stress maize yield penalty

New xylose transporters support the simultaneous consumption of glucose and xylose in Escherichia coli

在线全文

学校读者我要写书评

暂无评论

mLife 2022年第2期1卷 156-170页

作者： Xinna Zhu Feiyu Fan Huanna Qiu Mengyao Shao Di Li Yong Yu Changhao Bi Xueli Zhang Tianjin Institute of Industrial biotechnology Chinese Academy of SciencesTianjinChina key laboratory of systems microbial biotechnology Chinese Academy of SciencesTianjinChina College of biotechnology Tianjin University of Sciences and TechnologyTianjinChina University of Chinese Academy of Sciences BeijingChina

Glucose and xylose are two major components of *** consumption of glucose and xylose is critical for engineered microorganisms to produce fuels and chemicals from lignocellulosic *** many production limitations have been resolved,glucose‐induced inhibition of xylose transport remains a *** this study,a cell growthbased screening strategy was designed to identify xylose transporters uninhibited by *** glucose pathway was genetically blocked in Escherichia coli so that glucose functions only as an inhibitor and cells need xylose as the carbon source for *** adaptive evolution,omics analysis and reverse metabolic engineering,a new phosphoenolpyruvate:carbohydrate phosphotransferase system(PTS)galactitol transporter(GalABC,encoded by EcolC_1640,EcolC_1641,and EcolC_1642 genes)that is not inhibited by glucose was *** of adenylate cyclase led to increased expression of the EcolC_1642 gene,and a point mutation in gene EcolC_1642(N13S)further enhanced xylose *** the second round of gene mining,AraE and a new ABC transporter(AraFGH)of xylose were identified.A point mutation in the transcription regulator araC(L156I)caused increased expression of araE and araFGH genes without arabinose induction,and a point mutation in araE(D223Y)further enhanced xylose *** newly identified xylose transporters can support the simultaneous consumption of glucose and xylose and have potential use in producing chemicals from lignocellulose.

关键词： ABC transporter glucose PTS xylose xylose transporter

Enhanced validamycin production and gene expression at elevated temperature in Streptomyces hygroscopicus subsp. jingangensis 5008

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2009年第7期54卷 1204-1209页

作者： LI Lei BAI LinQuan ZHOU XiuFen DENG ZiXin School of Life Science & biotechnology and laboratory of microbial Metabolism Shanghai Jiao Tong University Shanghai 200030 China

Cultivation shift from 30℃ to 37℃ significantly enhanced validamycin (VAL) production. Analyzed by reverse-transcription PCR, the transcription of three val genes, valA, valK and valG, representing the three operons of the cluster was simultaneously increased at elevated temperature. Furthermore, the transcription of valP and valQ, a pair of two-component regulators in validamycin biosynthetic gene cluster, was also increased at 37℃. Inactivation of valP and valQ reduced validamycin production at 37℃ to the yield level of wild type strain at 30℃, and the val genes showed reduced expression in the mutant LL-8 at 37℃. These results revealed that the two-component regulator valP and valQ contribute to the elevated validamycin production.

关键词：有效霉素吸水链霉菌生产基因表达反转录聚合酶链反应高温生物合成基因簇转录基因

Data-Driven Synthetic Cell Factories Development for Industrial Biomanufacturing

在线全文

学校读者我要写书评

暂无评论

BioDesign Research 2022年第1期2022卷 236-247页

作者： Zhenkun Shi Pi Liu Xiaoping Liao Zhitao Mao Jianqi Zhang Qinhong Wang Jibin Sun Hongwu Ma Yanhe Ma key laboratory of systems microbial Technology Tianjin Institute of Industrial BiotechnologyChinese Academy of SciencesTianjin 300308China National Technology Innovation Center of Synthetic Biology Tianjin 300308China

Revolutionary breakthroughs in artificial intelligence (AI) and machine learning (ML) have had a profound impact on a widerange of scientific disciplines, including the development of artificial cell factories for biomanufacturing. In this paper, wereview the latest studies on the application of data-driven methods for the design of new proteins, pathways, and strains. Wefirst briefly introduce the various types of data and databases relevant to industrial biomanufacturing, which are the basis fordata-driven research. Different types of algorithms, including traditional ML and more recent deep learning methods, are alsopresented. We then demonstrate how these data-based approaches can be applied to address various issues in cell factorydevelopment using examples from recent studies, including the prediction of protein function, improvement of metabolicmodels, and estimation of missing kinetic parameters, design of non-natural biosynthesis pathways, and pathway *** the last section, we discuss the current limitations of these data-driven approaches and propose that data-driven methodsshould be integrated with mechanistic models to complement each other and facilitate the development of synthetic strains forindustrial biomanufacturing.

关键词： artificial breakthrough manufacturing

The PilZ domain of MrkH represents a nove ）NA binding motif

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Protein & Cell 2016年第10期7卷 766-772页

作者： Feng Wang Qing He Kaixuan Su Fei Gao Yan Huang Zong Lin Deyu Zhu Lichuan Gu State key laboratory of microbial Technology Shandong University Jinan 250100 China Department of biotechnology and Biomedicine Yangtze Delta Region Institute of Tsinghua University Jiaxing 314006 China

MrkH is the first characterized c-di-GMP related transcrip- tional regulator which affects type 3 fimbrial expression in response to cellular c-di-GMP level, and thus plays an important role in the biofilm formation of Klebsiella pneu- moniae （Murphy and Clegg, 2012; Wilksch et al., 2011）. However, how MrkH recognizes c-di-GMP and the target DNA sequence remains obscure.

关键词：

Development of an activity-directed selection system enabled significant improvement of the carboxylation efficiency of Rubisco

在线全文

学校读者我要写书评

暂无评论

Protein & Cell 2014年第7期5卷 552-562页

作者： Zhen Cai Guoxia Liu Junli Zhang Yin Li CAS key laboratory of microbial Physiological and Metabolic Engineering Institute of Microbiology Chinese Academy of Sciences Beijing 100101 China Tianjin Institute of Industrial biotechnology Chinese Academy of Sciences Tianjin 300308 China

Photosynthetic CO2 fixation is the ultimate source of organic carbon on earth and thus is essential for crop production and carbon sequestration, Ribulose-1,5-bis- phosphate carboxylase/oxygenase （Rubisco） catalyzes the first step of photosynthetic CO2 fixation. However, the extreme low carboxylation efficiency of Rubisco makes it the most attractive target for improving pho- tosynthetic efficiency. Extensive studies have focused on re-engineering a more efficient enzyme, but the effort has been impeded by the limited understanding of its structure-function relationships and the lack of an effi- cient selection system towards its activity. To address the unsuccessful molecular engineering of Rubisco, we developed an Escherichia coil-based activity-directed selection system which links the growth of host cell solely to the Rubisco activity therein. A Synechococcus sp. PCC7002 Rubisco mutant with E49V and D82G sub- stitutions in the small subunit was selected from a total of 15,000 mutants by one round of evolution. This mutant showed an 85% increase in specific carboxyla- tion activity and a 45% improvement in catalytic efficiency towards CO2. The small-subunit E49V mutation was speculated to influence holoenzyme catalysis through interaction with the large-subunit Q225. This interaction is conserved among various Rubisco from higher plants and Chlamydomonas reinhardtii. Knowledge of these might provide clues for engineering Rubisco from higher plants, with the potential of increasing the crop yield.

关键词： carboxylation efficiency CO2 fixation directed evolution Rubisco Synechococcus sp. PCC7002

Efect of the Gad system on Actinobacillus succinogenes during acid stress

在线全文

学校读者我要写书评

暂无评论

systems Microbiology and Biomanufacturing 2022年第1期2卷 177-185页

作者： Chunmei Chen Qun Zhang Junzhu Qian Dan Wu Pengcheng Chen Pu Zheng The key laboratory of Industrial biotechnology Ministry of EducationSchool of BiotechnologyJiangnan UniversityWuxi 214122China

The glutamate decarboxylase(Gad)system is an important amino acid-dependent acid resistance system commonly found in *** succinogenes is one of the best natural producers of succinic acid(SA)but lacks glutamate *** study assessed the efects of Gad system introduction into *** recombinant strains gadB-SW and gadBC-SW were constructed by heterologous expression of gadB alone,or gadB together with gadC,*** 1.0 and 1.5 h of acid stress at pH 4.6,cell survival of gadBC-SW was greater than *** growth of gadB-SW and gadBC-SW was both afected by the expression of heterologous proteins and byγ-aminobutyric acid,with gadBC-SW growth reduced at a neutral *** production in acidic conditions was evaluated by a shake fask and by 3-L bioreactor *** results showed gadBC-SW to increase SA production by 8.4%in shake fask compared to the parent strain,*** a 3-L bioreactor batch fermentation under acidic environment,the highest conversion rate of sugar to SA was observed for gadBC-SW,reaching 96%.However,SA concentration by gadBC-SW was only 47 g/L and 31 g/L at pH 6.5 and pH 6.0,*** summary,the introduction of heterologous gadB and gadC into *** not only improved acid tolerance but also infuenced the synthesis of SA and added a metabolic burden.

关键词： Actinobacillus succinogenes Acid stress Glutamate decarboxylase Succinic acid Glutamate

Screening of Highly Effective Sinorhizobium meliloti Strains for 'Vector' Alfalfa and Testing of Its Competitive Nodulation Ability in the Field

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2007年第2期17卷 219-228页

作者： ZENG Zhao-Hai CHEN Wen-Xin HU Yue-Gao SUI Xin-Hua CHEN Dan-Ming College of Agronomy and biotechnology China Agricultural University Beijing 100094 （China） College of Biology/key laboratory of Agro-microbial Resource and Application Ministry of Agriculture China Agricultural University Beijing 100094 （China）

Seventeen Sinorhizobium meliloti strains from seven provinces in China were used to screen highly effective strains for alfalfa cultivar in a greenhouse study and their symbiotic relationship and competitive ability were studied in the field. CCBAU30138 was the most effective strain, as evidenced by increase in dry weights. A field experiment showed that the inoculation of alfalfa with CCBAU30138 resulted in increases of 11.9% and 19.6% of dry matter production and crude protein production, respectively, in forage of monocultured plants. The total dry matter yields of alfalfa and tall fescue in binary culture were increased by 16.3% by inoculation of alfalfa with this strain. These results showed that S. rneliloti strain CCBAU30138 was an effective inoculant both in the greenhouse and in the field. The analysis of randomly amplified polymorphic DNA （RAPD） by polymerase chain reaction （PCR） from nodule extracts showed that the strain CCBAU30138 had high competitiveness in the field. It occupied 47.5% of nodules in alfalfa monoculture and 44.4% of nodules in alfalfa-tall fescue binary culture after 20 weeks of growth. In conclusion, a simple system to select highly effective and competitive symbiotic strains specific to alfalfa was established. Using this system, a *** suitable for the alfalfa cultivar ‘Vector＇ grown in Wuqiao County of Hebei Province was obtained.

关键词： alfalfa inoculant selection Sinorhizobium meliloti tall fescue

Enhanced thermostability and catalytic efciency of glucose oxidase in Pichia Pastoris

在线全文

学校读者我要写书评

暂无评论

systems Microbiology and Biomanufacturing 2022年第2期2卷 296-304页

作者： Hanlei Zhou Pu Zheng Pengcheng Chen Xiaowei Yu Dan Wu The key laboratory of Industrial biotechnology Ministry of EducationSchool of BiotechnologyJiangnan UniversityWuxi 214122China

Glucose oxidase(GOD)has many practical applications,but its poor thermostability limits its broader *** this research,three primary mutants of wild-type GOD were designed using rational mutagenesis,and the GODm mutant was constructed by combinatorial *** expression,purifcation,and enzymatic properties of the mutants were *** specifc enzyme activity of GODm was 2.10-fold higher than that of wild type,and the(k_(cat)/K_(m))value was increased by *** treatment at 55℃for 3 h,GODm retained 37.5%of its enzymatic activity,and the half-life(t_(1/2))of GODm at 55℃and 65℃was 2.28-fold and 3.36-fold higher than that of wild type,*** analyzing the three-dimensional structure of wild type and the GODm mutant,it was found that T30V formed a new hydrogen bond with FAD and strengthened the hydrophobic interaction,D315K optimized the surface electrostatic interaction,and A162T improved the efciency of the electron ***,a novel mutant with improved thermostability and catalytic efciency was obtained in this research.

关键词： Glucose oxidase Pichia pastoris Thermostability Catalytic efciency Rational mutagenesis