共查询到20条相似文献,搜索用时 15 毫秒
1.
Saul N Rocha José Abrahão-Neto María E Cerdán María I González-Siso Andreas K Gombert 《Microbial cell factories》2010,9(1):4
Background
In spite of its advantageous physiological properties for bioprocess applications, the use of the yeast Kluyveromyces marxianus as a host for heterologous protein production has been very limited, in constrast to its close relative Kluyveromyces lactis. In the present work, the model protein glucose oxidase (GOX) from Aspergillus niger was cloned into K. marxianus CBS 6556 and into K. lactis CBS 2359 using three different expression systems. We aimed at verifying how each expression system would affect protein expression, secretion/localization, post-translational modification, and biochemical properties. 相似文献2.
Xin Lu Jibin Sun Manfred Nimtz Josef Wissing An-Ping Zeng Ursula Rinas 《Microbial cell factories》2010,9(1):23
Background
The filamentous fungus Aspergillus niger is well-known as a producer of primary metabolites and extracellular proteins. For example, glucoamylase is the most efficiently secreted protein of Aspergillus niger, thus the homologous glucoamylase (glaA) promoter as well as the glaA signal sequence are widely used for heterologous protein production. Xylose is known to strongly repress glaA expression while maltose is a potent inducer of glaA promoter controlled genes. For a more profound understanding of A. niger physiology, a comprehensive analysis of the intra- and extracellular proteome of Aspergillus niger AB1.13 growing on defined medium with xylose or maltose as carbon substrate was carried out using 2-D gel electrophoresis/Maldi-ToF and nano-HPLC MS/MS. 相似文献3.
Danilo E Xavier Renata C Picão Raquel Girardello Lorena CC Fehlberg Ana C Gales 《BMC microbiology》2010,10(1):217
Background
Multi-drug efflux pumps have been increasingly recognized as a major component of resistance in P. aeruginosa. We have investigated the expression level of efflux systems among clinical isolates of P. aeruginosa, regardless of their antimicrobial susceptibility profile. 相似文献4.
Background
The two-component systems of Mycobacterium tuberculosis are apparently required for its growth and resistance in hostile host environments. In such environments, MtrAB has been reported to regulate the expression of the M. tuberculosis replication initiator gene, dnaA. However, the dnaA promoter binding sites and many potential target genes for MtrA have yet to be precisely characterized. 相似文献5.
Background
New fungal species that are morphologically similar to Aspergillus fumigatus were recently described and included in section Fumigati. Misidentification of such fungal species, particularly of the human pathogens, Aspergillus lentulus, Neosartorya fischeri, Neosartorya hiratsukae, Neosartorya pseudofischeri and Neosartorya udagawae, has been increasingly reported by numerous clinical labs. Nevertheless, A. fumigatus still accounts for more than 90% of all invasive aspergillosis cases. The purpose of the present study was to develop a rapid method for the molecular identification of A. fumigatus to distinguish it from other species within the section Fumigati. 相似文献6.
Khaled Khoufache Olivier Puel Nicolas Loiseau Marcel Delaforge Danièle Rivollet André Coste Catherine Cordonnier Estelle Escudier Françoise Botterel Stéphane Bretagne 《BMC microbiology》2007,7(1):5
Background
The role of Aspergillus fumigatus mycotoxins in the colonization of the respiratory tract by conidia has not been studied extensively, even though patients at risk from invasive aspergillosis frequently exhibit respiratory epithelium damage. In a previous study, we found that filtrates of A. fumigatus cultures can specifically alter the electrophysiological properties of human nasal epithelial cells (HNEC) compared to those of non pathogenic moulds. 相似文献7.
Mayken W Wadman Ronald P de Vries Stefanie IC Kalkhove Gerrit A Veldink Johannes FG Vliegenthart 《BMC microbiology》2009,9(1):59
Background
Aspergillus niger is an ascomycetous fungus that is known to reproduce through asexual spores, only. Interestingly, recent genome analysis of A. niger has revealed the presence of a full complement of functional genes related to sexual reproduction [1]. An example of such genes are the dioxygenase genes which in Aspergillus nidulans, have been shown to be connected to oxylipin production and regulation of both sexual and asexual sporulation [2–4]. Nevertheless, the presence of sex related genes alone does not confirm sexual sporulation in A. niger. 相似文献8.
Background
The amino acid derivative 3,4-dihydroxy L-phenylalanine (L-dopa) is gaining interest as a drug of choice for Parkinson's disease. Aspergillus oryzae is commonly used for L-dopa production; however, a slower growth rate and relatively lower tyrosinase activity of mycelia have led to an increasing interest in exploiting alternative fungal cultures. In the present investigation, we report on the microbiological transformation of L-tyrosine to L-dopa accomplished by a newly isolated filamentous fungus Aspergillus niger. 相似文献9.
Stefano Moretti Danitsja van Leeuwen Hans Gmuender Stefano Bonassi Joost van Delft Jos Kleinjans Fioravante Patrone Domenico Franco Merlo 《BMC bioinformatics》2008,9(1):361
Background
In gene expression analysis, statistical tests for differential gene expression provide lists of candidate genes having, individually, a sufficiently low p-value. However, the interpretation of each single p-value within complex systems involving several interacting genes is problematic. In parallel, in the last sixty years, game theory has been applied to political and social problems to assess the power of interacting agents in forcing a decision and, more recently, to represent the relevance of genes in response to certain conditions. 相似文献10.
Bevan KS Chung Suresh Selvarasu Andrea Camattari Jimyoung Ryu Hyeokweon Lee Jungoh Ahn Hongweon Lee Dong-Yup Lee 《Microbial cell factories》2010,9(1):50
Background
Pichia pastoris has been recognized as an effective host for recombinant protein production. A number of studies have been reported for improving this expression system. However, its physiology and cellular metabolism still remained largely uncharacterized. Thus, it is highly desirable to establish a systems biotechnological framework, in which a comprehensive in silico model of P. pastoris can be employed together with high throughput experimental data analysis, for better understanding of the methylotrophic yeast's metabolism. 相似文献11.
M. Storari R. von Rohr I. Pertot C. Gessler G.A.L. Broggini 《Journal of applied microbiology》2013,114(4):1193-1200
Aims
To develop two assays based on the loop‐mediated isothermal amplification (LAMP) of DNA for the quick and specific identification of Aspergillus carbonarius and ochratoxigenic strains of the Aspergillus niger clade isolated from grapes.Methods and Results
Two sets of primers were designed based on the polyketide synthase genes involved or putatively involved in ochratoxin A (OTA) biosynthesis in A. carbonarius and A. niger clade. Hydroxynaphthol blue was used as indirect method to indicate DNA amplification. The limit of detection of both assays was comparable to that of a PCR reaction. Specificities of the reactions were tested using DNA from different black aspergilli isolated from grapes. The two LAMP assays were then used to identify A. carbonarius and ochratoxigenic A. niger and A. awamori grown in pure cultures without a prior DNA extraction.Conclusions
The two LAMP assays permitted to quickly and specifically identify DNA from OTA‐producing black aspergilli, as well as isolates grown in pure culture.Significance and Impact of the Study
Monitoring vineyards for the presence of OTA‐producing strains is part of the measures to minimize the occurrence of OTA in grape products. The two LAMP assays developed here could be potentially used to speed the screening process of vineyards for the presence of OTA‐producing black aspergilli. 相似文献12.
Lutz Herrmann Michael Erkelenz Ingo Aldag Arno Tiedtke Marcus WW Hartmann 《BMC microbiology》2006,6(1):19-9
Background
Over the last decades molecular biologic techniques have been developed to alter the genome and proteome of Tetrahymena thermophila thereby providing the basis for recombinant protein expression including functional human enzymes. The biotechnological potential of Tetrahymena has been proved in numerous publications, demonstrating fast growth, high biomass, fermentation in ordinary bacterial/yeast equipment, up-scalability, existence of cheap and chemical defined media. For these reasons Tetrahymena offers promising opportunities for the development of a high expression system. Yet optimised high yield strains with protease deficiency such as commonly used in yeast and bacterial systems are not available. 相似文献13.
Xue Zhou Jori Symons Rieuwert Hoppes Christel Krueger Christian Berens Wolfgang Hillen Ben Berkhout Atze T Das 《BMC biotechnology》2007,7(1):6
Background
The Tet-Off (tTA) and Tet-On (rtTA) regulatory systems are widely applied to control gene expression in eukaryotes. Both systems are based on the Tet repressor (TetR) from transposon Tn10, a dimeric DNA-binding protein that binds to specific operator sequences (tetO). To allow the independent regulation of multiple genes, novel Tet systems are being developed that respond to different effectors and bind to different tetO sites. To prevent heterodimerization when multiple Tet systems are expressed in the same cell, single-chain variants of the transactivators have been constructed. Unfortunately, the activity of the single-chain rtTA (sc-rtTA) is reduced when compared with the regular rtTA, which might limit its application. 相似文献14.
Background
The nisin-controlled gene expression system NICE of Lactococcus lactis is one of the most widely used expression systems in Gram-positive bacteria. Despite its widespread use, no optimization of the culture conditions and nisin induction has been carried out to obtain maximum yields. As a model system induced production of lysostaphin, an antibacterial protein (mainly against Staphylococcus aureus) produced by S. simulans biovar. Staphylolyticus, was used. Three main areas need optimization for maximum yields: cell density, nisin-controlled induction and protein production, and parameters specific for the target-protein. 相似文献15.
Background
Cloning of genes in expression libraries, such as the yeast two-hybrid system (Y2H), is based on the assumption that the loss of target genes is minimal, or at worst, managable. However, the expression of genes or gene fragments that are capable of interacting with E. coli or yeast gene products in these systems has been shown to be growth inhibitory, and therefore these clones are underrepresented (or completely lost) in the amplified library. 相似文献16.
Irene Kouskoumvekaki Zhiyong Yang Svava Ó Jónsdóttir Lisbeth Olsson Gianni Panagiotou 《BMC bioinformatics》2008,9(1):59
Background
In the present investigation, we have used an exhaustive metabolite profiling approach to search for biomarkers in recombinantAspergillus nidulans(mutants that produce the 6- methyl salicylic acid polyketide molecule) for application in metabolic engineering. 相似文献17.
18.
Zhu-Mei He Michael S Price Gregory R OBrian D Ryan Georgianna Gary A Payne 《BMC microbiology》2007,7(1):104
Background
An available whole genome sequence for Aspergillus flavus provides the opportunity to characterize factors involved in pathogenicity and to elucidate the regulatory networks involved in aflatoxin biosynthesis. Functional analysis of genes within the genome is greatly facilitated by the ability to disrupt or mis-express target genes and then evaluate their result on the phenotype of the fungus. Large-scale functional analysis requires an efficient genetic transformation system and the ability to readily select transformants with altered expression, and usually requires generation of double (or multi) gene deletion strains or the use of prototrophic strains. However, dominant selectable markers, an efficient transformation system and an efficient screening system for transformants in A. flavus are absent. 相似文献19.
F. Mahboudi F. Barkhordari R.M. Godarzi S. Enayati F. Davami 《Journal of applied microbiology》2013,114(2):364-372
Aims
A novel chimeric‐truncated form of tissue‐type plasminogen activator (t‐PA) with improved fibrin affinity and resistance to PAI was successfully produced in CHO expression system during our previous studies. Considering advantages of prokaryotic expression systems, the aim in this study was to produce the novel protein in Escherichia coli (BL21) strain and compare the protein potency in batch and fed‐batch processes.Methods and Results
The expression cassette for the novel t‐PA was prepared in pET‐28a(+). The E. coli expression procedure was compared in traditional batch and newly developed fed batch, EnBase® Flo system. The protein was purified in soluble format, and potency results were identified using Chromolize t‐PA Assay Kit. The fed‐batch fermentation mode, coupled with a Ni‐NTA affinity purification procedure under native condition, resulted in higher amounts of soluble protein, and about a 30% of improvement in the specific activity of the resulted recombinant protein (46·66 IU mg?1) compared to traditional batch mode (35·8 IU mg?1).Conclusions
Considering the undeniable advantages of expression in the prokaryotic expression systems such as E. coli for recombinant protein production, applying alternative methods of cultivation is a promising approach. In this study, fed‐batch cultivation methods showed the potential to replace miss‐folded formats of protein with proper folded, soluble form with improved potency.Significance and Impact of the Study
Escherichia coli expression of recombinant proteins still counts for nearly 40% of marketed biopharmaceuticals. The major drawback of this system is the lack of appropriate post‐translational modifications, which may cause potency loss/decline. Therefore, applying alternative methods of cultivation as investigated here is a promising approach to overcome potency decrease problem in this protein production system. 相似文献20.