scholarly journals Parameterization of regulatory nodes for engineering broad host range heterologous gene expression

2021 ◽  
Author(s):  
Pablo Ivan Nikel ◽  
Ilaria Benedetti ◽  
Victor de Lorenzo ◽  
Belen Calles
Keyword(s):  
Heterologous Gene Expression ◽  
Coli Strain ◽  
Broad Host Range ◽  
Expression Systems ◽  
Chemical Inducers ◽  
Gram Positive Bacteria ◽  
Vector Backbone ◽  
Expression Noise ◽  
Dna Context ◽  
Dna Scaffold

By building on the SEVA (Standard European Vector Architecture) format we have refactored a number of regulatory nodes recruited from both Gram-negative and Gram-positive bacteria for rigorously comparing and parameterizing five expression devices that respond to diverse and unrelated chemical inducers, i.e. LacIq-Ptrc, XylS-Pm, AlkS-PalkB, CprK-PDB3 and ChnR-PchnB. These were assembled as cargoes following the SEVA standard within exactly the same vector backbone and bearing the different functional segments arrayed in an invariable DNA scaffold. Their performance in an Escherichia coli strain of reference were then analyzed through the readout a fluorescence reporter gene that contained strictly identical translation signal elements in all cases and in the same DNA context. This study allowed us to describe and compare the cognate expression systems with unprecedented quantitative detail. The systems under scrutiny diverged considerably in their capacity, expression noise, inducibility and OFF/ON ratios. These features, along with the absence of physiological effects caused by the inducers and the lack of cross regulation offer a panoply of choices to potential users and help interoperability of the specific constructs.

scholarly journals An overview on current molecular tools for heterologous gene expression in Trichoderma

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Irene Tomico-Cuenca ◽  
Robert L. Mach ◽  
Astrid R. Mach-Aigner ◽  
Christian Derntl
Keyword(s):  
Gene Expression ◽  
Protein Expression ◽  
Protein Secretion ◽  
Heterologous Gene Expression ◽  
Heterologous Gene ◽  
Molecular Tools ◽  
Expression Systems ◽  
Industrial Enzymes ◽  
Nutrient Sources ◽  
Transformation Methods

AbstractFungi of the genus Trichoderma are routinely used as biocontrol agents and for the production of industrial enzymes. Trichoderma spp. are interesting hosts for heterologous gene expression because their saprotrophic and mycoparasitic lifestyles enable them to thrive on a large number of nutrient sources and some members of this genus are generally recognized as safe (GRAS status). In this review, we summarize and discuss several aspects involved in heterologous gene expression in Trichoderma, including transformation methods, genome editing strategies, native and synthetic expression systems and implications of protein secretion. This review focuses on the industrial workhorse Trichoderma reesei because this fungus is the best-studied member of this genus for protein expression and secretion. However, the discussed strategies and tools can be expected to be transferable to other Trichoderma species.

scholarly journals The multifunctionality of expression systems in Bacillus subtilis: Emerging devices for the production of recombinant proteins

2021 ◽  
pp. 153537022110301
Author(s):  
Caio Coutinho de Souza ◽  
Jander Matos Guimarães ◽  
Soraya dos Santos Pereira ◽  
Luis André Morais Mariúba
Keyword(s):  
Bacillus Subtilis ◽  
Recombinant Proteins ◽  
Large Scale ◽  
Recombinant Expression ◽  
Academic Research ◽  
Future Research ◽  
Expression Systems ◽  
Bioactive Substances ◽  
Exogenous Dna ◽  
Chemical Inducers

Bacillus subtilis is a successful host for producing recombinant proteins. Its GRAS (generally recognized as safe) status and its remarkable innate ability to absorb and incorporate exogenous DNA into its genome make this organism an ideal platform for the heterologous expression of bioactive substances. The factors that corroborate its value can be attributed to the scientific knowledge obtained from decades of study regarding its biology that has fostered the development of several genetic engineering strategies, such as the use of different plasmids, engineering of constitutive or double promoters, chemical inducers, systems of self-inducing expression with or without a secretion system that uses a signal peptide, and so on. Tools that enrich the technological arsenal of this expression platform improve the efficiency and reduce the costs of production of proteins of biotechnological importance. Therefore, this review aims to highlight the major advances involving recombinant expression systems developed in B. subtilis, thus sustaining the generation of knowledge and its application in future research. It was verified that this bacterium is a model in constant demand and studies of the expression of recombinant proteins on a large scale are increasing in number. As such, it represents a powerful bacterial host for academic research and industrial purposes.

scholarly journals A Type IV-Secretion-Like System Is Required for Conjugative DNA Transport of Broad-Host-Range Plasmid pIP501 in Gram-Positive Bacteria

2007 ◽  
Vol 189 (6) ◽  
pp. 2487-2496 ◽  
Author(s):  
Mohammad Y. Abajy ◽  
Jolanta Kopeć ◽  
Katarzyna Schiwon ◽  
Michal Burzynski ◽  
Mike Döring ◽  
...  
Keyword(s):  
Host Range ◽  
Sequence Similarity ◽  
Type Iv Secretion ◽  
Conjugative Plasmid ◽  
Computer Assisted ◽  
Transcriptional Level ◽  
Broad Host Range ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Type Iv

ABSTRACT Plasmid pIP501 has a very broad host range for conjugative transfer among a wide variety of gram-positive bacteria and gram-negative Escherichia coli. Functionality of the pIP501 transfer (tra) genes in E. coli was proven by pIP501 retrotransfer to Enterococcus faecalis (B. Kurenbach, C. Bohn, J. Prabhu, M. Abudukerim, U. Szewzyk, and E. Grohmann, Plasmid 50:86-93, 2003). The 15 pIP501 tra genes are organized in a single operon (B. Kurenbach, J. Kopeć, M. Mägdefrau, K. Andreas, W. Keller, C. Bohn, M. Y. Abajy, and E. Grohmann, Microbiology 152:637-645, 2006). The pIP501 tra operon is negatively autoregulated at the transcriptional level by the conjugative DNA relaxase TraA. Three of the 15 pIP501-encoded Tra proteins show significant sequence similarity to the Agrobacterium type IV secretion system proteins VirB1, VirB4, and VirD4. Here we report a comprehensive protein-protein interaction map of all of the pIP501-encoded Tra proteins determined by the yeast two-hybrid assay. Most of the interactions were verified in vitro by isolation of the protein complexes with pull-down assays. In conjunction with known or postulated functions of the pIP501-encoded Tra proteins and computer-assisted prediction of their cellular location, we propose a model for the first type IV-secretion-like system encoded by a conjugative plasmid from gram-positive bacteria.

scholarly journals Plasmids for Independently Tunable, Low-Noise Expression of Two Genes

mSphere ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
João P. N. Silva ◽  
Soraia Vidigal Lopes ◽  
Diogo J. Grilo ◽  
Zach Hensel
Keyword(s):  
Gene Expression ◽  
Protein Expression ◽  
Low Noise ◽  
Expression Systems ◽  
Extrinsic Noise ◽  
Gene Expression Noise ◽  
Expression Noise ◽  
Foreign Proteins ◽  
Noise Limit ◽  
Cell Variation

ABSTRACTSome microbiology experiments and biotechnology applications can be improved if it is possible to tune the expression of two different genes at the same time with cell-to-cell variation at or below the level of genes constitutively expressed from the chromosome (the “extrinsic noise limit”). This was recently achieved for a single gene by exploiting negative autoregulation by the tetracycline repressor (TetR) and bicistronic gene expression to reduce gene expression noise. We report new plasmids that use the same principles to achieve simultaneous, low-noise expression for two genes inEscherichia coli. The TetR system was moved to a compatible plasmid backbone, and a system based on thelacrepressor (LacI) was found to also exhibit gene expression noise below the extrinsic noise limit. We characterized gene expression mean and noise across the range of induction levels for these plasmids, applied the LacI system to tune expression for single-molecule mRNA detection under two different growth conditions, and showed that two plasmids can be cotransformed to independently tune expression of two different genes.IMPORTANCEMicrobiologists often express foreign proteins in bacteria in order study them or to use bacteria as a microbial factory. Usually, this requires controlling the number of foreign proteins expressed in each cell, but for many common protein expression systems, it is difficult to “tune” protein expression without large cell-to-cell variation in expression levels (called “noise” in protein expression). This work describes two protein expression systems that can be combined in the same cell, with tunable expression levels and very low protein expression noise. One new system was used to detect single mRNA molecules by fluorescence microscopy, and the two systems were shown to be independent of each other. These protein expression systems may be useful in any experiment or biotechnology application that can be improved with low protein expression noise.

scholarly journals Synthetic Riboswitches That Induce Gene Expression in Diverse Bacterial Species

2010 ◽  
Vol 76 (23) ◽  
pp. 7881-7884 ◽  
Author(s):  
Shana Topp ◽  
Colleen M. K. Reynoso ◽  
Jessica C. Seeliger ◽  
Ian S. Goldlust ◽  
Shawn K. Desai ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bacterial Species ◽  
Human Pathogens ◽  
Expression Systems ◽  
Genetic Studies ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Control Gene Expression ◽  
Diverse Species ◽  
Wide Range

ABSTRACT We developed a series of ligand-inducible riboswitches that control gene expression in diverse species of Gram-negative and Gram-positive bacteria, including human pathogens that have few or no previously reported inducible expression systems. We anticipate that these riboswitches will be useful tools for genetic studies in a wide range of bacteria.

scholarly journals Novel Bacterial Artificial Chromosome Vector pUvBBAC for Use in Studies of the Functional Genomics of Listeria spp.

2008 ◽  
Vol 74 (6) ◽  
pp. 1892-1901 ◽  
Author(s):  
Torsten Hain ◽  
Sonja Otten ◽  
Ulrich von Both ◽  
Som S. Chatterjee ◽  
Ulrike Technow ◽  
...  
Keyword(s):  
Bacterial Artificial Chromosome ◽  
Functional Genomics ◽  
Bac Library ◽  
Virulence Gene ◽  
Artificial Chromosome ◽  
Broad Host Range ◽  
Actin Assembly ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Bacterial Artificial Chromosome Vector

ABSTRACT Bacterial artificial chromosome (BAC) vectors are important tools for microbial genome research. We constructed a novel BAC vector, pUvBBAC, for replication in both gram-negative and gram-positive bacterial hosts. The pUvBBAC vector was used to generate a BAC library for the facultative intracellular pathogen Listeria monocytogenes EGD-e. The library had insert sizes ranging from 68 to 178 kb. We identified two recombinant BACs from the L. monocytogenes pUvBBAC library that each contained the entire virulence gene cluster (vgc) of L. monocytogenes and transferred them to a nonpathogenic Listeria innocua strain. Recombinant L. innocua strains harboring pUvBBAC+vgc1 and pUvBBAC+vgc2 produced the vgc-specific listeriolysin (LLO) and actin assembly protein ActA and represent the first reported cloning of the vgc locus in its entirety. The use of the novel broad-host-range BAC vector pUvBBAC extends the versatility of this technology and provides a powerful platform for detailed functional genomics of gram-positive bacteria as well as its use in explorative functional metagenomics.

scholarly journals Selection and Characterization of a Multivalent Salmonella Phage and Its Production in a Nonpathogenic Escherichia coli Strain

2010 ◽  
Vol 76 (21) ◽  
pp. 7338-7342 ◽  
Author(s):  
S. B. Santos ◽  
E. Fernandes ◽  
C. M. Carvalho ◽  
S. Sillankorva ◽  
V. N. Krylov ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Host Range ◽  
Biocontrol Agent ◽  
Coli Strain ◽  
Broad Host Range ◽  
Restriction Profile ◽  
Phage Dna ◽  
Dna Restriction ◽  
Salmonella Phage

ABSTRACT We report the selection and amplification of the broad-host-range Salmonella phage phi PVP-SE1 in an alternative nonpathogenic host. The lytic spectrum and the phage DNA restriction profile were not modified upon replication in Escherichia coli Bl21, suggesting the possibility of producing this phage in a nonpathogenic host, contributing to the safety and easier approval of a product based on this Salmonella biocontrol agent.

scholarly journals Bacillus anthracis and Bacillus cereus PcrA Helicases Can Support DNA Unwinding and In Vitro Rolling-Circle Replication of Plasmid pT181 of Staphylococcus aureus

2004 ◽  
Vol 186 (7) ◽  
pp. 2195-2199 ◽  
Author(s):  
Syam P. Anand ◽  
Poulami Mitra ◽  
Asma Naqvi ◽  
Saleem A. Khan
Keyword(s):  
Staphylococcus Aureus ◽  
Bacillus Cereus ◽  
Bacillus Anthracis ◽  
Broad Host Range ◽  
Gram Positive ◽  
Rolling Circle ◽  
Initiator Protein ◽  
Gram Positive Bacteria ◽  
Plasmid Pt181

ABSTRACT Replication of rolling-circle replicating (RCR) plasmids in gram-positive bacteria requires the unwinding of initiator protein-nicked plasmid DNA by the PcrA helicase. In this report, we demonstrate that heterologous PcrA helicases from Bacillus anthracis and Bacillus cereus are capable of unwinding Staphylococcus aureus plasmid pT181 from the initiator-generated nick and promoting in vitro replication of the plasmid. These helicases also physically interact with the RepC initiator protein of pT181. The ability of PcrA helicases to unwind noncognate RCR plasmids may contribute to the broad-host-range replication and dissemination of RCR plasmids in gram-positive bacteria.

scholarly journals What an Escherichia coli Mutant Can Teach Us About the Antibacterial Effect of Chlorophyllin

2019 ◽  
Vol 7 (2) ◽  
pp. 59 ◽  
Author(s):  
Marcus Krüger ◽  
Peter Richter ◽  
Sebastian Strauch ◽  
Adeel Nasir ◽  
Andreas Burkovski ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
High Sensitivity ◽  
Coli Strain ◽  
Photodynamic Treatment ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Bacterial Model

Due to the increasing development of antibiotic resistances in recent years, scientists search intensely for new methods to control bacteria. Photodynamic treatment with porphyrins such as chlorophyll derivatives is one of the most promising methods to handle bacterial infestation, but their use is dependent on illumination and they seem to be more effective against Gram-positive bacteria than against Gram-negatives. In this study, we tested chlorophyllin against three bacterial model strains, the Gram-positive Bacillus subtilis 168, the Gram-negative Escherichia coli DH5α and E. coli strain NR698 which has a deficient outer membrane, simulating a Gram-negative “without” its outer membrane. Illuminated with a standardized light intensity of 12 mW/cm2, B. subtilis showed high sensitivity already at low chlorophyllin concentrations (≤105 cfu/mL: ≤0.1 mg/L, 106–108 cfu/mL: 0.5 mg/L), whereas E. coli DH5α was less sensitive (≤105 cfu/mL: 2.5 mg/L, 106 cfu/mL: 5 mg/L, 107–108 cfu/mL: ineffective at ≤25 mg/L chlorophyllin). E. coli NR698 was almost as sensitive as B. subtilis against chlorophyllin, pointing out that the outer membrane plays a significant role in protection against photodynamic chlorophyllin impacts. Interestingly, E. coli NR698 and B. subtilis can also be inactivated by chlorophyllin in darkness, indicating a second, light-independent mode of action. Thus, chlorophyllin seems to be more than a photosensitizer, and a promising substance for the control of bacteria, which deserves further investigation.

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