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Applied Microbiology and Biotechnology Oct 2007Bacillus megaterium has been industrially employed for more than 50 years, as it possesses some very useful and unusual enzymes and a high capacity for the production of... (Review)
Review
Bacillus megaterium has been industrially employed for more than 50 years, as it possesses some very useful and unusual enzymes and a high capacity for the production of exoenzymes. It is also a desirable cloning host for the production of intact proteins, as it does not possess external alkaline proteases and can stably maintain a variety of plasmid vectors. Genetic tools for this species include transducing phages and several hundred mutants covering the processes of biosynthesis, catabolism, division, sporulation, germination, antibiotic resistance, and recombination. The seven plasmids of B. megaterium strain QM B1551 contain several unusual metabolic genes that may be useful in bioremediation. Recently, several recombinant shuttle vectors carrying different strong inducible promoters and various combinations of affinity tags for simple protein purification have been constructed. Leader sequences-mediated export of affinity-tagged proteins into the growth medium was made possible. These plasmids are commercially available. For a broader application of B. megaterium in industry, sporulation and protease-deficient as well as UV-sensitive mutants were constructed. The genome sequence of two different strains, plasmidless DSM319 and QM B1551 carrying seven natural plasmids, is now available. These sequences allow for a systems biotechnology optimization of the production host B. megaterium. Altogether, a "toolbox" of hundreds of genetically characterized strains, genetic methods, vectors, hosts, and genomic sequences make B. megaterium an ideal organism for industrial, environmental, and experimental applications.
Topics: Bacillus megaterium; Genetic Engineering; Industrial Microbiology; Plasmids; Recombinant Proteins; Soil Microbiology
PubMed: 17657486
DOI: 10.1007/s00253-007-1089-3 -
Microbiology (Reading, England) May 1994It is evident that B. megaterium is an intriguing organism because of its biochemical versatility, its wide distribution ecologically, its ability to undergo... (Review)
Review
It is evident that B. megaterium is an intriguing organism because of its biochemical versatility, its wide distribution ecologically, its ability to undergo sporulation, and its usefulness as an industrial production strain and expression host. With the progress in genetics and the availability of molecular tools such as new transposons, vectors and efficient transformation, an understanding of some of the organization and regulation of many genes is increasing rapidly. Such recent discoveries as the ability of oxetanocin to combat some medically significant, recalcitrant viruses further demonstrates that there is much to be learned and much to benefit from continued study of B. megaterium.
Topics: Bacillus megaterium; Classification; Industrial Microbiology; Spores, Bacterial
PubMed: 8025666
DOI: 10.1099/13500872-140-5-1001 -
BMC Microbiology Nov 2020For microorganisms on a paper surface, the lack of water is one of the most important stress factors. A strain of Bacillus megaterium FDU301 was isolated from plaques on...
BACKGROUND
For microorganisms on a paper surface, the lack of water is one of the most important stress factors. A strain of Bacillus megaterium FDU301 was isolated from plaques on a paper surface using culture medium with polyethylene glycol 200 (PEG200) to simulate an arid condition. Global transcriptomic analysis of B. megaterium FDU301 grown under normal and simulated arid conditions was performed via RNA-seq technology to identify genes involved in arid stress adaptation.
RESULTS
The transcriptome of B. megaterium FDU301 grown in LB medium under arid (15% PEG200 (w/w)) and normal conditions were compared. A total of 2941 genes were differentially expressed, including 1422 genes upregulated and 1519 genes downregulated under arid conditions. Oxidative stress-responsive regulatory genes perR, fur, and tipA were significantly upregulated, along with DNA protecting protein (dps), and catalase (katE). Genes related to Fe uptake (feoB), sporulation stage II (spoIIB, spoIIE, spoIIGA), small acid-soluble spore protein (sspD), and biosynthesis of compatible solute ectoine (ectB, ectA) were also highly expressed to various degrees. Oxidative phosphorylation-related genes (atpB, atpE, atpF, atpH, atpA, atpG, atpD, atpC) and glycolysis-related genes (pgk, tpiA, frmA) were significantly downregulated.
CONCLUSION
This is the first report about transcriptomic analysis of a B. megaterium to explore the mechanism of arid resistance. Major changes in transcription were seen in the arid condition simulated by PEG200 (15%), with the most important one being genes related to oxidative stress. The results showed a complex mechanism for the bacteria to adapt to arid stress.
Topics: Adaptation, Physiological; Bacillus megaterium; Bacterial Proteins; Culture Media; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Paper; Polyethylene Glycols; Stress, Physiological; Transcriptome
PubMed: 33198631
DOI: 10.1186/s12866-020-02039-4 -
Microbial Cell Factories Nov 2017Over the last 10-15 years, a technology has been developed to engineer bacterial poly(3-hydroxybutyrate) (PHB) inclusions as functionalized beads, for applications such...
BACKGROUND
Over the last 10-15 years, a technology has been developed to engineer bacterial poly(3-hydroxybutyrate) (PHB) inclusions as functionalized beads, for applications such as vaccines, diagnostics and enzyme immobilization. This has been achieved by translational fusion of foreign proteins to the PHB synthase (PhaC). The respective fusion protein mediates self-assembly of PHB inclusions displaying the desired protein function. So far, beads have mainly been produced in recombinant Escherichia coli, which is problematic for some applications as the lipopolysaccharides (LPS) co-purified with such inclusions are toxic to humans and animals.
RESULTS
In this study, we have bioengineered the formation of functional PHB inclusions in the Gram-positive bacterium Bacillus megaterium, an LPS-free and established industrial production host. As B. megaterium is a natural PHB producer, the PHB-negative strain PHA05 was used to avoid any background PHB production. Plasmid-mediated T7 promoter-driven expression of the genes encoding β-ketothiolase (phaA), acetoacetyl-CoA-reductase (phaB) and PHB synthase (phaC) enabled PHB production in B. megaterium PHA05. To produce functionalized PHB inclusions, the N- and C-terminus of PhaC was fused to four and two IgG binding Z-domains from Staphylococcus aureus, respectively. The ZZ-domain PhaC fusion protein was strongly overproduced at the surface of the PHB inclusions and the corresponding isolated ZZ-domain displaying PHB beads were found to purify IgG with a binding capacity of 40-50 mg IgG/g beads. As B. megaterium has the ability to sporulate and respective endospores could co-purify with cellular inclusions, a sporulation negative production strain was generated by disrupting the spoIIE gene in PHA05. This strain did not produce spores when tested under sporulation inducing conditions and it was still able to synthesize ZZ-domain displaying PHB beads.
CONCLUSIONS
This study provides proof of concept for the successful genetic engineering of B. megaterium as a host for the production of functionalized PHB beads. Disruption of the spoIIE gene rendered B. megaterium incapable of sporulation but particularly suitable for production of functionalized PHB beads. This sporulation-negative mutant represents an improved industrial production strain for biotechnological processes otherwise impaired by the possibility of endospore formation.
Topics: Bacillus megaterium; Genetic Engineering; Prohibitins
PubMed: 29166918
DOI: 10.1186/s12934-017-0823-5 -
Archives of Microbiology Oct 2020Methanolic extract of Artemisia pallens (MEAP) (Asteraceae) was explored as greenbiocorrosion inhibitor for mild steel 1010 in 1.5% sodium chloride environment....
Methanolic extract of Artemisia pallens (MEAP) (Asteraceae) was explored as greenbiocorrosion inhibitor for mild steel 1010 in 1.5% sodium chloride environment. Bacillus megaterium SKR7 induces the development of biofilm on the metal surface and forms the pitting corrosion. MEAP was showed (25 ppm) optimum inhibition effect of biocorrosion and further corrosion rate was highly reduced (0.3335 mm/year) than the control system (0.009 mm/year). The electrochemical study has supported the results with a higher value of total resistance (34 Ω cm) when compared to control systems. It reveals the formation of a protective layer on the metal surface and reduces the adsorption of biofilm. This was due to the antimicrobial effect of MEAP. Overall, the results recognized that MEAP used as a green corrosion inhibitor for MS 1010 with 83% inhibition efficiency.
Topics: Artemisia; Bacillus megaterium; Biofilms; Corrosion; Methanol; Plant Extracts; Steel
PubMed: 32564100
DOI: 10.1007/s00203-020-01951-7 -
Journal of Microencapsulation Mar 2020To prolong the shelf life of NCT-2 by preparing microcapsules through spray drying, and evaluate their efficiency in secondary salinisation soil remediation. The wall...
To prolong the shelf life of NCT-2 by preparing microcapsules through spray drying, and evaluate their efficiency in secondary salinisation soil remediation. The wall material and spray drying conditions were optimised. Morphological characteristics of microcapsule were measured, and soil remediation effects were tested under field conditions. A relatively higher survival rate of microcapsule was obtained with 1:1 of chitosan/maltodextrin (w/w) when spray drying was performed at 150.0 °C, with the feed flow rates of 800 mL h and 1000 mL h, respectively. The span value of 0.93 ± 0.01 was obtained under above conditions. Microcapsule survival rate was 64.09 ± 0.12% after 6 months of storage. Moreover, microcapsule successfully decreased NO and EC value in strongly saline soil by 46.5 ± 1.48% and 45.2 ± 1.51%, respectively. NCT-2 microcapsules have application potential in the remediation of secondary salinisation soil.
Topics: Bacillus megaterium; Capsules; Desiccation; Microbial Viability; Soil; Soil Microbiology
PubMed: 31847637
DOI: 10.1080/02652048.2019.1705409 -
Journal of Biotechnology Jan 2013The high industrial relevance of the soil bacterium Bacillus megaterium as host for recombinant proteins is driving systems-wide analyses of its metabolic and regulatory... (Review)
Review
The high industrial relevance of the soil bacterium Bacillus megaterium as host for recombinant proteins is driving systems-wide analyses of its metabolic and regulatory networks. The present review highlights novel systems biology tools available to unravel the various cellular components on the level of metabolic and regulatory networks. These provide a rational platform for systems metabolic engineering of B. megaterium. In line, a number of interesting studies have particularly focused on studying recombinant B. megaterium in its industrial bioprocess environment thus integrating systems metabolic engineering with systems biotechnology and providing the full picture toward optimal processes.
Topics: Bacillus megaterium; Biotechnology; Metabolic Engineering; Recombinant Proteins; Systems Biology
PubMed: 22750448
DOI: 10.1016/j.jbiotec.2012.06.018 -
PloS One 2018The intense use of herbicides for weed control in agriculture causes selection pressure on soil microbiota and water ecosystems, possibly resulting in changes to...
The intense use of herbicides for weed control in agriculture causes selection pressure on soil microbiota and water ecosystems, possibly resulting in changes to microbial processes, such as biogeochemical cycles. These xenobiotics may increase the production of reactive oxygen species and consequently affect the survival of microorganisms, which need to develop strategies to adapt to these conditions and maintain their ecological functionality. This study analyzed the adaptive responses of bacterial isolates belonging to the same species, originating from two different environments (water and soil), and subjected to selection pressure by herbicides. The effects of herbicide Callisto and its active ingredient, mesotrione, induced different adaptation strategies on the cellular, enzymatic, and structural systems of two Bacillus megaterium isolates obtained from these environments. The lipid saturation patterns observed may have affected membrane permeability in response to this herbicide. Moreover, this may have led to different levels of responses involving superoxide dismutase and catalase activities, and enzyme polymorphisms. Due to these response systems, the strain isolated from water exhibited higher growth rates than did the soil strain, in evaluations made in oligotrophic culture media, which would be more like that found in semi-pristine aquatic environments. The influence of the intracellular oxidizing environments, which changed the mode of degradation of mesotrione in our experimental model and produced different metabolites, can also be observed in soil and water at sites related to agriculture. Since the different metabolites may present different levels of toxicity, we suggest that this fact should be considered in studies on the fate of agrochemicals in different environments.
Topics: Adaptation, Physiological; Bacillus megaterium; Biodegradation, Environmental; Cyclohexanones; Ecosystem; Herbicides; Lipid Peroxidation; Microbial Viability; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Soil Microbiology; Water Microbiology
PubMed: 29694403
DOI: 10.1371/journal.pone.0196166 -
Bioengineered Dec 2021High production costs still hamper fast expansion of commercial production of polyhydroxyalkanoates (PHAs). This problem is greatly related to the cultivation medium...
High production costs still hamper fast expansion of commercial production of polyhydroxyalkanoates (PHAs). This problem is greatly related to the cultivation medium which accounts for up to 50% of the whole process costs. The aim of this research work was to evaluate the potential of using volatile fatty acids (VFAs), derived from acidogenic fermentation of food waste, as inexpensive carbon sources for the production of PHAs through bacterial cultivation. could assimilate glucose, acetic acid, butyric acid, and caproic acid as single carbon sources in synthetic medium with maximum PHAs production yields of 9-11%, on a cell dry weight basis. Single carbon sources were then replaced by a mixture of synthetic VFAs and by a VFAs-rich stream from the acidogenic fermentation of food waste. After 72 h of cultivation, the VFAs were almost fully consumed by the bacterium in both media and PHAs production yields of 9-10%, on cell dry weight basis, were obtained. The usage of VFAs mixture was found to be beneficial for the bacterial growth that tackled the inhibition of propionic acid, iso-butyric acid, and valeric acid when these volatile fatty acids were used as single carbon sources. The extracted PHAs were revealed to be polyhydroxybutyrate (PHB) by characterization methods of Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The obtained results proved the possibility of using VFAs from acidogenic fermentation of food waste as a cheap substrate to reduce the cost of PHAs production.
Topics: Acids; Bacillus megaterium; Biomass; Calorimetry, Differential Scanning; Fatty Acids, Volatile; Fermentation; Food; Glucose; Hydrogen-Ion Concentration; Polyhydroxyalkanoates; Refuse Disposal; Spectroscopy, Fourier Transform Infrared
PubMed: 34115556
DOI: 10.1080/21655979.2021.1935524 -
FEMS Microbiology Letters Nov 2019In the present study, the taxonomic position of Bacillus aryabhattai and Bacillus megaterium was evaluated using morphological, biochemical, phylogenomic and genome...
In the present study, the taxonomic position of Bacillus aryabhattai and Bacillus megaterium was evaluated using morphological, biochemical, phylogenomic and genome analysis. The morphological and biochemical of these two species were almost similar with few exceptions. The major fatty acids in B. megaterium DSM 32T and B. aryabhattai 21047T were anteiso-C15:0 and iso-C15:0. In the phylogenomic tree, both species clade together and shared high 16S rRNA gene sequence similarity (99.6%). The average nucleotide identity values between Bacillus aryabhattai and Bacillus megaterium were above the threshold values for bacterial species delineation. Based upon morphological, biochemical, chemotaxonomic and comparative genome analysis, we propose to reclassify Bacillus aryabhattai Shivaji et al. 2009 as a later heterotypic synonym of Bacillus megaterium de Bary 1884 (Approved Lists 1980).
Topics: Bacillus; Bacillus megaterium; Cluster Analysis; Cytosol; DNA, Bacterial; DNA, Ribosomal; Fatty Acids; Genomics; Mycological Typing Techniques; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid
PubMed: 31913456
DOI: 10.1093/femsle/fnz258