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Applied and Environmental Microbiology Oct 2011The metabolic cooperation in the ecosystem of Bacillus megaterium and Ketogulonicigenium vulgare was investigated by cultivating them spatially on a soft agar plate. We...
The metabolic cooperation in the ecosystem of Bacillus megaterium and Ketogulonicigenium vulgare was investigated by cultivating them spatially on a soft agar plate. We found that B. megaterium swarmed in a direction along the trace of K. vulgare on the agar plate. Metabolomics based on gas chromatography coupled with time-of-flight mass spectrometry (GC-TOF-MS) was employed to analyze the interaction mechanism between the two microorganisms. We found that the microorganisms interact by exchanging a number of metabolites. Both intracellular metabolism and cell-cell communication via metabolic cooperation were essential in determining the population dynamics of the ecosystem. The contents of amino acids and other nutritional compounds in K. vulgare were rather low in comparison to those in B. megaterium, but the levels of these compounds in the medium surrounding K. vulgare were fairly high, even higher than in fresh medium. Erythrose, erythritol, guanine, and inositol accumulated around B. megaterium were consumed by K. vulgare upon its migration. The oxidization products of K. vulgare, including 2-keto-gulonic acids (2KGA), were sharply increased. Upon coculturing of B. megaterium and K. vulgare, 2,6-dipicolinic acid (the biomarker of sporulation of B. megaterium), was remarkably increased compared with those in the monocultures. Therefore, the interactions between B. megaterium and K. vulgare were a synergistic combination of mutualism and antagonism. This paper is the first to systematically identify a symbiotic interaction mechanism via metabolites in the ecosystem established by two isolated colonies of B. megaterium and K. vulgare.
Topics: Agar; Bacillus megaterium; Chromatography, Gas; Culture Media; Ecosystem; Locomotion; Metabolome; Microbial Interactions; Rhodobacteraceae; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 21803889
DOI: 10.1128/AEM.05123-11 -
Journal of Microbiology and... Nov 2010A bacterial strain capable of producing extracellular alpha-galactosidase was isolated from sugar cane industrial waste soil sample. Microbiological, physiological, and...
A bacterial strain capable of producing extracellular alpha-galactosidase was isolated from sugar cane industrial waste soil sample. Microbiological, physiological, and biochemical studies revealed that isolate belonged to Bacillus sp,. Furthermore, 16S rDNA sequence analysis of new isolates was identified as Bacillus megaterium VHM1. The production of alpha-galactosidase was optimized by various physical culture conditions. Guar gum and yeast extract acted as the best carbon and nitrogen source, respectively for the production of alpha-galactosidase. The enzyme showed an optimum pH at 7.5 and was stable over a pH between 5 and 9. The enzyme was optimally active in 55degreesC and the enzyme was thermostable with half life of 120 minutes at 55 degrees C and lost their 90%, residual activity in 120 minutes at 60 degrees C. alpha-Galactosidase was strongly inhibited by Ag2, Cu2, and Hg2+ at 1mM concentration. The metal ions Fe2, Mn2+, and Mg2+ had no effect on alpha-galactosidase activity, Zn2+,Ni2+, and Ca2+ reduced the enzyme activity slightly. The B megaterium VHM1 enzyme treatment completely hydrolyzed flatulence-causing sugars of soymilk within one and half hour.
Topics: Antifoaming Agents; Bacillus megaterium; Bacterial Proteins; Carbohydrates; Enzyme Stability; Flatulence; Molecular Sequence Data; Phylogeny; Saccharum; Soy Milk; alpha-Galactosidase
PubMed: 21124061
DOI: 10.4014/jmb.0912.12012 -
Brazilian Journal of Microbiology :... Mar 2021As a key precursor of vitamin C, 2-keto-L-gulonic acid (2-KLG) was mainly produced from L-sorbose by mixed fermentation of Ketogulonicigenium vulgare and a helper strain...
As a key precursor of vitamin C, 2-keto-L-gulonic acid (2-KLG) was mainly produced from L-sorbose by mixed fermentation of Ketogulonicigenium vulgare and a helper strain (Bacillus spp.) with a low conversion rate for decades. The aim of this study was to enhance the 2-KLG production by co-culturing K. vulgare and Bacillus megaterium using three-stage temperature control (TSTC) strategy. By investigating the temperature effect on the 2-KLG fermentation, the optimum temperatures for the growths of K. vulgare and B. megaterium were 32 °C and 29 °C, respectively, while the optimum temperature for 2-KLG production was 35 °C. We developed a TSTC process: the temperature was kept at 32 °C during the first 16 h of fermentation, then decreased to 29 °C for the following 14 h, and maintained at 35 °C to the end of fermentation. By using this new process, the productivity and yield of 2-KLG from L-sorbose were obtained at 2.19 ± 0.19 g/L/h and 92.91 ± 1.02 g/L in 20-L fermentors for 5 batches, respectively, which were 22.35% and 6.02% higher than that of the control treatment (the single temperature of 29 °C). The increased cell density of K. vulgare during the exponential phase and the enhanced SDH activity (increased by 25.18% at 36 h, 17.14% at 44 h) in the production stage might be the reasons for enhanced 2-KLG conversion rate and yield. Our results demonstrated the feasibility of the TSTC strategy for 2-KLG production.
Topics: Bacillus megaterium; Bacteriological Techniques; Bioreactors; Culture Media; Fermentation; Rhodobacteraceae; Sorbose; Sugar Acids; Temperature
PubMed: 33145708
DOI: 10.1007/s42770-020-00396-w -
Journal of Bacteriology Mar 2014Previous work demonstrated that Bacillus megaterium QM B1551 spores that are null for the sleB and cwlJ genes, which encode cortex-lytic enzymes (CLEs), either of which...
Previous work demonstrated that Bacillus megaterium QM B1551 spores that are null for the sleB and cwlJ genes, which encode cortex-lytic enzymes (CLEs), either of which is required for efficient cortex hydrolysis in Bacillus spores, could germinate efficiently when complemented with a plasmid-borne copy of ypeB plus the nonlytic portion of sleB encoding the N-terminal domain of SleB (sleB(N)). The current study demonstrates that the defective germination phenotype of B. megaterium sleB cwlJ spores can partially be restored when they are complemented with plasmid-borne ypeB alone. However, efficient germination in this genetic background requires the presence of sleL, which in this species was suggested previously to encode a nonlytic epimerase. Recombinant B. megaterium SleL showed little, or no, activity against purified spore sacculi, cortical fragments, or decoated spore substrates. However, analysis of muropeptides generated by the combined activities of recombinant SleB and SleL against spore sacculi revealed that B. megaterium SleL is actually an N-acetylglucosaminidase, albeit with apparent reduced activity compared to that of the homologous Bacillus cereus protein. Additionally, decoated spores were induced to release a significant proportion of dipicolinic acid (DPA) from the spore core when incubated with recombinant SleL plus YpeB, although optimal DPA release required the presence of endogenous CLEs. The physiological basis that underpins this newly identified dependency between SleL and YpeB is not clear, since pulldown assays indicated that the proteins do not interact physically in vitro.
Topics: Bacillus megaterium; Bacterial Proteins; Gene Expression Regulation, Bacterial; Hydrolysis; Spores, Bacterial
PubMed: 24375103
DOI: 10.1128/JB.01298-13 -
Applied and Environmental Microbiology Apr 2018DNA damage kills dry-heated spores of , but dry-heat-treatment effects on spore germination and outgrowth have not been studied. This is important, since if...
DNA damage kills dry-heated spores of , but dry-heat-treatment effects on spore germination and outgrowth have not been studied. This is important, since if dry-heat-killed spores germinate and undergo outgrowth, toxic proteins could be synthesized. Here, Raman spectroscopy and differential interference contrast microscopy were used to study germination and outgrowth of individual dry-heat-treated and spores. The major findings in this work were as follows: (i) spores dry-heat-treated at 140°C for 20 min lost nearly all viability but retained their Ca-dipicolinic acid (CaDPA) depot; (ii) in most cases, dry-heat treatment increased the average times and variability of all major germination events in spore germination with nutrient germinants or CaDPA, and in one nutrient germination event with spores; (iii) spore germination with dodecylamine, which activates the spore CaDPA release channel, was unaffected by dry-heat treatment; (iv) these results indicate that dry-heat treatment likely damages spore proteins important in nutrient germinant recognition and cortex peptidoglycan hydrolysis, but not CaDPA release itself; and (v) analysis of single spores incubated on nutrient-rich agar showed that while dry-heat-treated spores that are dead can complete germination, they cannot proceed into outgrowth and thus not to vegetative growth. The results of this study provide new information on the effects of dry heat on bacterial spores and indicate that dry-heat sterilization regimens should produce spores that cannot outgrow and thus cannot synthesize potentially dangerous proteins. Much research has shown that high-temperature dry heat is a promising means for the inactivation of spores on medical devices and spacecraft decontamination. Dry heat is known to kill spores by DNA damage. However, knowledge about the effects of dry-heat treatment on spore germination and outgrowth is limited, especially at the single spore level. In the current work, Raman spectroscopy and differential interference contrast microscopy were used to analyze CaDPA levels in and kinetics of nutrient- and non-nutrient germination of multiple individual dry-heat-treated and spores that were largely dead. The outgrowth and subsequent cell division of these germinated but dead dry-heat-treated spores were also examined. The knowledge obtained in this study will help understand the effects of dry heat on spores both on Earth and in space, and indicates that dry heat can be safely used for sterilization purposes.
Topics: Bacillus megaterium; Bacillus subtilis; Hot Temperature; Kinetics; Microscopy, Interference; Spectrum Analysis, Raman; Spores, Bacterial; Sterilization
PubMed: 29330188
DOI: 10.1128/AEM.02618-17 -
BioMed Research International 2016A bioflocculant-producing bacterium, SP1, was isolated from biofloc in pond water and identified by using both 16S rDNA sequencing analysis and a Biolog GEN III...
A bioflocculant-producing bacterium, SP1, was isolated from biofloc in pond water and identified by using both 16S rDNA sequencing analysis and a Biolog GEN III MicroStation System. The optimal carbon and nitrogen sources for SP1 were 20 g L of glucose and 0.5 g L of beef extract at 30°C and pH 7. The bioflocculant produced by strain SP1 under optimal culture conditions was applied into aquaculture wastewater treatment. The removal rates of chemical oxygen demand (COD), total ammonia nitrogen (TAN), and suspended solids (SS) in aquaculture wastewater reached 64, 63.61, and 83.8%, respectively. The volume of biofloc (FV) increased from 4.93 to 25.97 mL L. The addition of SP1 in aquaculture wastewater could effectively improve aquaculture water quality, promote the formation of biofloc, and then form an efficient and healthy aquaculture model based on biofloc technology.
Topics: Ammonia; Aquaculture; Bacillus megaterium; Biological Oxygen Demand Analysis; Carbon; Flocculation; Nitrogen; Phylogeny; Wastewater; Water Purification
PubMed: 27840823
DOI: 10.1155/2016/2758168 -
Microbiological Research Jun 2021Since sugarcane is a ratoon crop, genome analysis of plant growth-promoting bacteria that exist in its soil rhizosphere, can provide opportunity to better understand...
Whole genome sequence insight of two plant growth-promoting bacteria (B. subtilis BS87 and B. megaterium BM89) isolated and characterized from sugarcane rhizosphere depicting better crop yield potentiality.
Since sugarcane is a ratoon crop, genome analysis of plant growth-promoting bacteria that exist in its soil rhizosphere, can provide opportunity to better understand their characteristics and use of such bacteria in turn, may especially improve perennial crop productivity. In the present study, genome of two bacterial strains, one each of B. megaterium (BM89) and B. subtilis (BS87), isolated and reported earlier (Chandra et al., 2018), were sequenced and characterized. Though both strains have demonstrated plant growth promoting properties and enhanced in-vitro plant growth responses, functional annotation and analysis of genes indicated superiority of BS87 as it possessed more plant growth promotion attributable genes over BM89. Apart from some common genes, trehalose metabolism, glycine betaine production, peroxidases, super oxide dismutase, cold shock proteins and phenazine production associated genes were selectively identified in BS87 genome indicating better plant growth performances and survival potential under harsh environmental conditions. Genes for chitinase, d-cysteine desulfhydrase and γ-aminobutyric acid (GABA), as found in BM89, propose its selective utilization in defense and bio-control measures. Concomitant with better settlings' growth, scanning electron micrographs indicated these isolated and characterized bacteria exhibiting healthy colonization within root of sugarcane crop. Kegg pathways' assignment also revealed added pathways namely carbohydrate and amino acid metabolism attached to B. subtilis strain BS87, a preferable candidate for bio-fertilizer and its utilization to promote growth of both plant and ratoon crops of sugarcane usually experiencing harsh environmental conditions.
Topics: Bacillus megaterium; Bacillus subtilis; Cold Shock Proteins and Peptides; Crop Production; Crops, Agricultural; Fertilizers; Genome, Bacterial; Phylogeny; Plant Development; Rhizosphere; Saccharum; Soil; Soil Microbiology; Whole Genome Sequencing
PubMed: 33676313
DOI: 10.1016/j.micres.2021.126733 -
International Journal of Molecular... Jun 2016Plant-growth-promoting rhizobacteria can improve plant growth, development, and stress adaptation. However, the underlying mechanisms are still largely unclear. We...
Plant-growth-promoting rhizobacteria can improve plant growth, development, and stress adaptation. However, the underlying mechanisms are still largely unclear. We investigated the effects of Bacillus megaterium BOFC15 on Arabidopsis plants. BOFC15 produced and secreted spermidine (Spd), a type of polyamine (PA) that plays an important role in plant growth. Moreover, BOFC15 induced changes in the cellular PAs of plants that promoted an increase of free Spd and spermine levels. However, these effects were remarkably abolished by the addition of dicyclohexylamine (DCHA), a Spd biosynthetic inhibitor. Additionally, the inoculation with BOFC15 remarkably increased plant biomass, improved root system architecture, and augmented photosynthetic capacity. Inoculated plants also displayed stronger ability to tolerate drought stress than non-inoculated (control) plants. Abscisic acid (ABA) content was notably higher in the inoculated plants than in the control plants under drought stress and polyethylene glycol (PEG)-induced stress conditions. However, the BOFC15-induced ABA synthesis was markedly inhibited by DCHA. Thus, microbial Spd participated in the modulation of the ABA levels. The Spd-producing BOFC15 improved plant drought tolerance, which was associated with altered cellular ABA levels and activated adaptive responses.
Topics: Abscisic Acid; Arabidopsis; Bacillus megaterium; Biomass; Droughts; Photosynthesis; Polyethylene Glycols; Rhizome; Spermidine; Stress, Physiological
PubMed: 27338359
DOI: 10.3390/ijms17060976 -
Revista Argentina de Microbiologia 2016Tetracyclines are used for the prevention and control of dairy cattle diseases. Residues of these drugs can be excreted into milk. Thus, the aim of this study was to...
Tetracyclines are used for the prevention and control of dairy cattle diseases. Residues of these drugs can be excreted into milk. Thus, the aim of this study was to develop a microbiological method using Bacillus megaterium to detect tetracyclines (chlortetracycline, oxytetracycline and tetracycline) in milk. In order to approximate the limits of detection of the bioassay to the Maximum Residue Limit (100μg/l) for milk tetracycline, different concentrations of chloramphenicol (0, 1000, 1500 and 2000μg/l) were tested. The detection limits calculated were similar to the Maximum Residue Limits when a bioassay using B. megaterium ATCC 9885 spores (2.8×10(8)spores/ml) and chloramphenicol (2000μg/l) was utilized. This bioassay detects 105μg/l of chlortetracycline, 100μg/l of oxytetracycline and 134μg/l of tetracycline in 5h. Therefore, this method is suitable to be incorporated into a microbiological multi-residue system for the identification of tetracyclines in milk.
Topics: Animals; Anti-Bacterial Agents; Argentina; Bacillus megaterium; Biological Assay; Chloramphenicol; Drug Residues; Food Contamination; Maximum Allowable Concentration; Milk; Sensitivity and Specificity; Spores, Bacterial; Tetracyclines
PubMed: 27131738
DOI: 10.1016/j.ram.2016.02.001 -
Biochemistry Jul 2017Electron-transfer kinetics have been measured in four conjugates of cytochrome P450 with surface-bound Ru-photosensitizers. The conjugates are constructed with enzymes...
Electron-transfer kinetics have been measured in four conjugates of cytochrome P450 with surface-bound Ru-photosensitizers. The conjugates are constructed with enzymes from Bacillus megaterium (CYP102A1) and Sulfolobus acidocaldarius (CYP119). A W96 residue lies in the path between Ru and the heme in CYP102A1, whereas H76 is present at the analogous location in CYP119. Two additional conjugates have been prepared with (CYP102A1)W96H and (CYP119)H76W mutant enzymes. Heme oxidation by photochemically generated Ru leads to P450 compound II formation when a tryptophan residue is in the path between Ru and the heme; no heme oxidation is observed when histidine occupies this position. The data indicate that heme oxidation proceeds via two-step tunneling through a tryptophan radical intermediate. In contrast, heme reduction by photochemically generated Ru proceeds in a single electron tunneling step with closely similar rate constants for all four conjugates.
Topics: Archaeal Proteins; Bacillus megaterium; Bacterial Proteins; Cytochrome P-450 Enzyme System; Electron Transport; Heme; Models, Molecular; NADPH-Ferrihemoprotein Reductase; Oxidation-Reduction; Photosensitizing Agents; Ruthenium; Sulfolobus acidocaldarius; Tryptophan
PubMed: 28689401
DOI: 10.1021/acs.biochem.7b00432