Metabolites Of Bacillus Research Articles

Reparative and Immunomodulatory Potential of Low-Molecular-Weight Fractions of Secondary Metabolites of Bacillus sp.

The experiment was performed on male BALB/c mice with modeled skin wound. Two chromatographic fractions of secondary metabolites of permafrost bacteria Bacillus sp., that represent a mixture of polyethylene-polypropylene glycols oligomers with a molecular weight from 900 to 1350 Da were used as therapeutic agents. Application of the test substances on the wound surface and their parenteral administration significantly accelerated wound epithelialization in comparison with untreated control, activated metabolic processes, and improved humoral immunity. In in vitro experiments, the fractions activated the synthesis of IFNγ and IL-4 by human peripheral blood mononuclear cells. We conclude that polyethylene-polypropylene glycol oligomers can be a part of effector molecules that determine the repair and immunomodulatory potential of secondary metabolites of permafrost microorganisms Bacillus sp.

Influence of bacterial metabolites from permafrost on morphophysiological parameters of potato material in vitro*

The effect of secondary metabolites of bacteria from permafrost rocks on the in vitro morphophysiological parameters of potato microplants has been studied. Microplants of Zhukovsky ranniy potato variety were used as the object of the study. The experimental results indicate that when potato microplants are grown in vitro together in the Murashige-Skoog nutrient medium with the bacteria metabolites of the Bacillus cereus 9-08-CH9 and Achromobacter spanius 10-50TS2 strains introduced at the grafting time at a dose of 250 μl, they have the highest inhibitory effect. Secondary metabolites of these bacterial strains have a significant increase in the number of internodes at all stages of plant cultivation, which can accelerate the in vitro replication of material for original potato seed production. Metabolites of the bacterial strain Bacillus cereus 875TS in the indicated concentrations cause growth inhibition and delay in the development of microplants’ root system at the initial cultivation stages.

Key elements and regulation strategies of NRPSs for biosynthesis of lipopeptides by Bacillus.

Lipopeptides are a group of second metabolites of Bacillus and have multiple activities such as inhibiting fungi, bacteria, viruses, and tumors, showing a great potential application in agricultural and biomedical fields. However, low production severely restrained their application in practice. Deeply understanding the key elements of lipopeptide synthesis and the regulatory strategies is essential to target the improvement of lipopeptide production. The synthetic pathways of different lipopeptides are different, but closely and mutually interfered. The loading of fatty acid chains and the extension of peptide chains are two key steps for the synthesis of different lipopeptides by Bacillus. The selection of fatty acid chains, the loading order of amino acids, and the recognition of the final cyclization site are the critical steps to determine the end products of different lipopeptides. In order to find the key elements for precisely directing the formation of different lipopeptides by Bacillus, the key structural elements and possible regulatory strategies that have been reported in the production of different lipopeptides, mainly surfactin, iturin, and fengycin by Bacillus, were summarized and compared. The possible ways to improve the production of different targeted lipopeptides were proposed. KEY POINTS: • The selectivity of fatty acids is determined by specific domains. • The COM domain and the PKS docking domain determine the order of amino acids. • The regulation patterns of different domains for lipopeptide synthesis are different. • The regulation of different lipopeptide products overlaps each other.

Effects of Secondary Metabolites of Permafrost Bacillus sp. on Cytokine Synthesis by Human Peripheral Blood Mononuclear Cells.

We studied the effects of secondary metabolites of Bacillus sp. isolated from late Neogene permafrost on secretion of proinflammatory (TNF-α, IL-1β, IL-8, IL-2, and IFNγ) and antiinflammatory (IL-4 and IL-10) cytokines by human peripheral blood mononuclear cells. It was found that metabolites of Bacillus sp. produced more potent effect on cytokine secretion than mitogen phytohemagglutinin and metabolites of Bacillus cereus, medicinal strain IP5832. Activity of metabolites depended on the temperature of bacteria incubation. "Cold" metabolites of Bacillus sp. (isolated at -5°C) primarily induced Th1-mediated secretion of IFNγ, while "warm" metabolites (obtained at 37°C) induced Th2-mediated secretion of IL-4. The results suggest that Bacillus sp. metabolites are promising material for the development of immunomodulating drugs.

Antidiatom activity of marine bacteria associated with sponges from San Juan Island, Washington

Crude extracts of 52 marine bacteria associated with sponges, which were collected from the sea near San Juan Island, Washington, USA, were screened using diatom attachment assays against Amphora sp., Nitzschia closterium, Sellaphora sp. and Stauroneis sp. to investigate their antidiatom activities. Among these samples, five expressed strong anti-adhesion effects on all four tested diatoms. There was no negative effect observed from those five active samples on the growth of Amphora sp. Those five active samples were prepared from respective isolates, which all belonged to the genus Bacillus based on 16S rRNA gene sequencing analysis. The results of present study indicate that Bacillus may play important roles for sponges' chemical defence against biofouling of diatoms and that the metabolites of Bacillus may be a potential source of natural antifouling compounds.

Tandem mass spectrometry for on-line fermentation monitoring

Membrane introduction mass spectrometry has been employed for on-line determination of the major products and volatile metabolites ofBacillus polymyxa fermentation. Samples were introduced into the mass spectrometer via a direct insertion membrane probe in which the aqueous solution flowed past a membrane located in the ion source of the mass spectrometer. Concentrations of the products 2,3-butanediol, acetoin, ethanol and acetic acid in fermentation broth were measured by tandem mass spectrometry after permeation through the membrane and ionization by chemical ionization. External standards were employed for quantification and a large linear response range was available for each of the major products observed. Dissolved CO2 and O2, as well as CO2 in the off gases, were also monitored on-line by mass spectrometry. The use of tandem mass spectrometry has allowed the identification of products that were not previously known to be present in measurable amounts.