Biofilm formation is an effective survival strategy of plant-associated microorganisms in hostile environments, so the application of biofilm-forming and exopolysaccharide (EPS)-producing beneficial microbes to plants has received more attention in recent years. This study examined the ability of biofilm and EPS production of Bacillus subtilis and Bacillus thuringiensis strains under different NaCl concentrations (0, 50, 100, 200, and 400 mmol/L), pH values (5.5, 6.5, 7.5, and 8.5), and phosphate levels (0, 25, 50, and 100 mmol/L at 0 and 400 mmol/L NaCl). B. subtilis BS2 and B. thuringiensis BS6/BS7 strains significantly increased biofilm formation in a similar pattern to EPS production under salt stress. B. subtilis BS2/BS3 enhanced biofilm production at slightly acidic pH with a lower EPS production but the other strains formed considerably more amount of biofilm and EPS at alkaline pH. Interestingly, higher levels of phosphate substantially decreased biofilm and EPS production at 0 mmol/L NaCl but increased biofilm formation at 400 mmol/L salt concentration. Overall, contrary to phosphate, salt and pH differently influenced biofilm and EPS production by Bacillus strains. EPS production contributed to biofilm formation to some extent under all the conditions tested. Some Bacillus strains produced more abundant biofilm under salt and pH stress, indicating their potential to form in vivo biofilms in rhizosphere and on plants, particularly under unfavorable conditions.
- MeSH
- Bacillus subtilis fyziologie metabolismus účinky léků MeSH
- Bacillus thuringiensis fyziologie účinky léků MeSH
- bakteriální polysacharidy * metabolismus biosyntéza MeSH
- biofilmy * účinky léků růst a vývoj MeSH
- chlorid sodný * farmakologie metabolismus MeSH
- fosfáty * metabolismus farmakologie MeSH
- koncentrace vodíkových iontů MeSH
- Publikační typ
- časopisecké články MeSH
Bacterial metabolism of phytohormones includes several processes such as biosynthesis, catabolism, conjugation, hydrolysis and homeostatic regulation. However, only biosynthesis and occasionally catabolism are studied in depth in microorganisms. In this work, we evaluated and reconsidered IAA metabolism in Bradyrhizobiumjaponicum E109, one of the most widely used strains for soybean inoculation around the world. The genomic analysis of the strain showed the presence of several genes responsible for IAA biosynthesis, mainly via indole-3-acetonitrile (IAN), indole-3-acetamide (IAM) and tryptamine (TAM) pathways. However; in vitro experiments showed that IAA is not accumulated in the culture medium in significant amounts. On the contrary, a strong degradation activity was observed after exogenous addition of 0.1 mM of IAA, IBA or NAA to the medium. B. japonicum E109 was not able to grow in culture medium containing IAA as a sole carbon source. In YEM medium, the bacteria degraded IAA and hydrolyzed amino acid auxin conjugates with alanine (IAAla), phenylalanine (IAPhe), and leucine (IAPhe), releasing IAA which was quickly degraded. Finally, the presence of exogenous IAA induced physiological changes in the bacteria such as increased biomass and exopolysaccharide production, as well as infection effectiveness and symbiotic behavior in soybean plants.
- MeSH
- alanin metabolismus MeSH
- bakteriální polysacharidy biosyntéza MeSH
- Bradyrhizobium genetika metabolismus MeSH
- fenylalanin metabolismus MeSH
- Glycine max mikrobiologie MeSH
- kyseliny indoloctové metabolismus MeSH
- leucin metabolismus MeSH
- semena rostlinná mikrobiologie MeSH
- symbióza fyziologie MeSH
- tvorba kořenových hlízek fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
Stereospecific nucleation of mesoporous hybrid microspheres composed of CaCO3 and carrageenan was appended to one side of bacterial cellulose membrane synthesized in static cultures of Gluconacetobacter hansenii to develop an implantable drug delivery device. The synthesis of the hybrid microparticles proceeds by self-assembly mechanism in the presence of calcium and contains tailorable amounts of doxorubicin. However, in the absence of the particles, doxorubicin was distributed along the BC film, but without control release of drug. Infrared spectroscopy, confocal and scanning electron microscopies analyses demonstrate that the doxorubicin is entrapped inside the hybrid particles with approximately 80% drug loading compared to the 11% obtained for native bacterial cellulose. Doxorubicin content in the hybrid particles can be increased by a factor of 10 (from 258.6 to 2586.3 nmol ml−1), and also by the quantities of particles regulated by the CaCO3–carrageenan content and the physicochemical microenvironment. The hybrid BC system can be considered as smart device since the kinetic release of doxorubicin from the hybrid cellulose system rise from 1.50 to 2.75 μg/membrane/day when the pH decreases from 7.4 to 5.8 at 37 °C, a pathologic simulated environment. The hybrid microparticle system can be potentially used as an implantable drug delivery system for personalized oncological therapies.
- MeSH
- antitumorózní látky aplikace a dávkování terapeutické užití toxicita MeSH
- bakteriální polysacharidy biosyntéza farmakologie metabolismus MeSH
- biomedicínský výzkum metody trendy MeSH
- celulosa * biosyntéza farmakologie MeSH
- doxorubicin aplikace a dávkování farmakologie MeSH
- elektronová mikroskopie metody využití MeSH
- Gluconacetobacter růst a vývoj účinky léků MeSH
- individualizovaná medicína metody trendy využití MeSH
- karagenan * biosyntéza metabolismus MeSH
- konfokální mikroskopie metody využití MeSH
- lidé MeSH
- nanokompozity chemie mikrobiologie využití MeSH
- spektrofotometrie infračervená metody využití MeSH
- statistika jako téma metody MeSH
- systémy cílené aplikace léků metody využití MeSH
- techniky in vitro MeSH
- uhličitan vápenatý * chemická syntéza metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Biofilmy obklopené extracelulárními polymerními látkami představují jeden z nejčastěji objevujících se fenotypů v přírodě. Biofilmy jsou proto nedílnou součástí přirozených ekosystémů. Mikroorganismy interagují mezi sebou ale i s prostředím, ve kterém žijí. Přítomnost extracelulárních polymerních substancí na površích v kontaktu s jídlem umožňuje kolonizaci potenciálně nebezpečných patogenů nebo mikroorganismů hniloby a usnadňuje kontaminační proces. Hlubší poznání jednotlivých složek matrice může podpořit rozvoj strategií umožňujících účinné rozrušení a odstranění biofilmu. Tento článek je věnován především představení složek matrice a jejich základním funkcím.
Biofilms encased by extracellular polymeric substances are very common phenotype across the nature. Therefore they are inseparable part of natural habitats. Microorganisms interact with each other and also with environment they live in. Presence of extracellular polymeric substances on the surface facilitates colonisation of potentially dangerous pathogens or food spoilage. Better understanding of matrix components can support the development of treatment strategies that successfully disrupt biofilm structure. This article aims to characterise the matrix components and their basic functions.
- MeSH
- bakteriální adheziny biosyntéza chemie MeSH
- bakteriální polysacharidy biosyntéza chemie MeSH
- bakteriální proteiny biosyntéza metabolismus MeSH
- biofilmy * růst a vývoj MeSH
- biopolymery metabolismus škodlivé účinky MeSH
- DNA bakterií metabolismus MeSH
- extracelulární matrix - proteiny metabolismus škodlivé účinky MeSH
- Publikační typ
- práce podpořená grantem MeSH
The cell wall of the model actinomycete Streptomyces coelicolor M145 has recently been shown to contain the novel glycopolymer teichulosonic acid. The major building block of this polymer is 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (Kdn), suggesting initial clues about the genetic control of biosynthesis of this cell wall component. Here, through genome mining and gene knockouts, we demonstrate that the sco4879-sco4882 genomic region of S. coelicolor M145 is necessary for biosynthesis of teichulosonic acid. Specifically, mutants carrying individual knockouts of sco4879, sco4880 and sco4881 genes do not produce Kdn-containing glycopolymer and instead accumulate the minor cell wall component poly(diglycosyl 1-phosphate). Our studies provide evidence that this region is at least partly responsible for biosynthesis of Kdn, whereas flanking genes might control the other steps of teichulosonic acid formation.
- MeSH
- bakteriální polysacharidy biosyntéza MeSH
- buněčná stěna genetika metabolismus MeSH
- data mining MeSH
- DNA bakterií genetika MeSH
- inzerční mutageneze MeSH
- klonování DNA MeSH
- kyseliny cukerné metabolismus MeSH
- magnetická rezonanční spektroskopie MeSH
- Streptomyces coelicolor genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
( GOS) sú ne stráviteľné sacharidy známe ako prebiotiká – môžu stimulovať rast a aktivitu prospešnej črevnej mikroflóry ( bifidobaktérie a laktobacily ) a inhibujú rast potenciálne patogénnych baktérií. GOS sú komerčne vyrábané z laktózy pomocou mikrobiálnej β - galaktozidázy. Tieto enzýmy katalyzujú hydrolýzu , ako aj transgalaktozyláciu laktózy . Pomer medzi týmito reakciami sa líši v závislosti od zdroja enzýmu a podmienok enzýmovej . V poslednom období, inovačné stratégie pre syntézu GOS zahŕňajú imobilizáciu enzýmov a využitie srvátky ako základnej suroviny.
Galacto-oligosaccharides (GOS) are non-digestible carbohydrates know as a prebiotic – can stimulate growth and activity of beneficial intestinal microflora (bifidobacteria and lactobacilli) and inhibit the growth of potencially pathogenic bacteria. GOS are commercially produced from lactose using microbial β -galactosidases. These enzymes catalyze hydrolysis as well as the transgalactosylation of lactose. The proportion between these reactions varies depending on the source of the enzyme and conditions of enzymatic reaction. More recently, an innovative strategies for GOS synthesis are immobilization of enzymes and usage of whey as a source of the lactose.
- MeSH
- bakteriální polysacharidy biosyntéza MeSH
- biodegradace MeSH
- biopolymery biosyntéza MeSH
- finanční podpora výzkumu jako téma MeSH
- plastické hmoty chemická syntéza škodlivé účinky MeSH
- polyestery chemická syntéza MeSH
- polyvinylalkohol chemická syntéza MeSH
- škrob biosyntéza MeSH
- Publikační typ
- přehledy MeSH
Mutant strains of Mycobacterium sp. V-649 producing highly mucous colonies on a solid cultivation medium were prepared after treatment with N-methyl-N'-nitro-N-nitrosoguanidine and production of the exocellular polysaccharide was tested. The strains were cultivated in media with suitable sugar sources under submerged conditions. It was found that Mycobacterium sp. V-649/15 produces a maximum of 15-19% polymer after a 5-6-d cultivation. Gas chromatography indicated that the exocellular polysaccharide produced by this strain is of glucan type.
