Amylases and proteases are among the industrially most important enzymes for food processing, animal feed, brewing, starch processing, detergents, healthcare, leather processing, and biofuel production. In this study, we investigated the growth kinetics and statistically optimized the co-production of amylase and protease in a phylogenetically novel haloalkaliphilic actinomycete, Streptomyces lopnurensis KaM5 of seawater. The Plackett-Berman design using Minitab 14.0 software was employed to assess the impact of the nutritional factors, temperature, pH, and incubation time. Further, starch, yeast extract, NaCl concentrations, and incubation time were optimized by Box-Behnken design at their three levels. The Pareto charts, contour, surface plots, and individual factorial analysis expressed the variability and levels for the optimal enzyme production. ANOVA analysis admitted the statistical fitness and significance level among the variables. A two-fold increase in enzyme production was achieved by cost-effective co-production media. The study was further extended to growth kinetics associated with enzyme production. Specific growth rate (μ), maximal cell mass (Xmax), volumetric product formation (Pmax), rate of product formation (Qp), and generation time (g) were computed and analyzed. These parameters significantly improved when compared with the pre-optimized conditions, and the production economics of the enzyme was industrially viable. The initial studies on the characteristics of the enzymes suggested its ability to function under the combination of alkaline pH and high salt concentrations. The co-production of enzymes from extremophiles can be a potentially viable option for large-scale production and applications.
Industrial synthetic dyes cause health and environmental problems. This work describes the isolation of 84 bacterial strains from the midgut of the Lasius niger ant and the evaluation of their potential application in dye bioremediation. Strains were identified and classified as judged by rRNA 16S. The most abundant isolates were found to belong to Actinobacteria (49%) and Firmicutes (47.2%). We analyzed the content in laccase, azoreductase and peroxidase activities and their ability to degrade three known dyes (azo, thiazine and anthraquinone) with different chemical structures. Strain Ln26 (identified as Brevibacterium permense) strongly decolorized the three dyes tested at different conditions. Strain Ln78 (Streptomyces ambofaciens) exhibited a high level of activity in the presence of Toluidine Blue (TB). It was determined that 8.5 was the optimal pH for these two strains, the optimal temperature conditions ranged between 22 and 37 °C, and acidic pHs and temperatures around 50 °C caused enzyme inactivation. Finally, the genome of the most promising candidate (Ln26, approximately 4.2 Mb in size) was sequenced. Genes coding for two DyP-type peroxidases, one laccase and one azoreductase were identified and account for the ability of this strain to effectively oxidize a variety of dyes with different chemical structures.
- MeSH
- Actinobacteria enzymologie izolace a purifikace metabolismus MeSH
- Bacteria enzymologie izolace a purifikace metabolismus MeSH
- barvicí látky izolace a purifikace metabolismus MeSH
- biodegradace MeSH
- biotechnologie MeSH
- Brevibacterium enzymologie izolace a purifikace metabolismus MeSH
- Firmicutes enzymologie izolace a purifikace metabolismus MeSH
- Formicidae mikrobiologie MeSH
- lakasa izolace a purifikace metabolismus MeSH
- látky znečišťující životní prostředí izolace a purifikace metabolismus MeSH
- NADH, NADPH oxidoreduktasy izolace a purifikace metabolismus MeSH
- peroxidasa izolace a purifikace metabolismus MeSH
- Streptomyces enzymologie izolace a purifikace metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Low molecular weight signaling compounds (LMWC) are important players in regulating various aspects of Streptomyces biology. Their exact roles in certain strain will ultimately depend on overall configuration of regulatory network and thus cannot be predicted on basis of in silico studies. Here, we explored S. ghanaensis gene SSFG_07725 (afsAgh) presumably involved in initial steps of formation of γ-butyrolactone LMWC. Disruption of afsAgh impaired aerial mycelium formation and increased the transcription of pleiotropic regulatory gene adpAgh, whereas level of moenomycin production remained virtually unaffected. We provide evidence that morphogenetic deficiency of afsAgh-minus mutant was caused by inability to produce diffusible LMWC. Possible links between γ-butyrolactone signaling and various aspects of S. ghanaensis biology are discussed.
Two-component systems (TCSs) are an important signaling transduction pathway that adapt to changing environments. Commonly, a TCS comprises a sensor kinase that is usually an integral membrane histidine sensor kinase and a response regulator that mediates the cellular responses. Presently, however, we cloned a novel sensor kinase gene (tcsK) that is not adjacent to its cognate response regulator from Streptomyces acidiscabies that produces two secondary metabolites, thaxtomin A and WS5995B, and identified its functional involvement in the production of secondary metabolites and morphological differentiation. The elevated expression and disruption of the tcsK gene enhanced 7.1-fold and almost abolished WS5995B production in S. acidiscabies, respectively, but did not affect the production of thaxtomin A. In addition, spore formation of S. acidiscabies was decreased 120-fold by the disruption of tcsK, and the actinorhodin production of Streptomyces lividans TK24 was increased 5.7-fold by the high expression of tcsK. These results indicate that the novel unpaired tcsK gene may be related to the control of secondary metabolite production and spore formation in actinomycetes.
- MeSH
- biologické přípravky metabolismus MeSH
- exprese genu MeSH
- genový knockout MeSH
- indoly metabolismus MeSH
- klonování DNA MeSH
- piperaziny metabolismus MeSH
- proteinkinasy genetika izolace a purifikace metabolismus MeSH
- regulace genové exprese u bakterií * MeSH
- sekundární metabolismus * MeSH
- signální transdukce * MeSH
- spory bakteriální růst a vývoj MeSH
- Streptomyces cytologie enzymologie genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
NAG-thiazoline is a well-established competitive inhibitor of two physiologically relevant glycosidase families-β-N-acetylhexosaminidases (GH20) and β-N-acetylglucosaminidases (GH84). Based on the different substrate flexibilities of these enzyme groups, we designed and synthesized the 4-deoxy derivative of NAG-thiazoline aiming at the selective inhibition of GH20 β-N-acetylhexosaminidases. One GH84 and two GH20 microbial glycosidases were employed as model enzymes for the inhibition assays. Surprisingly, the new compound 4-deoxy-thiazoline exhibited no activity inhibition with either of the enzyme families of interest. Unlike with the substrates, the 4-hydroxyl group of the inhibitor's sugar ring seems to be crucial for binding the inhibitor to the active sites of these enzymes.
- MeSH
- acetylglukosamin analogy a deriváty chemická syntéza chemie metabolismus MeSH
- Bacteroides enzymologie MeSH
- bakteriální proteiny antagonisté a inhibitory metabolismus MeSH
- beta-N-acetylhexosaminidasy antagonisté a inhibitory metabolismus MeSH
- fungální proteiny antagonisté a inhibitory metabolismus MeSH
- houby enzymologie MeSH
- kinetika MeSH
- Streptomyces enzymologie MeSH
- substrátová specifita MeSH
- thiazoly chemická syntéza chemie metabolismus MeSH
- vazba proteinů MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The S-adenosyl-L-methionine (SAM)-dependent methyltransferase CcbJ from Streptomyces caelestis catalyzes one of the final steps in the biosynthesis of the antibiotic celesticetin, methylation of the N atom of its proline moiety, which greatly enhances the activity of the antibiotic. Since several celesticetin variants exist, this enzyme may be able to act on a variety of substrates. The structures of CcbJ determined by MAD phasing at 3.0 Å resolution, its native form at 2.7 Å resolution and its complex with S-adenosyl-L-homocysteine (SAH) at 2.9 Å resolution are reported here. Based on these structures, three point mutants, Y9F, Y17F and F117G, were prepared in order to study its behaviour as well as docking simulations of both CcbJ-SAM-substrate and CcbJ-SAH-product complexes. The structures show that CcbJ is a class I SAM-dependent methyltransferase with a wide active site, thereby suggesting that it may accommodate a number of different substrates. The mutation results show that the Y9F and F117G mutants are almost non-functional, while the Y17F mutant has almost half of the wild-type activity. In combination with the docking studies, these results suggest that Tyr9 and Phe117 are likely to help to position the substrate for the methyl-transfer reaction and that Tyr9 may also facilitate the reaction by removing an H(+) ion. Tyr17, on the other hand, seems to operate by helping to stabilize the SAM cofactor.
While it is known that several Actinobacteria produce enzymes that decompose polysaccharides or phenolic compounds in dead plant biomass, the occurrence of these traits in the environment remains largely unclear. The aim of this work was to screen isolated actinobacterial strains to explore their ability to produce extracellular enzymes that participate in the degradation of polysaccharides and their ability to cometabolically transform phenolic compounds of various complexities. Actinobacterial strains were isolated from meadow and forest soils and screened for their ability to grow on lignocellulose. The potential to transform (14)C-labelled phenolic substrates (dehydrogenation polymer (DHP), lignin and catechol) and to produce a range of extracellular, hydrolytic enzymes was investigated in three strains of Streptomyces spp. that possessed high lignocellulose degrading activity. Isolated strains showed high variation in their ability to produce cellulose- and hemicellulose-degrading enzymes and were able to mineralise up to 1.1% and to solubilise up to 4% of poplar lignin and to mineralise up to 11.4% and to solubilise up to 64% of catechol, while only minimal mineralisation of DHP was observed. The results confirm the potential importance of Actinobacteria in lignocellulose degradation, although it is likely that the decomposition of biopolymers is limited to strains that represent only a minor portion of the entire community, while the range of simple, carbon-containing compounds that serve as sources for actinobacterial growth is relatively wide.
- MeSH
- bakteriální proteiny biosyntéza MeSH
- beta-glukosidasa biosyntéza MeSH
- biodegradace MeSH
- biomasa MeSH
- celulosa-1,4-beta-cellobiosidasa biosyntéza MeSH
- celulosa metabolismus MeSH
- hydrolýza MeSH
- katecholy metabolismus MeSH
- kinetika MeSH
- lignin metabolismus MeSH
- Populus chemie MeSH
- půdní mikrobiologie * MeSH
- radioizotopy uhlíku MeSH
- Streptomyces enzymologie izolace a purifikace MeSH
- stromy chemie MeSH
- xylosidasy biosyntéza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The gene lmbB2 of the lincomycin biosynthetic gene cluster of Streptomyces lincolnensis ATCC 25466 was shown to code for an unusual tyrosine hydroxylating enzyme involved in the biosynthetic pathway of this clinically important antibiotic. LmbB2 was expressed in Escherichia coli, purified near to homogeneity and shown to convert tyrosine to 3,4-dihydroxyphenylalanine (DOPA). In contrast to the well-known tyrosine hydroxylases (EC 1.14.16.2) and tyrosinases (EC 1.14.18.1), LmbB2 was identified as a heme protein. Mass spectrometry and Soret band-excited Raman spectroscopy of LmbB2 showed that LmbB2 contains heme b as prosthetic group. The CO-reduced differential absorption spectra of LmbB2 showed that the coordination of Fe was different from that of cytochrome P450 enzymes. LmbB2 exhibits sequence similarity to Orf13 of the anthramycin biosynthetic gene cluster, which has recently been classified as a heme peroxidase. Tyrosine hydroxylating activity of LmbB2 yielding DOPA in the presence of (6R)-5,6,7,8-tetrahydro-L-biopterin (BH4) was also observed. Reaction mechanism of this unique heme peroxidases family is discussed. Also, tyrosine hydroxylation was confirmed as the first step of the amino acid branch of the lincomycin biosynthesis.
- MeSH
- antibakteriální látky biosyntéza MeSH
- bakteriální proteiny genetika metabolismus MeSH
- cirkulární dichroismus MeSH
- dihydroxyfenylalanin metabolismus MeSH
- Escherichia coli enzymologie genetika MeSH
- exprese genu MeSH
- hem chemie metabolismus MeSH
- hemoproteiny genetika metabolismus MeSH
- hydroxylace MeSH
- linkomycin biosyntéza MeSH
- multigenová rodina MeSH
- rekombinantní proteiny genetika metabolismus MeSH
- Streptomyces enzymologie genetika MeSH
- tyrosin-3-monooxygenasa genetika metabolismus MeSH
- tyrosin metabolismus MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- železo chemie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Clinically used lincosamide antibiotic lincomycin incorporates in its structure 4-propyl-L-proline (PPL), an unusual amino acid, while celesticetin, a less efficient related compound, makes use of proteinogenic L-proline. Biochemical characterization, as well as phylogenetic analysis and homology modelling combined with the molecular dynamics simulation were employed for complex comparative analysis of the orthologous protein pair LmbC and CcbC from the biosynthesis of lincomycin and celesticetin, respectively. The analysis proved the compared proteins to be the stand-alone adenylation domains strictly preferring their own natural substrate, PPL or L-proline. The LmbC substrate binding pocket is adapted to accommodate a rare PPL precursor. When compared with L-proline specific ones, several large amino acid residues were replaced by smaller ones opening a channel which allowed the alkyl side chain of PPL to be accommodated. One of the most important differences, that of the residue corresponding to V306 in CcbC changing to G308 in LmbC, was investigated in vitro and in silico. Moreover, the substrate binding pocket rearrangement also allowed LmbC to effectively adenylate 4-butyl-L-proline and 4-pentyl-L-proline, substrates with even longer alkyl side chains, producing more potent lincosamides. A shift of LmbC substrate specificity appears to be an integral part of biosynthetic pathway adaptation to the PPL acquisition. A set of genes presumably coding for the PPL biosynthesis is present in the lincomycin--but not in the celesticetin cluster; their homologs are found in biosynthetic clusters of some pyrrolobenzodiazepines (PBD) and hormaomycin. Whereas in the PBD and hormaomycin pathways the arising precursors are condensed to another amino acid moiety, the LmbC protein is the first functionally proved part of a unique condensation enzyme connecting PPL to the specialized amino sugar building unit.
- MeSH
- bakteriální proteiny chemie MeSH
- dipeptidy chemie MeSH
- linkomycin biosyntéza chemie MeSH
- linkosamidy biosyntéza chemie MeSH
- molekulární evoluce * MeSH
- simulace molekulární dynamiky * MeSH
- Streptomyces enzymologie MeSH
- terciární struktura proteinů MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Neomycin, produced by Streptomyces fradiae, has been widely used for the treatment of bacterial infections in clinical and agricultural applications. In this study, a neomycin nonproducing mutant of S. fradiae was obtained by gene disruption technique for mutational biosynthesis. A crucial gene neoC (neo7) which encodes 2-deoxystreptamine (2-DOS) synthases was disrupted. The mutant could resume producing neomycin in the presence of 2-DOS. Salen derivatives of 2-DOS were synthesized and individually added to cultures of the mutant. Antibacterial activity of the mutasynthesis products against Staphylococcus aureus and four plant pathogenic bacteria (Pseudomonas solanacarum, Erwinia carotovora, Xanthomonas oryzae, and Xanthomonas campestris) was detected quantitatively by Oxford cup method. It is suggested that all 2-DOS derivatives were incorporated by the mutant into new active neomycin analogs except for 2-DOS derivative 2d ((1R,2r,3S,4R,6S)-4,6-bis((E)-3,5-di-tert-butyl-2-hydroxybenzylideneamino)cyclohexane-1,2,3-triol). Neomycin analogs produced by feeding 2-DOS derivative 2a ((1R,2r,3S,4R,6S)-4,6-bis((E)-2 hydroxybenzylideneamino)cyclohexane-1,2,3-triol) to cultures of the mutant displayed a similar antibacterial activity with neomycin produced by wild strain.
- MeSH
- antibakteriální látky biosyntéza chemie MeSH
- bakteriální proteiny genetika metabolismus MeSH
- molekulární struktura MeSH
- mutace MeSH
- neomycin analogy a deriváty biosyntéza MeSH
- Streptomyces enzymologie genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
