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1.
Int J Biol Macromol ; 192: 219-231, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34624382

RESUMO

Trichoderma harzianum S7113 as an efficient fungal isolate for laccase production was identified using the 18S rRNA sequencing. T. harzianum S7113 attained its maximal laccase production level on the 14th day of static incubation at 28 °C and pH 5.0 using the inoculum size of 5 discs (14 mm), according to the one factor per time (OFT) method. The most appropriate carbon, organic and inorganic nitrogen sources to promote maximal laccase synthesis were glucose (15 g/L), beef extract (5 g/L), and ammonium chloride (4 g/L), respectively. Results of Response Surface Methodology (RSM) revealed that glucose, meat extract, and ammonium chloride concentrations of 17.54, 7.17, and 4.36 g/L respectively, at a pH value of 6.74 are the favorite conditions for high titer production. The ANOVA analysis highlighted an excellent match between the actual experimental results and the model predicted laccase production levels. The biodegradation of hydroquinone (HQ) by T. harzianum S7113 laccase was most efficient in the pH range of 5.0 to 6.5. The increase in laccase concentration led to a significant increase in the HQ conversion to get a biodegradation rate of 92 ± 2.6% with a laccase concentration of 0.75 U/mL after 3 h of reaction.

2.
Molecules ; 26(12)2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34200763

RESUMO

The development of new antimicrobial strategies that act more efficiently than traditional antibiotics is becoming a necessity to combat multidrug-resistant pathogens. Here we report the efficacy of laser-light-irradiated 5,10,15,20-tetrakis(m-hydroxyphenyl)porphyrin (mTHPP) loaded onto an ethylcellulose (EC)/chitosan (Chs) nanocomposite in eradicating multi-drug resistant Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans. Surface loading of the ethylcelllose/chitosan composite with mTHPP was carried out and the resulting nanocomposite was fully characterized. The results indicate that the prepared nanocomposite incorporates mTHPP inside, and that the composite acquired an overall positive charge. The incorporation of mTHPP into the nanocomposite enhanced the photo- and thermal stability. Different laser wavelengths (458; 476; 488; 515; 635 nm), powers (5-70 mW), and exposure times (15-45 min) were investigated in the antimicrobial photodynamic therapy (aPDT) experiments, with the best inhibition observed using 635 nm with the mTHPP EC/Chs nanocomposite for C. albicans (59 ± 0.21%), P. aeruginosa (71.7 ± 1.72%), and S. aureus (74.2 ± 1.26%) with illumination of only 15 min. Utilization of higher doses (70 mW) for longer periods achieved more eradication of microbial growth.


Assuntos
Antibacterianos/química , Celulose/análogos & derivados , Quitosana/química , Nanocompostos/química , Porfirinas/química , Piridonas/química , Pirróis/química , Animais , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Linhagem Celular , Celulose/química , Chlorocebus aethiops , Lasers , Luz , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Células Vero
3.
Mar Drugs ; 19(4)2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33924262

RESUMO

Epicotripeptin (1), a new cyclic tripeptide along with four known cyclic dipeptides (2-5) and one acetamide derivative (6) were isolated from seagrass-associated endophytic fungus Epicoccum nigrum M13 recovered from the Red Sea. Additionally, two new compounds, cyclodidepsipeptide phragamide A (7) and trioxobutanamide derivative phragamide B (8), together with eight known compounds (9-16), were isolated from plant-derived endophyte Alternaria alternata 13A collected from a saline lake of Wadi El Natrun depression in the Sahara Desert. The structures of the isolated compounds were determined based on the 1D and 2D NMR spectroscopic data, HRESIMS data, and a comparison with the reported literature. The absolute configurations of 1 and 7 were established by advanced Marfey's and Mosher's ester analyses. The antimicrobial screening indicated that seven of the tested compounds exhibited considerable (MIC range of 2.5-5 µg/mL) to moderate (10-20 µg/mL) antibacterial effect against the tested Gram-positive strains and moderate to weak (10-30 µg/mL) antibacterial effect against Gram-negative strains. Most of the compounds exhibited weak or no activity against the tested Gram-negative strains. On the other hand, four of the tested compounds showed considerable antibiofilm effects against biofilm forming Gram-positive and Gram-negative strains.


Assuntos
Alternaria/metabolismo , Antibacterianos/farmacologia , Ascomicetos/metabolismo , Biofilmes/efeitos dos fármacos , Bactérias Aeróbias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Antibacterianos/isolamento & purificação , Biofilmes/crescimento & desenvolvimento , Fermentação , Bactérias Aeróbias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Positivas/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade
4.
Prep Biochem Biotechnol ; 51(9): 926-935, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33529084

RESUMO

Silver nanoparticles (AgNPs) were synthesized using extracellular filtrates of some Lysinibacillus sphaericus (Ls) strains under simple conditions. Ls synthesized AgNPs showed the optical absorption peaks at 388-412 nm as detected by UV-visible spectrophotometer. Transmission electron micrographs of bacterial synthesized AgNPs revealed that they were polycrystalline with spherical, hexagonal, cuboidal, rod and irregular shapes. The average diameter of the tested AgNPs were ranged from 14-21 nm and they were negatively charged as detected by DLS (-18.2 to -28.9). FTIR spectra showed the presence of nitrogenous biomolecules capping the synthesized AgNPs. The filtrates of tested Ls strains showed nitrate reductase activity (1.45-2.56 µmol/ml/min). Tested AgNPs showed bactericidal activity against Gram positive and Gram negative bacteria, fungicidal activity against yeast and filamentous fungi, and virucidal activity against rotavirus. In addition, it showed synergistic antimicrobial effect to cephradine and nizoarm against all tested microorganisms. Cytotoxicity test revealed the safety of the tested nanoparticles at tested concentrations.Finally, Ls strains represent microbial sources for ecofriendly, simple and economic biosynthesis of antimicrobial AgNPs. Also, this research may contribute to the medicinal chemistry and pharmaceutical industry for the development of new products used for the public health.

5.
J Genet Eng Biotechnol ; 18(1): 80, 2020 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-33263861

RESUMO

BACKGROUND: Plasmid propagation in recombination strains such as Escherichia coli DH5α is regarded as a beneficial instrument for stable amplification of the DNA materials. Here, we show trans-conjugation of pGEM-T cloning vector (modified Promega PCR product cloning vector with tra genes, transposable element (Tn5)) and M13 sequence via α-complementation mechanism in order to activate ß-D-galactosidase gene in DH5α strain (non-lactose-fermenting host). RESULTS: Trans-conjugation with pGEM-T allows correction of LacZ gene deletion through Tn5, and successful trans-conjugants in DH5α host cells can be able to produce active enzyme, thus described as lactose fermenting strain. The intracellular ß-galactosidase was subjected to precipitation by ammonium sulfate and subsequently gel filtration, and the purified enzyme showed a molecular weight of approximately 72-kDa sodium dodecyl sulfate-polyacrylamid gel electrophoresis. The purified enzyme activity showed an optimal pH and temperature of 7.5 and 40 °C, respectively; it had a high stability within pH 6-8.5 and moderate thermal stability up to 50 °C. CONCLUSION: Trans-conjugant of E. coli DH5α- lacZ∆M15 was successfully implemented. UV mutagenesis of the potent trans-conjugant isolate provides an improvement of the enzyme productivity. The enzymatic competitive inhibition by D-galactose and hydrolysis of lactose at ambient temperatures could make this enzyme a promising candidate for use in the dairy industry.

6.
Arch Microbiol ; 202(1): 63-75, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31485713

RESUMO

Silver nanoparticles (AgNPs) were synthesized using cell-free filtrates of some mosquitocidal Bacilli. They showed the optical absorption peaks at 386-412 nm. They were polycrystalline spherical, hexagonal, cuboidal, rod and anisotropic shapes as detected by TEM. These nanoparticles were negatively charged with sizes ranging from 15 to 21 nm average diameter as detected by DLS. FTIR spectra showed that the main absorption bands of biomolecules capping AgNPs appeared at average wave numbers of 3435 cm-1 [ν(N-H) of amide A overlapped by ν(O-H)], 1631 cm-1 [(ν(C=O) of amide I], 1396 cm-1 [ν(C-N) of amide I], 2929 cm-1 (aliphatic C-H) and 1040 cm-1 (C-C-O). FTIR spectra confirmed the presence of protein biomolecules in the bacterial filtrate-formed coat covering AgNPs through free amide groups resulting in their stabilization in the aqueous medium. Nitrate reductase activity was found in all tested bacterial filtrates and ranged from 1.66 to 2.51 µmol/ml/min. These findings point to the probable role of nitrate reductase in reducing silver ions to silver nanoparticles and their stabilization. Tested AgNPs were multi-bioactive nanometals and showed mosquitocidal, bactericidal, fungicidal and virucidal activities. In addition, they exhibited highly synergistic mosquitocidal effect to spore toxin complex of mosquitocidal Bacilli at a very low concentration. AgNPs exhibited activities that were not or slightly cytotoxic to MA 104 cell line at tested concentrations. Therefore, they can be applied in the medical field. Finally, this study offered a simple, highly efficient, eco-friendly, economic method for biosynthesis of multi-bioactive AgNPs by some mosquitocidal Bacilli.


Assuntos
Bacillus/fisiologia , Nanopartículas Metálicas/química , Prata/química , Prata/farmacologia , Animais , Antibacterianos/química , Bacillus/enzimologia , Bacillus/metabolismo , Linhagem Celular , Chlorocebus aethiops , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Nitrato Redutase/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Int J Biol Macromol ; 138: 975-985, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31351958

RESUMO

Despite the advantages of bacterial cellulose (BC) over traditional cellulose, its low yield and little bioactivity makes a limitation to be used in an industrial scale. This paper was mainly dual aimed to increase the BC yield using a nanobioactive glass (NBG), and in situ synthesize BC/NBG bioactive nanocomposites by a novel and simple green method. Accordingly, the composites were prepared via in situ fermentation approach by incorporation of NBG particles into BC producing culture medium. The effect of NBG addition on the production process of cellulose, biocompatibility, bioactivity and antimicrobial activity were investigated. The results showed that NBG was enhanced and increased the BC yield and this has been achieved by maintaining these NBG on the pH value of the culture medium during the fermentation period. Moreover, it was effectively improved biocompatibility and antimicrobial properties of BC. This study evidenced that BC/NBG composite can be expected to be widely applied in biomedical industries such as bone regeneration and wound healing with the unique of being not harmful to humans.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Celulose/química , Vidro/química , Nanocompostos/química , Polissacarídeos Bacterianos/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Celulose/síntese química , Técnicas de Química Sintética , Química Verde , Humanos , Polissacarídeos Bacterianos/síntese química , Análise Espectral
8.
Carbohydr Polym ; 211: 75-83, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30824106

RESUMO

Potato peel waste (PPW) is employed as the first report on bacterial cellulose (BC) production by Gluconacetobacter xylinus. Scharification of PPW was performed by 2 M different mineral acids individually. The suitable pre-treatment conditions were determined by reducing sugar release. Although all acid PPW-hydrolysates culture media are studied to produce BCs. Nitric acid hydrolysate gives the high productivity value The influence of nitric acid PPW-hydrolysate culture condition parameters were applied throughout the Taguchi method and the optimum conditions for the highest BC yield (4.7 g/L) was observed after 6 days at 35 °C, pH 9, medium volume 55 ml and with 8% inoculum size. The instrumental analysis of PPW-BC, included FT-IR, Particle size distribution, BET, DSC, XRD and SEM are cleared that the PPW-BC recorded high crystalliny82.5%, excellent PDI. In general, this study revealed that nitric acid PPW-hydrolysate could be used as cost effective alternative medium for production of BC with sustainable processes that can overcome the environmental pollution.


Assuntos
Celulose/metabolismo , Gluconacetobacter xylinus/metabolismo , Solanum tuberosum , Química Verde , Ácido Nítrico/química , Reciclagem , Resíduos
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