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1.
Lett Appl Microbiol ; 77(1)2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38148133

RESUMO

The whole genome sequence (WGS) of Bacillus coagulans BCP92 is reported along with its genomic analysis of probiotics and safety features. The identification of bacterial strain was carried out using the 16S rDNA sequencing method. Furthermore, gene-related probiotic features, safety assessment (by in vitro and in silico), and genome stability were also studied using the WGS analysis for the possible use of the bacterial strain as a probiotic. From the BLAST analysis, bacterial strain was identified as Bacillus (Heyndrickxia) coagulans. WGS analysis indicated that the genome consists of a 3 475 658 bp and a GC-content of 46.35%. Genome mining of BCP92 revealed that the strain is consist of coding sequences for d-lactate dehydrogenase and l-lactate dehydrogenases, 36 genes involved in fermentation activities, 29 stress-responsive as well as many adhesions related genes. The genome, also possessing genes, is encoded for the synthesis of novel circular bacteriocin. Using an in-silico approach for the bacterial genome study, it was possible to determine that the Bacillus (Heyndrickxia) coagulans strain BCP92 contains genes that are encoded for the probiotic abilities and did not harbour genes that are risk associated, thus confirming the strain's safety and suitability as a probiotic to be used for human application.


Assuntos
Bacillus coagulans , Bacillus , Bacteriocinas , Probióticos , Humanos , Bacillus coagulans/genética , Bacillus/genética , Bacteriocinas/genética , Genoma Bacteriano
2.
Nature ; 617(7961): 524-528, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37198312

RESUMO

As an atom-efficient strategy for the large-scale interconversion of olefins, heterogeneously catalysed olefin metathesis sees commercial applications in the petrochemical, polymer and speciality chemical industries1. Notably, the thermoneutral and highly selective cross-metathesis of ethylene and 2-butenes1 offers an appealing route for the on-purpose production of propylene to address the C3 shortfall caused by using shale gas as a feedstock in steam crackers2,3. However, key mechanistic details have remained ambiguous for decades, hindering process development and adversely affecting economic viability4 relative to other propylene production technologies2,5. Here, from rigorous kinetic measurements and spectroscopic studies of propylene metathesis over model and industrial WOx/SiO2 catalysts, we identify a hitherto unknown dynamic site renewal and decay cycle, mediated by proton transfers involving proximal Brønsted acidic OH groups, which operates concurrently with the classical Chauvin cycle. We show how this cycle can be manipulated using small quantities of promoter olefins to drastically increase steady-state propylene metathesis rates by up to 30-fold at 250 °C with negligible promoter consumption. The increase in activity and considerable reduction of operating temperature requirements were also observed on MoOx/SiO2 catalysts, showing that this strategy is possibly applicable to other reactions and can address major roadblocks associated with industrial metathesis processes.

3.
3 Biotech ; 6(2): 227, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28330299

RESUMO

Thirty isolates of fluorescent pseudomonads were obtained from rhizosphere of different crops in Raichur, India. The fluorescent pseudomonad strains were characterized in vitro for biochemical traits, antimicrobial traits, and pyoluteorin antibiotic production. All the isolates that showed fluorescent pigment production under UV light were rod shaped, Gram negative, positive for oxidase, catalase and citrate utilization tests, and negative for indole test. Out of 30 isolates, 07 isolates were positive for HCN production, 15 isolates were positive for H2S production, and all the isolates were positive for siderophore production. Among all the isolates, RFP-22 showed the maximum percent inhibition of mycelium (46.66 %) of Rhizoctonia solani, the pathogen, and the remaining isolates showed the moderate to least inhibition of mycelium growth of R. solani. The 16S rRNA analysis confirmed that the antibiotic positive isolates belonged to genus Pseudomonas. The amplification of 779 bp region in isolates RFP- 4 and RFP-19 corresponded to pyoluteorin antibiotic-coding pltB gene. Further characterization of pyoluteorin antibiotic through TLC and TOF-MS analysis confirmed the presence of pyoluteorin at 274.26 (g/mol) peak and 2.10 min retention time. Biochemical and molecular analyses confirmed the antagonism of Pseudomonas and isolate through pyoluteorin production.

4.
J Colloid Interface Sci ; 407: 339-47, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23890593

RESUMO

A novel platform of anionic polymeric surfactants, poly(4HBA-oca(-)Na(+)), poly(4HBA-dea(-)Na(+)), and poly(4HBA-doa(-)Na(+)), has been synthesized by polymerizing benzoxazine monomers that are synthesized by reacting an aliphatic amine of variable chain length (C8, C10 and C12), with 4-hydroxybenzoic acid and paraformaldehyde. The structures of the monomers and polymeric surfactants are confirmed by NMR and FTIR. The ring-opening polymerization and thermal behavior of the benzoxazine monomers are studied by DSC and TGA. Size exclusion chromatography (SEC) coupled with Viscotek triple detection technique is used to characterize the molecular weight distribution of polybenzoxazine surfactants. The surfactants have low MW, varying from 2200 to 6000, and are fairly polydisperse. The influence of the structure on the surface activity is investigated by measuring the surface tension of aqueous solutions of the polymeric surfactants using the Wilhelmy plate method. The tensiometry results indicate that the adsorption at the air/water interface is similar for the octylamine, decylamine and dodecylamine-based surfactants. Increasing the alkyl chain length from C8 to C12 does not significantly affect the surface tension at the critical micelle concentration (γcmc), while the critical micelle concentration (cmc) gradually increases due to increasing hydrophobic effect. These polymeric surfactants give cmc values ranging from 0.12 g/L to 0.17 g/L, comparable to other polymeric surfactants reported in the literature. The influences of salt addition on the surface tension at the critical micelle concentration (γcmc) for these surfactants are studied. Theminimum values of the γcmc are observed around 1 wt% NaCl for the polybenzoxazine surfactant solution.

5.
Ann Biomed Eng ; 35(12): 2130-7, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17786555

RESUMO

Polydimethyl siloxane (PDMS) based pressure sensitive adhesives (PSA) incorporating organo-clays at different loadings were fabricated via solution casting. Partially exfoliated nanocomposites were obtained for the hydroxyl terminated PDMS in ethyl acetate solvent as determined by X-ray diffraction and atomic force microscopy. Drug release studies showed that the initial burst release was substantially reduced and the drug release could be controlled by the addition of organo-clay. Shear strength and shear adhesion failure temperature (SAFT) measurements indicated substantial improvement in adhesive properties of the PSA nanocomposite adhesives. Shear strength showed more than 200% improvement at the lower clay loadings and the SAFT increased by about 21% due to the reinforcement provided by the nano-dispersed clay platelets. It was found that by optimizing the level of the organosilicate additive to the polymer matrix, superior control over drug release kinetics and simultaneous improvements in adhesive properties could be attained for a transdermal PSA formulation.


Assuntos
Bandagens , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Nanoestruturas/química , Compostos de Organossilício/química , Adesivos Teciduais/química , Administração Tópica , Teste de Materiais , Nanoestruturas/administração & dosagem , Nanoestruturas/ultraestrutura , Pressão
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