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1.
Nutrients ; 16(13)2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38999863

RESUMO

The emptying rate of specific nutrients in enteral formulas is poorly understood, despite the importance of controlling the emptying rate in tube-fed patients. Because of their viscosity, thickened formulas are widely used to avoid gastric reflux and reduce the burden on caregivers. This study examined how thickeners in enteral formulas affected the gastric emptying rates of proteins and carbohydrates. A semi-dynamic gastric model was used to prepare and digest test enteral formulas that contained either no thickeners or agar (0.2%). The amounts of protein and carbohydrates in each emptied aliquot were determined, and the emptying rate was calculated. We found that agar accelerated protein emptying, and an exploratory experiment with agar (0.5%) suggested the possibility of concentration dependence. Additionally, experiments using gellan gum (0.08%), guar gum (0.2%), or carrageenan (0.08%, 0.2%) suggested that protein emptying could vary depending on the thickener type and that carrageenan might slow it. These results could help with the appropriate selection of thickeners added to liquid foods based on the patient's metabolic profile to manage nutrition, not only for tube-fed patients but also for those with oropharyngeal dysphagia or diabetes.


Assuntos
Proteínas Alimentares , Nutrição Enteral , Alimentos Formulados , Galactanos , Esvaziamento Gástrico , Mananas , Gomas Vegetais , Esvaziamento Gástrico/efeitos dos fármacos , Nutrição Enteral/métodos , Humanos , Mananas/farmacologia , Mananas/administração & dosagem , Viscosidade , Galactanos/farmacologia , Proteínas Alimentares/administração & dosagem , Carboidratos da Dieta/administração & dosagem , Carragenina , Ágar , Polissacarídeos Bacterianos/farmacologia , Modelos Biológicos
2.
Antonie Van Leeuwenhoek ; 117(1): 101, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39008162

RESUMO

Two novel Gram-stain-negative, aerobic, and non-motile strains, designated FZY0004T and YYF002T, were isolated from an agar-degrading co-culture, which was obtained from seawater of the intertidal zone of Yancheng City, the Yellow Sea of China. Strain FZY0004T optimally grew at 28 °C, pH 7.0, and 2-6% NaCl, while strain YYF002T optimally grew at 28 °C, pH 7.5, and 2-4% NaCl. Strain FZY0004T possessed Q-9 as the major respiratory quinone, and its major fatty acids (> 10%) were summed feature 8 (C18:1 ω7c), C16:0, and summed feature 3 (C16:1 ω7c/C16:1 ω6c). The polar lipids identified in strain FZY0004T were phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and several unidentified phospholipids (PL) and lipids (L). On the other hand, strain YYF002T had MK-6 as the predominant respiratory quinone and its major fatty acids consisted of iso-C15:0, iso-C15:1 G, and iso-C15:0 3-OH. The polar lipids identified in strain YYF002T were aminolipid (AL), PE, and several unidentified lipids. Strain FZY0004T shared 99.5% 16S rRNA gene sequence similarity and 90.1% average nucleotide identity (ANI) with T. povalilytica Zumi 95T, and strain YYF002T shared 99.2% 16S rRNA gene sequence similarity and 88.2% ANI with W. poriferorum JCM 12885T. The genomic DNA G + C contents of strains FZY0004T and YYF002T were 54.5% and 33.5%, respectively. The phylogenetic, phenotypic, and physiological characteristics permitted the distinction of the two strains from their neighbors, and we thus propose the names Thalassospira aquimaris sp. nov. (type strain FZY0004T = JCM 35895T = MCCC 1K08380T) and Winogradskyella marincola sp. nov. (type strain YYF002T = JCM 35950T = MCCC 1K08382T).


Assuntos
Ágar , DNA Bacteriano , Ácidos Graxos , Filogenia , RNA Ribossômico 16S , Água do Mar , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , DNA Bacteriano/genética , Ágar/metabolismo , Ácidos Graxos/metabolismo , Composição de Bases , Técnicas de Tipagem Bacteriana , China , Fosfolipídeos/metabolismo , Técnicas de Cocultura , Análise de Sequência de DNA
3.
Sci Rep ; 14(1): 16417, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39013910

RESUMO

The goal of the current work was to optimize the growth parameters needed to manufacture agarase enzyme from a non-marine PI strain of Bacillus subtilis on an agar-based medium. Using Plackett-Burman design (PBD), nine process parameters were evaluated, and agar, peptone, and yeast-extract were identified as the most significant independent factors influencing agarase production with confidence levels more than 90%. To evaluate the optimal concentrations of the indicated process parameters on agarase production, the Box-Behnken design (BBD) was applied. After optimization, B. subtilis strain PI produced 119.8 U/ml of agarase, representing a 1.36-fold increase. In addition the agar hydrolysate fermented products contain the liberated oligosaccharide acts as strong antioxidant which has 62.4% scavenging activity. Also, the agarase yields increased (1141.12, 1350.253, 1684.854 and 1921.863 U/ml) after substitution the agar with algal biomass of Carolina officinalis at different concentrations (2, 5, 10 and 15%), respectively. After completing the saccharification process, the resulted hydrolysate was used to produce ethanol through fermentation with Pichia pastoris yeast strain as an economical method giving yields (6.68317, 7.09748, 7.75648 and 8.22332 mg/ml), that are higher than using yeast extract peptone dextrose (YPD) medium (4.461 mg/ml).


Assuntos
Bacillus subtilis , Biomassa , Etanol , Fermentação , Glicosídeo Hidrolases , Bacillus subtilis/metabolismo , Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/enzimologia , Etanol/metabolismo , Glicosídeo Hidrolases/metabolismo , Meios de Cultura/química , Ágar/química , Hidrólise , Antioxidantes/metabolismo
4.
Carbohydr Polym ; 340: 122293, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38858005

RESUMO

A few protein- and polysaccharide-based particles have shown promising potential as stabilizers in multi-phase food systems. By incorporating polymer-based particles and modifying the wettability of colloidal systems, it is possible to create particle-stabilized emulsions with excellent stability. A Pickering emulsifier (AGMs) with better emulsifying properties was obtained by the Maillard reaction between acid-hydrolysed agar and gelatin. Laser confocal microscopy imaging revealed that AGMs particles can be used as solid emulsifiers to produce a typical O/W Pickering emulsion, with AGMs adsorbing onto the droplet surface to form a dense interfacial layer. Cryo-scanning electron microscopy analysis showed that AGMs self-assembled into a three-dimensional network structure, which prevented droplets aggregation through strong spatial site resistance, contributing to emulsion stabilization. These emulsions exhibited stability within a pH range of 1 to 11, NaCl concentrations not exceeding 300 mM, and at temperatures below 80 °C. The most stable emulsion oil-water ratio was 6:4 at a particle concentration of 0.75 % (w/v). AGMs-stabilized Pickering emulsion was utilized to create a semi-solid mayonnaise as a replacement for hydrogenated oil. Rheological analysis demonstrated that low-fat mayonnaise stabilized with AGMs exhibited similar rheological behavior to traditional mayonnaise, offering new avenues for the application of Pickering emulsions in the food industry.


Assuntos
Ágar , Emulsificantes , Emulsões , Gelatina , Reação de Maillard , Gelatina/química , Ágar/química , Emulsões/química , Emulsificantes/química , Reologia , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Temperatura
5.
Sci Rep ; 14(1): 12756, 2024 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-38830930

RESUMO

Caenorhabditis elegans is an appealing tool for experimental evolution and for working with antiparasitic drugs, from understanding the molecular mechanisms of drug action and resistance to uncover new drug targets. We present a new methodology for studying the impact of antiparasitic drugs in C. elegans. Viscous medium was initially designed for C. elegans maintenance during long-term evolution experiments. Viscous medium provides a less structured environment than the standard nematode growth media agar, yet the bacteria food source remains suspended. Further, the Viscous medium offers the worm population enough support to move freely, mate, and reproduce at a rate comparable to standard agar cultures. Here, the Viscous medium was adapted for use in antiparasitic research. We observed a similar sensitivity of C. elegans to anthelmintic drugs as in standard liquid media and statistical difference to the standard agar media through a larval development assay. Using Viscous medium in C. elegans studies will considerably improve antiparasitic resistance research, and this medium could be used in studies aimed at understanding long-term multigenerational drug activity.


Assuntos
Anti-Helmínticos , Caenorhabditis elegans , Meios de Cultura , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/crescimento & desenvolvimento , Animais , Anti-Helmínticos/farmacologia , Meios de Cultura/química , Viscosidade , Ágar , Resistência a Medicamentos/efeitos dos fármacos , Larva/efeitos dos fármacos
6.
J Med Microbiol ; 73(6)2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38935081

RESUMO

Introduction. The absence of a gold-standard methodology for the microbiological diagnosis of urinary tract infections (UTI) has led to insufficient standardization of criteria for the interpretation of results and processing methods, particularly incubation time and culture media.Hypothesis. 48-hour incubation time period and use of blood agar enhances the sensitivity of microorganisms isolated significantly.Aim. To determine the sensitivity of blood agar and Brilliance UTI chromogenic agar, incubating for different periods (24-48 hours), for the detection of positive urine cultures.Methodoloy. Comparisons were made between all possible combinations of media and incubation times. As the gold-standard reference, we used the routine methodology of our laboratory, which involves prior screening with available clinical data, flow cytometry, sediment analysis and/or Gram staining. Screened samples were then cultured on blood agar and chromogenic agar and incubated for 48 hours. Also, based on the results of Gram staining, additional media were added in selected cases.Results. The most significant difference was found between chromogenic agar incubated for 24 hours and blood agar incubated for 48 hours, with the latter method allowing the recovery of 10.14 % more microorganisms (P < 0.0001). Furthermore, the value of performing Gram staining to guide processing was demonstrated, as it avoided the loss of at least 5.14 % of isolates.Conclusions. At least in urological and nephrological patients it is essential to include enriched culture media (blood agar) or to extend the incubation times due to the improvement of the diagnostic sensitivity of urine cultures. Gram staining also can help detect the presence of fastidious microorganisms or mixed infections, indicating whether rich and/or selective media should be included to enhance the diagnostic sensitivity of cultures. If this methodology is not followed, it should be noted that besides fastidious species, fastidious strains of Escherichia coli, Proteus mirabilis, Pseudomonas aerugniosa and Stenotrophomonas maltophilia will also be missed.


Assuntos
Meios de Cultura , Sensibilidade e Especificidade , Infecções Urinárias , Infecções Urinárias/diagnóstico , Infecções Urinárias/microbiologia , Humanos , Meios de Cultura/química , Fatores de Tempo , Técnicas Bacteriológicas/métodos , Técnicas Bacteriológicas/normas , Bactérias/isolamento & purificação , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Ágar , Urina/microbiologia
7.
Food Chem ; 455: 139911, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38823129

RESUMO

Ti-metal organic framework (Ti-MOF) doped with carbon dots (CDs) with enhanced antibacterial potential was synthesized using solvothermal-assisted mechanical stirring and used for the fabrication of CMC/Agar-based active packaging films. The incorporation of CD@Ti-MOF not only improved the tensile strength of the CMC/Agar film by 17.4% but also exhibited strong antioxidant activity with 100% of ABTS and 57.8% of DPPH radical scavenging using 0.64 cm2/mL of CMC/Agar/CD@Ti-MOF film. Furthermore, water vapor permeability, oxygen permeability, and ultraviolet light-blocking ability (95.7% of UV-B and 84.7% of UV-A) were improved significantly. The CMC/Agar/CD@Ti-MOF film showed strong antibacterial activity and could inhibit the progress of E. coli up to 8.2 Log CFU/mL and completely stopped the growth of L.monocytogenes after 12 h of incubation. Additionally, CMC/Agar/CD@Ti-MOF film extended the shelf life of cherry tomatoes preserved at 4 °C and delayed the quality degradation, maintaining the visual aspects of the packaging.


Assuntos
Ágar , Antibacterianos , Carbono , Embalagem de Alimentos , Frutas , Estruturas Metalorgânicas , Embalagem de Alimentos/instrumentação , Carbono/química , Frutas/química , Antibacterianos/farmacologia , Antibacterianos/química , Estruturas Metalorgânicas/química , Ágar/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Titânio/química , Armazenamento de Alimentos , Solanum lycopersicum/química , Solanum lycopersicum/crescimento & desenvolvimento , Conservação de Alimentos/métodos , Conservação de Alimentos/instrumentação , Pontos Quânticos/química , Antioxidantes/química , Antioxidantes/farmacologia
8.
Int J Biol Macromol ; 273(Pt 1): 132952, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38848830

RESUMO

This work focuses on the potential of agar from the seaweed Gracilaria fisheri to modify the properties of starch foam. The effects of different ratios of glycerol and agar on the properties of starch foams were investigated. All formulations used in this study produced easy-to-handle, smooth, single-use foam trays with no visible cracks. The addition of agar slightly affected the off-white color of the foam but red and yellow color values significantly decreased with increments of agar content. As the agar content was increased, the foam became less dense. A foam produced at a glycerol:agar ratio of 3:7 exhibited the highest values of flexural stress at maximum load (3.23 MPa), modulus (194.46 MPa) and hardness (97.50), and the highest temperature at maximum weight loss (Tmax) (337 °C). Therefore, starch foam modified with agar from Gracilaria fisheri showed suitable physical, mechanical and thermal properties for food packaging, and could possibly be used in the place of expanded polystyrene (EPS) foam.


Assuntos
Ágar , Gracilaria , Amido , Ágar/química , Amido/química , Gracilaria/química , Alga Marinha/química , Temperatura , Glicerol/química , Glicerol/farmacologia , Embalagem de Alimentos/métodos
9.
Eur J Clin Microbiol Infect Dis ; 43(7): 1349-1353, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38780755

RESUMO

INTRODUCTION: Burkholderia cepacia complex (BCC) are non-fermenting Gram-negative bacteria that can chronically colonize the lungs of people with cystic fibrosis (pwCF), causing a severe and progressive respiratory failure, post-transplant complications and epidemic outbreaks. Therefore, rapid and accurate identification of these bacteria is relevant for pwCF, in order to facilitate early eradication and prevent chronic colonization. However, BCCs are often quite difficult to detect on culture media as they have a slow growth rate and can be hidden by other fast-growing microorganisms, including Pseudomonas aeruginosa and filamentous fungi. MATERIAL AND METHODS: We evaluated the sensitivity of CHROMagar™ B. cepacia agar using 11 isolates from a well-characterized BCC collection, using BCA agar (Oxoid, UK) as a gold standard. We also studied 180 clinical sputum samples to calculate positive (PPV) and negative (NPV) predictive values. Furthermore, we used three of the well-characterized BCC isolates to determine the limit of detection (LOD). RESULTS: Eleven isolates grew on CHROMagar™ B. cepacia at 37ºC after 48 h. The NPV and PPV of CHROMagar™ B. cepacia were 100% and 87.5%, respectively. The LOD of CHROMagar™ B. cepacia was around 1 × 103 CFU/ml, requiring a ten-fold dilution lower bacterial load than BCA for BCC detection. CONCLUSION: CHROMagar™ B. cepacia agar proved to have a very good sensitivity and specificity for the detection of clinical BCCs. Moreover, the chromogenic nature of the medium allowed us to clearly differentiate BCC from other Gram-negative species, filamentous fungi and yeasts, thereby facilitating the identification of contaminants.


Assuntos
Ágar , Técnicas Bacteriológicas , Infecções por Burkholderia , Complexo Burkholderia cepacia , Meios de Cultura , Fibrose Cística , Sensibilidade e Especificidade , Escarro , Humanos , Fibrose Cística/microbiologia , Fibrose Cística/complicações , Complexo Burkholderia cepacia/isolamento & purificação , Complexo Burkholderia cepacia/classificação , Escarro/microbiologia , Infecções por Burkholderia/microbiologia , Infecções por Burkholderia/diagnóstico , Meios de Cultura/química , Técnicas Bacteriológicas/métodos
10.
J Clin Microbiol ; 62(7): e0036924, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38819167

RESUMO

Azole resistance screening in Aspergillus fumigatus sensu stricto can be routinely carried out by using azole-containing agar plates (E.Def 10.2 procedure); however, conidial suspension filtering and inoculum adjustment before inoculum preparation are time-consuming. We evaluated whether skipping the filtration and inoculum adjustment steps negatively influenced the performance of the E.Def 10.2 procedure. A. fumigatus sensu stricto isolates (n = 98), previously classified as azole susceptible or azole resistant (E.Def 9.4 method), were studied. Azole-resistant isolates had either the wild-type cyp51A gene sequence (n = 1) or the following cyp51A gene substitutions: TR34-L98H (n = 41), G54R (n = 5), TR46-Y121F-T289A (n = 1), or G448S (n = 1). In-house azole-containing agar plates were prepared according to the EUCAST E.Def 10.2 procedure. Conidial suspensions obtained by adding distilled water (Tween 20 0.1%) were either filtered and the inocula adjusted to 0.5 McFarland or left unfiltered and unadjusted. Agreements between the agar screening methods using inocula prepared by each procedure were high for itraconazole (99%), voriconazole (100%), and posaconazole (94.9%). Sensitivity and specificity (considering the susceptibility category as per the microdilution E.Def 9.4 method as the gold standard) of E.Def 10.2 were 100% to rule in or rule out resistance when unfiltered and unadjusted suspensions were used; the resistance phenotype of isolates harboring the TR34-L98H, G54R, or TR46-Y121F-T289A substitutions was correctly detected. Unfiltered and unadjusted conidial suspensions do not negatively influence the performance of the E.Def 10.2 method when screening for azole resistance in A. fumigatus sensu stricto. IMPORTANCE: Azole resistance screening in Aspergillus fumigatus sensu stricto can be routinely carried out by using azole-containing plates (E.Def 10.2 procedure); however, conidial suspension filtering and inoculum adjustment before inoculation of plates are time-consuming. We, here, showed that unfiltered and unadjusted conidial suspensions do not negatively influence the performance of the E.Def 10.2 method when screening for azole resistance in A. fumigatus sensu stricto.


Assuntos
Antifúngicos , Aspergillus fumigatus , Azóis , Farmacorresistência Fúngica , Testes de Sensibilidade Microbiana , Esporos Fúngicos , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/genética , Aspergillus fumigatus/isolamento & purificação , Azóis/farmacologia , Antifúngicos/farmacologia , Testes de Sensibilidade Microbiana/métodos , Humanos , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/genética , Meios de Cultura/química , Proteínas Fúngicas/genética , Ágar , Sistema Enzimático do Citocromo P-450/genética
11.
J Appl Microbiol ; 135(5)2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38749678

RESUMO

AIM: The main objective of the study was to develop and validate a model for the growth of Aspergillus brasiliensis on surfaces, specifically on agar culture medium. An additional aim was to determine conditions for complete growth inhibition of this micromycete using two different nonthermal plasma (NTP) sources. METHODS AND RESULTS: The developed model uses two key parameters, namely the growth rate and growth delay, which depend on the cultivation temperature and the amount of inoculum. These parameters well describe the growth of A. brasiliensis and the effect of NTP on it. For complete fungus inactivation, a single 10-minute exposure to a diffuse coplanar surface barrier discharge was sufficient, while a point-to-ring corona discharge required several repeated 10-minute exposures at 24-h intervals. CONCLUSIONS: The article presents a model for simulating the surface growth of A. brasiliensis and evaluates the effectiveness of two NTP sources in deactivating fungi on agar media.


Assuntos
Aspergillus , Meios de Cultura , Gases em Plasma , Aspergillus/crescimento & desenvolvimento , Aspergillus/efeitos dos fármacos , Gases em Plasma/farmacologia , Modelos Biológicos , Temperatura , Ágar
12.
Int J Biol Macromol ; 270(Pt 1): 132343, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38750841

RESUMO

Color indicator films incorporating aronia extract powder (AEP) and biopolymers like agar, carrageenan, and cellulose nanofiber (CNF) were developed to monitor kimchi freshness. AEP-containing films showed strong UV-barrier properties, and reduced light transmittance by 99.12 % for agar, 98.86 % for carrageenan, and 98.67 % for CNF-based films. All AEP-films exhibited high sensitivity to pH changes and vapor exposure to ammonia and acetic acid. Color change notably influenced by the polymer type, particularly evident with ammonia vapor exposure, especially in the AEP/carrageenan film. The chemical structure and thermal stability of the biopolymers remained unchanged after AEP-addition. Tensile strength increased by 24.2 % for AEP/CNF but decreased by 19.4 % for AEP/agar and 24.3 % for AEP/carrageenan films. AEP-containing films displayed strong antioxidant activity, with 99 % free radical scavenging in ABTS and ~ 80 % in DPPH assays. Alkalized AEP-indicator films were more effective in detecting color changes during kimchi packaging tests. Among the labels, alkalized AEP/agar film showed the most obvious color change from green-gray (fresh kimchi, pH 5.5, acidity 0.48 %) to pale brown (optimal fermentation, pH 4.6, acidity 0.70 %), and pale violet-brown (over-fermented, pH 3.80, acidity 1.35 %). Alkalized AEP-indicator films offer promising real-time detection of packed fermented foods like kimchi.


Assuntos
Ágar , Carragenina , Celulose , Colorimetria , Embalagem de Alimentos , Nanofibras , Extratos Vegetais , Carragenina/química , Nanofibras/química , Ágar/química , Celulose/química , Colorimetria/métodos , Embalagem de Alimentos/métodos , Extratos Vegetais/química , Antioxidantes/química , Antioxidantes/análise , Resistência à Tração , Cor , Concentração de Íons de Hidrogênio
13.
Sci Rep ; 14(1): 10508, 2024 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714808

RESUMO

In this study, a novel nanobiocomposite consisting of agar (Ag), tragacanth gum (TG), silk fibroin (SF), and MOF-5 was synthesized and extensively investigated by various analytical techniques and basic biological assays for potential biomedical applications. The performed Trypan blue dye exclusion assay indicated that the proliferation percentage of HEK293T cells was 71.19%, while the proliferation of cancer cells (K-562 and MCF-7) was significantly lower, at 10.74% and 3.33%. Furthermore, the Ag-TG hydrogel/SF/MOF-5 nanobiocomposite exhibited significant antimicrobial activity against both E. coli and S. aureus strains, with growth inhibition rates of 76.08% and 69.19% respectively. Additionally, the hemolytic index of fabricated nanobiocomposite was found approximately 19%. These findings suggest that the nanobiocomposite exhibits significant potential for application in cancer therapy and wound healing.


Assuntos
Ágar , Fibroínas , Hidrogéis , Nanocompostos , Tragacanto , Fibroínas/química , Humanos , Hidrogéis/química , Ágar/química , Nanocompostos/química , Tragacanto/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Staphylococcus aureus/efeitos dos fármacos , Células HEK293 , Zinco/química , Proliferação de Células/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Testes de Sensibilidade Microbiana , Células MCF-7 , Linhagem Celular Tumoral
14.
Int J Mol Sci ; 25(9)2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38731824

RESUMO

Agar, as a seaweed polysaccharide mainly extracted from Gracilariopsis lemaneiformis, has been commercially applied in multiple fields. To investigate factors indicating the agar accumulation in G. lemaneiformis, the agar content, soluble polysaccharides content, and expression level of 11 genes involved in the agar biosynthesis were analysed under 4 treatments, namely salinity, temperature, and nitrogen and phosphorus concentrations. The salinity exerted the greatest impact on the agar content. Both high (40‱) and low (10‱, 20‱) salinity promoted agar accumulation in G. lemaneiformis by 4.06%, 2.59%, and 3.00%, respectively. The content of agar as a colloidal polysaccharide was more stable than the soluble polysaccharide content under the treatments. No significant correlation was noted between the two polysaccharides, and between the change in the agar content and the relative growth rate of the algae. The expression of all 11 genes was affected by the 4 treatments. Furthermore, in the cultivar 981 with high agar content (21.30 ± 0.95%) compared to that (16.23 ± 1.59%) of the wild diploid, the transcriptional level of 9 genes related to agar biosynthesis was upregulated. Comprehensive analysis of the correlation between agar accumulation and transcriptional level of genes related to agar biosynthesis in different cultivation conditions and different species of G. lemaneiformis, the change in the relative expression level of glucose-6-phosphate isomerase II (gpiII), mannose-6-phosphate isomerase (mpi), mannose-1-phosphate guanylyltransferase (mpg), and galactosyltransferase II (gatII) genes was highly correlated with the relative agar accumulation. This study lays a basis for selecting high-yield agar strains, as well as for targeted breeding, by using gene editing tools in the future.


Assuntos
Ágar , Rodófitas , Rodófitas/genética , Rodófitas/metabolismo , Rodófitas/crescimento & desenvolvimento , Salinidade , Regulação da Expressão Gênica de Plantas , Polissacarídeos/metabolismo , Polissacarídeos/biossíntese , Temperatura , Nitrogênio/metabolismo
15.
Int J Biol Macromol ; 268(Pt 2): 131760, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38663693

RESUMO

In the adsorption process for wastewater treatment, the adsorbent plays an important role. A composite adsorptive material composed of graphitic carbon nitride and agar-derived porous carbon (CNPC) was fabricated from simple precursors (melamine, thiourea, and agar) and through a facile procedure with different melamine and thiourea ratios. Characterization of CNPC proved a successful formation of a porous structure consisting of mesopores and macropores, wherein CNPC holds distinctive electrochemical (lowered resistance and higher specific capacity) and photochemical properties (lowered bandgap to 2.33 eV) thanks to the combination of graphitic carbon nitride (CN) and agar-derived porous carbon (PC). Inheriting the immanent nature, CNPC was subjected to the adsorption of methylene blue (MB) dye in an aqueous solution. The highest adsorption capacity was 133 mg/g for CNPC-4 which was prepared using a melamine to thiourea ratio of 4:4 - equivalent to the removal rate of 53.2 % and following the pseudo-I-order reaction rate. The effect of pH points out that pH 7 and 9 were susceptible to maximum removal and pretreatment is not required while the optimal ratio of 7.5 mg of MB and 30 mg of material was also determined to yield the highest performance. Furthermore, the reusability of the material for three consecutive cycles was evaluated based on two methods pyrolysis at 200 °C and photocatalytic degradation by irradiation under visible light. In general, the photocatalytic regeneration pathway is more ample and efficient than pyrolysis in terms of energy efficiency (saving energy over 10 times) and adsorption capacity stability. As a whole, the construction of accessible regenerative and stable adsorbent could be a venturing step into the sustainable development spearhead for industries.


Assuntos
Ágar , Grafite , Azul de Metileno , Poluentes Químicos da Água , Adsorção , Grafite/química , Porosidade , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Azul de Metileno/química , Ágar/química , Purificação da Água/métodos , Triazinas/química , Recuperação e Remediação Ambiental/métodos , Carbono/química , Águas Residuárias/química , Concentração de Íons de Hidrogênio , Compostos de Nitrogênio/química , Cinética , Tioureia/química
16.
Int J Biol Macromol ; 268(Pt 2): 131767, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38657918

RESUMO

In this study, linalool-nanoparticles (L-NPs) were prepared (encapsulation efficiency was 68.54 %) and introduced pH-indicator film based on cranberry-extract (CEF) to develop multifunctional smart films. XRD analysis and FTIR spectroscopy indicated that cranberry-extract (CE) and L-NPs were uniformly distributed in the gelatin/agar matrix and could change the intermolecular structure of the film. Color change of smart films showed that CE endowed the film with pH-sensitive property. As CE and L-NPs were added to the film, the water contact angle (WCA) was increased from 57.03° to 117.73°, the elongation at break (EAB) was increased from 12.30 % to 34.60 %. Additionally, the introduction of L-NPs enhanced the antioxidant activity (DPPH free radical scavenging rate increased from 26.80 % to 36.35 %) and antibacterial activity (against S. aureus and E. coli) of the smart film, which were verified by its retarding effect on pork spoilage.


Assuntos
Monoterpenos Acíclicos , Antioxidantes , Gelatina , Nanopartículas , Extratos Vegetais , Vaccinium macrocarpon , Monoterpenos Acíclicos/química , Monoterpenos Acíclicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Concentração de Íons de Hidrogênio , Gelatina/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Nanopartículas/química , Vaccinium macrocarpon/química , Ágar/química , Escherichia coli/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Staphylococcus aureus/efeitos dos fármacos , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Testes de Sensibilidade Microbiana
17.
J Indian Soc Pedod Prev Dent ; 42(1): 15-21, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38616422

RESUMO

BACKGROUND: In cariology studies, mitis-salivarius-bacitracin (MSB) agar has been commonly considered as the selective medium for Streptococcusmutans growth. The present study was the part of a funded project (a noninferiority randomized controlled trial) which compared the efficacy of a plant extract-based mouth rinse with that of a fluoride mouth rinse on the S.mutans counts of the children. AIM: This study aimed to identify the frequency of detection of S.mutans and nonstreptococcal bacterial species from the dental plaque of caries active children using a combined technique of anaerobic culture and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. SETTINGS AND METHODS: Caries-active children (8-12 years old) were enrolled from a pediatric dental outpatient department at a tertiary care hospital. From each participant, dental plaque samples were collected from carious surfaces under sterilized conditions and then subjected to anaerobic culture. After 48 h of incubation, the bacterial colonies were isolated by sub-culture and identified by the MALDI-TOF. RESULTS: In all, 13 different bacterial species were isolated from the MSB agar medium. Other than S.mutans species, colonies of bacterial species such as Veillonelladispar,Streptococcusanginosus, Veillonellaparvula, and Streptococcusgordonii were also frequently observed from the medium. CONCLUSIONS: The study concluded that several bacterial strains, both streptococcal and nonstreptococcal, could be isolated from the MSB agar medium; hence, this medium should no longer be considered selective medium for the culture of S.mutans in clinical and epidemiological studies.


Assuntos
Cárie Dentária , Placa Dentária , Criança , Humanos , Ágar , Bacitracina , Suscetibilidade à Cárie Dentária , Antissépticos Bucais
18.
Open Vet J ; 14(1): 449-458, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38633146

RESUMO

Background: Avian salmonellosis is a group of diseases caused by bacteria from the genus Salmonella with a negative impact on poultry, particularly chickens. In addition, salmonellosis is a global food-borne infection. Aim: The aim of this study was to evaluate the effect of nano-emulsion difloxacin (NED) and commercial difloxacin (CD) water supplement on broiler's growth, feed intake, and body weight, weight gain, growth rate, feed conversion ratio (FCR), and mortality rate (MR). The antibiotic sensitivity was determined both in-vivo and in-vitro for NED against Salmonella enterica Serovar enteritidis in chickens. Methods: 1500 one-day of age chicks were grouped into five groups as follows: group 1 (G1) control negative group, G2 control positive group (infected and not treated), G3 (infected and treated with CD, and G4 and G5 (infected and treated with NED at different doses). Samples, including the intestine, liver, and spleen were collected. Agar well diffusion test and minimum inhibitory concentrations were adopted. Histopathological lesions on different tissues were studied. During 35 days of the experiment, the feed intake, growth rate, growth gain, FCR, and MR were recorded daily. In addition, a variety of analytical techniques including transmission electron microscopic analysis, dynamic light scattering, UV-visible spectroscopy, and zeta-potential analysis were applied to characterize NED. Results: The agar well diffusion test indicated that NED was in-vitro effective against S. enteritidis isolates than CD. The minimum inhibitory concentration was recorded as NED inhibited bacterial growth till well 8 at a concentration of 0.78 µg/ml; on the other hand, the CD inhibited bacterial growth till well 6 at a concentration of 0.62 µg/ml. Growth performance and MRs in the groups treated with NED are significantly reduced. Conclusion: Treatment of broiler's drinking water with NED at doses of 0.5 and 1 ml instead of pure CD was able to enforce a new perspective, antibacterial efficacy, enhancing the productive performance, and reducing the MRs of broilers.


Assuntos
Ciprofloxacina/análogos & derivados , Infecções por Salmonella , Salmonella enteritidis , Animais , Antibacterianos/farmacologia , Galinhas , Ágar/farmacologia
19.
J Basic Microbiol ; 64(6): e2400091, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38651780

RESUMO

Brevibacillus thermoruber strain Nabari cells grow as widely spreading dendritic colonies on reasoner's 2A-agar (1.5%) plates at around 55°C but as small motile colonies at 37°C. Motile colonies can be divided into colonies that move in straight or curved lines over long distances (wandering colonies), and colonies that rotate at a fixed location (rotating colonies). The addition of surfactant to the agar medium greatly increased the frequency of wandering colonies and facilitated the study of such colonies. The morphology of the wandering colonies varied: circular at the tip and pointed at the back, lemon-shaped with pointed ends, crescent-shaped, bullet-shaped, fish-like, and so on. A single colony may split into multiple colonies as it moves, or multiple colonies may merge into a single colony. The most surprising aspect of the movement of wandering colonies was that when a moving colony collides with another colony, it sometimes does not make a U-turn, but instead retreats straight back, as if bouncing back. The migration mechanisms of wandering colonies are discussed based on optical microscopic observations of swimming patterns of single cells in water and scanning electron microscopy of the arrangement of bacterial cells in wandering colonies.


Assuntos
Ágar , Brevibacillus , Meios de Cultura , Brevibacillus/crescimento & desenvolvimento , Brevibacillus/fisiologia , Brevibacillus/metabolismo , Meios de Cultura/química , Temperatura , Microscopia Eletrônica de Varredura , Movimento , Tensoativos
20.
PeerJ ; 12: e17165, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38590706

RESUMO

Background: Plastic waste is a global environmental issue that impacts the well-being of humans, animals, plants, and microorganisms. Microplastic contamination has been previously reported at Kung Wiman Beach, located in Chanthaburi province along with the Eastern Gulf of Thailand. Our research aimed to study the microbial population of the sand and plastisphere and isolate microorganisms with potential plastic degradation activity. Methods: Plastic and sand samples were collected from Kung Wiman Beach for microbial isolation on agar plates. The plastic samples were identified by Fourier-transform infrared spectroscopy. Plastic degradation properties were evaluated by observing the halo zone on mineral salts medium (MSM) supplemented with emulsified plastics, including polystyrene (PS), polylactic acid (PLA), polyvinyl chloride (PVC), and bis (2-hydroxyethyl) terephthalate (BHET). Bacteria and fungi were identified by analyzing nucleotide sequence analysis of the 16S rRNA and internal transcribed spacer (ITS) regions, respectively. 16S and ITS microbiomes analysis was conducted on the total DNA extracted from each sample to assess the microbial communities. Results: Of 16 plastic samples, five were identified as polypropylene (PP), four as polystyrene (PS), four as polyethylene terephthalate (PET), two as high-density polyethylene (HDPE), and one sample remained unidentified. Only 27 bacterial and 38 fungal isolates were found to have the ability to degrade PLA or BHET on MSM agar. However, none showed degradation capabilities for PS or PVC on MSM agar. Notably, Planococcus sp. PP5 showed the highest hydrolysis capacity of 1.64 ± 0.12. The 16S rRNA analysis revealed 13 bacterial genera, with seven showing plastic degradation abilities: Salipiger, Planococcus, Psychrobacter, Shewanella, Jonesia, Bacillus, and Kocuria. This study reports, for the first time of the BHET-degrading properties of the genera Planococcus and Jonesia. Additionally, The ITS analysis identified nine fungal genera, five of which demonstrated plastic degradation abilities: Aspergillus, Penicillium, Peacilomyces, Absidia, and Cochliobolus. Microbial community composition analysis and linear discriminant analysis effect size revealed certain dominant microbial groups in the plastic and sand samples that were absent under culture-dependent conditions. Furthermore, 16S and ITS amplicon microbiome analysis revealed microbial groups were significantly different in the plastic and sand samples collected. Conclusions: We reported on the microbial communities found on the plastisphere at Kung Wiman Beach and isolated and identified microbes with the capacity to degrade PLA and BHET.


Assuntos
Actinomycetales , Microbiota , Actinomycetales/genética , Ágar/metabolismo , Bactérias/genética , Microbiota/genética , Plásticos/metabolismo , Poliésteres/metabolismo , Poliestirenos/metabolismo , RNA Ribossômico 16S/genética , Areia
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