RESUMO
Heavy metal pollution, particularly the excessive release of copper (Cu), is an urgent environmental concern. In this study, sodium lignosulfonate/carboxymethyl sa-son seed gum (SL-Cg-g-PAA) designed for remediation of Cu-contaminated water and soil was successfully synthesized through a free radical polymerization method using lignin as a raw material. This hydrogel exhibits remarkable Cu adsorption capability when applied to water, with a maximum adsorption capacity reaching 172.41 mg/g. Important adsorption mechanisms include surface complexation and electrostatic attraction between Cu(â ¡) and oxygen-containing functional groups (-OH, -COOH), as well as cation exchange involving -COONa and -SO3Na. Furthermore, SL/Cg-g-PAA effectively mitigated the bioavailability of heavy metals within soil matrices, as evidenced by a notable 14.1% reduction in DTPA extracted state Cu (DTPA-Cu) content in the S4 treatment (0.7% SL/Cg-g-PAA) compared to the control group. Concurrently, the Cu content in both the leaves and roots of pakchoi exhibited substantial decreases of 55.19% and 36.49%, respectively. These effects can be attributed to the precipitation and complexation reactions facilitated by the hydrogel. In summary, this composite hydrogel is highly promising for effective remediation of heavy metal pollution in water and soil, with a particular capability for the immobilization of Cu(â ¡) and reduction of its adverse effects on ecosystems.
Assuntos
Cobre , Recuperação e Remediação Ambiental , Hidrogéis , Lignina , Poluentes do Solo , Poluentes Químicos da Água , Hidrogéis/química , Cobre/química , Lignina/química , Lignina/análogos & derivados , Poluentes do Solo/química , Adsorção , Poluentes Químicos da Água/química , Recuperação e Remediação Ambiental/métodosRESUMO
Sucrose isomerase (SIase) catalyzes the hydrolysis and isomerization of sucrose to form isomaltulose, a valuable functional sugar widely used in the food industry. However, the lack of safe and efficient heterologous expression systems hinders SIase production and application. In this study, we achieved antibiotic-free SIase expression in Bacillus subtilis through genome integration. Using CRISPR/Cas9 system, SIase expression cassettes were integrated into various genomic loci, including amyE and ctc, both individually and in combination, resulting in single-copy and muti-copy integration strains. Engineered strains with a maltose-inducible promoter effectively expressed and secreted SIase. Notably, multi-copy strain exhibited enhanced SIase production, achieving 4.4 U/mL extracellular activity in shake flask cultivations. Furthermore, crude enzyme solution from engineered strain transformed high concentrations sucrose into high yields of isomaltulose, reaching a maximum yield of 94.6%. These findings demonstrate antibiotic-free SIase production in B. subtilis via genome integration, laying the foundation for its industrial production and application.
Assuntos
Bacillus subtilis , Glucosiltransferases , Isomaltose , Bacillus subtilis/genética , Bacillus subtilis/enzimologia , Isomaltose/metabolismo , Isomaltose/análogos & derivados , Glucosiltransferases/genética , Glucosiltransferases/metabolismo , Sacarose/metabolismo , Engenharia Metabólica/métodos , Sistemas CRISPR-Cas/genética , Genoma Bacteriano/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismoRESUMO
Rice (Oryza sativa L.) is an important social-economic crop, and rice seedlings are easily affected by salt stress. Chitosan oligosaccharide (COS) plays a positive role in promoting plant growth and development. To gain a better understanding of the salt tolerance mechanism of rice under the action of COS, Nipponbare rice seedlings were selected as the experimental materials, and the physiological and biochemical indexes of rice seedlings in three stages (normal growth, salt stress and recovery) were measured. Unlabelled quantitative proteomics technology was used to study differential protein and signaling pathways of rice seedlings under salt stress, and the mechanism of COS to improve rice tolerance to salt stress was elucidated. Results showed that after treatment with COS, the chlorophyll content of rice seedlings was 1.26 times higher than that of the blank group (CK). The root activity during the recovery stage was 1.46 times that of the CK group. The soluble sugar in root, stem and leaf increased by 53.42%, 77.10% and 9.37%, respectively. The total amino acid content increased by 77% during the stem recovery stage. Furthermore, the malondialdehyde content in root, stem and leaf increased by 21.28%, 26.67% and 32.69%, respectively. The activity of oxide dismutase (SOD), peroxidase (POD) and oxygenase (CAT) were increased. There were more differentially expressed proteins in the three parts of the experimental group than in the CK group. Gene Ontology (GO) annotation of these differentially expressed proteins revealed that the experimental group was enriched for more entries. Then, through the Kyoto Encyclopedia of Genes and Genomes (KEGG), the top ten pathways enriched with differentially expressed proteins in the two groups (COS and CK groups) were utilized, and a detailed interpretation of the glycolysis and photosynthesis pathways was provided. Five key proteins, including phosphofructokinase, fructose bisphosphate aldolases, glycer-aldehyde-3-phosphate dehydrogenase, enolase and pyruvate kinase, were identified in the glycolysis pathway. In the photosynthesis pathway, oxygen evolution enhancement proteins, iron redox proteins and ferredoxin-NADPH reductase were the key proteins. The addition of COS led to an increase in the abundance of proteins, a response of rice seedlings to salt stress. COS helped rice seedlings resist salt stress. Furthermore, using COS as biopesticides and biofertilizers can effectively increase the utilization of saline-affected farmland, thereby contributing to the alleviating of the global food crisis.
Assuntos
Quitosana , Oligossacarídeos , Oryza , Proteínas de Plantas , Proteoma , Tolerância ao Sal , Plântula , Oryza/metabolismo , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Oryza/genética , Quitosana/farmacologia , Plântula/metabolismo , Plântula/efeitos dos fármacos , Oligossacarídeos/metabolismo , Proteoma/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Proteômica/métodos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Clorofila/metabolismoRESUMO
Lignin hydrothermal silica-carbon material served as a backbone for MgCl2 activation to prepare lignin-based silicon/magnesia biochar (ALB/Si-Mg) for Cd2+, Pb2+, Cu2+, and Zn2+ removal from water and soil environment. Characterization studies revealed a 1017.71-fold increase in the specific surface area of ALB/Si-Mg compared to the original lignin biochar (ALB), producing abundant oxygen functional groups (OC-O, Si-O, Mg-O), and mineral matter (Mg2SiO4 and MgO). Crucially, batch adsorption experiments demonstrated that the adsorption capacity of ALB/Si-Mg for Cd2+, Pb2+, Cu2+, and Zn2+ was 848.17, 665.07, 151.84, and 245.78 mg/g, which were 29.09-140.45 times of the ALB. Soil remediation experiments showed that applying ALB/Si-Mg increased soil effective silicon (109.04%-450.2%) and soil exchangeable magnesium (276.41%-878.66%), enhanced plant photosynthesis, and notably reduced the bioavailability of heavy metals in soil as well as the content of heavy metals in Pakchoi, thereby promoting Pakchoi growth and development. The presence of oxygen-containing functional groups on ALB/Si-Mg, along with Mg2SiO4 and MgO nanoparticles, enhanced the adsorption capacity for heavy metals through the promotion of heavy metal precipitation, ion exchange, and complexation mechanisms. This study establishes the groundwork for the coupling of silica and magnesium elements in biochar and the remediation of composite heavy metal environmental pollution.
Assuntos
Carvão Vegetal , Recuperação e Remediação Ambiental , Lignina , Metais Pesados , Dióxido de Silício , Metais Pesados/química , Carvão Vegetal/química , Dióxido de Silício/química , Lignina/química , Adsorção , Recuperação e Remediação Ambiental/métodos , Magnésio/química , Solo/química , Poluentes do Solo/químicaRESUMO
Catalase, which catalyzes the decomposition of H2O2 to H2O and O2, is widely used to reduce H2O2 in industrial applications, such as in food processing, textile dyeing and wastewater treatment. In this study, the catalase (KatA) from Bacillus subtilis was cloned and expressed in the yeast Pichia pastoris X-33. The effect of the promoter in the expression plasmid on the activity level of the secreted KatA protein was also studied. First, the gene encoding KatA was cloned and inserted into a plasmid containing an inducible alcohol oxidase 1 promoter (pAOX1) or a constitutive glyceraldehyde-3-phosphate dehydrogenase promoter (pGAP). The recombinant plasmids were validated by colony PCR and sequencing and then linearized and transformed into the yeast P. pastoris X-33 for expression. With the promoter pAOX1, the maximum yield of KatA in the culture medium reached 338.8 ± 9.6 U/mL in 2 days of shake flask cultivation, which was approximately 2.1-fold greater than the maximum yield obtained with the promoter pGAP. The expressed KatA was then purified from the culture medium by anion exchange chromatography, and its specific activity was determined to be 14826.58 U/mg. Finally, the purified KatA exhibited optimum activity at 25 °C and pH 11.0. Its Km for hydrogen peroxide was 10.9 ± 0.5 mM, and its kcat/Km was 5788.1 ± 25.6 s-1 mM-1. Through the work presented in this article, we have therefore demonstrated efficient expression and purification of KatA in P. pastoris, which might be advantageous for scaling up the production of KatA for use in a variety of biotechnological applications.
Assuntos
Bacillus subtilis , Pichia , Proteínas Recombinantes , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Pichia/genética , Pichia/metabolismo , Catalase/genética , Catalase/metabolismo , Peróxido de Hidrogênio , Saccharomyces cerevisiae/metabolismoRESUMO
To date, due to the low accessibility of enzymes to xanthan substrates, the enzymolysis of xanthan remains deficient, which hinders the industrial production of functional oligoxanthan. To enhance the enzymatic affinity against xanthan, the essential role of two carbohydrate binding modules-MiCBMx and PspCBM84, respectively, derived from Microbacterium sp. XT11 and Paenibacillus sp. 62047-in catalytic properties of endotype xanthanase MiXen were investigated for the first time. Basic characterizations and kinetic parameters of different recombinants revealed that, compared with MiCBMx, PspCBM84 dramatically increased the thermostability of endotype xanthanase, and endowed the enzyme with higher substrate affinity and catalytic efficiency. Notably, the activity of endotype xanthanase was increased by 16 times after being fused with PspCBM84. In addition, the presence of both CBMs obviously enabled endotype xanthanase to produce more oligoxanthan, and xanthan digests prepared by MiXen-CBM84 showed better antioxidant activity due to the higher content of active oligosaccharides. The results of this work lay a foundation for the rational design of endotype xanthanase and the industrial production of oligoxanthan in the future.
Assuntos
Oligossacarídeos , Polissacarídeos Bacterianos , Polissacarídeos Bacterianos/metabolismo , Oligossacarídeos/metabolismoRESUMO
A simple and efficient method was developed for the preparation of high-purity trehalulose from the waste syrup of isomaltulose production. The waste syrup was pre-treated with C18 solid-phase extraction, where 98% decolorization and 97% reducing sugar recovery were obtained, followed by hydrophilic interaction liquid chromatography separation on a cysteine-bonded zwitterionic column. Under optimized conditions, trehalulose was separated from isomaltulose isomer and prepared on a semi-preparative scale with >99% purity. The structure of the prepared trehalulose was subsequently confirmed by nuclear magnetic resonance, and three tautomers of trehalulose (α-D-glucosylpyranosyl-1,1-ß-D-fructopyranose, α-D-glucosylpyranosyl-1,1-ß-D-fructofuranose, and α-D-glucosylpyranosyl-1,1-α-D-fructofuranose) were detected and completely characterized by 13 C NMR spectroscopy for the first time in this study. The tautomerization of α-D and ß-D type transition was observed by hydrophilic interaction liquid chromatography on an AdvanceBio Glycan Mapping column, with smaller particle size (2.7 µm). Furthermore, the prepared trehalulose was applied as a standard for trehalulose quantification during the sucrose conversion by Klebsiella sp. LX3. The combination of solid-phase extraction and hydrophilic interaction liquid chromatography offers a new avenue for the preparation of sugar isomers from complex natural or fermentation products.
Assuntos
Dissacarídeos/isolamento & purificação , Isomaltose/análogos & derivados , Extração em Fase Sólida , Resíduos/análise , Cromatografia Líquida de Alta Pressão , Dissacarídeos/química , Interações Hidrofóbicas e Hidrofílicas , Isomaltose/químicaRESUMO
The widespread use of caffeine in food and drug industries has caused great environmental pollution. Herein, an efficient caffeine-degrading strain Paraburkholderia caffeinilytica CF1 isolated from a tea garden in China can utilize caffeine as its sole carbon and nitrogen source. Combination of chromatographic and spectrophotometric techniques confirmed that strain CF1 adopts N-demethylation pathway for caffeine degradation. Whole genome sequencing of strain CF1 reveals that it has two chromosomes with sizes 3.62 Mb and 4.53 Mb, and a 174-kb mega-plasmid. The plasmid P1 specifically harbors the genes essential for caffeine metabolism. By analyzing the sequence alignment and quantitative real-time PCR data, the redundant gene cluster of caffeine degradation was elucidated. Genes related to catalyzing the N1-demethylation of caffeine to theobromine, the first step of caffeine degradation were heterologously expressed, and methylxanthine N1-demethylase was purified and characterized. Above all, this study systematically unravels the molecular mechanism of caffeine degradation by Paraburkholderia. KEY POINTS: ⢠Caffeine degradation cluster in Paraburkholderia caffeinilytica CF1 was located in mega-plasmid P1. ⢠The whole genome and the caffeine degrading pathway of P. caffeinilytica CF1 were sequenced and elucidated, respectively. ⢠This study succeeded in heterologous expression of methylxanthine N1-demethylase (CdnA) and Rieske oxygenase reductase (CdnD) and illuminated the roles of CdnA and CdnD in caffeine degradation of P. caffeinilytica CF1.
Assuntos
Burkholderiaceae/genética , Cafeína/metabolismo , Família Multigênica , Plasmídeos/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Burkholderiaceae/isolamento & purificação , Burkholderiaceae/metabolismo , Cromossomos Bacterianos/genética , Desmetilação , Genes Bacterianos , Genoma Bacteriano/genética , Redes e Vias Metabólicas/genética , Plasmídeos/metabolismo , Xantinas/metabolismoRESUMO
OBJECTIVE: To investigate an improvement of barley germination by application of biochar leacheate in the steeping solution for upgrading malt quality. RESULTS: Barley germination was improved when biochar leacheate was used in the steeping water during the first steeping cycle. A clear decrease in the time to reach 50% of final germination percentage was detected due to an addition of biochar leacheate, but no significant difference was observed in the percent germination at the end of germination. Hydrolase activities including α-amylase, proteinase and ß-glucanase in barley grains were maximally increased during the malting process when 10% biochar leacheate was added to the first steeping water. The wort yielding indexes including both glucose and maltose content and the free amino nitrogen content were significantly increased but the ß-glucan content was significantly decreased at a level of p < 0.05 when 10% biochar leacheate was added to the steeping water. CONCLUSIONS: Biochar leacheate could be used as a stimulator in the steeping solution during the first steeping cycle to improve barley germination and so upgrade malt quality.
Assuntos
Carvão Vegetal/farmacologia , Hordeum/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Germinação/efeitos dos fármacos , Glicosídeo Hidrolases/metabolismo , Hordeum/efeitos dos fármacos , Hordeum/metabolismo , Fatores de Tempo , Regulação para Cima , alfa-Amilases/metabolismoRESUMO
OBJECTIVE: The objective is to study the effect of individual N-glycosylation sequon on Suc2 activity and stability, and improve inulin conversion capacity and ethanol production of yeast by manipulating the key N-glycosylation sequon in Suc2. RESULTS: Based on previous reported data, it could be deduced that both the activity and thermal stability of Suc2 are probably influenced by some key N-glycosylation sequons. Thus, totally 13 N-glycosylation residues of Suc2 were individually deglycosylated by site-directed mutagenesis. Fermentation results indicated that deglycosylation at N4, N78 and N146 sequons improved Suc2 activity and ethanol production of host strains, whereas deglycosylation at N45 showed an opposite effect. Carbohydrate depletion of Suc2 N4 especially endowed the host strain with better ethanol fermentation performance from inulin when the strain was cultured under the higher temperature for 48 h, indicating that deglycosylation of N4 might improve the thermal stability of the Suc2. CONCLUSIONS: Carbohydrate chains at N4, N45, N78 and N146 played an important role in modulating Suc2 activity and inulin catabolism of the S. cerevisiae strain. These key N-deglycosylation sequons should become potential targets for rational engineering of S. cerevisiae strains to enhance the ethanol production from inulin.
Assuntos
Etanol/metabolismo , Inulina/metabolismo , Saccharomyces cerevisiae/metabolismo , Glicosilação , Inulina/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae , beta-FrutofuranosidaseRESUMO
Under general aqueous conditions, xanthan appears in an ordered conformation, which makes its backbone largely resistant to degradation by known cellulases. Therefore, the xanthan degradation mechanism is still unclear because of the lack of an efficient hydrolase. Here, we report the catalytic properties of MiXen, a xanthan-degrading enzyme identified from the genus Microbacterium MiXen is a 952-amino-acid protein that is unique to strain XT11. Both the sequence and structural features suggested that MiXen belongs to a new branch of the GH9 family and has a multimodular structure in which a catalytic (α/α)6 barrel is flanked by an N-terminal Ig-like domain and by a C-terminal domain that has very few homologues in sequence databases and functions as a carbohydrate-binding module (CBM). Based on circular dichroism, shear-dependent viscosity, and reducing sugar and gel permeation chromatography analysis, we demonstrated that recombinant MiXen efficiently and randomly cleaved glucosidic bonds within the highly ordered xanthan substrate. A MiXen mutant free of the C-terminal CBM domain partially lost its xanthan-hydrolyzing ability because of decreased affinity toward xanthan, indicating the CBM domain assisted MiXen in hydrolyzing highly ordered xanthan via recognizing and binding to the substrate. Furthermore, side chain substituents and the terminal mannosyl residue significantly influenced the activity of MiXen via the formation of barriers to enzymolysis. Overall, the results of this study provide insight into the hydrolysis mechanism and enzymatic properties of a novel endotype xanthanase that will benefit future applications.IMPORTANCE This work characterized a novel endotype xanthanase, MiXen, and elucidated that the C-terminal carbohydrate-binding module of MiXen could drastically enhance the hydrolysis activity of the enzyme toward highly ordered xanthan. Both the sequence and structural analysis demonstrated that the catalytic domain and carbohydrate-binding module of MiXen belong to the novel branch of the GH9 family and CBMs, respectively. This xanthan cleaver can help further reveal the enzymolysis mechanism of xanthan and provide an efficient tool for the production of molecular modified xanthan with new physicochemical and physiological functions.
Assuntos
Actinomycetales/genética , Proteínas de Bactérias/genética , Polissacarídeos Bacterianos/metabolismo , Actinomycetales/enzimologia , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Catálise , Alinhamento de SequênciaRESUMO
To study the role of MAPK signaling pathway in the development of Epithelial-mesenchymal transition in oral squamous cell carcinoma induced by inflammatory factor TNF-α. After the action of TNF-α, the expression of JNK, ERK, P38 in MAPK signaling pathway increased and the expression of E-cadherin, Claudin1 decreased significantly compared to the normal control group. After the addition of corresponding inhibitor, the expression of JNK, ERK, P38 decreased and the expression of E-cadherin, Claudin1 increased compared with TNF-α group. TNF-α regulated the role of EMT in promoting the invasion and metastasis of oral squamous carcinoma cells through MAPK signaling pathway.
Assuntos
Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Transição Epitelial-Mesenquimal , Sistema de Sinalização das MAP Quinases , Neoplasias Bucais/metabolismo , Neoplasias Bucais/patologia , Fator de Necrose Tumoral alfa/metabolismo , Biomarcadores , Carcinoma de Células Escamosas/genética , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Neoplasias Bucais/genética , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
The quality traits of beer, which include flavor, texture, foam stability, gushing, and haze formation, rely on contributions from beer proteins and peptides. Large-scale proteomic analysis of beer is gaining importance, not only with respect to authenticity of raw material in beer but also to improve quality control during beer production. In this work, foam proteins were first isolated from beer by virtue of their high hydrophobicity. Then sequential filter-aided sample preparation coupled with liquid chromatography and tandem mass spectrometry was used to analyze both beer protein and foam protein. Finally, 4692 proteins were identified as beer proteins, and 3906 proteins were identified as foam proteins. In total, 7113 proteins were identified in the beer sample. Several proteins contributing to beer quality traits, including lipid transfer protein, serpin, hordein, gliadin, and glutenin, were detected in our proteins list. This work constructed a comprehensive beer proteome map that may help to evaluate potential health risks related to beer consumption in celiac patients.
Assuntos
Cerveja/análise , Proteínas de Plantas/análise , Proteoma/análise , Cromatografia Líquida , Humanos , Espectrometria de Massas em TandemRESUMO
OBJECTIVE: To enhance the production of phenolic compounds during barley germination using chitooligosaccharide as an elicitor to improve the antioxidant capacity of malt. RESULTS: When used as an elicitor for barley germination, chitooligosaccharide with a molecular weight of 3 kDa, added at 10 mg/kg barley kernels during the first steeping cycle, led to the maximum production of phenolic compounds. Compared with the control with no chitooligosaccharide added to the steeping water, the total phenolic content was increased by 54.8%. Increases in the total phenolic content of the barley malt occurred when chitooligosaccharide was applied during the first or both the first and the second steeping cycles. Thus the antioxidant capacity of barley malt was increased significantly by adding chitooligosaccharide during the steeping process. CONCLUSION: Applying chitooligosaccharides during the steeping process increased the content of phenolic compounds thus improving the antioxidant capacity of the barley malt.
Assuntos
Antioxidantes/metabolismo , Quitina/análogos & derivados , Germinação , Hordeum/crescimento & desenvolvimento , Hordeum/metabolismo , Fenóis/metabolismo , Compostos Fitoquímicos/metabolismo , Quitina/metabolismo , Quitosana , OligossacarídeosRESUMO
OBJECTIVE: To improve beer flavour stability by adding chitooligosaccharides that prevent formation of staling compounds and also scavenge radicals in stale beer. RESULTS: Chitooligosaccharides, at 0.001-0.01%, inhibited the formation of staling compounds in forced aged beer. The formation of 5-hydroxymethylfurfural, trans-2-nonenal and phenylacetaldehyde were decreased by 105, 360 and 27%, respectively, when compared with those in stale beer without chitooligosaccharide addition. The capability of chitooligosaccharides to prevent staling compound formation depended on their molecular size (2 or 3 kDa). The DPPH/hydroxyl radical scavenging activity in fresh beer significantly lower than that in forced aged beer in the presence of chitooligosaccharides. When compared with stale beer without added chitooligosaccharides, the radical scavenging activity could be increased by adding chitooligosaccharides to forced aged beer. CONCLUSIONS: Chitooligosaccharides play an active part in the prevention of beer flavour deterioration by inhibiting the formation of staling compounds and increasing radical scavenging activity.
Assuntos
Antioxidantes/metabolismo , Cerveja/microbiologia , Oligossacarídeos/metabolismo , Quitina/análogos & derivados , Quitina/metabolismo , Quitosana , Aromatizantes/metabolismo , Conservação de AlimentosRESUMO
Biochar can enhance soil fertility to increase agricultural productivity, whereas its improvement in soil microbial activity is still unclear. In this article, the influence of biochar on the cell growth and the potassium-solubilizing activity of Bacillus mucilaginosus AS1153 was examined. The impact on cell growth is related to the biochar-derived feedstocks and the particle size of biochar. Both intrinsic features and inner component fraction can promote the cell growth of B. mucilaginosus AS1153. The potassium-solubilizing activity was increased by 80% when B. mucilaginosus was incubated in conjunction with the biochar derived from corn stover. The survival time of B. mucilaginosus also was prolonged by adsorption in biochar. The experimental results suggested that the biochar containing B. mucilaginosus could be used as a potential biofertilizer to sustain crop production.
Assuntos
Bacillus/metabolismo , Carvão Vegetal , Fertilizantes , Potássio/metabolismo , Adsorção , Bacillus/crescimento & desenvolvimento , Produtos Agrícolas , Tamanho da Partícula , SolubilidadeRESUMO
OBJECTIVES: To study enhanced barley germination by chitooligosaccharide as an elicitor for improving the quality of malt. RESULTS: Barley germination for both radical and leaf sprouts was enhanced when chitooligosaccharide was added to the steeping water in the first steeping cycle. The activities of hydrolases (α-/ß-amylase, proteinase and ß-glucanase) and antioxidases (superoxide dismutase and catalase) in the resultant malt were increased in a dose-dependent manner when chitooligosaccharide was supplemented in the steeping water. Maximal promotion was at 1 mg chitooligosaccharide/l for α-/ß-amylase and proteinase, and at 10 mg/l for ß-glucanase, superoxide dismutase and catalase. Malt quality, including free α-amino nitrogen content, Kolbach index, malt extract content, diastatic power, wort viscosity and the ratio of glucose, maltose and maltotriose, was significantly improved by chitooligosaccharide in seed priming at 1 mg/l. CONCLUSION: Application of chitooligosaccharide in the steeping water promotes barley germination and improves the quality of malt.
Assuntos
Quitina/análogos & derivados , Germinação/efeitos dos fármacos , Hordeum/crescimento & desenvolvimento , Quitina/farmacologia , Quitosana , Qualidade dos Alimentos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Hordeum/enzimologia , Hidrolases/metabolismo , Oligossacarídeos , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Plântula/enzimologiaRESUMO
OBJECTIVES: To identify a biological preservative that can protect beer from microbial contamination, which often results in the production of turbidity and off-flavor. RESULTS: The antimicrobial activity of a chitooligosaccharide against beer-spoilage bacteria and its effect on the fermentation performance of brewer's yeast was studied. Chitooligosaccharide with an average 2 kDa molecular weight was the best at inhibiting all tested beer-spoilage bacteria. The application of chitooligosaccharide in the brewing process did not influence the fermentation of brewer's yeast. The change in beer performance induced by the contamination of Lactobacillus brevis could be effectively controlled by application of chitooligosaccharide in the beer brewing process. CONCLUSION: The experimental data suggested that chitooligosaccharide should be an excellent preservative to inhibit beer-spoilage bacteria in the brewing process and in the end product.
Assuntos
Anti-Infecciosos/farmacologia , Cerveja/microbiologia , Quitina/análogos & derivados , Lactobacillus/efeitos dos fármacos , Quitina/farmacologia , Quitosana , Fermentação , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Oligossacarídeos , Saccharomyces cerevisiae/crescimento & desenvolvimentoRESUMO
Endo-ß-mannanase, catalyzing the random hydrolysis of ß-1,4-mannosidic linkage in the backbone of (hetero) mannan, can increase feed conversion efficiency of animal feed or form functional mannanooligosaccharides. In this study, a gram-positive, straight-rod, facultative anaeorobic bacterium producing endo-ß-mannanase was isolated from soil sample. The isolate only fermented glucose, galactose, sorbose, and raffinose to acid. The test in hydrogen sulfide production was positive. Combining the data acquired from phenotypic analysis and phylogenetic analysis based on 16S rRNA gene sequences, this strain presumably represented a novel species of the genus Bacillus and was designated as LX114. The strain LX114 could break down guar gum molecules, leading to a rapid decrease of the viscosity of guar gum solutions. Endo-ß-mannanase activity was also detected in the culture supernatant. The isolate LX114 would be useful for potential application in degrading plant cell walls for increasing feed conversion efficiency and formation of functional oligosaccharides.
Assuntos
Bacillus , Galactanos , Mananas , Gomas Vegetais , beta-Manosidase/metabolismoRESUMO
CONTEXT: Nanostructured lipid carriers (NLC) are potentially good colloidal drug carriers for gene delivery. They are advised to be the second lifetime of lipid nanocarriers. OBJECTIVE: The aim of this study is to develop novel modified NLC as nanomedicine for delivery of plasmid-containing enhanced green fluorescence protein (pEGFP). This system could target the lung cancer cells through receptor-mediated pathways to increase the nuclear uptake of genetic materials. METHODS: In the present study, pEGFP-loaded NLC (NLC/pEGFP) were prepared. Transferrin (Tf) containing ligands were used for the surface coating of the vectors. In vitro transfection efficiency of the modified vectors was evaluated in human alveolar adenocarcinoma cell line (A549 cells) and in vivo transfection efficiency of the modified vectors was evaluated on mice bearing A549 cells model. RESULTS: Tf-modified NLC/pEGFP (Tf-NLC/pEGFP) has a particle size of 157 nm, and â¼ 82% of gene loading quantity. Tf-NLC/pEGFP displayed remarkably higher transfection efficiency than non-modified NLC/pEGFP both in vitro and in vivo. CONCLUSION: The results demonstrate that the novel NLC gene delivery system offers an effective strategy for lung cancer gene therapy.