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1.
J Microbiol ; 58(2): 163-172, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31993989

RESUMO

α-Glucosidase is a crucial enzyme for the production of isomaltooligosaccharide. In this study, a novel method comprising eosin Y (EY) and α-D-methylglucoside (AMG) in glass plates was tested for the primary screening of α-glucosidaseproducing strains. First, α-glucosidase-producing Aspergillus niger strains were selected on plates containing EY and AMG based on transparent zone formation resulting from the solubilization of EY by the hydrolyzed product. Conventional methods that use trypan blue (TB) and p-nitrophenyl-α-D-glucopyranoside (pPNP) as indicators were then compared with the new strategy. The results showed that EY-containing plates provide the advantages of low price and higher specificity for the screening of α-glucosidase-producing strains. We then evaluated the correlation between the hydrolytic activity of α-glucosidase and diffusion distance, and found that good linearity could be established within a 6-75 U/ml enzyme concentration range. Finally, the hydrolytic and transglycosylation activities of α-glucosidase obtained from the target isolates were determined by EY plate assay and 3,5-dinitrosalicylic acid-Saccharomyces cerevisiae assay, respectively. The results showed that the diameter of the transparent zone varied among isolates was positively correlated with α-glucosidase hydrolytic activity, while good linearity could also be established between α-glucosidase transglycosylation activity and non-fermentable reducing sugars content. With this strategy, 7 Aspergillus niger mutants with high yield of α-glucosidase from 200 obvious single colonies on the primary screen plate were obtained.


Assuntos
Aspergillus niger/metabolismo , alfa-Glucosidases/biossíntese , Amarelo de Eosina-(YS)/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Hidrólise , Metilglucosídeos/metabolismo , Saccharomyces cerevisiae/metabolismo
2.
J Food Sci ; 85(2): 340-348, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31957898

RESUMO

Rapeseed meal (RSM) is an important source of protein, but its value is limited due to the poor digestibility and the presence of many antinutritional factors. In this study, a two-step biological method was developed for detoxifying RSM and increasing its protein value. In the first stage, various detoxifying enzymes and proteases were produced by Aspergillus niger during solid-state fermentation (SSF). In the second stage, coordinated enzymatic hydrolysis was employed to further degrade the antinutritional factors and macromolecular proteins in the fermented RSM. Following fermentation at 30 °C for 48 hr and enzymatic hydrolysis at 45 °C for 24 hr, the content of trichloroacetic acid soluble protein (TCA-SP) and glucosinolates (GLS) in RSM was increased by 81.70% and reduced by 30.06%, respectively, compared with that obtained using the SSF process alone. Moreover, to improve the efficiency of enzymatic hydrolysis, the yield of acid protease was increased by optimizing the composition of the medium so that the TCA-SP content was increased to 208.39 mg/g and accounted for 51.62% of the total RSM protein, which was 99.36% and 629.66% higher than that in the fermented RSM and control, respectively. Overall, these results demonstrate that the two-step process could be more effective for the degradation of the antinutritional factors and improvement of the protein quality of RSM compared to use of the SSF method alone, which may improve the utilization of RSM in food and animal feed. PRACTICAL APPLICATION: Rapeseed meal (RSM) is a protein source that provides high-quality nutrition and can be applied to the development of value-added products for humans and animal feed. To improve the utilization of RSM, a combined method of solid-state fermentation and enzymatic digestion was developed. Compared with the traditional solid-state fermentation method, the present method further improves the quality of RSM and demonstrates improved efficacy in increasing the small peptide content while reducing the levels of antinutritional factors.


Assuntos
Brassica napus/química , Manipulação de Alimentos/métodos , Proteínas de Plantas/química , Ração Animal/análise , Animais , Aspergillus niger/metabolismo , Brassica napus/microbiologia , Digestão , Fermentação , Valor Nutritivo
3.
Environ Sci Pollut Res Int ; 27(7): 7647-7656, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31889269

RESUMO

This study investigated the application of fungus Aspergillus niger and geological fluorapatite (FAp) to cadmium (Cd) immobilization in aqueous solution. The initial Cd concentrations were set at 100, 50, 25, and 10 mg L-1. The mineralogy of the products was investigated by using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and attenuated total reflection-infrared spectroscopy (ATR-IR). In both A. niger + FAp + Cd and A. niger + Cd treatments, A. niger secreted abundant oxalic acid, then dissolved the FAp, and reacted with Cd2+ cations to produce relatively insoluble Cd oxalate. Meanwhile, FAp can provide P source to improve microbial growth. The fungal tolerance to Cd2+ was identified at around 100 mg L-1. The final Cd concentrations of 13.7, 3.2, and 0.2 mg L-1 were recorded for A. niger + FAp + Cd treatments with initial Cd concentrations of 50, 25, and 10 mg L-1 respectively. Meanwhile, it was observed that the Cd concentration at 25 mg L-1 stimulated higher bioactivities of A. niger, which further enhanced Cd bioremediation. The immobilization efficiency (%) of the treatments at low to medium Cd concentrations was in the order: Asp + FAp > Asp > FAp, while FAp alone was most efficient at the high Cd concentration of 100 mg L-1. This research provides insights into the mechanisms of combining fungus and FAp as a composite to Cd contamination at various Cd levels.


Assuntos
Apatitas/química , Aspergillus niger/metabolismo , Biodegradação Ambiental , Cádmio/química , Concentração de Íons de Hidrogênio
4.
Prep Biochem Biotechnol ; 50(1): 1-9, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31441715

RESUMO

Isoquercitrin is a flavonoid with important applications in the pharmaceutical and nutraceutical industries. However, a low yield and high production cost hinders the industrial preparation of isoquercitrin. In the present study, isoquercitrin was prepared by biotransformation of rutin using α-L-rhamnosidase from Aspergillus niger JMU-TS528 combined with high-speed countercurrent chromatography (HSCCC) purification. As a result, the optimum transformation pH, temperature, and time were pH 4.0, 60 °C, and 60 min, respectively. The Km and Vmax were 0.36 mM and 0.460 mmol/min, respectively. For isoquercitrin production, the optimal rutin concentration and transformation time were approximately 1000 mg/L and 60 min. The rutin transformation rate reached 96.44%. The isoquercitrin was purified to a purity of 97.83% using one-step purification with HSCCC. The isoquercitrin was identified using UPLC-Q-TOF-MS. The comprehensive results indicated that the biotransformation procedure using the α-L-rhamnosidase from A. niger JMU-TS528 combined with HSCCC was a simple and effective process to prepare isoquercitrin, which might facilitate the production of isoquercitrin for industrial use.


Assuntos
Aspergillus niger/metabolismo , Glicosídeo Hidrolases/metabolismo , Quercetina/análogos & derivados , Rutina/metabolismo , Biotransformação , Distribuição Contracorrente , Microbiologia Industrial , Quercetina/isolamento & purificação , Quercetina/metabolismo
5.
Bioelectrochemistry ; 131: 107394, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31710892

RESUMO

Mold has a strong impact on the corrosion behavior of metals, especially under environmental conditions conducive to mold growth. However, the magnetic fields generated by electronic devices have effects on the metal corrosion and mold growth. In this study, a 10 mT static magnetic field (SMF) perpendicular to the surface of samples was applied to study the corrosion of a copper-clad printed circuit board (PCB-Cu) by mold under the SMF. Based on the analysis of the corrosion morphology of the PCB-Cu after a test in the atmosphere and the composition of the corrosion products, the corrosion behavior of mold on the PCB-Cu in the presence or absence of the SMF was revealed. In the absence of a magnetic field, mold formed a spore-centered corrosion pit group on the surface of the PCB-Cu, which was macroscopically characterized by regional uniform corrosion. When a 10 mT SMF was applied, the magnetic field exhibited an inhibitory effect on the growth of mold, which was hindered, and the corrosion of the PCB-Cu surface slowed down.


Assuntos
Aspergillus niger/metabolismo , Eletrônica , Fungos , Magnetismo , Corrosão
6.
Molecules ; 24(20)2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31614997

RESUMO

Fermentation in solid state culture (SSC) has been the focus of increasing interest because of its potential for industrial applications. In previous studies SSC of pomegranate wastes by Aspergillus niger has been extensively developed and optimized for the recovery of ellagic acid (EA), a high value bioactive. In this study we comparatively investigated the SSC of powdered pomegranate husks by A. niger and Saccharomyces cerevisiae and evaluated the recovery yields of EA by an ultrasound and microwave-assisted 7:3 water/ethanol extraction. Surprisingly enough, the yields obtained by S. cerevisiae fermentation (4% w/w) were found 5-fold higher than those of the A. niger fermented material, with a 10-fold increase with respect to the unfermented material. The EA origin was traced by HPLC analysis that showed a significant decrease in the levels of punicalagin isomers and granatin B and formation of punicalin following fermentation. Other extraction conditions that could warrant a complete solubilization of EA were evaluated. Using a 1:100 solid to solvent ratio and DMSO as the solvent, EA was obtained in 4% yields from S. cerevisiae fermented husks at a high purity degree. Hydrolytic treatment of S. cerevisiae fermented pomegranate husks afforded a material freed of the polysaccharides components that gave recovery yields of EA up to 12% w/w.


Assuntos
Ácido Elágico/química , Frutas/química , Resíduos Sólidos , Aspergillus niger/química , Aspergillus niger/metabolismo , Ácido Elágico/isolamento & purificação , Etanol/química , Fermentação , Hidrólise , Taninos Hidrolisáveis/química , Taninos Hidrolisáveis/isolamento & purificação , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo
7.
Braz J Microbiol ; 50(4): 1091-1098, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31515726

RESUMO

Ochratoxin A (OTA) is a mycotoxin found in several agricultural commodities. Produced by Aspergillus spp., it is nephrotoxic and hepatotoxic and can be carcinogenic. Preventive measures are preventing fungal growth and OTA production. In this study, fungal strains (Rhizopus oryzae, Lichtheimia ramosa, Aspergillus westerdijkiae, Aspergillus niger, Aspergillus tamarii, Aspergillus sp., and Aspergillus fumigatus) isolated from coffee beans were identified for their abilities to inhibit the growth of Aspergillus ochraceus, Aspergillus westerdijkiae, Aspergillus carbonarius, and Aspergillus niger, and OTA production. All fungi strains tested were able to inhibit growth of the four Aspergillus species and OTA production, where A. niger showed the best results in both tests. L. ramosa showed the lowest growth-reducing potential, while the other fungal strains had a growth-reducing potential higher than 70% against all Aspergillus species tested. Regarding OTA production, L. ramosa and Aspergillus sp. completely inhibited the mycotoxin production by A. ochraceus and non-toxigenic strain A. niger completely inhibited OTA production by A. niger. Our findings indicate that the strains tested can be used as an alternative means to control growth of OTA-producing fungi and production of the mycotoxin in coffee beans.


Assuntos
Antibiose , Aspergillus niger/crescimento & desenvolvimento , Aspergillus niger/metabolismo , Coffea/microbiologia , Fungos/fisiologia , Ocratoxinas/biossíntese , Sementes/microbiologia , Aspergillus niger/fisiologia , Contaminação de Alimentos/prevenção & controle , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Filogenia
8.
Appl Microbiol Biotechnol ; 103(19): 8105-8114, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31392377

RESUMO

The filamentous fungus Aspergillus niger is widely used in the biotechnology industry for the production of chemicals and enzymes. Engineering of this valuable organism to improve its productivity is currently hampered by the lack of efficient genetic tools. Here, a Cre-loxP-based system for gene editing in A. niger was developed and its application in construction of A. niger cell factories to produce various organic acids was explored. Two established inducible systems, the xylanase A gene promoter Pxln and Tet-on system, were examined for driving cre expression and thus selection marker hyh deletion. Under inducing conditions, the efficiency of loxP site-specific recombination in the strain with cre driven by Pxln is about 2%, while cre driven by Tet-on system is about 34% which was used as the platform strain for further genetic engineering. As a proof of application of this system, strains containing different copies of oxaloacetate acetylhydrolase-encoding gene (oahA) were constructed, and the resultant strain S428 showed as high as 3.1-fold increase in oxalic acid production. Furthermore, an efficient malate-producing strain was generated through four-step genetic manipulation (oahA deletion, pyc, mdh3 and C4-dicarboxylate transporter gene c4t318 insertion). The resultant strain S575 achieved a titer 120.38 g/L malic acid with the flask culture, and a titer 201.24 g/L malic acid in fed-batch fermentation. These results demonstrated that this modified Cre-loxP system is a powerful tool for genetic engineering in A. niger, which has the potential to be genetically modified as a viable aciduric platform strain to produce high levels of various organic acids.


Assuntos
Aspergillus niger/genética , Aspergillus niger/metabolismo , Ácidos Carboxílicos/metabolismo , Edição de Genes/métodos , Engenharia Metabólica/métodos , Redes e Vias Metabólicas/genética , Recombinação Genética
9.
Drug Dev Ind Pharm ; 45(11): 1770-1776, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31418595

RESUMO

Halogenated boroxine dipotassium trioxohydroxytetrafluorotriborate, K2[B3O3F4OH] (boroxine) was previously shown to be very effective in inhibition of several carcinoma cell lines, including the skin cancer. Here, we investigated its antimicrobial potential by targeting the multidrug-resistant opportunistic pathogens associated with skin and wound infections. The antimicrobial testing against eleven bacterial and four fungal species revealed good activity of boroxine against pathogenic filamentous fungi Penicillium funiculosum and Aspergillus niger (MIC50 64 and 128 µg/ml), and a moderate bioactivity against the yeast Candida albicans (MIC50 512 µg/ml). Among the tested multidrug-resistant bacteria, the best antibacterial effect, stable over a 24-h period, was observed against the methicillin-resistant Staphylococcus aureus strain (MRSA) at MIC of 1024 µg/ml. The atomic force microscopy (AFM) used to investigate the morphology of S. aureus cells revealed indentations on its cell envelope after the boroxine exposure. These results show that in addition to the antitumor effect, boroxine exerts wide spectrum antimicrobial activity, thus may help preventing the development of skin and wound-related opportunistic infections.


Assuntos
Compostos de Boro/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Infecções Oportunistas/prevenção & controle , Resistência beta-Lactâmica/efeitos dos fármacos , Inibidores de beta-Lactamases/farmacologia , Aspergillus niger/efeitos dos fármacos , Aspergillus niger/metabolismo , Compostos de Boro/química , Compostos de Boro/uso terapêutico , Candida albicans/efeitos dos fármacos , Candida albicans/metabolismo , Halogenação , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/metabolismo , Testes de Sensibilidade Microbiana , Estrutura Molecular , Infecções Oportunistas/microbiologia , Penicillium/efeitos dos fármacos , Penicillium/metabolismo , Dermatopatias Infecciosas/microbiologia , Dermatopatias Infecciosas/prevenção & controle , Infecção dos Ferimentos/microbiologia , Infecção dos Ferimentos/prevenção & controle , Inibidores de beta-Lactamases/química , Inibidores de beta-Lactamases/uso terapêutico , beta-Lactamases/metabolismo
10.
Appl Microbiol Biotechnol ; 103(19): 7883-7889, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31440792

RESUMO

Glucosamine (GlcN) is an amine sugar, in which a hydroxyl group of glucose is replaced with an amino group. It is an important part of the polysaccharides chitin and chitosan and is highly hydrophilic. It is also an important compound required for the formation of cartilage cells and represents one of the elementary units of the cartilage matrix and joint fluid. GlcN has been widely used in food, cosmetics, health care, and pharmaceutical industries. This paper fully addresses the categories and biomanufacturing methods of GlcN, including its production by fermentation with wild-type as well as engineered microorganisms and enzymatic catalysis with a series of chitinolytic enzymes. However, GlcN is usually produced from glucose by fermentation in a coupled manner with N-acetylglucosamine (GlcNAc). Enzymatic catalysis is thus a specific pathway for production of GlcN where chitin can be directly hydrolyzed to GlcN. In industry, GlcN produced with fungal mycelium as raw materials (plant GlcN) is thought as a high-end product because of vegetarian and non-transgenosis. In our opinion, more studies should be performed in order to develop a competitive enzymatic pathway using Aspergillus niger mycelium for the preparation of high-end GlcN.


Assuntos
Aspergillus niger/metabolismo , Biocatálise , Glucosamina/metabolismo , Redes e Vias Metabólicas , Fermentação , Glucosamina/isolamento & purificação , Microbiologia Industrial/métodos , Micélio/metabolismo
11.
Biomed Res Int ; 2019: 9020178, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31275990

RESUMO

The ability of Aspergillus niger strain to reduce organic and mineral pollution as well as the toxicity of two tannery wastewaters, the unhairing effluent (UE) and the final effluent (FE), taken from a local Tunisian tannery and under nonsterile conditions, was studied. Raw effluents show alkaline pH ≥11; thus experiments were carried out at initial pH values and at pH adjusted to 6. Characterization of effluents also revealed high salt levels (EC > 17 mS/cm) and high organic matter content (25 g/L for the UE and 7.2 g/L for the FE) but a low biodegradability since BOD5 did not exceed 2.5 and 1.25 g/L for the UE and the FE, respectively. The results of the biological treatment showed that A. niger was able not only to grow at high pH and salinity values, but also to reduce organic and mineral pollutant load. After treatment, the COD reduction for the UE reached 90% and 70% at pH=6 and at initial pH (12.13), respectively. For the FE, the decrease of COD values reached 75% at pH=6 and 64% at initial pH (11.64). Monitoring of mineral pollution levels showed a reduction in chromium (Cr) concentrations reaching 70% for the FE. This was reflected by an increase of the biomass of A. niger from 9.25 g/L (control) to 9.84 g/L for the FE. To confirm the efficiency of the biological treatment using A. niger, phytotoxicity (tomato seeds) and microtoxicity (Escherichia coli and Bacillus subtilis) tests were carried out. Results of this monitoring showed an important decrease in the toxicity levels for both effluents.


Assuntos
Aspergillus niger/metabolismo , Bioensaio/métodos , Curtume , Águas Residuárias/microbiologia , Purificação da Água/métodos , Bacillus subtilis/crescimento & desenvolvimento , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Escherichia coli/crescimento & desenvolvimento , Inativação Metabólica , Testes de Toxicidade , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/isolamento & purificação
12.
Sci Total Environ ; 689: 875-882, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31280169

RESUMO

The microorganism Arthrobacter. ZXY-2 exhibits excellent degradation efficiency for atrazine in free cells. However, its poor fixability makes it hard to be kept and recycled in water. To conquer the problem, this work employed mycelial pellets of Aspergillus niger Y3 to immobilize ZXY-2, which formed a self-immobilized biomixture (SIB) to remove atrazine. SIB could completely degrade 57.3 mg/L atrazine within 10 h. The SIB exhibited the highest degradation efficiency at pH = 7 and 40 °C. Degradation of atrazine with initial concentrations of 57.3 mg/L and 17.5 mg/L was described well by zero and first-order reaction kinetics, respectively. The recycling experiments demonstrated that SIB could be recycled for 5 batches. The results of SEM, FT-IR, and zeta potential analysis showed that porous structure, functional groups, and electronegativity of SIB all contributed to its stable formation. Therefore, this study demonstrates that SIB could be formed stably and could remove atrazine efficiently.


Assuntos
Arthrobacter/metabolismo , Aspergillus niger/metabolismo , Atrazina/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Biodegradação Ambiental , Recuperação e Remediação Ambiental/métodos , Herbicidas/análise , Poluição Química da Água/análise
13.
Pak J Pharm Sci ; 32(3 (Supplementary)): 1163-1166, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31303585

RESUMO

In recent years, silver nanoparticles have gained attention because of their high surface area to volume ratio that makes them more advantageous than their bulky counterparts. Apart of chemical and physical methods of silver nanoparticles (AgNPs) production, green synthesis is being exploited by the researchers. Aspergillus niger are among some fungi being used in fabrication of silver nanoparticles and their antifungal activities are being studied. We have experimented using A. niger Gin for extracellular silver nanoparticle synthesis. Characterization of AgNPs was done by UV-Visible spectroscopy and SEM-EDS.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Aspergillus niger/metabolismo , Nanopartículas Metálicas/química , Prata/química , Química Verde , Microscopia Eletrônica de Varredura , Prata/farmacologia , Espectrometria por Raios X , Espectrofotometria Ultravioleta
14.
World J Microbiol Biotechnol ; 35(6): 93, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31187335

RESUMO

Siderophores are extra-cellular inducible compounds produced by aerobic microorganisms and plants to overcome iron insolubility via its chelation and then uptake inside the cell. This work aims to study the characteristics of siderophore that is produced by a rhizosphere-inhabiting fungus. This fungus has been morphologically and molecularly identified as Aspergillus niger with the ability to produce 87% siderophore units. The obtained siderophore in PDB medium gave a positive result with tetrazolium test and a characteristic spectrum with a maximum absorbance at 450 nm in FeCl3 test that did not shift in response to different pH degrees (5-9). This indicates that the obtained siderophore is a trihydroxymate in nature. After purification, the FTIR and NMR analyses showed that the obtained siderophore is considered to be ferrichrome. The purified siderophore has been further evaluated as a tool to extract uranium, thorium and rare earth elements (REEs) from Egyptian phosphorites obtained from Abu Tartur Mine area. The inductively coupled plasma atomic emission spectroscopy analysis showed that the highest removal efficiency percentage was for uranium (69.5%), followed by samarium (66.7%), thorium (55%), lanthanum (51%), and cerium (50.1%). This result confirmed the ability of hydroxymate siderophores to chelate the aforementioned precious elements, a result that paves the way for bioleaching to replace abiotic techniques in order to save the cost of such elements in an environmentally friendly way.


Assuntos
Aspergillus niger/isolamento & purificação , Aspergillus niger/metabolismo , Sideróforos/isolamento & purificação , Sideróforos/metabolismo , Microbiologia do Solo , Aspergillus niger/classificação , Aspergillus niger/genética , Egito , Ácidos Graxos/análise , Ferricromo , Concentração de Íons de Hidrogênio , Ferro , Minerais , Fosfatos , Rizosfera
15.
Biotechnol Appl Biochem ; 66(5): 833-841, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31222824

RESUMO

This study is focused on employing a potential process technology for enhancing hemoglobin peptides production from chicken blood. Effects of surfactants on chicken blood biodegradation and hemoglobin polypeptide accumulation were evaluated and the bioconversion conditions were optimized. Results suggested that surfactants exhibited the positive effect on hemoglobin peptides production during chicken blood bioconversion by Aspergillus niger. Dodecyl glucopyranoside was selected as the optimal surfactant and added at the 48th hour of the fermentation process (64 H) at the concentration of 6.0 g/L. Under the optimized conditions, 104.5 mg·N/mL amino nitrogen, 638.3 mg·N/mL nonprotein nitrogen, and 766.3 mg·N/mL soluble nitrogen were detected, which increased by approximately 0.7-, 3.7-, and 3.8-fold, respectively, compared with the control. Furthermore, the acid protease stability was remarkably intensified and the accumulated peptides were mainly distributed at 500-2,000 Da. Results from this work corroborate the potential of applying dodecyl glucopyranoside in hemoglobin polypeptide production from chicken blood.


Assuntos
Aspergillus niger/metabolismo , Fermentação , Glucosídeos/metabolismo , Hemoglobinas/biossíntese , Peptídeos/metabolismo , Tensoativos/metabolismo , Animais , Galinhas , Glucosídeos/química , Hemoglobinas/química , Peptídeos/química , Tensoativos/química , Fatores de Tempo
16.
Mol Biotechnol ; 61(9): 663-673, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31228008

RESUMO

The prevalence of insect resistance against Bt toxins has led to the idea of enhancing demethylation from cell wall pectin by pectin methylesterase enzyme for overproduction of methanol which is toxic to insects pests. The AtPME and AnPME fragments ligated into pCAMBIA1301 vector were confirmed through restriction digestion with EcoR1 and BamH1. Excision of 3363 bp fragment from 11,850 bp vector confirmed the ligation of both fragments into pCAMBIA1301 vector. Transformation of pectin methylesterase-producing genes, i.e., AtPME and AnPME from Arabidopsis thaliana and Aspergillus niger cloned in plant expression vector pCAMBIA1301 under 35S promoter into cotton variety CEMB-33 harboring two Bt genes Cry1Ac and Cry2A, respectively, was done by using shoot apex-cut Agrobacterium-mediated transformation method. The plantlets were screened on MS medium supplemented with hygromycin on initial basis. Amplification of 412 and 543 bp, respectively, through gene-specific primer has been obtained which confirmed the successful introduction of pCAMBIA AtPME and AnPME genes into cotton variety CEMB 33. Relative expression of AtPME and AnPME genes through real-time PCR determined the expression level of both gene ranges between 3- and 3.5-fold in different transgenic cotton lines along with quantity of methanol ranging from 0.8 to 0.9% of maximum while 0.5% to 0.6% of minimum but no expression was obtained in negative non-transgenic control cotton plant with least quantity of methanol, i.e., 0.1%. Almost 100% mortality was observed in insect bioassay for Helicoverpa armigera on detached leaves bioassay and 63% for Pink Bollworm (Pectinophora gossypiella) on growing transgenic cotton bolls as compared to positive control transgenic cotton with double Bt genes where mortality was found to be 82% for H. armigera and 50% for P. gossypiella while 0% in negative control non-transgenic plants.


Assuntos
Hidrolases de Éster Carboxílico/genética , Proteínas Fúngicas/genética , Gossypium/genética , Larva/efeitos dos fármacos , Metanol/toxicidade , Mariposas/efeitos dos fármacos , Proteínas de Plantas/genética , Agrobacterium/genética , Agrobacterium/metabolismo , Animais , Arabidopsis/genética , Arabidopsis/metabolismo , Aspergillus niger/genética , Aspergillus niger/metabolismo , Hidrolases de Éster Carboxílico/metabolismo , Parede Celular/química , Parede Celular/metabolismo , Parede Celular/parasitologia , Clonagem Molecular , Proteínas Fúngicas/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Gossypium/parasitologia , Herbivoria/efeitos dos fármacos , Herbivoria/fisiologia , Inseticidas/química , Inseticidas/toxicidade , Larva/patogenicidade , Metanol/metabolismo , Mariposas/patogenicidade , Células Vegetais/metabolismo , Células Vegetais/parasitologia , Folhas de Planta/genética , Folhas de Planta/parasitologia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transgenes
17.
Int J Mol Sci ; 20(12)2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31234450

RESUMO

 Mono-saturated polyprenols (dolichols) have been found in almost all Eukaryotic cells, however, dolichols containing additional saturated bonds at the ω-end, have been identified in A. fumigatus and A. niger. Here we confirm using an LC-ESI-QTOF-MS analysis, that poly-saturated dolichols are abundant in other filamentous fungi, Trichoderma reesei, A. nidulans and Neurospora crassa, while the yeast Saccharomyces cerevisiae only contains the typical mono-saturated dolichols. We also show, using differential scanning calorimetry (DSC) and fluorescence anisotropy of 1,6-diphenyl-l,3,5-hexatriene (DPH) that the structure of dolichols modulates the properties of membranes and affects the functioning of dolichyl diphosphate mannose synthase (DPMS). The activity of this enzyme from T. reesei and S. cerevisiae was strongly affected by the structure of dolichols. Additionally, the structure of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) model membranes was more strongly disturbed by the poly-saturated dolichols from Trichoderma than by the mono-saturated dolichols from yeast. By comparing the lipidome of filamentous fungi with that from S. cerevisiae, we revealed significant differences in the PC/PE ratio and fatty acids composition. Filamentous fungi differ from S. cerevisiae in the lipid composition of their membranes and the structure of dolichols. The structure of dolichols profoundly affects the functioning of dolichol-dependent enzyme, DPMS.


Assuntos
/metabolismo , Proteínas Fúngicas/metabolismo , Fungos/metabolismo , Glicosiltransferases/metabolismo , Aspergillus niger/química , Aspergillus niger/metabolismo , Membrana Celular/química , Membrana Celular/metabolismo , Fungos/química , Lipídeos de Membrana/química , Lipídeos de Membrana/metabolismo , Modelos Moleculares , Neurospora crassa/química , Neurospora crassa/metabolismo , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Trichoderma/química , Trichoderma/metabolismo
18.
Poult Sci ; 98(11): 5636-5647, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31237336

RESUMO

Flaxseed cake (FSC) is a potential alternative feed source in poultry. However, cyanogenetic glycosides limit its widespread use in feed. In this study, we optimized the parameters of fermentation by Aspergillus niger and Candida utilis and compared the growth performance, serum lipid parameters, and organ indexes of Cherry Valley duckling feed with unfermented FSC (UFSC) or fermented FSC (FFSC). A total of 420 one-day-old male Cherry Valley ducklings were randomly assigned into a 1 plus 2 × 3 factorial design including 2 different FSC resources (UFSC and FFSC) at 3 levels (50, 100, or 150 g/kg) for 3 wk. Each treatment group included 6 pens with 10 ducklings per pen. The hydrocyanic acid (HCN) level was reduced under the following conditions: 1:0.8 FSC:water (w:v), inoculum ratio of 1 mL:1 mL, 30°C, and 60 h. FFSC had higher crude protein (CP) and calcium (Ca) levels and lower HCN levels compared with UFSC (P < 0.05). There was no interactive effect between FSC sources and levels on growth performance. Final body weight (FBW), average daily feed intake (ADFI), and average daily gain (ADG) in UFSC groups and ADFI in FFSC groups decreased linearly with increasing FSC levels (P < 0.01). There were no differences in FBW, ADG, or feed:gain ratio (F/G) among FFSC groups, and all 7 FSC groups had no differences in the F/G ratio (P > 0.05). Dietary FSC supplementation decreased triglyceride (TG) (P < 0.01), total cholesterol (TC) (P < 0.01), high-density lipoprotein (HDL) (P = 0.01), and low-density lipoprotein (LDL) (P < 0.01). No interactive effect between FSC levels and sources was observed for serum TG, TC, HDL, or LDL. Ducklings fed FFSC had lower TG (P < 0.01), TC (P = 0.05), and LDL (P < 0.01) levels compared with ducklings fed UFSC. The 150 g/kg FFSC group had the lowest TG, TC, HDL, and LDL levels among all 7 groups. Flaxseed cake supplementation decreased the relative weight of the left breast, but FFSC increased the relative weight of the gizzard compared with UFSC. In conclusion, fermentation could increase the nutritional value and usage of FSC in ducklings.


Assuntos
Aspergillus niger/metabolismo , Candida/metabolismo , Patos/fisiologia , Fermentação , Linho/química , Valor Nutritivo , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Dieta/veterinária , Suplementos Nutricionais/análise , Patos/sangue , Patos/crescimento & desenvolvimento , Masculino , Tamanho do Órgão/efeitos dos fármacos , Tamanho do Órgão/fisiologia , Distribuição Aleatória
19.
J Biosci Bioeng ; 128(3): 384-390, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31103424

RESUMO

The present work investigates the bioconversion of the olive cake (OC) generated by olive oil industries in Morocco through solid-state fermentation using selected filamentous fungi to increase its nutritional values for subsequent valorization as ruminants feed. The fungi, namely Beauveria bassiana, Fusarium flocciferum, Rhizodiscina cf. lignyota, and Aspergillus niger were cultured on OC for 15 days. Chemical composition as well as enzymes activities were determined. Results showed (i) an increase in protein content of up to 94% for treated OC and (ii) significant (P < 0.05) decreases of phenolic compounds, up to 43%, 70% and 42% for total phenolic content, total flavonoids content, and total condensed tannins, respectively. Moreover, the RP-HPLC analysis of fermented OC confirmed the degradation of individual phenolic compounds by the strains. These findings demonstrate that F. flocciferum and Rhizodiscina cf. lignyota are efficient enzymes producers leading to a nutritive enhancement of this by-product.


Assuntos
Ração Animal , Fermentação , Manipulação de Alimentos/métodos , Valor Nutritivo/fisiologia , Olea/química , Proteínas de Vegetais Comestíveis/análise , Proteínas de Vegetais Comestíveis/metabolismo , Ração Animal/efeitos adversos , Ração Animal/análise , Animais , Aspergillus niger/metabolismo , Reatores Biológicos , Análise de Alimentos , Fungos/metabolismo , Olea/metabolismo , Resíduos Sólidos , Técnicas de Síntese em Fase Sólida
20.
Acta Biochim Biophys Sin (Shanghai) ; 51(6): 638-644, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31081016

RESUMO

The purpose of this study was to obtain an engineered Aspergillus niger strain with high glucoamylase activity by overexpressing the glucoamylase gene glaA and α-amylase gene amyA in A. niger CICC2462. Three recombinant strains containing a single copy of amyA (1A), containing two copies of amyA (2A), and coexpressing amyA and glaA (AG), respectively, were constructed. The transcript levels of amyA in 1A and 2A were increased by 2.95 folds and 3.09 folds, respectively. The levels of amyA and glaA in AG were increased by 1.21 folds and 2.86 folds, but the maximum extracellular glucoamylase activities did not differ significantly. In addition, after 1% casein phosphopeptides (CPPs) was added to the fermentation medium, the maximum extracellular glucoamylase activities for strains 1A, 2A, and AG were 35,200, 37,300, and 40,710 U/ml, respectively, which were significantly higher than that of the parental strain CICC2462 (28,250 U/ml), while CPPs alone had no effect on the parental strain CICC2462. We demonstrate that overexpression of amyA and glaA substantially increases the expression and secretion of glucoamylase in A. niger, and CPPs effectively improves the yield of glucoamylase in recombinant A. niger strains overexpressing amyA and glaA. The newly developed strains and culture methods may have extensive industrial applications.


Assuntos
Aspergillus niger/genética , Proteínas Fúngicas/genética , Glucana 1,4-alfa-Glucosidase/genética , alfa-Amilases/genética , Aspergillus niger/enzimologia , Aspergillus niger/metabolismo , Caseínas/metabolismo , Caseínas/farmacologia , Fermentação/efeitos dos fármacos , Proteínas Fúngicas/metabolismo , Regulação Enzimológica da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Engenharia Genética/métodos , Glucana 1,4-alfa-Glucosidase/metabolismo , Fosfopeptídeos/metabolismo , Fosfopeptídeos/farmacologia , alfa-Amilases/metabolismo
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