Aspergillus Niger ATCC Research Articles

Bacterial Biofilm Removal Using Solid-State-Produced Enzymes

The objective of this study was to evaluate the removal capacity of bacterial film formed by Pseudomonas sp., using commercial enzymes (pectinase, cellulase, and amylase) and the enzymatic extract obtained by solid-state cultivation (SSC) from Aspergillus niger ATCC 9642. The bacterial biofilm removal (Pseudomonas sp.) was evaluated using the commercial enzyme microplate technique and the crude enzyme extract (SSC). The effects of orange peel (9.28–22.72 g), corn steep liquor (0.32–3.68 g), and wheat bran (0–4 g) concentrations were evaluated on pectinase production in solid-state cultivation. The enzyme extract (SSC) satisfactorily removed 77 % of biofilm after 10 min contact, taking into account that there was no enzymatic extract purification treatment. The results indicated a promising and economically viable alternative to enzymatic removal of biofilms in the food industry.

Cytotoxic and antimicrobial effects of biosynthesized ZnO nanoparticles using of Chelidonium majus extract

The basic goal of this study was to synthesize zinc oxide nanoparticles using the Chelidonium majus extract and asses their cytotoxic and antimicrobial properties. The synthesized ZnO NPs were characterized by UV-Vis, Scanning Electron Microscopy (SEM) with EDS profile, Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM). The aforementioned methods confirmed that the size of synthesized ZnO nanoparticles was at the range of 10 nm. The antimicrobial activity of ZnO nanoparticles synthesized using the Ch. majus extract was tested against standard strains of bacteria (Staphylococcus aureus NCTC 4163, Pseudomonas aeruginosa NCTC 6749, Escherichia coli ATCC 25922), yeast (Candida albicans ATCC 10231), filamentous fungi (molds: Aspergillus niger ATCC 16404, dermatophytes: Trichophyton rubrum ATCC 28188), clinical strains of bacteria (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus) and yeast (Candida albicans). The study showed that zinc oxide nanoparticles were excellent antimicrobial agents. What is more, biologically synthesized ZnO nanoparticles demonstrate high efficiency in treatment of human non-small cell lung cancer A549.

β-Asarone Exhibits Antifungal Activity by Inhibiting Ergosterol Biosynthesis in Aspergillus niger ATCC 16888

Fungi play an important role in the degradation of leather goods. Economics often influence the choice of fungicide, thus, search for highly effective and low cost fungicides is immensely important. The authors have screened antifungal activity of ten Indian traditional medicinal plants viz Acalypha fruticosa, Acalypha indica, Aegle marmelos, Adathoda vasika, Calotropis gigantea, Erythrina indica, Morinda citrifolia, Nerium oleander, Pithecellobium dulce, and Acorus calamus based upon their traditional knowledge and usage. Various solvent extracts and essential oils were screened for antifungal activity against Aspergillus niger. The antifungal potency was compared to untreated control and standard antifungal drugs itraconazole and voriconazole. The bioactive principle from highly active fragment was isolated and chemically characterized. The mode of action was determined by a range of studies that include the lesion of plasma membrane, ergosterol content in the plasma membrane, acidification of external medium, and mitochondrial dehydrogenase activity in A. niger ATCC 16888. Among the ten plants studied, A. calamus exhibited greater antifungal potency in comparison to untreated control and standard drugs itraconazole and voriconazole. The minimum inhibitory concentration of both methanolic extract and essential oil of A. calamus against A. niger ATCC 16888 is around 5 µg/ml. The authors identified β-Asarone as the bioactive principle of A. calamus using spectral studies viz ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy and gas chromatography coupled mass spectroscopy. The results indicate that β-Asarone interfere and reduces the ergosterol content in the plasma membrane of A. niger ATCC 16888 thus exert their antifungal activity.

Inulinolytic activity of broths of Aspergillus niger ATCC 204447 cultivated in shake flasks and stirred tank bioreactor.

It is the first detailed study of an inulinolytic fungus Aspergillus niger ATCC 204447 since its discovery, covering submerged cultivations both in shake flasks and a stirred tank bioreactor. Various carbon sources were applied to induce the inulinolytic activity in shake flask cultures. The highest volumetric and specific (per gram of biomass) activities (respectively 0.68 U/mL and 184 U g/X) were observed for the initial inulin and sucrose concentrations equal to 20 g/L. The fungus grew as large (>3 mm) spherical pellets. The influence of inoculum density and application of microparticle-enhanced cultivation (MPEC) were studied in the batch bioreactor cultivations. Inoculum density moderately affected the inulinolytic activities, whose highest values were 0.7 U/mL and 165 U g/X at the lowest studied spore density of 3.33·108 L-1. Dispersed hyphae evolved in the bioreactor made the broth difficult to aerate due to high apparent viscosity (exceeding 200 Pa sn at shear rate about 0.05 s-1) and shear thinned properties (flow behavior index below 0.2). In MPEC (10 μm talc microparticles) the pellets of diameter between 1 and 2 mm were formed, which facilitated the aeration of the broth and increased the specific inulinolytic activity 3.5-fold.

Recovery of Pectinase Obtained by Solid-State Cultivation of Agro-Industrial Residues

Abstract This work aimed to optimize the process parameters for exo-polygalacturonase (exo-PG) recovery and production from Aspergillus niger ATCC 9642. Different types of solvents and extraction solutions (distilled water, NaCl, Tween 80, citrate buffer, and acetate buffer) have been evaluated for enzymes recovery using agitation (12 to 348 rpm), time (4.8 to 55.2 min), temperature (13.2 to 46.8°C), and extraction cycles (10 cycles). Our work's maximum exo-PG activity was 23 U/gwm (68 U/gdm), obtained after 192 h of bioproduction with 9 g orange peel, 4 g corn steep liquor, and 7 g wheat bran concentrations, at 30°C, and 5 × 106 spores/gwm. The maximum recovery was obtained using NaCl (0.1 mol/L) as solvent at a 5:1 (v:w) ratio, 30-55 min, 180 rpm, in one extraction cycle. Optimum pH and temperature for crude enzyme extract were 4.5 and 55°C, respectively.

Synthesis and Bioconversion of Curcumin Analogs

Hydrogdnation of curcumin (1), a chemopreventive agent from Turmeric (Curcuma longa L.) yielded three major compounds: 1,7-bis(4-hydroxy-3- methoxyphenyl)heptane-3,5-dione (2), 5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptan-3-one (3), and 1,7-bis(4-hydroxy-3-methoxyphenyl)heptane- 3,5-diol (4). Incubation of compound (2) with Beauveria bassiana ATCC 7159 afforded the hexahydrocurcumin (3) as the sole metabolite while biotransformation.of curcumin (1) with B. bassiana gave metabolites 2-4 along with the curcumin-4'-0-4"'-O-methyl-β-D-glucopyranoside (5) and octahydrocurcumih-4'-O-4"'-O-methyl--β-D-glucopyranoside (6). The bioconversion of curcumin (1) with Rhizopus oryzae ATCC 11145 yielded analogs 2-4 while no transformation of curcumin (1) was observed with Aspergillus niger ATCC 16888. The preparation, structural elucidation and biological activities of these metabolites are reported herein.

Enhancing fructooligosaccharides production by genetic improvement of the industrial fungus Aspergillus niger ATCC 20611

Aspergillus niger ATCC20611 is one of the most potent filamentous fungi used commercially for production of fructooligosaccharides (FOS), which are prospective components of functional food by stimulating probiotic bacteria in the human gut. However, current strategies for improving FOS yield still rely on production process development. The genetic engineering approach hasn’t been applied in industrial strains to increase FOS production level. Here, an optimized polyethylene glycol (PEG)-mediated protoplast transformation system was established in A. niger ATCC 20611 and used for further strain improvement. The pyrithiamine resistance gene (ptrA) was selected as a dominant marker and protoplasts were prepared with high concentration (up to 108g−1 wet weight mycelium) by using mixed cell wall-lysing enzymes. The transformation frequency with ptrA can reach 30–50 transformants per μg of DNA. In addition, the efficiency of co-transformation with the EGFP reporter gene (egfp) was high (approx. 82%). Furthermore, an activity-improved variant of β-fructofuranosidase, FopA(A178P), was successfully overexpressed in A. niger ATCC 20611 by using the transformation system. The transformant, CM6, exhibited a 58% increase in specific β-fructofuranosidase activity (up to 507U/g), compared to the parental strain (320U/g), and effectively reduced the time needed for completion of FOS synthesis. These results illustrate the feasibility of strain improvement through genetic engineering for further enhancement of FOS production level.

The impact of dust in filter materials of respiratory protective devices on the microorganisms viability

Plant biomass processed in a heat and power plant is a source of airborne dust present in the working environment. The aim of this study was to assess the influence of various levels of organic dust content in the filter material on the viability of microorganisms in model conditions, taking into consideration the workplace environment and the physico-chemical as well as the microbiological characteristics of the dust particles. The possibility of a biofilm developing on the reusable filtering facepiece respirators (FFR) in standard use by heat and power plant workers for respiratory tract protection was also investigated.Standard reusable filtering half masks FFP3R and high-performance melt-blown fabrics were used in the study. The biomass dust characteristics were determined using an elementary analyser and a condensation particle counter with an electrostatic classifier. For quantitative analysis of microbiological pollution we used the plate count method with the microorganisms identified either using the API biochemical tests (for bacteria and yeasts) and the taxonomic key (for moulds). Biofilm development on the filtering half masks was assessed using SEM scanning microscopy. The viability of microorganisms (namely Escherichia coli ATCC 10536, Staphylococcus aureus ATCC 6538, Candida albicans ATCC 10231, Aspergillus niger ATCC 16404; Bacillus subtilis NCAIM 01644) on the filter materials with different dust content was measured using the quantitative method AATCC 100-2004 (2008).In the plant biomass processed at the heat and power plant, a high concentration of bacteria (2.30 × 107 CFU g−1) and a lower concentration of fungi (4.46 × 105 CFU g−1) were detected. It was determined to be a good environment for the growth of microorganisms (the carbon to nitrogen ratio was 48:1). The presence of dust and the development of microbiological biofilms on reusable FFR, which is used by the heat and power plant workers for processing the plant biomass in increased humidity conditions, were also confirmed.It was found that the viability of microorganisms on a filter material depends on the kind of microorganism and the dust content on the material. Model research showed that biomass dust in filter materials stimulates the growth of E. coli. Moreover, dust concentration above 21% inhibited the growth of S. aureus and C. albicans but had no significant influence on the growth of B. subtilis and A. niger.

Substituted Pyrazolo[3,4-B]Pyridin-3-Ones and Pyrazolo[3,4-B]Pyridine-5- Carbaldehyde, New One-Pot Synthesis Strategy Amelioration Using Vinamidinium Salts, Antibacterial and Antifungal Activities Promising Environmental Protection

This review summarizes the current knowledge about the syntheses and biological behavior of some pyrazolo[5,4-b]pyridines. So, an expedient method for the synthesis of 2-phenyl-5-aryl-1,6-dihydropyrazolo[3,4- b]pyridin-3-ones and 2-phenyl-3-oxo-1,6-dihydropyrazolo[3,4-b]pyridine-5-carbaldehyde in a single-step via condensation of vinamidinium salts with 3-amino-1-phenyl-2-pyrazolin-5-one is described according to our recent study with synthesis strategy amelioration. Five derivatives (PYR1-5) were prepared and characterized by spectral data (NMR and MS spectral studies). All the derivatives were studied for their antimicrobial activities. So, we screened for antibacterial effects at 1:2, and 1:4 dilutions by the paper disc diffusion method against respectively Bacteria (Escherichia coli CIP 53126 and Bacillus subtilis CIP 5262) and Fungi (Candida albicans ATCC 10231). Then, we screened for Fungi (Aspergillus niger ATCC 16404) by the dilution method (agar and liquid broth). The agar diffusion method (paper disc and well) and the dilution method (agar and liquid broth) are described.

Facile green one‐pot synthesis of novel thiazolo[3,2‐a]pyrimidine derivatives using Fe3O4@l‐arginine and their biological investigation as potent antimicrobial agents

Thiazolopyrimidine derivatives are well known because of their excellent therapeutic properties. In this investigation, an effective one‐pot three‐component method is described for the synthesis of novel 2‐[(Z)‐1‐(substituted phenyl)methylidine]‐7‐methyl‐3‐oxo‐5‐(substituted phenyl)‐2,3‐dihydro‐5H‐thiazolo[3,2‐a]pyrimidine‐6‐carboxilic acid tert‐butyl ester derivatives by condensation reaction of 3,4‐dihydropyrimidine‐2(1H)‐thiones, various aromatic aldehydes and chloroacetyl chloride under reflux conditions in the presence of Fe3O4@l‐arginine nanoparticles as a magnetically reusable and eco‐friendly catalyst with short reaction times and moderate yields. The chemical structures of all synthesized compounds were determined using infrared, 1H NMR and 13C NMR spectroscopies. In vitro antimicrobial activities of 3,4‐dihydropyrimidine‐2(1H)‐thiones and newly fused thiazolo[3,2‐a]pyrimidine derivatives were examined using the well diffusion method against diverse pathogenic strains, namely Staphylococcus aureus ATCC 6538, S. epidermidis ATCC 12228, Escherichia coli ATCC 8739 and Pseudomonas aeruginosa ATCC 9027 (bacteria), Candida albicans ATCC 10231 (yeast) and Aspergillus niger ATCC 16404 (fungus). The compounds having 2‐hydroxy, 4‐hydroxy, 2‐chloro and 4‐chloro groups attached to the phenyl ring on the pyrimidine and 4‐CH3, 4‐OCH3 and 3‐NO2 groups attached to benzylidine on the thiazolo moiety showed significant antibacterial activity.

β-galactosidase Production by Aspergillus niger ATCC 9142 Using Inexpensive Substrates in Solid-State Fermentation: Optimization by Orthogonal Arrays Design.

Background:Enzymatic hydrolysis of lactose is one of the most important biotechnological processes in the food industry, which is accomplished by enzyme β-galactosidase (β-gal, β-D-galactoside galactohydrolase, EC 3.2.1.23), trivial called lactase. Orthogonal arrays design is an appropriate option for the optimization of biotechnological processes for the production of microbial enzymes.Methods:Design of experimental (DOE) methodology using Taguchi orthogonal array (OA) was employed to screen the most significant levels of parameters, including the solid substrates (wheat straw, rice straw, and peanut pod), the carbon/nitrogen (C/N) ratios, the incubation time, and the inducer. The level of β-gal production was measured by a photometric enzyme activity assay using the artificial substrate ortho-Nitrophenyl-β-D-galactopyranoside.Results:The results showed that C/N ratio (0.2% [w/v], incubation time (144 hour), and solid substrate (wheat straw) were the best conditions determined by the design of experiments using the Taguchi approach.Conclusion:Our finding showed that the use of rice straw and peanut pod, as solid-state substrates, led to 2.041-folds increase in the production of the enzyme, as compared to rice straw. In addition, the presence of an inducer did not have any significant impact on the enzyme production levels.

Synthesis and Biological Activity of Alkyl Pyridinium Aldoxime Based Surfactants

AbstractA series of N-alkyl pyridinium aldoxime surfactants was synthesized by the reaction of pyridinium aldoxime with long chain alkyl halides (decyl, dodecyl, tetradecyl and hexadecyl bromide). The chemical structure of the synthesized compounds was confirmed by elemental analysis and FTIR spectra. Surface tension was measured in aqueous solutions for different concentrations at 25 °C. Various surface properties of the synthesized surfactants were evaluated, particularly the critical micelle concentration (CMC), effectiveness (πCMC), efficiency (PC20) as well as the maximum surface excess (Γmax) and minimum surface area (Amin). Also, the micellization and adsorption at liquid/air interfaces were investigated. The synthesized cationic surfactants were evaluated for their biocidal activity. Good antibacterial and antifungal activities were recorded against Gram-positive bacteria (Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 25922), followed by Gram-negative bacteria (Escherichia coli ATCC 23282, Pseudomonas aeruginosa ATCC 10145), yeast (Candida albicans IMRU 3669) and filamentous fungus (Aspergillus niger ATCC 16404).

In vitro antifungal efficacy of Aspergillus niger ATCC 9642 chitosan-AgNPs composite against post-harvest disease of citrus fruits

Green and blue mold postharvest diseases are the most vital negative components influencing the local market of citrus fruits. Citrus fruits were collected, and fungi were isolated. Among the fungal isolates identified, Penicillium digitatum and Penicillium italicum recorded the highest occurrence of 39.5 and 25.6%, respectively. In this work, we extracted chitosan from Aspergillum niger ATCC 9642. Fourier transform infrared spectroscopy was utilized to confirm the functional groups of the obtained compound, which exhibited the main characteristic bands of O–H stretching at 3302 cm-1, and C–O–C band at 1125 cm-1. A. niger ATCC 9642 chitosan had the degree of deacetylation of 88.5%, a molecular weight of 1.8 × 105 Da, and viscosity of 7.3 centipoises; these values were comparable to those for standard shrimp chitosan. Ultraviolet-visible light spectra revealed the presence of A. niger ATCC 9642 chitosan-AgNPs composite. Using antifungal and spore germination assays, it was found that this composite exhibited effective antifungal action against P. digitatum and P. italicum compared with a chitosan standard. In a comet assay, the percentage of tail DNA was considered as a parameter that indicated DNA damage. The comet parameter increased significantly (P < 0.05) with A. niger ATCC 9642 chitosan–AgNPs composite, and the increase was dose-dependent. The increase in the DNA damage positively correlated with the inhibition performance of the A. niger ATCC 9642 chitosan–AgNPs composite.

Design of an enzyme cocktail consisting of different fungal platforms for efficient hydrolysis of sugarcane bagasse: Optimization and synergism studies.

Lignocellulosic materials represent a very important and promising source of renewable biomass. In order to turn them into fermentable sugars, synergism among the different enzymes that carry out bioconversion of these materials is one of the main factors that should be considered. Experimental mixture design was performed to optimize the proportion of enzymes produced by native strains of Trichoderma harzianum IOC 3844, Penicillium funiculosum ATCC 11797, and Aspergillus niger ATCC 1004, resulting in a proportion of 15, 50, and 35%, respectively. This mixture was able to hydrolyze 25 g/L of pretreated sugarcane bagasse with 91% of yield after 48 h of enzymatic reaction. Synergism along the hydrolysis process, besides the influence of lignin, hemicellulose, and solids loading, were also studied. Response surface methodology (RSM) based on Central Composite Rotatable Design was used to optimize solids and protein loadings to increase glucose release and enzymatic hydrolysis yield. The optimum solid and protein loadings established with RSM were 196 g/L and 24 mg/g cellulose, respectively, and under these conditions (94.1 ± 8) g/L of glucose were obtained, corresponding to a hydrolysis yield of 64%. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1222-1229, 2016.

Ultrasound- and Molecular Sieves-Assisted Synthesis, Molecular Docking and Antifungal Evaluation of 5-(4-(Benzyloxy)-substituted phenyl)-3-((phenylamino)methyl)-1,3,4-oxadiazole-2(3H)-thiones.

A novel series of 5-(4-(benzyloxy)substituted phenyl)-3-((phenyl amino)methyl)-1,3,4-oxadiazole-2(3H)-thione Mannich bases 6a–o were synthesized in good yield from the key compound 5-(4-(benzyloxy)phenyl)-1,3,4-oxadiazole-2(3H)-thione by aminomethylation with paraformaldehyde and substituted amines using molecular sieves and sonication as green chemistry tools. The antifungal activity of the new products was evaluated against seven human pathogenic fungal strains, namely, Candida albicans ATCC 24433, Candida albicans ATCC 10231, Candida glabrata NCYC 388, Cryptococcus neoformans ATCC 34664, Cryptococcus neoformans PRL 518, Aspergillus fumigatus NCIM 902 and Aspergillus niger ATCC 10578. The synthesized compounds 6d, 6f, 6g, 6h and 6j exhibited promising antifungal activity against the tested fungal pathogens. In molecular docking studies, derivatives 6c, 6f and 6i showed good binding at the active site of C. albicans cytochrome P450 enzyme lanosterol 14 α-demethylase. The in vitro antifungal activity results and docking studies indicated that the synthesized compounds have potential antifungal activity and can be further optimized as privileged scaffolds to design and develop potent antifungal drugs.

Solid-state fermentation for the production of biomass valorizing feruloyl esterase

Abstract Aspergillus niger ATCC 13497 has been used to produce feruloyl esterase type A enzyme. The process parameters were optimized to attain a maximum of 11984.1 U/gds of enzyme activity within a period of 72 h using destarched wheat bran as a substrate. The purified enzyme studied in the present work displays a pH optimum of 5, and a temperature optimum of 37 °C. The enzyme has a size of 35 kDa and exhibited moderate thermostability, with 41% of activity retained at 90 °C. Ni +2 and Co +2 ions were found to have stimulatory activity on the enzyme with 66% and 78% increase in activity respectively. Cu+2 inhibited the activity by 88%. Statistical optimization enhanced the enzyme activity by 2.47 fold.

Valorization of Potato Peels Residues on Cellulase Production Using a Mixed Culture of Aspergillus niger ATCC 16404 and Trichoderma reesei DSMZ 970

In this paper, we report on the utilization of potato peel residues (PPR) as a substrate and support for the production of cellulase complexes by mono-and co-culture of Aspergillus niger ATCC 16404 and Trichoderma reesei DSMZ 970 by solid state fermentation. A significant increase in cellulase production, especially CMC-ase, was obtained during co-culture compared to respective monocultures. The effect of PPR pretreatment with acid and alkali on cellulase production was also investigated. Characterization of the pretreated substrate by Fourier transformed infrared spectroscopy and thermogravimetric analysis highlighted a structural alteration of the constitutive components of potato peels residues. These pretreated substrates were tested for their ability to support cellulase production by co-culture of A. niger ATCC 16404 and T. reesei DSMZ 970. Time course measurements of cellulase activity clearly demonstrated that substrate pretreatment had a negative effect on cellulase production. The highest yields of cellulase were obtained using untreated substrate with 80, 199, 48 UI/gds for FP-ase, CMC-ase and β-glucosidase, respectively.

Response surface methodology for optimal immobilization of Aspergillus niger ATCC 1015 lipase by adsorption method

&lt;p&gt;Optimization of Vegetable Sponge (&lt;em&gt;Luffa aegyptiaca&lt;/em&gt;) (VS) - immobilization conditions of &lt;em&gt;Aspergillus niger&lt;/em&gt; ATCC 1015 lipase on Solid State Fermentation (SSF) was carried out using Response Surface Methodology (RSM). Four independent variables (temperature, pH, enzyme loading and enzyme stability) were optimized using Central Composite Design of RSM for lipase production in a solid rice bran-physic nut cake medium. The optimal immobilization conditions obtained were 45 °C, pH 7.0, 2.5% (w/v) enzyme loading and 32.5% (v/v) enzyme stability (using glutaraldehyde as crosslinking agent) resulted into lipase activity of 98.6 Ug&lt;sup&gt;-1&lt;/sup&gt;. The result demonstrates the potential application of vegetable sponge under SSF system in immobilizing lipase, thus contributed to efficiency of the use of this biomatrix as an immobilizing agent. The statistical tools employed predicted the optimal conditions for the production of the immobilized lipase thus revealing the full potential of the support.&lt;/p&gt;

Biomimetic Mineralization of the Alginate/Gelatin/Calcium Oxalate Matrix for Immobilization of Pectinase: Influence of Matrix on the Pectinolytic Activity.

Pectinases catalyze the degradation of pectic substances and are used in several processes, mainly in food and textile industries. In this study, a biomimetic matrix of alginate/gelatin/calcium oxalate (AGOCa) was synthesized for the in situ immobilization via encapsulation of crude pectinase from Aspergillus niger ATCC 9642, obtaining an immobilization efficiency of about 61.7%. To determine the performance of AGOCa matrix, this was compared to control matrices of alginate/calcium oxalate (AOxal) and alginate/water (ACa). By the evaluation of pH and temperature effects on the enzyme activity, it was observed an increase on pectinolytic activity for both three tested matrices with an increase on pH and temperature. The kinetic parameters for pectinase immobilized in the three matrices were determined using citric pectin as substrate. Values of K m of 0.003, 0.0013, and 0.0022gmL(-1) and V max of 3.85, 4.32, and 3.17μmolmin(-1)g(-1) for AGOCa, AOxal, and ACa matrices were obtained, respectively. After 33days of storage, the pectinase immobilized in the three different matrices kept its initial activity, but that immobilized in AGOCa presented high stability to the storage with a relative activity of about 160%. The enzyme immobilized in AGOCa, AOxal, and ACa could be used in 10, 8, and 7cycles, respectively, keeping 40% of its initial activity.

La localité d’échantillonnage influence-t-elle l’activité antifongique des flavonoïdes de Marrubium vulgare vis-à-vis de Aspergillus niger et Candida albicans ?

The study was undertaken to determine the effect of the sampling locality on the antifungal activity of the flavonoids extracted from the leaves of Marrubium vulgare L. against two fungal strains; Aspergillus niger ATCC 16404 and Candida albicans ATCC 10231. The leaves were collected from three different sampling localities belonging northwest Algeria: Tessala mount, M'sila forest and Ain Skhouna. The flavonoid extraction was carried out by using organic solvents with increasing polarity. A phytochemical screening was performed by staining test tubes. The inhibition diameters were measured by solid medium diffusion method. The minimum inhibitory concentrations were determined by dilution method on solid medium. The antifungal activity varied significantly (P<0.001) according to the sampling locality of the leaves, the flavonoid extract and its concentration, and the strain fungal type. The inhibition diameters varied between 8.16 and recorded 37.5mm even recording a total inhibition of fungal growth and often exceed those induced marketed antifungals (Amphotericin, Fluconazole, Terbinafine and econazole nitrate). The minimum inhibitory concentrations (MICs) obtained range between 6.25 and 100μg/mL; experiencing strong antifungal inhibition. The phytochemical screening revealed the existence of certain flavonoids classes such as flavans and flavanols which may be responsible of this remarkable antifungal power. The sampling locality of Marrubium vulgare leaves influenced on the antifungal activity of flavonoids. These have proven very good fungistatic and worth valuing in pharmacology.