Showing papers on "Aspergillus niger published in 2018"
24 May 2018
TL;DR: This review assesses main developments in the field of A. niger biology over the last 100 years and highlights scientific breakthroughs and discoveries which were influential for both basic and applied fungal research in and outside the A.Niger community.
Abstract: In 1917, a food chemist named James Currie made a promising discovery: any strain of the filamentous mould Aspergillus niger would produce high concentrations of citric acid when grown in sugar medium. This tricarboxylic acid, which we now know is an intermediate of the Krebs cycle, had previously been extracted from citrus fruits for applications in food and beverage production. Two years after Currie’s discovery, industrial-level production using A. niger began, the biochemical fermentation industry started to flourish, and industrial biotechnology was born. A century later, citric acid production using this mould is a multi-billion dollar industry, with A. niger additionally producing a diverse range of proteins, enzymes and secondary metabolites. In this review, we assess main developments in the field of A. niger biology over the last 100 years and highlight scientific breakthroughs and discoveries which were influential for both basic and applied fungal research in and outside the A. niger community. We give special focus to two developments of the last decade: systems biology and genome editing. We also summarize the current international A. niger research community, and end by speculating on the future of fundamental research on this fascinating fungus and its exploitation in industrial biotechnology.
161 citations
TL;DR: In this paper, the extracellular synthesis of ZnO NPs using culture filtrates of Aspergillus niger was evaluated using FTIR bands and showed the appearance of carboxylic acid and strong aromatic ring that could be responsible for the synthesis of NPs.
148 citations
Technical University of Denmark1, United States Department of Energy2, Amyris3, Sandia National Laboratories4, Pacific Northwest National Laboratory5, Concordia University6, Aix-Marseille University7, Institut national de la recherche agronomique8, King Abdulaziz University9, Utrecht University10, Lawrence Berkeley National Laboratory11, University of Helsinki12, University of California, Berkeley13
TL;DR: Experimental and computational analyses showed that both secondary metabolism and regulation are key factors that are significant in the delineation of Aspergillus species.
Abstract: Aspergillus section Nigri comprises filamentous fungi relevant to biomedicine, bioenergy, health, and biotechnology. To learn more about what genetically sets these species apart, as well as about potential applications in biotechnology and biomedicine, we sequenced 23 genomes de novo, forming a full genome compendium for the section (26 species), as well as 6 Aspergillus niger isolates. This allowed us to quantify both inter- and intraspecies genomic variation. We further predicted 17,903 carbohydrate-active enzymes and 2,717 secondary metabolite gene clusters, which we condensed into 455 distinct families corresponding to compound classes, 49% of which are only found in single species. We performed metabolomics and genetic engineering to correlate genotypes to phenotypes, as demonstrated for the metabolite aurasperone, and by heterologous transfer of citrate production to Aspergillus nidulans. Experimental and computational analyses showed that both secondary metabolism and regulation are key factors that are significant in the delineation of Aspergillus species.
147 citations
TL;DR: Phytotoxicity and microtoxicity tests confirmed that degradation metabolites were less toxic than original dye.
Abstract: Congo red is one of the best known and used azo dyes which has two azo bonds (-N=N-) chromophore in its molecular structure. Its structural stability makes it highly toxic and resistant to biodegradation. The objective of this study was to assess the congo red biodegradation and detoxification by Aspergillus niger. The effects of pH, initial dye concentration, temperature, and shaking speed on the decolorization rate and enzymes production were studied. The maximum decolorization was correlated with lignin peroxidase and manganese peroxidase production. Above 97% were obtained when 2 g mycelia were incubated at pH 5, in presence of 200 mg/L of dye during 6 days at 28°C and under 120 to 150 rpm shaking speed. The degraded metabolites were characterized by using LC-MS/MS analyses and the biodegradation mechanism was also studied. Congo red bioconversion formed degradation metabolites mainly by peroxidases activities, i.e., the sodium naphthalene sulfonate (m/z = 227) and the cycloheptadienylium (m/z = 91). Phytotoxicity and microtoxicity tests confirmed that degradation metabolites were less toxic than original dye.
132 citations
TL;DR: The synthesis of pure zinc oxide nanoparticles (ZnO NPs) using Scadoxus multiflorus leaf powder aqueous extract as a capping and stabilizing agent demonstrated an irregular spherical shape, and anti-fungal studies were also conducted, which demonstrated a higher inhibition rate for Aspergillus flavus compared to As pergillus niger.
Abstract: Green synthesis of nanoparticles can be an important alternative compared to conventional physio-chemical synthesis We utilized Scadoxus multiflorus leaf powder aqueous extract as a capping and stabilizing agent for the synthesis of pure zinc oxide nanoparticles (ZnO NPs) Further, the synthesized ZnO NPs were subjected to various characterization techniques Transmission electron microscope (TEM) analysis showed an irregular spherical shape, with an average particle size of 31 ± 2 nm Furthermore, the synthesized ZnO NPs were tested against Aedes aegypti larvae and eggs, giving significant LC50 value of 3404 ppm Ovicidal activity resulted in a higher percentage mortality rate of 964 ± 024 at 120 ppm with LC50 value of 3273 ppm Anti-fungal studies were also conducted for ZnO NPs against Aspergillus niger and Aspergillus flavus, which demonstrated a higher inhibition rate for Aspergillus flavus compared to Aspergillus niger
106 citations
TL;DR: A green, efficient, and simple process was developed to recycle and detoxify Li, Mn, Cu, Al, Co, and Ni from spent lithium-ion mobile phone batteries using adapted Aspergillus niger as mentioned in this paper.
101 citations
TL;DR: In this paper, an endophytic fungus, Aspergillus niger CSR3, was isolated from Cannabis sativa and culture filtrate (CF) was initially screened for growth-promoting activities such as the presence of the fungus.
Abstract: In this study, an endophytic fungus, Aspergillus niger CSR3, was isolated from Cannabis sativa. The culture filtrate (CF) was initially screened for growth-promoting activities such as the presence...
73 citations
TL;DR: This study demonstrates how one gold-standard genome can improve functional prediction across closely related species to be able to identify key enzymes, reactions and pathways with the focus on primary carbon metabolism.
55 citations
TL;DR: The objective of this work was to study the resistance and removal capacity of heavy metals by the fungus Aspergillus niger and found that this removal was achieved for zinc, lead, mercury, fluor, cobalt, and copper.
Abstract: The objective of this work was to study the resistance and removal capacity of heavy metals by the fungus Aspergillus niger. We analyzed the resistance to some heavy metals by dry weight and plate: the fungus grew in 2000 ppm of zinc, lead, and mercury, 1200 and 1000 ppm of arsenic (III) and (VI), 800 ppm of fluor and cobalt, and least in cadmium (400 ppm). With respect to their potential of removal of heavy metals, this removal was achieved for zinc (100%), mercury (83.2%), fluor (83%), cobalt (71.4%), fairly silver (48%), and copper (37%). The ideal conditions for the removal of 100 mg/L of the heavy metals were 28°C, pH between 4.0 and 5.5, 100 ppm of heavy metal, and 1 g of fungal biomass.
52 citations
TL;DR: Two types of pathway for itaconic acid biosynthesis as well as recent advances by metabolic engineering strategies and process optimization are reviewed to enhance itaconed acid productivity in native producers and heterologous hosts.
Abstract: Itaconic acid, 2-methylidenebutanedioic acid, is a precursor of polymers, chemicals, and fuels. Many fungi can synthesize itaconic acid; Aspergillus terreus and Ustilago maydis produce up to 85 and 53 g l−1, respectively. Other organisms, including Aspergillus niger and yeasts, have been engineered to produce itaconic acid. However, the titer of itaconic acid is low compared with the analogous major fermentation product, citric acid, for which the yield is > 200 g l−1. Here, we review two types of pathway for itaconic acid biosynthesis as well as recent advances by metabolic engineering strategies and process optimization to enhance itaconic acid productivity in native producers and heterologous hosts. We also propose further improvements to overcome existing problems.
50 citations
TL;DR: The enzyme exhibited noteworthy antiproliferative activity against various cancer cell lines tested and retained activity over a wide range of pH, i.e. pH 4-10.
TL;DR: The mixed culture of the recombinant T. reesei and Aspergillus niger was introduced and it was found to produce the most robust cellulase, which had the highest enzymatic hydrolysis yield and the lowest cellulase input.
Abstract: It is well known that Trichoderma reesei's cellulase is deficient in β-glucosidase and cellobiohydrolase II, hampering the synergism of cellulase components and attenuating the cellulose-degrading capability. T. reesei was engineered to enhance its cellobiohydrolase II and cellulase production. However, it was still deficient in β-glucosidase. Therefore, the mixed culture of the recombinant T. reesei and Aspergillus niger was introduced to further improve cellulase production and the performance in enzymatic hydrolysis. It was found to produce the most robust cellulase, whose filter paper activity was 12.17 ± 1.18 FPIU/mL, cellobiohydrolase activity 53.10 ± 2.95 U/mL, endoglucanase activity 716.11 ± 41.16 U/mL, and β-glucosidase activity 1.93 ± 0.28 IU/mL. It had the highest enzymatic hydrolysis yield 89.35%, the lowest cellulase input 25.18 FPIU for 1 g glucose. It just needed 1.96 g SECS (dry material) for producing 1 g glucose. This work is profound and meaningful for lignocellulose-based biorefineries.
TL;DR: Results from this research indicate that Aspergillus sydowii NRRL250 was an effective strain to degrade caffeine, and theophylline and 3-methlxanthine were the main caffeine degradation products.
Abstract: Pu-erh tea is a traditional Chinese tea and produced by natural solid-state fermentation. Several studies show that the natural microbiota influence caffeine level in pu-erh tea. Our previous research also found that the caffeine declined significantly (p < 0.05) in the fermentation, which suggested that the caffeine level could be influenced by specific strains. The purpose of this study was to isolate and identify microorganisms for caffeine degradation, and this research explored the degradation products from caffeine and optimal condition for caffeine degradation. 11 Fungi were isolated from pu-erh tea fermentation and 7 strains could survive in caffeine solid medium. Two superior strains were identified as Aspergillus niger NCBT110A and Aspergillus sydowii NRRL250 by molecular identification. In the substrate tests with caffeine, A. niger NCBT110A could use caffeine as a potential carbon source while glucose is absent, A. sydowii NRRL250 could degrade 600 mg/L caffeine completely in a liquid medium. During the degradation product analysis of A. sydowii NRRL250, theophylline and 3-methlxanthine were detected, and the level of theophylline and 3-methlxanthine increased significantly (p < 0.05) with the degradation of caffeine. The single factor analysis showed that the optimum conditions of caffeine degradation were 1) substrate concentration of 1200 mg/L, 2) reaction temperature at 30 °C, and 3) pH of 6. In the submerged fermentation of tea infusion by A. sydowii NRRL250, 985.1 mg/L of caffeine was degraded, and 501.2 mg/L of theophylline was produced. Results from this research indicate that Aspergillus sydowii NRRL250 was an effective strain to degrade caffeine. And theophylline and 3-methlxanthine were the main caffeine degradation products.
TL;DR: The citric acid yield and the conversion rate of glucose of chsC-3 were both improved by 3.6%, when compared with that of the original strain in the stirred tank bioreactor, and the high-yield strain chsD-3 exhibited excellentcitric acid production potential in the scale-up process.
Abstract: The mycelial morphology of Aspergillus niger, a major filamentous fungus used for citric acid production, is important for citric acid synthesis during submerged fermentation. To investigate the involvement of the chitin synthase gene, chsC, in morphogenesis and citric acid production in A. niger, an RNAi system was constructed to silence chsC and the morphological mutants were screened after transformation. The compactness of the mycelial pellets was obviously reduced in the morphological mutants, with lower proportion of dispersed mycelia. These morphological changes have caused a decrease in viscosity and subsequent improvement in oxygen and mass transfer efficiency, which may be conducive for citric acid accumulation. All the transformants exhibited improvements in citric acid production; in particular, chsC-3 showed 42.6% higher production than the original strain in the shake flask. Moreover, the high-yield strain chsC-3 exhibited excellent citric acid production potential in the scale-up process.The citric acid yield and the conversion rate of glucose of chsC-3 were both improved by 3.6%, when compared with that of the original strain in the stirred tank bioreactor.
TL;DR: This paper identifies enzymes that are phenol tolerant, and whose adoption for lignocellulose hydrolysis could contribute to reductions in enzyme loading needed to hydrolyze alkali pretreated lignOcellulosic substrates in the presence of lignin derived phenols.
TL;DR: In this article, the authors focused on the changes in polyphenols, antioxidant activities and lipid compositions from chokeberry pomace during solid-state fermentation (SSF) with Aspergillus niger and Rhizopus oligosporus.
Abstract: The present study focused on the changes in polyphenols, antioxidant activities and lipid compositions from chokeberry pomace during solid-state fermentation (SSF) with Aspergillus niger and Rhizopus oligosporus . The extractable phenolics increased more than 1.7- fold during both fermentation processes. A similar trend was observed for total flavonoids. The obtained results also indicated that a longer fermentation period resulted in a greater loss of anthocyanins. The free radical scavenging ability of phenolic extracts, evaluated by DPPH and TEAC assays, were significantly enhanced during the SSFs. HPLC-MS analysis of phenolic compounds showed that the amounts of flavonols and cinnamic acids increased while the concentrations of glycosylated anthocyanins decreased substantially. The SSF of chokeberry pomace also resulted in a significant increase in lipids with high linoleic acid content (57–61% of the total fatty acids). The present investigation demonstrated that SSF enriched the chokeberry pomace with phenolic antioxidants and lipids with better nutritional-quality characteristics.
TL;DR: The role of carbon and nitrogen sources in the production of cellulase and hemicellulase by Aspergillus strains is investigated.
Abstract: AIMS We investigated the role of carbon and nitrogen sources in the production of cellulase and hemicellulase by Aspergillus strains. METHODS AND RESULTS The strains Aspergillus niger SCBM1 and Aspergillus fumigatus SCBM6 were cultivated under solid-state fermentation (SSF), with biomass sorghum (BS) and wheat bran (WB) as lignocellulosic substrates, in different proportions, along with variable nitrogen sources. The best SSF condition for the induction of such enzymes was observed employing A. niger SCBM1 in BS supplemented with peptone; maximum production levels were achieved as follows: 72 h of fermentation for xylanase and exoglucanase (300·07 and 30·64 U g-1 respectively), 120 h for β-glucosidase and endoglucanase (54·90 and 41·47 U g-1 respectively) and 144 h for β-xylosidase (64·88 U g-1 ). CONCLUSIONS This work demonstrated the viability of the use of BS for the production of hemi- and cellulolytic enzymes; the high concentration of celluloses in BS could be associated with the significant production of cellulases, mainly exoglucanase. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first study which presents the promising use of biomass sorghum (genetically modified sorghum to increase its biomass content) as an alternative carbon source for the production of enzymes by SSF.
TL;DR: A novel antibiotic peptide is isolated from the culture medium of Emericellopsis alkalina that exhibited a strong antifungal effect against the yeast Candida albicans, the mold fungus Aspergillus niger, and human pathogen clinical isolates and exhibited antimicrobial activity against some Gram-positive and Gram-negative bacteria.
Abstract: Soil fungi are known to contain a rich variety of defense metabolites that allow them to compete with other organisms (fungi, bacteria, nematodes, and insects) and help them occupy more preferential areas at the expense of effective antagonism. These compounds possess antibiotic activity towards a wide range of other microbes, particularly fungi that belong to different taxonomical units. These compounds include peptaibols, which are non-ribosomal synthesized polypeptides containing non-standard amino acid residues (alpha-aminoisobutyric acid mandatory) and some posttranslational modifications. We isolated a novel antibiotic peptide from the culture medium of Emericellopsis alkalina, an alkalophilic strain. This peptide, called emericellipsin A, exhibited a strong antifungal effect against the yeast Candida albicans, the mold fungus Aspergillus niger, and human pathogen clinical isolates. It also exhibited antimicrobial activity against some Gram-positive and Gram-negative bacteria. Additionally, emericellipsin A showed a significant cytotoxic effect and was highly active against Hep G2 and HeLa tumor cell lines. We used NMR spectroscopy to reveal that this peptaibol is nine amino acid residues long and contains non-standard amino acids. The mode of molecular action of emericellipsin A is most likely associated with its effects on the membranes of cells. Emericellipsin A is rather short peptaibol and could be useful for the development of antifungal, antibacterial, or anti-tumor remedies.
02 Mar 2018
TL;DR: This study shows that the product portfolio of Aspergillus niger can be expanded from enniatin to other CDPs such as beauvericin and bassianolide, as well as derivatives thereof, and shows the capability of A. niger to produce a range of different peptide natural products in titres high enough to become industrially relevant.
Abstract: Fungal cyclodepsipeptides (CDPs) are non-ribosomally synthesized peptides produced by a variety of filamentous fungi and are of interest to the pharmaceutical industry due to their anticancer, antimicrobial and anthelmintic bioactivities. However, both chemical synthesis and isolation of CDPs from their natural producers are limited due to high costs and comparatively low yields. These challenges might be overcome by heterologous expression of the respective CDP-synthesizing genes in a suitable fungal host. The well-established industrial fungus Aspergillus niger was recently genetically reprogrammed to overproduce the cyclodepsipeptide enniatin B in g/L scale, suggesting that it can generally serve as a high production strain for natural products such as CDPs. In this study, we thus aimed to determine whether other CDPs such as beauvericin and bassianolide can be produced with high titres in A. niger, and whether the generated expression strains can be used to synthesize new-to-nature CDP derivatives. The beauvericin and bassianolide synthetases were expressed under control of the tuneable Tet-on promoter, and titres of about 350–600 mg/L for bassianolide and beauvericin were achieved when using optimized feeding conditions, respectively. These are the highest concentrations ever reported for both compounds, whether isolated from natural or heterologous expression systems. We also show that the newly established Tet-on based expression strains can be used to produce new-to-nature beauvericin derivatives by precursor directed biosynthesis, including the compounds 12-hydroxyvalerate-beauvericin and bromo-beauvericin. By feeding deuterated variants of one of the necessary precursors (d-hydroxyisovalerate), we were able to purify deuterated analogues of beauvericin and bassianolide from the respective A. niger expression strains. These deuterated compounds could potentially be used as internal standards in stable isotope dilution analyses to evaluate and quantify fungal spoilage of food and feed products. In this study, we show that the product portfolio of A. niger can be expanded from enniatin to other CDPs such as beauvericin and bassianolide, as well as derivatives thereof. This illustrates the capability of A. niger to produce a range of different peptide natural products in titres high enough to become industrially relevant.
TL;DR: Results indicated that use of the new adsorption immobilization system could greatly improve citric acid productivity in repeated fed-batch fermentation and could provide a guideline for A.niger or other filamentous fungi immobilization in industry.
TL;DR: The results reported here showed that the range of characteristics exhibited by the xylanases could make them widely applicable in various industries, and also an important way for the valorization of agricultural waste.
Abstract: The increasing awareness of importance of xylanases in various industrial processes has led to intensive research in effective production of xylanases. In this study, eight fungal strains were screened for the production of xylanases in submerged (SmF) and solid state fermentations (SSF) in corncob-based media. Positive results of reddish orange halo-zones of hydrolysis were obtained for qualitative screening. In SmF, xylanase activity from Aspergillus fumigatus SD5A yielded highest activity (50.55 U/ml) in 168 h, while Aspergillus flavus SD4A, A. fumigatus L1, Fusarium solani SD3C, Aspergillus niger L3, Trichoderma longibrachiatum L2, Botryodiplodia sp. L5 and A. flavus L4, showed xylanase activities ranging from 10.38 to 44.81 U/ml. In SSF, xylanase activities ranged from 12.30 to 48.63 U/g in 120 h, with the highest activity obtained from A. fumigatus L1. Optimum temperatures for xylanases obtained in SmF ranged from 55 to 70 °C, while that of SSF ranged from 50 to 70 °C. Also, the optimum pH for xylanases obtained in both SmF and SSF ranged from 5.0 to 7.0. All the fungi did not produce aflatoxin on neutral red desiccated coconut agar. The fungal xylanases improved dough rising of bread and clarification of orange juice by 1.87–2.2-folds and 58.12–74.22% respectively. The results reported here showed that the range of characteristics exhibited by the xylanases could make them widely applicable in various industries, and also an important way for the valorization of agricultural waste.
TL;DR: The results relating to flavor, flavonoids, enzymes, crude protein, and reducing sugars showed A. niger Gyx086 strain was capable of efficiently fermenting ginkgo leaves, which generated a strong sweet-smelling odor and could be identified by electronic nose equipment using a cluster analysis.
Abstract: To improve the quality of Ginkgo biloba leaves as biological feed additives, twelve Aspergillus niger strains were evaluated for their growth in the moisture ginkgo leaf meal media through solid-state fermentation. The results relating to flavor, flavonoids, enzymes, crude protein, and reducing sugars showed A. niger Gyx086 strain was capable of efficiently fermenting ginkgo leaves. The optimal cultural conditions were three loops of spores inoculation to every 75 g medium containing 60 % water, grew at 28˚C for 48 h. The Gyx086 grew well in the medium. The fermented leaves generated a strong sweet-smelling odor, could be identified by electronic nose equipment using a cluster analysis, other than the original offensive smell from non-fermented ginkgo leaves. Each gram dried culture with Gyx086 showed 2.83 × 109 CFU of A. niger; 3.19 ± 0.37 FPU of acid-resistant filter paper activity. Its total contents of flavonoids, reducing sugars, and crude proteins were 19.95 ± 0.23 mg, 24.28 ± 2.35 mg, and 162.81 ± 3.46 mg in each gram of leaves, 26.03 %, 62.73 %, and 14.58 % higher than the controls, respectively. The essential amino acids and total amino acids contents were 96.41 % and 16.49 % higher than the controls.
TL;DR: Results revealed that morphological control of A. niger is an efficient method for increased malic acid production when crude glycerol derived from biodiesel production is used as feedstock.
TL;DR: A new biocatalyst was high thermostability and resistance to acidic pHvalues was produced and purified, and a great variety of metal ions showed to have a beneficent effect on the enzyme, significantly increasing its catalysis.
TL;DR: A comprehensive characterization of the sugar transportome of A. niger is reported, which revealed that transporter genes from the same phylogenetic clade displayed very diverse expression patterns and were regulated by different transcriptional factors.
Abstract: Aspergillus niger is one of the most widely used fungi to study the conversion of the lignocellulosic feedstocks into fermentable sugars. Understanding the sugar uptake system of A. niger is essential to improve the efficiency of the process of fungal plant biomass degradation. In this study, we report a comprehensive characterization of the sugar transportome of A. niger by combining phylogenetic and comparative transcriptomic analyses. We identified 86 putative sugar transporter (ST) genes based on a conserved protein domain search. All these candidates were then classified into nine subfamilies and their functional motifs and possible sugar-specificity were annotated according to phylogenetic analysis and literature mining. Furthermore, we comparatively analyzed the ST gene expression on a large set of fungal growth conditions including mono-, di- and polysaccharides, and mutants of transcriptional regulators. This revealed that transporter genes from the same phylogenetic clade displayed very diverse expression patterns and were regulated by different transcriptional factors. The genome-wide study of STs of A. niger provides new insights into the mechanisms underlying an extremely flexible metabolism and high nutritional versatility of A. niger and will facilitate further biochemical characterization and industrial applications of these candidate STs.
TL;DR: Overexpression of gaaR resulted in an increased transcription of the genes encoding pectinases, (putative) GA transporters, and catabolic pathway enzymes even under non-inducing conditions, i.e., in the absence of GA.
Abstract: The transcription factor GaaR is needed for the expression of genes required for pectin degradation and transport and catabolism of the main degradation product, D-galacturonic acid (GA) in Aspergillus niger. In this study, we used the strong constitutive gpdA promoter of Aspergillus nidulans to overexpress gaaR in A. niger. Overexpression of gaaR resulted in an increased transcription of the genes encoding pectinases, (putative) GA transporters, and catabolic pathway enzymes even under non-inducing conditions, i.e., in the absence of GA. Exoproteome analysis of a strain overexpressing gaaR showed that this strain secretes highly elevated levels of pectinases when grown in fructose. The genes encoding exo-polygalacturonases were found to be subjected to CreA-mediated carbon catabolite repression, even in the presence of fructose. Deletion of creA in the strain overexpressing gaaR resulted in a further increase in pectinase production in fructose. We showed that GaaR localizes mainly in the nucleus regardless of the presence of an inducer, and that overexpression of gaaR leads to an increased concentration of GaaR in the nucleus.
TL;DR: In this article, Aspergillus niger was used to improve the physiological characteristics of Magnolia officinalis bark (MOB) extracts by fermentation, which exhibited the highest antityrosinase activity, total phenolic content, and antioxidant activity.
Abstract: This study intended to improve physiological characteristics of Magnolia officinalis bark (MOB) extracts by Aspergillus niger fermentation. M. officinalis bark was extracted using distilled water, 95% ethanol, and methanol, and it was then fermented by A. niger. The physiological characteristics of the fermented extracts, namely, tyrosinase inhibitory activity, antioxidant activity, antibacterial activity, and anti-skin-aging activity, were evaluated and compared with those of unfermented extracts. To determine the safety of the fermented extracts, their cytotoxicity was analyzed by measuring the cell viability of CCD-966SK and human epidermal melanocytes (HEMn) after exposure. The fermented methanol extract exhibited the highest antityrosinase activity, total phenolic content, and antioxidant activity. The total phenolic content of the extracts fermented by A. niger was 3.52 times greater than that of the unfermented extracts. The optimal IC50 values for tyrosinase inhibition and 2,2-diphenyl-1-picrylhydrazyl (DPPH) removal by the A. niger-fermented extracts were 30 and 12 μg/mL, respectively. The fermented methanol extracts inhibited skin-aging-related enzymes such as collagenase, elastase, MMP-1, and MMP-2. Compared with the unfermented extracts, the fermented extracts also contained greater antibacterial activity against tested stains including MRSA. These results could be attributed to an increase in the concentration of original active compounds and the biosynthesis of new compounds during fermentation. In cytotoxicity assays, the A. niger-fermented extracts were nontoxic to CCD-966SK cells, even at 500 μg/mL. Hence, in general, methanol-extracted M. officinalis fermented by A. niger for 72 h has the most active antioxidant, skincare, or antiaging compounds for healthy food or cosmetics applications.
TL;DR: Cellulase of newly isolated fungi A. niger RCKH-3 shows potential in biofuel applications based on its comparatively higher saccharification abilities and lower production costs.
TL;DR: The enhancement of bioelectrochemical properties of microorganism by in situ formation of conducting polymer within the cell structures was performed and the synthesis of polypyrrole (Ppy) within fungi (Aspergillus niger) cells was achieved.
TL;DR: The produced enzyme was able to recover silver from used X-ray film under optimized condition using statistical methodology (CCD) and showed excellent stability and compatibility in presence of organic solvents and detergents.