Aspergillus Japonicus Research Articles

Exploring Aspergillus biomass for fast and effective Direct Black 22-dye removal

Azo dyes are widely used in the textile industry due to their stability and resistance. These properties also make them recalcitrant xenobiotics, toxic, mutagenic, and carcinogenic, even at low concentrations. Considered emerging pollutants, there is an urgency to address mechanisms capable of remediating these contaminants, with Aspergillus fungi standing out as an effective solution. Fifteen strains of Aspergillus were investigated for the decolorization of the tetra azo dye Direct Black 22. The influence of different culture media was evaluated on fungi biomass production, dye concentrations (50–300 mg/L), biomass concentrations (1–5g), and the reuse of biomass in continuous batches. The strains that stood out the most were Aspergillus japonicus URM 5620, Aspergillus niger URM 5741, and A. niger URM 5838. Obtaining biomass in less nutrient-rich medium favored decolorization by forming more organized pellets. The live biomass of these fungi was 59% more efficient than the dead biomass. The decolorization efficiency was not affected at lower dye concentrations, showing a decrease in decolorization only when the concentration reached 300 mg/L. Increasing the amount of biomass resulted in proportionally greater decolorization. Even with just 1 g of biomass, the three fungi could remove more than 90% of the dye in less than 60 minutes, and with 5 g, the dye was completely removed in 10 minutes. Thebiomass was reused in three consecutive decolorization cycles, and the fungus that best withstood the cycles was A. niger URM 5741. These results demonstrate the potential of the genus Aspergillus fungi tested in this study as sustainable and efficient biosorbents for the remediation of azo dyes such as Direct Black 22, with potential for colored industrial effluent treatment.

Filamentous fungi associated with the brown mussel, Perna perna (Bivalvia: Mytilidae), off the coast of Rio de Janeiro, Brazil

ABSTRACT Bivalves are known to be infected by filamentous fungi, many of which have pathogenic and toxicogenic properties, and may represent a risk to human health. The present study investigated the mycological characteristics of Perna perna obtained from Guanabara Bay, Brazil. The mussels were sealed individually in sterile bags, weighed and measured, and the internal organs were examined. The organs were grown in different culture media. All but one of the 31 mussels (96.7%) examined contained fungi, and a total of 84 fungal colonies were isolated. The genera identified were Aspergillus (40.5%), Didymella (35.7%), Penicillium (10.7%), Aureobasidium (1.2%), Cladosporium (1.2%) and Phaeoisaria (1.2%). The molecular sequences obtained 99.8 and 100% identity with Didymella sp., Phaeoisaria sp. and Aureobasidium pullulans, and were deposited in GenBank. This is the first record of Didymella and Phaeoisaria in a bivalve. The digestive gland was the organ with the greatest diversity of fungi genera. A number of the fungi identified here, as Aspergillus awamori, Aspergillus japonicus, Aspergillus niger, Aspergillus versicolor and Aspergillus sydowii, are known to produce mycotoxins and others are opportunistic forms, which reinforces the need for the systematic monitoring of the study area to guarantee the safe exploitation of these bivalves for human consumption.

Chemical constituents and chemotaxonomic research of the deep-sea-derived fungus Aspergillus japonicus W6

Aspergillus japonicus was isolated from polymetallic sulfide thulium deposits in the South Atlantic. A systematic investigation on its secondary metabolites led to the isolation of one new (1) and 23 known (2–24) compounds. Mainly by detailed analysis of the NMR and HRESIMS spectroscopic data, DP4+ probability, as well as calculated ECD spectra, the absolute configuration of 1 was finally determined to be (3S,5R,7R,9R,11S) methyl-3,5,9-trihydroxy-7,11-epoxytetradecanoate. Compound 1 could be used as chemotaxonomic marker of A. japonicus W6 to distinguish the other A. japonicus.

Funcionalidade nutricional do complexo xilanolítico obtida de Aspergillus japonicus var. aculeatus UFMS 48.136 em dietas para suínos

Abstract The objective of this study was to evaluate the nutritional functionality of the xylanolytic complex produced from Aspergillus japonicus var. aculeatus UFMS 48.136 isolated from the Cerrado/ Pantanal biome in Mato Grosso do Sul, compared to commercial xylanase, in swine diets. Sixteen barrows were used, with an initial weight of 64.23 ± 10.5 kg, distributed in a randomized block experimental design, with four diets: control, formulated according to nutritional recommendations; negative control, formulated with a reduction of 100 Kcal / kg of metabolizable energy (ME); negative control + xylanase Cerrado / Pantanal; negative control + commercial xylanase; with four repetitions each. The xylanase supplementation provided higher (P<0.05) values of digestible energy (DE), ME, and higher (P<0.05) digestibility of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF), and acid detergent fiber (ADF) in relation to the negative control diet, but without differing (P>0.05) from the control diet. The inclusion of xylanases increased (P<0.05) in the coefficients of digestibility (CD) and metabolism of crude energy (CE), DM, OM, CP, EE, NDF, and ADF. There was no difference (P>0.05) in digestibility and CD values between Cerrado/Pantanal and commercial xylanase. The inclusion of xylanases made it possible to reduce 100 Kcal of ME per kilogram of diet. Cerrado/Pantanal xylanases therefore have the same nutritional efficiency as commercial xylanases.

Nutritional functionality of the xylanolytic complex obtained from Aspergillus japonicus var. aculeatus UFMS 48.136 in swine diets

Resumo Realizou-se este estudo com o objetivo de avaliar a funcionalidade nutricional do complexo xilanolítico produzido a partir de fungos da linhagem Aspergillus japonicus var. aculeatus UFMS 48.136, oriundo do bioma Cerrado/Pantanal sul mato-grossense em comparação à xilanase comercial, em dietas de suínos. Foram utilizados dezesseis suínos machos, com peso inicial de 64,23 ± 10,5 kg, distribuídos em delineamento experimental de blocos ao acaso, com quatro dietas: controle, formulado de acordo com as recomendações nutricionais; controle negativo, formulado com redução de 100 Kcal / kg de energia metabolizável (EM); controle negativo + xilanase Cerrado / Pantanal; controle negativo + xilanase comercial; com quatro repetições cada. A suplementação das xilanases proporcionou maiores (P<0,05) valores de energia digestível (ED), metabolizável (EM) e maiores (P<0,05) digestibilidade da matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), extrato etéreo (EE), fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA) em relação à dieta controle negativo, mas sem diferir (P>0,05) da dieta controle. A inclusão das xilanases proporcionou aumento (P<0,05) nos coeficientes de digestibilidade (CD) e metabolizabilidade da energia bruta (EB), MS, MO, PB, EE, FDN e FDA. Não foi constatada diferença (P>0,05) nos valores de digestibilidade e de CD entre as xilanase Cerrado/Pantanal e Comercial. A inclusão das xilanases possibilita a redução de 100 Kcal de EM por kg da dieta. A xilanase Cerrado / Pantanal possui a mesma eficiência nutricional em comparação com a xilanase comercial.

Mycosynthesis of silver nanoparticles using marine fungi and their antimicrobial activity against pathogenic microorganisms

ObjectivesAt the present time, there is a persistent need to get rid of environmental contaminants by eco-friendly, sustainable, and economical technologies. Uncontrolled disposal practices of domestic and industrial solid and liquid wastes led to water pollution which has negative impacts on public health, environment, and socio-economic development. Several water-borne diseases are spreading man to man by microorganisms such as pathogenic bacteria. For the protection of water bodies, all wastewater from various sources should be managed and remediated properly. Myco-remediation is a form of bioremediation in which fungi are used to get rid of contaminants. Fungi are attractive agents for the biosynthesis of nanoparticles especially silver nanoparticles (AgNPs) which are considered one of the most widely utilized nanoparticles because of their unique characteristics such as antibacterial, antiviral, antifungal, and anti-inflammatory properties. MethodsThis study uses silver nitrate and supernatants of four marine fungi; Penicillium simplicissimum, Aspergillus terreus, Aspergillus japonicus, and Aspergillus oryzae for extracellular biosynthesis of silver nanoparticles and to evaluate its activity against different pathogenic microorganisms. These nanoparticles may subsequently be applied for the treatment or nano-bioremediation of microbial contaminants in water bodies and improve water quality. ResultsSilver nanoparticles were synthesized and the results revealed that spherical and well-dispersed nanoparticles of different sizes were formed with sizes ranging between 3.8 and 23 nm. Characterization results approved the existence of stable nanocrystalline elemental silver. Antibacterial activity results revealed that AgNPs can be used as a powerful antimicrobial agent for several pathogenic bacteria, yeast, and fungi. Among the biosynthesized NPs mediated by the four marine fungi, AgNPs mediated by A. japonicus (5 mM) had the highest antibacterial activity, while AgNPs mediated by Penicillium simplicissmum (8 mM) had the highest antifungal activity. ConclusionMarine fungi can biosynthesize stable AgNPs that exhibit potent antimicrobial activity against a variety of pathogens.

Pathogenic fungi shape the fungal community, network complexity, and pathogenesis in kiwifruit.

Kiwifruit decay caused by endophytic fungi is affected by exogenous pathogens that trigger changes in fungal community composition and interact with the endophytic fungal community. Four fungal pathogens of kiwifruit were identified. These were Aspergillus japonicus, Aspergillus flavus, Botryosphaeria dothidea, and Penicillium oxalicum. Except for P. oxalicum, the remaining three species represent newly described pathogens of kiwifruit. All four fungal species caused disease and decay in mature kiwifruit. Results of the fungal community analysis indicated that three pathogens that A. japonicus, A. flavus and P. oxalicum were the most dominant, however, other fungal species that did not cause disease symptoms were also present. Positive interactions between fungal species were found in asymptomatic, symptomatic, and infected kiwifruit. The ability of all four pathogens to infect kiwifruit was confirmed in an inoculation experiment. The presence of any one of the four identified pathogens accelerated decay development and limited the postharvest longevity of harvested kiwifruit. Results of the study identified and confirmed the ability of four fungal species to infect and cause decay in harvested kiwifruit. Changes in the structure and composition of the kiwifruit microbiome during the decay process were also characterized. This provides a foundation for the further study of the microbiome of kiwifruit and their involvement in postharvest diseases.

Biochemical characterization of an acid-thermostable glucoamylase from Aspergillus japonicus with potential application in the paper bio-deinking.

Aspergillus species have been highlighted in enzyme production looking for industrial applications, notably, amylases are one of the most interesting enzymes. They are capable of hydrolyzing α-glycosidic linkages of starch and widely used in industrial processes to produce ethanol, glucose, and fructose syrup as well as in the textiles, detergents, and paper industries applications. In this context, this work aimed at the biochemical characterization of the glucoamylase from Aspergillus japonicus and its application in the bio-bleaching process of recycled paper. The optimum temperature and pH for the glucoamylase assay were standardized as 50°C and 5.5. After 1 h of incubation, glucoamylase retained 90% of its activity at 30-50°C. It also kept 70% of its activity in the pH range of 4.0-6.5 after an hour of incubation. The enzyme led to an increase of 30% in the relative whiteness of 10 dry grams of sulfite paper and magazine paper when applied along with commercial cellulase and 10 mM MnCl2 . In addition, after the treatments, the glucoamylase recovered activity was 30%-32%, which indicates a prolonged availability of the enzyme and can considerably curtail the redundant downstream process of the recycled paper bio-bleaching. Thus, the glucoamylase from A. japonicus has a significant role in bio-bleaching recycled paper, reducing the necessity of hard chemicals, and improving the industrial process in an interesting economic and ecological mode.

Isolation and Identification of Microfungi from Diesel Oil Contaminated Soils and Their Physico-Chemical Analysis

Diesel oil contaminated soils were collected and analyzed for various Physico-chemical properties that included moisture content, total carbon, total nitrogen and phosphorus using standard protocol and the data compared from normal uncontaminated soils. Analysis revealed that all 5 samples of diesel oil contaminated soils possessed higher percent of moisture content, greater amounts of total carbon, nitrogen and phosphorus in comparison to non-contaminated control soils. The diesel oil contaminated soils are not suitable for cultivation of agricultural crops. Though, several species of fungi were isolated from diesel contaminated soils but only 6 species of Aspergillus utilized diesel oil as sole carbon and nitrogen source as these grew well and sporulated normally on 2% agar that contained 10% of diesel oil only as nutrient. These included Aspergillus luchuensis, Aspergillus violaceofuscus, Aspergillus niveus, Aspergillus terreus, Aspergillus japonicus, Aspergillus ustus. which also grew well in broth containing 0.5% jaggery (for initial growth) supplemented with 10% diesel oil only which suggest that these species could utilize diesel oil as sole carbon and nitrogen source because no other nutrient other than diesel oil was added into the medium. The role of carbon, nitrogen and phosphorus is soils has been discussed in this paper.

Optimisation of β-Glucosidase Production in a Crude Aspergillus japonicus VIT-SB1 Cellulase Cocktail Using One Variable at a Time and Statistical Methods and its Application in Cellulose Hydrolysis.

Pulp and paper mill sludge (PPMS) is currently disposed of into landfills which are reaching their maximum capacity. Valorisation of PPMS by enzymatic hydrolysis using cellulases is an alternative strategy. Existing commercial cellulases are expensive and contain low titres of β-glucosidases. In this study, β-glucosidase production was optimised by Aspergillus japonicus VIT-SB1 to obtain higher β-glucosidase titres using the One Variable at a Time (OVAT), Plackett Burman (PBD), and Box Behnken design (BBD)of experiments and the efficiency of the optimised cellulase cocktail to hydrolyse cellulose was tested. β-Glucosidase production was enhanced from 0.4 to 10.13 U/mL, representing a 25.3-fold increase in production levels after optimisation. The optimal BBD production conditions were 6 days of fermentation at 20 °C, 125 rpm, 1.75% soy peptone, and 1.25% wheat bran in (pH 6.0) buffer. The optimal pH for β-glucosidase activity in the crude cellulase cocktail was (pH 5.0) at 50 °C. Optimal cellulose hydrolysis using the crude cellulase cocktail occurred at longer incubation times, and higher substrate loads and enzyme doses. Cellulose hydrolysis with the A. japonicus VIT-SB1 cellulase cocktail and commercial cellulase cocktails resulted in glucose yields of 15.12 and 12.33 µmol/mL glucose, respectively. Supplementation of the commercial cellulase cocktail with 0.25 U/mg of β-glucosidase resulted in a 19.8% increase in glucose yield.

Production and Biochemical Characterization of Aspergillus japonicus Pectinase Using a Low-Cost Alternative Carbon Source for Application in the Clarification of Fruit Juices

Production and Biochemical Characterization of Aspergillus japonicus Pectinase Using a Low-Cost Alternative Carbon Source for Application in the Clarification of Fruit Juices

Proficient bioconversion of rice straw biomass to bioethanol using a novel combinatorial pretreatment approach based on deep eutectic solvent, microwave irradiation and laccase

Current study is the first report of the combined application of chemical (deep eutectic solvent), physical (microwave irradiation) and biological (laccase) pretreatment strategies for enhancing the enzymatic digestibility of rice straw biomass. Pretreated rice straw biomass was saccharified by cellulase/xylanase from Aspergillus japonicus DSB2 to get a sugar yield of 252.36 mg/g biomass. Design of Experiment based optimization of pretreatment and saccharification variables increased the total sugar yield by 1.67 times (421.5 mg/g biomass, saccharification efficiency 72.6%). Sugary hydrolysate was ethanol-fermented by Saccharomyces cerevisiae and Pichia stipitis to achieve an ethanol yield of 214 mg/g biomass (bioconversion efficiency 72.5%). Structural/chemical aberrations induced in the biomass due to pretreatment were elucidated by X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and 1H nuclear magnetic resonance techniques to unravel the pretreatment mechanisms. Combined application of various physico-chemical/biological pretreatment may be a promising approach for proficient bioconversion of rice straw biomass.

PHYTOCHEMICALS, ANTIOXIDANT AND ANTIMICROBIAL ACTIVITY OF CENTELLA ASIATICA EXTRACTED BY SOLVENT-FREE MICROWAVE EXTRACTION

Solvent-free microwave extraction (SFME) is a green extraction method that requires no solvent and has a short extraction time. This study extracted Centella asiatica using SFME and analysed the extract for its phytoconstituents, phenolic content, antioxidant, and antimicrobial activity. Extraction of 20 g fresh C. asiatica by SFME was carried out for 15 min at 300 W, under vacuum and with stirring. Analysis by gas chromatography-mass spectroscopy (GC-MS) demonstrated that the extract contained phytonutrients such as flavonoids, polyphenol, tannins, and volatile oils. The extract from SFME also produced an IC50 of 0.06 mg/ml and 10.75±0.61 mg GAE/g dry weight of TPC. Using the disc diffusion method, the extract of C. asiatica also exhibited antimicrobial activity against Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Enterobacter sp., Aspergillus niger, Aspergillus flavus, Penicillium chrysogenum and Aspergillus japonicus. This study showed that the C. asiatica extract from SFME retained the antioxidant and antimicrobial properties but in a shorter extraction time and without any solvent. As a result, using green extraction to extract this plant can help to preserve its nutritional content and valuable compounds, which is essential when formulating pharmaceutical, food, and cosmetic products.

Japonamides A and B, Two New Cyclohexadepsipeptides from the Marine-Sponge-Derived Fungus Aspergillus japonicus and Their Synergistic Antifungal Activities

Two new cyclohexadepsipeptides japonamides A (1) and B (2) were isolated from the ethyl acetate extract of a marine-sponge-derived fungus Aspergillus japonicus based on molecular networking. Their structures were elucidated by comprehensive spectral analysis and their absolute configurations were confirmed by Marfey’s method. Compounds 1 and 2 showed no antifungal activities against Candida albicans SC5314 measured by the broth microdilution method but exhibited prominent synergistic antifungal activities in combination with fluconazole, ketoconazole, or rapamycin. The Minimum inhibitory concentrations (MICs) of rapamycin, fluconazole, and ketoconazole were significantly decreased from 0.5 to 0.002 μM, from 0.25 to 0.063 μM, and from 0.016 to 0.002 μM, in the presence of compounds 1 or 2 at 3.125 μM, 12.5 μM, and 6.25 μM, respectively. Surprisingly, the combination of compounds 1 or 2 with rapamycin showed a strong synergistic effect, with fractional inhibitory concentration index (FICI) values of 0.03.

Bioconversion of Some Agro-Residues into Organic Acids by Cellulolytic Rock-Phosphate-Solubilizing Aspergillus japonicus

Biological-based conversion of agricultural residues into bioactive compounds may be considered to be the basis for various vital industries. However, finding a suitable microorganism is a challenge in the bioconversion process. Therefore, this study was conducted to find local fungal isolates able to convert a combination of plant biomass residues into organic acids (OAs). Based on their cellulase and phytase activities and rock phosphate (RP) solubilization potential, an efficient 15 fungal isolates (named F1 to F15) were selected and identified by both morphological and molecular methods using the 18S rRNA sequencing technique. The best fungal isolate (F15) was identified as Aspergillus japonicus. After 4 weeks of incubation below solid-state fermentation (SSF) with a mix of sugarcane bagasse and faba bean straw (3:7), with 7.5% (v/w) fungal inoculum to the growth medium, the biodegradation process by the fungus reached its peak, i.e., maximum cellulolytic activity and RP solubilization ability. Under such fermentation conditions, seven organic acids were detected using HPLC, in the following order: ascorbic acid > oxalic acid > formic acid > malic acid > succinic acid > lactic acid > citric acid. Based on the results, Aspergillus japonicus (F15) could produce OAs and cellulose enzymes, and could be considered a new single-step bio-converter of sugarcane bagasse and faba bean straw residues into OAs. Furthermore, this fungus could be a new source of fungal cellulose, and could present a practical approach to reducing environmental contamination. Additional work is encouraged for more optimization of fermentation conditions.

Relationship Among Fungi Associated with Whole and Rotting Solanum Lycopersicum L. and Two Capsicum Species from Different Locations

The relationship among fungi associated with whole and rotting Solanum lycopersicum L., and two capsicum species was examined. Whole (healthy looking) and rotting vegetable fruits (Solanum lycopersicum L., Capsicum annum L. and Capsicum chinense) were obtained from three different units within two markets (Atakumosa and Bodija) in two different states (Osun and Oyo) and brought to the laboratory under sterile conditions. Cut sections from the whole and rotting samples were cultured on Acidified Potato Dextrose Agar (APDA) and incubated at 300C ± 20C for 7 days. Growing fungi were sub-cultured on fresh APDA Petri plates to obtain pure cultures. All experiments were done in triplicates. After identification, each fungus was recorded as present (1) or absent (0). Molecular identification were carried out by DNA barcoding using the ITS region sequencing. The ITS rDNA sequences were compared to those in database using NCBI blast and the genetic distance were used to compare the relationship. Data collected were analyzed using descriptive statistics at p≤0.05. Thirty two fungi were obtained and were identified into nine different genera. These were Saturnispora diversa, Kodamea ohmerii, Pichia kudravizevii, Geotrichum candidum, Aspergillus japonicus, Candida sorboxylosa, Aspergillus niger, Penicillium chrysogenum, Fusarium oxysporum, Rhizopus oryzae, Aspergillus flavus and Penicillum rubens. Pichia kudravizevii had the highest incidence in the whole and rotting fruits. Pencillium chrysogenum, Rhizopus oryzae, Geotrichum candidum, Pichia kudravizevii and Fusarium oxysporum were isolated from both whole and rotting fruits obtained from the two locations. The genera Aspergillus, Pencillium, Fusarium, Rhizopus, Candida and Pichia isolated from Solanum lycopersicum L., Capsicum annum L. and Capsicum chinense obtained from the different locations were genetically related. The genera Saturnispora, Kodamea and Geotrichum obtained from the different locations were also genetically related. Fungal isolates of different genera from different pepper and tomato samples obtained from different locations can sometimes be genetically related. Fungal isolates of the same genus obtained from different locations can also be genetically related.

Effects of Ultraviolet Exposure on the Tropical Fungi Aspergillus carbonarius and Aspergillus japonicus: Survival, Amylase Production, and Thermostability

Background and Research Aims Although fundamental to tropical forest biodiversity, fungi have been largely neglected in conservation research. To examine the fungal response to increased ultraviolet C (UVC) radiation, we analyzed UVC radiation effects on the survival, growth, and amylase activity of Aspergillus carbonarius and Aspergillus japonicus. Methods A. carbonarius (strain URM 7305) and A. japonicus (URM 7270) were exposed to UVC (254 nm) for different periods, and morphological changes were compared to the control. Results Survival capacity and growth decreased after 10 min of exposure in A. carbonarius and after 25 min in A. japonicus. After 40 min, amylase activity decreased ( A. carbonarius: 35.8%; A. japonicus: 30.3%). Amylase thermostability at 60°C was lower in UVC-exposed strains (T50 15 min) compared to controls ( A. japonicus, 45 min; A. carbonarius, 30 min). However, the protein amount remained stable in all UVC-treated strains. Contamination by other fungi was observed in the UVC-exposed strains, confirming competitive strength loss in both species. This was not observed in the controls due to secondary metabolite production, which increased their competitive fitness. Conclusion We provide new information about UVC’s adverse effects on the survival and enzyme production of A. carbonarius and A. japonicus, which could mean a loss of species essential for proper soil functioning and biodiversity. Implications for conservation Experimental manipulation of biochemical and physiological reactions advances fungal conservation beyond distributional data. The experimental evidence supports previous studies, suggesting that the increased UV radiation caused by climate change may drastically affect fungal biochemistry and physiology.

Beyond the cyclopropyl ring formation: fungal Aj_EasH catalyzes asymmetric hydroxylation of ergot alkaloids.

Ergot alkaloids (EAs) are among the most important bioactive natural products. FeII/α-ketoglutarate-dependent dioxygenase Aj_EasH from Aspergillus japonicus is responsible for the formation of the cyclopropyl ring of the ergot alkaloid (EA) cycloclavine (4). Herein we reconstituted the biosynthesis of 4 in vitro from prechanoclavine (1) for the first time. Additionally, an unexpected activity of asymmetric hydroxylation at the C-4 position of EA compound festuclavine (5) for Aj_EasH was revealed. Furthermore, Aj_EasH also catalyzes the hydroxylation of two more EAs 9,10-dihydrolysergol (6) and elymoclavine (7). Thus, our results proved that Aj_EasH is a promiscuous and bimodal dioxygenase that catalyzes both the formation of cyclopropyl ring in 4 and the asymmetric hydroxylation of EAs. Molecular docking (MD) revealed the substrate-binding mode as well as the catalytic mechanism of asymmetric hydroxylation, suggesting more EAs could potentially be recognized and hydroxylated by Aj_EasH. Overall, the newly discovered activity empowered Aj_EasH with great potential for producing more diverse and bioactive EA derivatives. KEY POINTS: • Aj_EasH was revealed to be a promiscuous and bimodal FeII/α-ketoglutarate-dependent dioxygenase. • Aj_EasH converted festuclavine, 9,10-dihydrolysergol, and elymoclavine to their hydroxylated derivatives. • The catalytic mechanism of Aj_EasH for hydroxylation was analyzed by molecular docking.

Polygalacturonase from Aspergillus japonicus (PGAj): Enzyme production using low-cost carbon source, biochemical properties and application in clarification of fruit juices

Aspergillus japonicus polygalacturonase (PGAj) was produced using passion fruit peel, a residue from the agricultural and juice industries, as a low-cost carbon source. The biochemical properties of the enzyme and its application in the clarification of fruit juices were investigated. The maximum PGAj production was obtained using solid state fermentation (SSF) in 48 h (227.75 ± 13.1 U). PGAj was purified in two chromatography steps with a specific activity of 7.9 U/mg protein, 2.9 -fold purification, and 81% final yield, exhibiting a molecular weight about 40 kDa. The optimal pH and temperature for PGAj activity were pH 4.0 and 55 °C, respectively. Moreover, the PGAj enzyme retained up to 90% of its initial activity for 4 h at pH 4.0, 5.0 and 6.0. The enzyme maintained 83% residual activity after 20 min at 50 °C. PGAj best preferred citrus pectin (8.45 ± 1.6 U/mg protein) as substrate. The best results for juice clarification using 3 U/mL PGAj were obtained with the pulp of Palmer and Tommy mango varieties, white guava, banana, and apple, with increases of 65%, 41%, 40%, 11%, and 9.4% in transmittance values, respectively, compared to the control. This was superior to that obtained using commercial pectinase for some of the pulps, as 49% and 21% for Palmer and Tommy mango pulps, respectively. Thus, PGAj may be suitable for application as a clarifying agent in the fruit juice industry. • Polygalacturonase (PGAj) was produced using a low-cost carbon source (passion fruit peel). • PGAj was obtained in 48 h solid state fermentation (SSF). • Better clarification of mango juice achieved with PGAj than with commercial pectinase.

Utilization of Clay Materials as Support for Aspergillus japonicus Lipase: An Eco-Friendly Approach

Lipase is an important group of biocatalysts, which combines versatility and specificity, and can catalyze several reactions when applied in a high amount of industrial processes. In this study, the lipase produced by Aspergillus japonicus under submerged cultivation, was immobilized by physical adsorption, using clay supports, namely, diatomite, vermiculite, montmorillonite KSF (MKSF) and kaolinite. Besides, the immobilized and free enzyme was characterized, regarding pH, temperature and kinetic parameters. The most promising clay support was MKSF that presented 69.47% immobilization yield and hydrolytic activity higher than the other conditions studied (270.7 U g−1). The derivative produced with MKSF showed high stability at pH and temperature, keeping 100% of its activity throughout 12 h of incubation in the pH ranges between 4.0 and 9.0 and at a temperature from 30 to 50 °C. In addition, the immobilized lipase on MKSF support showed an improvement in the catalytic performance. The study shows the potential of using clays as support to immobilized lipolytic enzymes by adsorption method, which is a simple and cost-effective process.