Production and Application of Pectinases from Aspergillus niger Obtained in Solid State Cultivation

Improvement of fruit juice quality: novel endo-polygalacturonase II from Aspergillus tubingensis FAT 43 for enhanced liquefaction, clarification, and antioxidant potential

This study focuses on the isolation, purification, and characterisation of endo-polygalacturonase II from Aspergillus tubingensis FAT43, particularly emphasising its potential applications in the fruit juice industry. A comprehensive screening test revealed the temporal dynamics of endo-polygalacturonase production during a 96-hour fermentation process. The purification process, involving ammonium sulfate and ethanol precipitation followed by ion-exchange chromatography, resulted in a 3.3-fold purification of PG II with a yield of 16% and a specific activity of 6001.67 U mg-1. Molecular analysis confirmed the identity of PG II, its gene (pgaII), and a high degree of sequence identity with Aspergillus tubingensis in the SWISS-PROT database. The optimal pH for PG II activity was 3.5-4.5, with robust stability across a broad pH spectrum (3-7). The enzyme exhibited optimal temperature activity at 45 °C, with a retention of 90% activity at 50 °C. The calculated activation energy for PG II was 62.1 kJ mol-1, indicating good stability. Inactivation kinetics revealed a half-life of 13.7 h at 40 °C, 5.4 h at 50 °C, and 0.85 h at 60 °C, with an activation energy of denaturation of 32.8 kJ mol-1. Compared to literature-reported PGs, PG II from A. tubingensis FAT43 demonstrated superior thermal stability. Hydrolysis experiments on different pectins revealed the highest specificity for non-methylated substrates (polygalacturonic acid). In fruit juice processing, PG II significantly increased juice yield and clarity, with the highest impact observed in strawberry juice. Antioxidant activity assays indicated enhanced antioxidant potential in enzyme-treated juices, especially strawberry, quince, and apple juices. The study highlights PG II's potential as an industrially valuable enzyme for fruit juice processing, offering improved thermostability and versatility across various fruit types.

Role of ascomycete and basidiomycete fungi in meeting established and emerging sustainability opportunities: a review

Fungal biomass is the future's feedstock. Non-septate Ascomycetes and septate Basidiomycetes, famously known as mushrooms, are sources of fungal biomass. Fungal biomass, which on averagely comprises about 34% protein and 45% carbohydrate, can be cultivated in bioreactors to produce affordable, safe, nontoxic, and consistent biomass quality. Fungal-based technologies are seen as attractive, safer alternatives, either substituting or complementing the existing standard technology. Water and wastewater treatment, food and feed, green technology, innovative designs in buildings, enzyme technology, potential health benefits, and wealth production are the key sectors that successfully reported high-efficiency performances of fungal applications. This paper reviews the latest technical know-how, methods, and performance of fungal adaptation in those sectors. Excellent performance was reported indicating high potential for fungi utilization, particularly in the sectors, yet to be utilized and improved on the existing fungal-based applications. The expansion of fungal biomass in the industrial-scale application for the sustainability of earth and human well-being is in line with the United Nations' Sustainable Development Goals.

Enzymatic Extraction of Sapodilla (Manilkara achras L.) Juice: Process Optimization and Characterization

Conventional treatment of sapodilla pulp yields very viscous, turbid, and low juice recovery. Sapodilla processing for juice requires liquefying enzyme that leads to rectifying flow of juice. This study was conducted to optimize the enzymatic pectolytic conditions of sapodilla fruit processing to extract maximum juice using a central composite design (CCD). The effect of processing variables on recovery of juice, total soluble solids (TSS), viscosity, clarity, and L-value along with physicochemical analysis was investigated. The optimized processing conditions were pectinase concentration (0.120%) at 42.02°C for 167.83 min resulting in juice recovery (62.08 ± 0.38%), viscosity (4.81 ± 0.02cP), TSS (21.48 ± 0.19 °Brix), clarity (0.72 ± 0.05%T), and L-value (28.79 ± 0.96). Optimized sapodilla juice showed higher filterability (24.16 ± 1.04 min−1), conductivity (69.46 ± 0.30 S/m), total phenolic content (35.86 ± 0.60 mg/100 mL), ascorbic acid (6.38 ± 0.58 mg/100 mL), moisture content (84.85 ± 0.21% WB), and titratable acidity (0.143 ± 0.0% citric acid) as compared to control sample (60.5 ± 1.80 min−1, 30.43 ± 0.35 S/m, 30.68 ± 0.85 mg/100 mL, 4.64 ± 0.0 mg/100 mL, 83.69 ± 0.18%, and 0.130 ± 0.0%). Optimized sapodilla juice was lower in sedimentation index (0.73 ± 0.11%), turbidity (13.73 ± 1.10 NTU), ash (0.57 ± 0.031%), and β-carotene (0.173 ± 0.008 μg/100 mL) as compared to control sample (1.07 ± 0.02%, 79 ± 0.75 NTU, 0.65 ± 0.031%, and 0.306 ± 0.007 μg/100 mL). The flow behavior index (n) was closer to 1 in both juice samples, which indicated Newtonian-like flow behavior. Conclusively, sapodilla juice extraction at optimal condition (0.120% of pectinase concentration) and 42.02°C/167.83 min would be potentiated to the beverage industry. The use of pectinase might reduce membrane fouling and facilitates processing operation efficiently.

Optimization of substrate composition for pectinase production from Satkara (Citrus macroptera) peel using Aspergillus niger-ATCC 1640 in solid-state fermentation

Pectinase is an enzyme having a broad industrial and commercial application. However, higher production costs may be the major constraint for the wide-scale application of pectinase. Therefore, researchers are trying to reduce the pectinase production cost for subsequent application in the industrial processes by using a unique substrate and optimizing the fermentation medium components and process conditions. The main purpose of the current study was to optimize medium composition for pectinase production using Aspergillus niger-ATCC 1640 in the solid-state fermentation. The Response Surface Methodology (RSM) was performed to evaluate the effects of variables, specifically the concentrations of Satkara peel, urea, (NH₄)₂PO₄, NH₄NO₃, KH₂PO₄, ZnSO₄, and MgSO₄.7H₂O on pectinase production in the solid substrate. Firstly, a two-factorial design, Plackett-Burman design (PBD) was applied to screen the variables that significantly influenced the pectinase production. After finding the critical variables, 15 experimental runs were carried out using a Box-Behnken design (BBD) to derive a statistical model for optimizing the concentrations of the selected variables. The PBD model revealed that Satkara peel, urea, and (NH₄)₂SO₄ significantly affected the pectinase production. RSM results indicated that the predicted response for pectinase production was in good agreement with experimental data (R² = 0.9836). Under the optimized condition of Satkara peel (8.4 g/L), urea (0.5 g/L), and (NH₄)₂SO4 (2.7 g/L), the pectinase activity was predicted to be 0.6178 μmol/mL. In the present study, the experimental pectinase production achieved 0.6045 μmol/mL. The study revealed that optimization through RSM could improve the pectinase production from Satkara peel.

Biochemical Prospects of Various Microbial Pectinase and Pectin: An Approachable Concept in Pharmaceutical Bioprocessing

Both pectin and pectinase are vitally imperative biomolecules in the biotechnological sector. These molecules are a feasible non-toxic contrivance of nature with extensive applicative perception. Understanding pectic substances and their structure, unique depolymerization, and biochemical properties such as a catalytic mechanism and the strong interrelationship among these molecules could immensely enhance their applicability in industries. For instance, gaining knowledge with respect to the versatile molecular heterogeneity of the compounds could be considered as the center of concern to resolve the industrial issues from multiple aspects. In the present review, an effort has been made to orchestrate the fundamental information related to structure, depolymerization characteristics, and classification of pectin as well as the types and biochemical properties of pectinase. Furthermore, various production methods related to the optimization of the product and its significant contribution to the pharmaceutical industry (either pectinase or derived pectic substances) are described in this article.

Production, Characterization, and Industrial Application of Pectinase Enzyme Isolated from Fungal Strains

Pectinases are the group of enzymes that catalyze the degradation of pectic substances. It has wide applications in food industries for the production and clarification of wines and juices. The aim of this study was to isolate, screen and characterize pectinase from fungi isolated from various soil samples and evaluate its application in juice clarification. Fungal strains were isolated and screened primarily using 1% citruspectin incorporated potato dextrose agar (PDA) and secondarily using pectinase screening agar medium (PSAM) for pectinolytic organisms. The enzyme was produced by submerged state fermentation and assayed using the dinitro salicylic acid (DNS) method. From 20 different soil samples, 55 fungal isolates were screened primarily and, among them, only 14 isolates were subjected for secondary screening. Out of 14, only four strains showed the highest pectinolytic activity. Among four strains, Aspergillus spp. Gm showed the highest enzyme production at a 48-h incubation period, 1% substrate concentration, and 30 °C temperature. The thermal stability assessment resulted that the activity of pectinase enzyme declines by 50% within 10 min of heating at 60 °C. The optimum temperature, pH, and substrate concentration for the activity of enzyme was 30 °C (75.4 U/mL), 5.8 (72.3 U/mL), and 0.5% (112.0 U/mL), respectively. Furthermore, the yield of the orange juice, the total soluble solid (TSS), and clarity (% transmittance) was increased as the concentration of the pectinase increased, indicating its potential use in juice processing. Overall, the strain Aspergillus spp. Gm was identified as a potent strain for pectinase production in commercial scale.

Evolution of World and Brazilian Markets for Enzymes Produced by Solid-state Fermentation: A Patent Analysis

BACKGROUND

The use of enzymes in various industrial processes has become increasingly frequent. When added to productive processes, it can accelerate reactions and generate a number of new products. The solid state fermentation (SSF), among other applications, has been employed also to obtain enzymes.

OBJECTIVE

The purpose of this prospection was to map registered patent documents about enzymes production by this type of fermentation in the world, identify the most obtained enzymes with patent documents and compilate information about the world and Brazilian enzyme markets.

METHODS

The experimental design was carried out by the keyword-driven scope through the advanced search in the Espacenet database European Patent Office (EPO). The keywords selected were solid-state fermentation and the International Patent Classification code, C12N9 (enzymes; proenzymes), for prospecting of interest.

RESULTS

In 2012, there was the higher number of registered patents (12). China holds 84% of deposited patents. Among the types of depositors, 54% of the selected patent documents were deposited by universities and institutes, and 44% by companies. 76.5% of the evaluated patents used fungi as enzyme producer. Analyzing the enzymes obtained in the registered patents, it is verified that the majority belongs to the group of carbohydrases with 43%, followed by proteases (25%), which are also the two classes of enzymes most commercialized in the market.

CONCLUSION

China holds the majority of the registered patents but North America gets the largest global enzyme market revenue followed by Europe and Pacific Asia. Carbohydrases were the most commercialized enzymes and with the highest number of patents registered. Among the carbohydrases, cellulases, xylanases and amylases are the most frequent in patent registration while being fungi produced.

Subtopic: Advances in water and wastewater treatment harvesting of Chlorella sp. microalgae using Aspergillus niger as bio-flocculant for aquaculture wastewater treatment

Microalgae have been increasingly used to generate biofuel, thus a sustainable technique should be implemented to harvest the biomass to ensure its existence in the environment. Aspergillus niger was used as bio-flocculant to harvest microalgae from aquaculture wastewater via flocculation technique over a range of pH and mixing rate. The bio-flocculant showed ability to adapt at a wide range of pH from 3.0 to 9.0 and at a mixing rate of 100-150 rpm, producing a harvesting efficiency of higher than 90%. The treated water possessed low concentration of chlorophyll-a (0.3-0.6 mg L^-1) and cell density (2 × 10⁶-3 × 10⁶ cell mL^-1). These indicate that Aspergillus niger is a promising bio-flocculant to be used in harvesting microalgae, thus promoting the use of flocculation as a green technology in aquaculture wastewater treatment.

Multidisciplinary involvement and potential of thermophiles

The full biotechnological exploitation of thermostable enzymes in industrial processes is necessary for their commercial interest and industrious value. The heat-tolerant and heat-resistant enzymes are a key for efficient and cost-effective translation of substrates into useful products for commercial applications. The thermophilic, hyperthermophilic, and microorganisms adapted to extreme temperatures (i.e., low-temperature lovers or psychrophiles) are a rich source of thermostable enzymes with broad-ranging thermal properties, which have structural and functional stability to underpin a variety of technologies. These enzymes are under scrutiny for their great biotechnological potential. Temperature is one of the most critical parameters that shape microorganisms and their biomolecules for stability under harsh environmental conditions. This review describes in detail the sources of thermophiles and thermostable enzymes from prokaryotes and eukaryotes (microbial cell factories). Furthermore, the review critically examines perspectives to improve modern biocatalysts, its production and performance aiming to increase their value for biotechnology through higher standards, specificity, resistance, lowing costs, etc. These thermostable and thermally adapted extremophilic enzymes have been used in a wide range of industries that span all six enzyme classes. Thus, in particular, target of this review paper is to show the possibility of both high-value-low-volume (e.g., fine-chemical synthesis) and low-value-high-volume by-products (e.g., fuels) by minimizing changes to current industrial processes.