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

Resource recovery and treatment of wastewaters using filamentous fungi

Industrial wastewater, often characterized by its proximity to neutral pH, presents a promising opportunity for fungal utilization despite the prevalent preference of fungi for acidic conditions. This review addresses this discrepancy, highlighting the potential of certain industrial wastewaters, particularly those with low pH levels, for fungal biorefinery. Additionally, the economic implications of biomass recovery and compound separation, factors that require explicit were emphasized. Through an in-depth analysis of various industrial sectors, including food processing, textiles, pharmaceuticals, and paper-pulp, this study explores how filamentous fungi can effectively harness the nutrient-rich content of wastewaters to produce valuable resources. The pivotal role of ligninolytic enzymes synthesized by fungi in wastewater purification is examined, as well as their ability to absorb metal contaminants. Furthermore, the diverse benefits of fungal biorefinery are underscored, including the production of protein-rich single-cell protein, biolipids, enzymes, and organic acids, which not only enhance environmental sustainability but also foster economic growth. Finally, the challenges associated with scaling up fungal biorefinery processes for wastewater treatment are critically evaluated, providing valuable insights for future research and industrial implementation. This comprehensive analysis aims to elucidate the potential of fungal biorefinery in addressing industrial wastewater challenges while promoting sustainable resource utilization.

Temperature-driven divergence in molecular distribution and microbial invasion and the associated texture softening during dual-phase fermentation of Paocai

Temperature is an important driving force that shapes the texture of fermented vegetables through driving the molecular distribution and microbial invasion between the liquid phase (brine) and the solid phase (vegetables) during fermentation. The objective of this study was to investigate the texture softening by investigating firmness, microstructure, physicochemical properties, molecular distribution and microbial community between brine and vegetables of Paocai as affected by fermentation temperatures of 10 °C, 20 °C and 30 °C. Results demonstrated that, compared with 10 °C and 30 °C, 20 °C attenuated softening of Paocai by restraining microbial invasion and suppressing pectinolysis. Moreover, at 20 °C, a balanced molecular distribution and microbial community were achieved between vegetables and brine, thus accomplishing acid-production fermentation. By contrast, 10 °C and 30 °C promoted nonfermentative microbial genera, retarding fermentation. This study provided an understanding of the divergent influence of temperature on quality formation of fermented vegetables during fermentation.

The postbiotic potential of Aspergillus oryzae - a narrative review

The filamentous fungus Aspergillus oryzae has a long tradition in East Asian food processing. It is therefore not surprising that in recent years fermentation products of A. oryzae have attracted attention in the emerging field of postbiotics. This review aims to provide a comprehensive summary of the potential postbiotic effects of fermentation products from A. oryzae, by discussing possible mechanisms of action against the background of the molecular composition determined so far. In particular, cell wall constituents, enzymes, extracellular polymeric substances, and various metabolites found in A. oryzae fermentation preparations are described in detail. With reference to the generally assumed key targets of postbiotics, their putative beneficial bioactivities in modulating the microbiota, improving epithelial barrier function, influencing immune responses, metabolic reactions and signaling through the nervous system are assessed. Drawing on existing literature and case studies, we highlight A. oryzae as a promising source of postbiotics, particularly in the context of animal health and nutrition. Challenges and opportunities in quality control are also addressed, with a focus on the necessity for standardized methods to fully harness the potential of fungal-based postbiotics. Overall, this article sheds light on the emerging field of A. oryzae-derived postbiotics and emphasizes the need for further research to fully realize their therapeutic potential.

Optimizing pectin lyase production using the one-factor-at-a-time method and response surface methodology

Pectinases are commonly industrially synthesized by molds. This study aimed to optimize pectin lyase synthesis by a bacterium, Pseudomonas fluorescens, using both the one-factor-at-a-time (OFAT) method and response surface methodology. First, on optimization of pectin lyase fermentation by the OFAT method, the effects of pectin, peptone, yeast extract, (NH4)2SO4, pH, and salts were investigated. The highest pectin lyase activity was determined to be 28.63 U/mL at pH 8, 30°C, with 1% (w/v) pectin and 0.14% (w/v) (NH4)2SO4 concentration at the 90th hour. The effect of substrate inhibition on the microbial growth was also investigated, and the results showed that the process can be described by noncompetitive inhibition model. The values of kinetic constants were determined as µm = 0.175 h-1, KS = 6.931 g/L, and, KI = 6.932 g/L by nonlinear regression analysis. It was reported that pectin lyase enzymes exhibited peak activity at 50°C and pH 8. Finally, response surface methodology (RSM) was utilized to optimize pH, concentrations of ammonium sulfate, and pectin, which were chosen as independent variables. The interactions between these variables were also examined. According to RSM, the optimum values of the parameters to achieve a maximum pectin lyase activity of 35.62 U/mL were determined to be pH 7.97, 1.25% (w/v) pectin concentration, and 0.25% (w/v) (NH4)2SO4 concentration.

Fungal-mediated nanoparticles for industrial applications: synthesis and mechanism of action

The advancement of safe, eco-friendly, and cost-efficient techniques for nanoparticle production is a crucial objective in nanotechnology. Among the various sustainable methods, the biological synthesis of nanoparticles utilizing fungi, bacteria, yeasts, and plants stands out. Fungi, in particular, are well suited for this task because of their capacity to secrete numerous enzymes and streamline subsequent processes. Using fungal strains for nanoparticle biosynthesis is both technologically appealing and economically viable. The utilization of fungal strains for nanoparticle biosynthesis is both technologically appealing and economically viable. Fungi have long been acknowledged as adept natural engineers capable of creating a wide array of nanoparticles with distinct properties and applications. This article provides an overview of fungus-mediated nanoparticle development, shedding light on the underlying mechanisms of their synthesis and the factors influencing their characteristics. Furthermore, the potential of fungus-mediated nanoparticles in the industrial domain has been explored. These findings emphasize the importance of different fungal species in nanoparticle synthesis, as well as the biocompatibility and environmental friendliness of fungus-mediated nanoparticles. By underscoring the essential role of fungi in connecting natural knowledge with innovative industrial applications, recent progress in enhancing nanoparticle production and optimizing synthesis conditions through fungi has been examined to underscore the feasibility of extensive industrial nanoparticle utilization via fungi.

Adhesion Peptide-Functionalized Biobased Microgels for Controlled Delivery of Pesticides

Widespread use of plant protection agents in agriculture is a major cause of pollution. Apart from active ingredients, the environmental impact of auxiliary synthetic polymers should be minimized if they are highly persistent. An alternative to synthetic polymers is the use of natural polysaccharides, which are abundant and biodegradable. In this study, we explore pectin microgels functionalized with anchor peptides (P-MAPs) to be used as an alternative biobased pesticide delivery system. Using copper as the active ingredient, P-MAPs effectively prevented infection of grapevine plants with downy mildew under semi-field conditions on par with commercial copper pesticides. By using anchor peptides, the microgels tightly bind to the leaf surface, exhibiting excellent rain fastness and prolonged fungicidal activity. Finally, P-MAPs are shown to be easily degradable by enzymes found in nature, demonstrating their negligible long-term impact on the environment.

Morphological variation and expressed sequence tags-simple sequence repeats-based genetic diversity of Aspergillus cristatus in Chinese dark tea

Introduction

Aspergillus cristatus is a homothallic fungus that is used in the natural fermentation process of Chinese Fuzhuan tea and has been linked to the production of bioactive components. However, not much is known about the variations present in the fungus. To understand the variation of the dominant microorganism, A. cristatus, within dark tea, the present study investigated the genetic and morphological diversity of 70 A. cristatus collected across six provinces of China.

Methods

Expressed sequence tags-simple sequence repeats (EST-SSR) loci for A. cristatus were identified and corresponding primers were developed. Subsequently, 15 specimens were selected for PCR amplification.

Results

The phylogenetic tree obtained revealed four distinct clusters with a genetic similarity coefficient of 0.983, corresponding to previously identified morphological groups. Five strains (A1, A11, B1, D1, and JH1805) with considerable differences in EST-SSR results were selected for further physiological variation investigation. Microstructural examinations revealed no apparent differentiation among the representative strains. However, colony morphology under a range of culture media varied substantially between strains, as did the extracellular enzymatic activity (cellulase, pectinase, protease, and polyphenol oxidase); the data indicate that there are differences in physiological metabolic capacity among A. cristatus strains.

Discussion

Notably, JH1805, B1, and A11 exhibited higher enzymatic activity, indicating their potential application in the production of genetically improved strains. The findings provide valuable insights into species identification, genetic diversity determination, and marker-assisted breeding strategies for A. cristatus.

Simple one-step treatment for saccharification of mango peels using an optimized enzyme cocktail of Aspergillus niger ATCC 9642

Developing efficient microbiological methods to convert polysaccharide-rich materials into fermentable sugars, particularly monosaccharides, is vital for advancing the bioeconomy and producing renewable chemicals and energy sources. This study focused on optimizing the production conditions of an enzyme cocktail from Aspergillus niger ATCC 9642 using solid-state fermentation (SSF) and assessing its effectiveness in saccharifying mango peels through a simple, rapid, and efficient one-step process. A rotatable central composite design was employed to determine optimal conditions of moisture, time, and pH for enzyme production in SSF medium. The optimized enzyme cocktail exhibited cellulase activity (CMCase) at 6.28 U/g, filter paper activity (FPase) at 3.29 U/g, and pectinase activity at 117.02 U/g. These optimal activities were achieved with an SSF duration of 81 h, pH of 4.66, and a moisture content of 59%. The optimized enzyme cocktail effectively saccharified the mango peels without the need for chemical agents. The maximum saccharification yield reached approximately 81%, indicating efficient conversion of mango peels into sugars. The enzyme cocktail displayed consistent thermal stability within the tested temperature range of 30-60°C. Notably, the highest sugar release occurred within 36 h, with glucose, arabinose, galactose, and xylose being the primary monosaccharides released during saccharification. This study highlights the potential application of Aspergillus niger ATCC 9642 and SSF for enzymatic production, offering a simple and high-performance process for monosaccharide production. The optimized enzyme cocktail obtained through solid-state fermentation demonstrated efficient saccharification of mango peels, suggesting its suitability for industrial-scale applications.

Molecular identification and lipolytic potential of filamentous fungi isolated from residual cooking oil

Filamentous fungi, microorganisms that develop and are located in different habitats, are considered important producers of enzymes and metabolites with potential for the biotechnology industry. The objective of this work was to isolate and identify filamentous fungi that grow in used oil. Two fungal species were characterised through their morphology and molecular identification. The DNA of each extracted strain was amplified by PCR using primers ITS1 and ITS4, obtaining sequences that were later in GenBank (NCBI). A white coloured strain (HB) with a cottony, white, hyaline morphology and irregular borders was observed; so too, a brown colony (HC) with a sandy surface, a well-defined border of beige colour in early growth until it became a dark brown colour. The identity result by homology of the sequences in the BLASTn database was 100% and 99.55%, indicating that they correspond to Cladosporiumtenuissimum and Fomitopsismeliae, respectively. Finally, the results in lipolytic activity show greater potential for Fomitopsismeliae with 0.61 U/l in residual oil. Thus, it is important to highlight the potential of this type of waste to favour the prospection of microorganisms for a sustainable alternative for future studies of biological conversion.

Pharmamedia and pectinase production by Bacillus subtilis Mz-12P

Bacterial isolates collected from the environment were screened for pectinolytic activity, and a strain with the highest activity was selected and identified as Bacillus subtilis Mz-12. The presence of pectin hydrolase, lyase, and esterase activities was confirmed. Pectinase was purified and characterized. Enzyme production was optimized with respect to temperature, pH, and growth medium. Enzyme stability and activity were characterized under different temperatures and pH values. The results showed that this strain was capable of producing high yields of pectinase in commercial medium (Pharmamedia) 24.6 U/mL compared to other media. The purified pectinase of 22.3 kDa produced was constitutive in nature. The isolated enzyme from this strain displayed a wide range of temperature and pH stability, with the optimal activity observed at pH 9.0 and 50°C. These results indicate that the B. subtilis Mz-12 strain is a favorable candidate for industrial enzyme production. The use of Pharmamedia is reported for first time for pectinase production.

Synthesis of dietary lipids from pumpkin (Cucurbita pepo. L) oil obtained by enzymatic extraction: a sustainable approach

This study aimed to assess the nutritional properties of dietary lipids obtained through the modification of aqueous enzymatically extracted pumpkin seed (Cucurbita pepo. L) oil. The optimal growth conditions for producing pectinase using strain Aspergillus sp. 391 were determined, and partial characterization of pectinase and commercial cellulase was conducted. The enzymatic extraction was performed at pH 4.0, 50 °C, for 24 h, using a combination of pectinase and cellulase for optimum effectiveness. The crude oil obtained was analyzed for acid, peroxide, and fatty acid composition. The study found a high amount of unsaturated fatty acids, mainly linoleic acid (C18:2), and a 59% oil recovery rate. Subsequently, this oil was subjected to enzymatic acidolysis with capric acid in solvent-free media, catalyzed by lipase Lipozyme RM IM®, resulting in a product with a higher incorporation degree (48.39 ± 0.5 mol%), observed after 24 h at 60 °C using molar ratio oil:acid capric of 1:9 (run 4). The nutritional properties of this oil were improved.

Pectinases as promising green biocatalysts having broad-spectrum applications: Recent trends, scope, and relevance

Pectinases are a collection of multiple enzymes that have a common substrate, that is, pectin. They can act on different parts of pectin due to the structural heterogeneity of pectin. Therefore, they have been placed in different groups, such as protopectinases, polygalacturonases, polymethylesterases, pectin lyases, and pectate lyases. They are naturally present both in multicellular organisms such as higher plants and in unicellular organisms such as microbes. In past decade, it has been witnessed that chemical and mechanical methods employed in industrial processes have led to environmental hazards and serious health disorders, thus increasing the search for eco-friendly approaches with minimal health risks. Hence, microbial enzymes have been extensively used as safer alternative for these environmentally unsafe methods. Among these microbial enzymes, pectinases hold great significance and is one of the principal enzymes that have been used commercially. It is predominantly used as a green biocatalyst for fruit, fiber, oil, textile, beverage, pulp, and paper industry. Thus, this review focuses on the structure of pectin, microbial sources of pectin, and principle industrial applications of pectinases.

Fungal pectinases: an insight into production, innovations and applications

The fungal system holds morphological plasticity and metabolic versatility which makes it unique. Fungal habitat ranges from the Arctic region to the fertile mainland, including tropical rainforests, and temperate deserts. They possess a wide range of lifestyles behaving as saprophytic, parasitic, opportunistic, and obligate symbionts. These eukaryotic microbes can survive any living condition and adapt to behave as extremophiles, mesophiles, thermophiles, or even psychrophile organisms. This behaviour has been exploited to yield microbial enzymes which can survive in extreme environments. The cost-effective production, stable catalytic behaviour and ease of genetic manipulation make them prominent sources of several industrially important enzymes. Pectinases are a class of pectin-degrading enzymes that show different mechanisms and substrate specificities to release end products. The pectinase family of enzymes is produced by microbial sources such as bacteria, fungi, actinomycetes, plants, and animals. Fungal pectinases having high specificity for natural sources and higher stabilities and catalytic activities make them promising green catalysts for industrial applications. Pectinases from different microbial sources have been investigated for their industrial applications. However, their relevance in the food and textile industries is remarkable and has been extensively studied. The focus of this review is to provide comprehensive information on the current findings on fungal pectinases targeting diverse sources of fungal strains, their production by fermentation techniques, and a summary of purification strategies. Studies on pectinases regarding innovations comprising bioreactor-based production, immobilization of pectinases, in silico and expression studies, directed evolution, and omics-driven approaches specifically by fungal microbiota have been summarized.

Assessment of cultivation parameters influencing pectinase production by Aspergillus niger LFP-1 in submerged fermentation

BACKGROUND

Pectinase is helpful in food and beverage industries, particularly in the preparation of fruit juice, the extraction of vegetable oil, and the fermentation of coffee. The current work aimed to screen Aspergillus niger LFP-1, a recently identified fungal strain, for its ability to produce pectinase and to ascertain the contribution of various physicochemical factors to pectinase production.

RESULTS

The primary and secondary pectinase activity screenings by Aspergillus niger LFP-1 were performed using pectin screening agar and shake flask system, respectively. The finding revealed that the locally isolated strain is able to secrete favourable pectinase production. Before improvement, the pectinase production was 0.88 ± 0.09 U/mL. However, the improved conditions such as 6 days of the cultivation period, agitation speed of 150 rpm, inoculum size of 1 × 10⁶ spores/mL, 2.5% (w/v) citrus pectin, and 0.4% (w/v) ammonium nitrate could significantly increase pectinase production up to 7.41 ± 0.24 U/mL, representing an 88% increase. In this study, supplementing 2.5% (w/v) citrus pectin to the culture medium as a carbon source increased enzyme production by up to 3.07 ± 0.17 U/mL. Meanwhile, 0.4% (w/v) ammonium nitrate was used as a nitrogen source yielding the highest enzyme activity with a value of 6.86 ± 0.07 U/mL.

CONCLUSION

Thus, the locally isolated fungal strain, A. niger LFP-1 has outstanding pectinase-producing capability and can be utilized for the commercial production of pectinase. The improved cultural conditions significantly increase pectinase production and shorten the incubation period from 8 days (before improvement) to 6 days (after improvement).

Comparison of Trichoderma longibrachiatum Xyloglucanase Production Using Tamarind (Tamarindus indica) and Jatoba (Hymenaea courbaril) Seeds: Factorial Design and Immobilization on Ionic Supports

Xyloglucan (XG) is the predominant hemicellulose in the primary cell wall of superior plants. It has a fundamental role in controlling the stretching and expansion of the plant cell wall. There are five types of enzymes known to cleave the linear chain of xyloglucan, and the most well-known is xyloglucanase (XEG). The immobilization process can be used to solve problems related to stability, besides the economic benefits brought by the possibility of its repeated use and recovery. Therefore, this study aims at the optimization of the xyloglucanase production of Trichoderma longibrachiatum using a central composite rotatable design (CCRD) with tamarind and jatoba seeds as carbon sources, as well as XEG immobilization on ionic supports, such as MANAE (monoamine-N-aminoethyl), DEAE (diethylaminoethyl)-cellulose, CM (carboxymethyl)-cellulose, and PEI (polyethyleneimine). High concentrations of carbon sources (1.705%), at a temperature of 30 °C and under agitation for 72 h, were the most favorable conditions for the XEG activity from T. longibrachiatum with respect to both carbon sources. However, the tamarind seeds showed 23.5% higher activity compared to the jatoba seeds. Therefore, this carbon source was chosen to continue the experiments. The scaling up from Erlenmeyer flasks to the bioreactor increased the XEG activity 1.27-fold (1.040 ± 0.088 U/mL). Regarding the biochemical characterization of the crude extract, the optimal temperature range was 50–55 °C, and the optimal pH was 5.0. Regarding the stabilities with respect to pH and temperature, XEG was not stable for prolonged periods, which was crucial to immobilizing it on ionic resins. XEG showed the best immobilization efficiency on CM-cellulose and DEAE-cellulose, with activities of 1.16 and 0.89 U/g of the derivative (enzyme plus support), respectively. This study describes, for the first time in the literature, the immobilization of a fungal xyloglucanase using these supports.

Production, Partial Purification, and Characterization of Polygalacturonase from Aureobasidium pullulans P56 under Submerged Fermentation Using Agro-Industrial Wastes

Polygalacturonase (PGase) production by Aureobasidium pullulans P56 under submerged fermentation was investigated using agro-industrial wastes and commercial carbon and nitrogen sources. The maximum PGase concentration was equivalent to 8.6 U/mL that was obtained in presence of citrus pectin at 150 rpm, 30 °C, pH = 5.5, and 60 h of fermentation conditions. However, a significant amount of enzyme production was also recorded upon the utilization of corncob (5.3 U/mL) and wheat bran (4.4 U/mL) as carbon sources. Amongst the different nitrogen sources, the highest enzyme production (8.2 U/mL) was obtained in presence of ammonium sulphate and yeast extract simultaneously at a ratio of 1:1. The enzyme was partially purified by gel filtration using Sephadex G50 equilibrated and washed with 50 mM-sodium acetate buffer. The obtained yield and specific activity were determined equivalent to 17% and 9.53 U/mg, respectively. The molecular weight of the partially purified enzyme was estimated as 54 kDa on SDS-PAGE. The conditions affecting the enzyme activity were determined and the highest enzyme activity was recorded at 40 °C and 4.5 pH. Amongst the tested metal ions, 2 and 5 mM of CaCl₂ concentrations increased the enzymatic activity by 30%. Overall, the use of corncob (2.5%) to produce PGase by A. pullulans represents an attractive agro-industrial substrate.

Extracellular Enzyme of Endophytic Fungi Isolated from Ziziphus spina Leaves as Medicinal Plant

Endophytic fungi live inside plants or any part of them without creating any visible pathogenic signs. Endophytic fungi are found within medicinal plants and have shown strong biologic activity, such as anticancer and antioxidant activities, as well as producing extracellular enzymes. In this study, different fungal strains were isolated from the leaves of the medicinal plant Ziziphus spina, including Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Cladosporium sp., Rhizopus sp., and Mucor sp. Extracellular enzymes have been quantified using agar plate-based methods in which fungi were grown in specified growth media to detect the enzymes produced. The results showed that A. niger has the highest ability to produce amylase, Cladosporium sp. has the highest ability to produce protease and pectinase, Rhizopus and Mucor sp. have the highest ability to produce cellulase, and A. niger and Cladosporium sp. have the same ability to produce lipase and laccase. The ability of medicinal plant endophytic fungi to produce extracellular enzymes has great therapeutic potential in clinical microbiology. Some of the isolates showed great activity in secreting particular enzymes, indicating that the enzymes of these fungi could be used in a variety of applications.

Microbial production of multienzyme preparation from mosambi peel using Trichoderma asperellum

Fruit and vegetable wastes create unhygienic conditions and pose a environmental pollution. The utilization of such wastes as carbon sources for production of enzyme with microbial intervention could be an ecofriendly and profitable approach, apart from diminishing the waste load. The present investigation focused on the feasibility of using mosambi (Citrus limetta) peel as substrate for multienzyme production (pectinase, cellulase and amylase) through microbial intervention. Fifteen fungi were isolated from organic waste and screened in vitro their potential of biodegradation of mosambi peel through enzymes production. The best performing isolate was selected and identified as Trichoderma asperellum NG-125 (accession number-MW287256). Conditions viz. temperature, pH, incubation time and nutrient addition were optimized for efficient enzymes production. The maximum enzyme activity (U ml^-1 min^-1) of pectinase (595.7 ± 2.47), cellulase (497.3 ± 2.06) and amylase (440.9 ± 1.44) were observed at pH 5.5, incubation temperature of 30 °C after 10 days of fermentation. Moreover, macro-nutrients such as ammonium sulfate (0.1%) and potassium-di-hydrogen-ortho-phosphate (0.01%) further also enhanced the production of enzymes. The SDS-PAGE analysis of purified pectinase, cellulase and amylase using showed molecular mass of 43, 66 and 33 kDa, respectively. The enzyme retention activity (ERA) of aforesaid enzymes was also tested with four different natural fiber matrices viz., bagasse, rice husk, paddy straw and wheat straw. Among these, the maximum ERA was observed on bagasse matrix (pectinase-56.35%, cellulose-77.68% and amylase 59.54%). Enzymatic juice clarification yield obtained with test enzyme was 75.8%, as compared to 80.5% of commercial enzyme. The result indicates that T. asperellum may be exploited as multifaceted biocatalysis.

Response-Surface Statistical Optimization of Submerged Fermentation for Pectinase and Cellulase Production by Mucor circinelloides and M. hiemalis

Cellulase and pectinase are degrading cellulosic and pectic substances that form plant cell walls and, thereby, they have a wide range of applications in the agro-industrial by-products recycling and food industries. In the current research, Mucor circinelloides and M. hiemalis strains were tested for their ability to produce cellulase and pectinase from tangerine peel by submerged fermentation. Experiments on five variables: temperature, pH, incubation period, inoculum size, and substrate concentration, were designed with a Box–Behnken design, as well as response surface methodology (RSM), and analysis of variance was performed. In addition, cellulase and pectinase were partially purified and characterized. At their optimum parameters, M. circinelloides and M. hiemalis afforded high cellulase production (37.20 U/mL and 33.82 U/mL, respectively) and pectinase (38.02 U/mL and 39.76 U/mL, respectively). The partial purification of M. circinelloides and M. hiemalis cellulase produced 1.73- and 2.03-fold purification with 31.12 and 32.02% recovery, respectively; meanwhile, 1.74- and 1.99-fold purification with 31.26 and 31.51% recovery, respectively, were obtained for pectinase. Partially purified cellulase and pectinase from M. circinelloides and M. hiemalis demonstrated the highest activity at neutral pH, and 70 and 50 °C, for cellulase and 50 and 60 °C, for pectinase, respectively. Moreover, 10 mM of K+ increased M. circinelloides enzymatic activity. The production of cellulase and pectinase from M. circinelloides and M. hiemalis utilizing RSM is deemed profitable for the decomposition of agro-industrial wastes.

Metabolic Potential of Halophilic Filamentous Fungi—Current Perspective

Salty environments are widely known to be inhospitable to most microorganisms. For centuries salt has been used as a food preservative, while highly saline environments were considered uninhabited by organisms, and if habited, only by prokaryotic ones. Nowadays, we know that filamentous fungi are widespread in many saline habitats very often characterized also by other extremes, for example, very low or high temperature, lack of light, high pressure, or low water activity. However, fungi are still the least understood organisms among halophiles, even though they have been shown to counteract these unfavorable conditions by producing multiple secondary metabolites with interesting properties or unique biomolecules as one of their survival strategies. In this review, we focused on biomolecules obtained from halophilic filamentous fungi such as enzymes, pigments, biosurfactants, and osmoprotectants.

A novel method of affinity purification and characterization of polygalacturonase of Aspergillus flavus by galacturonic acid engineered magnetic nanoparticle

Pectinases hydrolyze pectin and make up 25% of global food processing enzyme sales. In this study, we aimed to purify exo-polygalacturonase (Exo-PG) by using galacturonic acid conjugated magnetic nanoparticles (MNPs) and examined its application in juice purification. The submerged fermentation was carried out in the presence of apple pectin (1%) to promote production of exo-PG from Aspergillus flavus. Maximum exo-PG activity was observed after 4 days (30 °C and pH 5.0). A single protein band (66 kDa) of purified exo-PG was observed in SDS-PAGE. Purification of exo-PG enzyme was ∼ 10 fold with a yield of 29%. The enzyme retained 98% activity in the presence of 15 % glycerol at 4 °C. The purified exo-PG using MNPs yielded a 10-12% increase in juice production as compare to without treated fruit juice. To the best of our knowledge, this is the first report of affinity purification of exo-PG enzyme, using engineered magnetic nanoparticles.

Biochemical Characterization of Two Rhamnogalacturonan Lyases From Bacteroides ovatus ATCC 8483 With Preference for RG-I Substrates

Rhamnogalacturonan lyase (RGL) cleaves backbone α-1,4 glycosidic bonds between L-rhamnose and D-galacturonic acid residues in type I rhamnogalacturonan (RG-I) by β-elimination to generate RG oligosaccharides with various degrees of polymerization. Here, we cloned, expressed, purified and biochemically characterized two RGLs (Bo3128 and Bo4416) in the PL11 family from Bacteroides ovatus ATCC 8483. Bo3128 and Bo4416 displayed maximal activity at pH 9.5 and pH 6.5, respectively. Whereas the activity of Bo3128 could be increased 1.5 fold in the presence of 5 mM Ca²⁺, Bo4416 required divalent metal ions to show any enzymatic activity. Both of RGLs showed a substrate preference for RG-I compared to other pectin domains. Bo4416 and Bo3128 primarily yielded unsaturated RG oligosaccharides, with Bo3128 also producing them with short side chains, with yields of 32.4 and 62.4%, respectively. Characterization of both RGLs contribute to the preparation of rhamnogalacturonan oligosaccharides, as well as for the analysis of the fine structure of RG-I pectins.

Advances in solid-state fermentation for bioconversion of agricultural wastes to value-added products: Opportunities and challenges

The increase in solid waste has become a common problem and causes environmental pollution worldwide. A green approach to valorise solid waste for sustainable development is required. Agricultural residues are considered suitable for conversion into profitable products through solid-state fermentation (SSF). Agricultural wastes have high organic content that is used as potential substrates to produce value-added products through SSF. The importance of process variables used in solid-phase fermentation is described. The applications of SSF developed products in the food industry as flavouring agents, acidifiers, preservatives and flavour enhancers. SSF produces secondary metabolites and essential enzymes. Wastes from agricultural residues are used as bioremediation agents, biofuels and biocontrol agents through microbial processing. In this review paper, the value addition of agricultural wastes by SSF through green processing is discussed with the current knowledge on the scenarios, sustainability opportunities and future directions of a circular economy for solid waste utilisation.

Enzymatic Bioprospecting of Fungi Isolated from a Tropical Rainforest in Mexico

The humid tropical environment provides an ideal place for developing a high diversity of plants; this is why it is an interesting site for the enzymatic bioprospecting of fungi that are responsible for the recycling of organic matter in an efficient and accelerated way and whose enzymes could have multiple biotechnological applications. For this study, 1250 isolates of macroscopic and microscopic fungal morphotypes were collected from soil, leaf litter, and wood. One hundred and fifty strains (50 from each source) were selected for the enzymatic screening. From the first phase, 51 strains with positive activity for laccase, protease, amylase, xylanase, and lipase enzymes were evaluated, of which 20 were isolated from leaf litter, 18 from the soil, and 13 from wood. The 10 best strains were selected for the enzymatic quantification, considering the potency index and the production of at least two enzymes. High laccase activity was detected for Trametes villosa FE35 and Marasmius sp. CE25 (1179 and 710.66 U/mg, respectively), while Daedalea flavida PE47 showed laccase (521.85 U/mg) and protease activities (80.66 U/mg). Fusarium spp. PH79 and FS400 strains had amylase (14.0 U/mg, 49.23 U/mg) and xylanase activities (40.05 U/mg, 36.03 U/mg) respectively. These results confirm the enzymatic potential of fungi that inhabit little-explored tropical rainforests with applications in industry.

A Comprehensive Insight into Fungal Enzymes: Structure, Classification, and Their Role in Mankind's Challenges

Enzymes have played a crucial role in mankind's challenges to use different types of biological systems for a diversity of applications. They are proteins that break down and convert complicated compounds to produce simple products. Fungal enzymes are compatible, efficient, and proper products for many uses in medicinal requests, industrial processing, bioremediation purposes, and agricultural applications. Fungal enzymes have appropriate stability to give manufactured products suitable shelf life, affordable cost, and approved demands. Fungal enzymes have been used from ancient times to today in many industries, including baking, brewing, cheese making, antibiotics production, and commodities manufacturing, such as linen and leather. Furthermore, they also are used in other fields such as paper production, detergent, the textile industry, and in drinks and food technology in products manufacturing ranging from tea and coffee to fruit juice and wine. Recently, fungi have been used for the production of more than 50% of the needed enzymes. Fungi can produce different types of enzymes extracellularly, which gives a great chance for producing in large amounts with low cost and easy viability in purified forms using simple purification methods. In the present review, a comprehensive trial has been advanced to elaborate on the different types and structures of fungal enzymes as well as the current status of the uses of fungal enzymes in various applications.

Metabolic engineering of Bacillus subtilis with an endopolygalacturonase gene isolated from Pectobacterium. carotovorum; a plant pathogenic bacterial strain

Pectinolytic enzymes or pectinases are synthesized naturally by numerous microbes and plants. These enzymes degrade various kinds of pectin which exist as the major component of the cell wall in plants. A pectinase gene encoding endo-polygalacturonase (endo-PGase) enzyme was isolated from Pectobacterium carotovorum a plant pathogenic strain of bacteria and successfully cloned into a secretion vector pHT43 having σA-dependent promoter for heterologous expression in Bacillus subtilis (WB800N).The desired PCR product was 1209bp which encoded an open reading frame of 402 amino acids. Recombinant proteins showed an estimated molecular weight of 48 kDa confirmed by sodium dodecyl sulphate-polyacrylamide-gel electrophoresis. Transformed B. subtilis competent cells harbouring the engineered pHT43 vector with the foreign endo-PGase gene were cultured in 2X-yeast extract tryptone medium and subsequently screened for enzyme activity at various temperatures and pH ranges. Optimal activity of recombinant endo-PGase was found at 40°C and pH 5.0. To assay the catalytic effect of metal ions, the recombinant enzyme was incubated with 1 mM concentration of various metal ions. Potassium chloride increased the enzyme activity while EDTA, Zn++ and Ca++, strongly inhibited the activity. The chromatographic analysis of enzymatic hydrolysates of polygalacturonic acid (PGA) and pectin substrates using HPLC and TLC revealed tri and tetra-galacturonates as the end products of recombinant endo-PGase hydrolysis. Conclusively, endo-PGase gene from the plant pathogenic strain was successfully expressed in Bacillus subtilis for the first time using pHT43 expression vector and could be assessed for enzyme production using a very simple medium with IPTG induction. These findings proposed that the Bacillus expression system might be safer to escape endotoxins for commercial enzyme production as compared to yeast and fungi. Additionally, the hydrolysis products generated by the recombinant endo-PGase activity offer their useful applications in food and beverage industry for quality products.

New insights in pectinase production development and industrial applications

Pectinase, a group of pectin degrading enzymes, is one of the most influential industrial enzymes, helpful in producing a wide variety of products with good qualities. These enzymes are biocatalysts and are highly specific, non-toxic, sustainable, and eco-friendly. Consequently, both pectin and pectinase are crucially essential biomolecules with extensive applicatory perception in the biotechnological sector. The market demand and application of pectinases in new sectors are continuously increasing. However, due to the high cost of the substrate used for the growth of microbes, the production of pectinase using microorganisms is limited. Therefore, low-cost or no-cost substrates, such as various agricultural biomasses, are emphasized in producing pectinases. The importance and implications of pectinases are rising in diverse areas, including bioethanol production, extraction of DNA, and protoplast isolation from a plant. Therefore, this review briefly describes the structure of pectin, types and source of pectinases, substrates and strategies used for pectinases production, and emphasizes diverse potential applications of pectinases. The review also has included a list of pectinases producing microbes and alternative substrates for commercial production of pectinase applicable in pectinase-based industrial technology.Key points• Pectinase applications are continuously expanding.• Organic wastes can be used as low-cost sources of pectin.• Utilization of wastes helps to reduce pollution.

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.

Cost-effective production of biocatalysts using inexpensive plant biomass: a review

Enzymes are the complex protein moieties, catalyze the rate of chemical reactions by transforming various substrates to specific products and play an integral part in multiple biochemical cycles. Advancement in enzyme research and its integration with industries have reformed the biotech industries. It provides a superior monetary and ecological exchange to traditional material measures in an efficient and environmentally sustainable manner. The cost-effective production of pure and highly active enzymes is still a challenge for the biocatalyst industries. The use of high purity substrates further raises the cost of a typical biocatalyst. The use of low-cost plant-based biomasses as an enticing and sustainable substrate for enzyme production is the most cost-effective approach to these problems. Given the relevance of biomass as a substrate for enzyme development, this review article focuses on the key source, composition and major enzyme generated using various biomass residues. Furthermore, the difficulties associated with the use of biomass as a substrate and technical developments in this area, are also addressed. The use of waste biomass as a substrate lowers the ultimate cost for the production of biocatalysts while simultaneously reduces the waste burden from the environment.

Conversion of Pectin-Containing By-Products to Pectinases by Bacillus amyloliquefaciens and Its Applications on Hydrolyzing Banana Peels for Prebiotics Production

The utilization of pectin-containing by-products may be useful in a variety of fields. This study aims to establish the processing of pectin-containing by-products to produce pectinases using Bacillus amyloliquefaciens TKU050 strain. In this study, several kinds of agricultural pectin-containing by-products from banana (banana peel), rice (rice bran), orange (orange peel), coffee (spent coffee grounds), and wheat (wheat bran) were utilized to provide carbon sources for the production of a pectinase by B. amyloliquefaciens TKU050. B. amyloliquefaciens TKU050 expressed the highest pectinase productivity (0.76 U/mL) on 0.5% wheat bran-containing medium at 37°C for four days. A 58 kDa pectinase was purified from the four-day cultured medium fermented under optimized culture conditions with 7.24% of a recovery ratio and 0.51 U/mg of specific activity, respectively. The optimum temperature, optimum pH, thermal stability, and pH stability of the TKU050 pectinase were 50 °C, pH 6, <50 °C, and pH 6–9, respectively. The TKU050 pectinase was inhibited by sodium dodecyl sulfate and Cu²⁺. The reducing sugar obtained by hydrolyzing banana peel with TKU050 pectinase showed the growth-enhancing effect on the growth of four tested lactic acid bacteria.