Novel enzymatic processes applied to the food industry

Protein secretion and associated stress in industrially employed filamentous fungi

Application of filamentous fungi for the production of commercial enzymes such as amylase, cellulase, or xylanase is on the rise due to the increasing demand to degrade several complex carbohydrates as raw material for biotechnological processes. Also, protein production by fungi for food and feed gains importance. In any case, the protein production involves both cellular synthesis and secretion outside of the cell. Unfortunately, the secretion of proteins or enzymes can be hampered due to accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) as a result of too high synthesis of enzymes or (heterologous) protein expression. To cope with this ER stress, the cell generates a response known as unfolded protein response (UPR). Even though this mechanism should re-establish the protein homeostasis equivalent to a cell under non-stress conditions, the enzyme expression might still suffer from repression under secretory stress (RESS). Among eukaryotes, Saccharomyces cerevisiae is the only fungus, which is studied quite extensively to unravel the UPR pathway. Several homologs of the proteins involved in this signal transduction cascade are also found in filamentous fungi. Since RESS seems to be absent in S. cerevisiae and was only reported in Trichoderma reesei in the presence of folding and glycosylation inhibitors such as dithiothreitol and tunicamycin, more in-depth study about this mechanism, specifically in filamentous fungi, is the need of the hour. Hence, this review article gives an overview on both, protein secretion and associated stress responses in fungi. KEY POINTS: • Enzymes produced by filamentous fungi are crucial in industrial processes • UPR mechanism is conserved among many fungi, but mediated by different proteins • RESS is not fully understood or studied in industrially relevant filamentous fungi.

Bioprospecting of endophytic fungi from semidesert candelilla (Euphorbia antisyphilitica Zucc): Potential for extracellular enzyme production

Endophytic microbial communities colonize plants growing under various abiotic stress conditions. Candelilla (Euphorbia antisyphilitica Zucc.) is a shrub that develops functionally in arid and semi-arid zones of Mexico; these conditions generate an association between the plant and the microorganisms, contributing to the production of enzymes as a defense mechanism for resistance to abiotic stress. The objective of this research was to isolate and identify endophyte fungi of candelilla and bioprospection of these endophytic fungi for enzyme production using candelilla by-products. Fungi were isolated and identified using ITS1/ITS4 sequencing. Their potency index (PI) was evaluated in producing endoglucanase, xylanase, amylase, and laccase. Fermentation was carried out at 30°C for 8 days at 200 rpm, with measurements every 2 days, using candelilla by-products as substrate. All fungi exhibited higher cellulase, amylase, and laccase activities on the 2nd, 6th, and 8th day of fermentation, respectively, of fermentation. The fungus Aspergillus niger ITD-IN4.1 showed the highest amylase activity (246.84 U/mg), the genus Neurospora showed the highest cellulase activity, reaching up to 13.45 FPU/mg, and the strain Neurospora sp. ITD-IN5.2 showed the highest laccase activity (3.46 U/mg). This work provides the first report on the endophytic diversity of E. antisyphilitica and its potential role in enzyme production.

Harnessing genetic engineering to drive economic bioproduct production in algae

Our reliance on agriculture for sustenance, healthcare, and resources has been essential since the dawn of civilization. However, traditional agricultural practices are no longer adequate to meet the demands of a burgeoning population amidst climate-driven agricultural challenges. Microalgae emerge as a beacon of hope, offering a sustainable and renewable source of food, animal feed, and energy. Their rapid growth rates, adaptability to non-arable land and non-potable water, and diverse bioproduct range, encompassing biofuels and nutraceuticals, position them as a cornerstone of future resource management. Furthermore, microalgae's ability to capture carbon aligns with environmental conservation goals. While microalgae offers significant benefits, obstacles in cost-effective biomass production persist, which curtails broader application. This review examines microalgae compared to other host platforms, highlighting current innovative approaches aimed at overcoming existing barriers. These approaches include a range of techniques, from gene editing, synthetic promoters, and mutagenesis to selective breeding and metabolic engineering through transcription factors.

Easy and Versatile Technique for the Preparation of Stable and Active Lipase-Based CLEA-like Copolymers by Using Two Homofunctional Cross-Linking Agents: Application to the Preparation of Enantiopure Ibuprofen

An easy and versatile method was designed and applied successfully to obtain access to lipase-based cross-linked-enzyme aggregate-like copolymers (CLEA-LCs) using one-pot, consecutive cross-linking steps using two types of homobifunctional cross-linkers (glutaraldehyde and putrescine), mediated with amine activation through pH alteration (pH jump) as a key step in the process. Six lipases were utilised in order to assess the effectiveness of the technique, in terms of immobilization yields, hydrolytic activities, thermal stability and application in kinetic resolution. A good retention of catalytic properties was found for all cases, together with an important thermal and storage stability improvement. Particularly, the CLEA-LCs derived from Candida rugosa lipase showed an outstanding behaviour in terms of thermostability and capability for catalysing the enantioselective hydrolysis of racemic ibuprofen ethyl ester, furnishing the eutomer (S)-ibuprofen with very high conversion and enantioselectivity.

Machine Learning for Prediction, Classification, and Identification of Immobilized Enzymes for Biocatalysis

BACKGROUND

Enzyme immobilization is a beneficial component involved in biocatalytic strategies. Understanding and evaluating the enzyme immobilization system plays an important role in the successful development and implementation of the biocatalysis route. Ensuring the implementation of a successful enzyme immobilization process is vital for realizing a highly functioning and well suited biocatalytic process within pharmaceutical development.

AIM

To develop a method which can accurately and objectively identify and classify differences within enzyme immobilization systems, sample preparation methods, and data collection parameters.

METHODS

Raman hyperspectral imaging was used to obtain a total of eight spectral data sets from enzyme immobilization samples. Partial least squares discriminant analysis (PLS-DA) was used to classify and identify the samples based on their differences.

RESULTS

Several two-class, four-class, and eight-class PLS-DA models were built to classify the different sample data sets. All models reached between 92-100% accuracy after cross-validation and external validation, illustrating great success of the models for identifying differences between the samples.

CONCLUSION

Raman hyperspectral imaging with machine learning can be used to investigate, interpret, and classify different data collection parameters, sample preparation methods, and enzyme immobilization supports, providing crucial insight into enzyme immobilization process development.

Penicillium chrysogenum as a fungal factory for feruloyl esterases

Plant biomass is a promising substrate for biorefinery, as well as a source of bioactive compounds, platform chemicals, and precursors with multiple industrial applications. These applications depend on the hydrolysis of its recalcitrant structure. However, the effective biological degradation of plant cell walls requires several enzymatic groups acting synergistically, and novel enzymes are needed in order to achieve profitable industrial hydrolysis processes. In the present work, a feruloyl esterase (FAE) activity screening of Penicillium spp. strains revealed a promising candidate (Penicillium rubens Wisconsin 54-1255; previously Penicillium chrysogenum), where two FAE-ORFs were identified and subsequently overexpressed. Enzyme extracts were analyzed, confirming the presence of FAE activity in the respective gene products (PrFaeA and PrFaeB). PrFaeB-enriched enzyme extracts were used to determine the FAE activity optima (pH 5.0 and 50-55 °C) and perform proteome analysis by means of MALDI-TOF/TOF mass spectrometry. The studies were completed with the determination of other lignocellulolytic activities, an untargeted metabolite analysis, and upscaled FAE production in stirred tank reactors. The findings described in this work present P. rubens as a promising lignocellulolytic enzyme producer. KEY POINTS: • Two Penicillium rubens ORFs were first confirmed to have feruloyl esterase activity. • Overexpression of the ORFs produced a novel P. rubens strain with improved activity. • The first in-depth proteomic study of a P. rubens lignocellulolytic extract is shown.

Plant associated endophytic fungi as potential bio-factories for extracellular enzymes: Progress, Challenges and Strain improvement with precision approaches

There is an intricate network of relations between endophytic fungi and their hosts that affects the production of various bioactive compounds. Plant-associated endophytic contain industrially important enzymes and have the potential to fulfill their rapid demand in the international market to boost business in technology. Being safe and metabolically active, they have replaced the usage of toxic and harmful chemicals and hold a credible application in biotransformation, bioremediation, and industrial processes. Despite these, there are limited reports on fungal endophytes that can directly cater to the demand and supply of industrially stable enzymes. The underlying reasons include low endogenous production and secretion of enzymes from fungal endophytes which have raised concern for widely accepted applications. Hence it is imperative to augment the biosynthetic and secretory potential of fungal endophytes. Modern state-of-the-art biotechnological technologies aiming at strain improvement using cell factory engineering as well as precise gene editing like Clustered Regularly Interspaced Palindromic Repeats (CRISPR) and its Associated proteins (Cas) systems which can provide a boost in fungal endophyte enzyme production. Additionally, it is vital to characterize optimum conditions to grow one strain with multiple enzymes (OSME). The present review encompasses various plants-derived endophytic fungal enzymes and their applications in various sectors. Further, we postulate the feasibility of new precision approaches with an aim for strain improvement and enhanced enzyme production.

Sucrose Hydrolysis in a Continuous Packed-Bed Reactor with Auto-immobilise Aspergillus niger Biocatalyst Obtained by Solid-State Fermentation

Invertase from Aspergillus niger C28B25 was produced by solid-state fermentation (SSF). Fermented solids were used directly as a biocatalyst for batch and continuous hydrolysis of sucrose in a packed-bed reactor under different operational conditions with various temperatures, sucrose concentrations, and feed flow rates. The SSF allowed obtaining a biocatalyst with an invertase activity of 82.2 U/g db. The biocatalyst maintained its activity in the range of 40 to 70 °C for at least 70 h of continuous operation. In a 20-mL packed bed reactor, the highest hydrolysis rate (12.3 g/g db h) was obtained at 40 °C with 2 M sucrose. Continuous hydrolysis in 20-mL and 200-mL reactors at 60 °C led to sucrose hydrolysis above 60% (8.5 residence times) and above 55% (4.5 residence times), respectively. The auto-immobilised biocatalyst produced by SSF without recovery, purification, and immobilisation stages offers an economical alternative for developing accessible biocatalysts that can be applied in batch or continuous sucrose hydrolysis processes. This study shows the potential of biocatalyst production by SSF for other enzymatic systems.

The role of filamentous fungi in advancing the development of a sustainable circular bioeconomy

Human activities generate enormous amounts of organic wastes and residues. Filamentous fungi (FF) are able to grow on a broad range of substrates and survive over a wide spectrum of growth conditions. These characteristics enable FF to be exploited in biorefineries for various waste streams. Valorization of food industry byproducts into biomass and various arrays of value-added products using FF creates promising pathways toward a sustainable circular economy. This approach might also contribute to reaching the sustainable development goals set by the United Nations, particularly for zero hunger as well as affordable and clean energy. This paper presents the application of filamentous fungi in food, feeds, fuels, biochemicals, and biopolymers. The nutritional values, health benefits, and safety of foods derived from byproducts of food industries are also addressed. The technoeconomical feasibilities, sustainability aspects and challenges and future perspectives for biorefineries using filamentous fungi are discussed.

A Bibliometric Analysis and Review of Pullulan-Degrading Enzymes—Past and Current Trends

Starch and pullulan degrading enzymes are essential industrial biocatalysts. Pullulan-degrading enzymes are grouped into pullulanases (types I and type II) and pullulan hydrolase (types I, II and III). Generally, these enzymes hydrolyse the α-1,6 glucosidic bonds (and α-1,4 for certain enzyme groups) of substrates and form reducing sugars such as glucose, maltose, maltotriose, panose or isopanose. This review covers two main aspects: (i) bibliometric analysis of publications and patents related to pullulan-degrading enzymes and (ii) biological aspects of free and immobilised pullulan-degrading enzymes and protein engineering. The collective data suggest that most publications involved researchers within the same institution or country in the past and current practice. Multi-national interaction shall be improved, especially in tapping the enzymes from unculturable prokaryotes. While the understanding of pullulanases may reach a certain extend of saturation, the discovery of pullulan hydrolases is still limited. In this report, we suggest readers consider using the next-generation sequencing technique to fill the gaps of finding more new sequences encoding pullulan-degrading enzymes to expand the knowledge body of this topic.

Recent progress in magnetic nanoparticles and mesoporous materials for enzyme immobilization: an update

Enzymes immobilized onto substrates with excellent selectivity and activity show a high stability and can withstand extreme experimental conditions, and their performance has been shown to be retained after repeated uses. Applications of immobilized enzymes in various fields benefit from their unique characteristics. Common methods, including adsorption, encapsulation, covalent attachment and crosslinking, and other emerging approaches (e.g., MOFs) of enzyme immobilization have been developed mostly in recent years. In accordance with these immobilization methods, the present review elaborates the application of magnetic separable nanoparticles and functionalized SBA-15 and MCM-41 mesoporous materials used in the immobilization of enzymes.

Computational Study on Temperature Driven Structure-Function Relationship of Polysaccharide Producing Bacterial Glycosyl Transferase Enzyme

Glycosyltransferase (GTs) is a wide class of enzymes that transfer sugar moiety, playing a key role in the synthesis of bacterial exopolysaccharide (EPS) biopolymer. In recent years, increased demand for bacterial EPSs has been observed in pharmaceutical, food, and other industries. The application of the EPSs largely depends upon their thermal stability, as any industrial application is mainly reliant on slow thermal degradation. Keeping this in context, EPS producing GT enzymes from three different bacterial sources based on growth temperature (mesophile, thermophile, and hyperthermophile) are considered for in silico analysis of the structural–functional relationship. From the present study, it was observed that the structural integrity of GT increases significantly from mesophile to thermophile to hyperthermophile. In contrast, the structural plasticity runs in an opposite direction towards mesophile. This interesting temperature-dependent structural property has directed the GT–UDP-glucose interactions in a way that thermophile has finally demonstrated better binding affinity (−5.57 to −10.70) with an increased number of hydrogen bonds (355) and stabilizing amino acids (Phe, Ala, Glu, Tyr, and Ser). The results from this study may direct utilization of thermophile-origin GT as best for industrial-level bacterial polysaccharide production.

Engineering interventions in enzyme production: Lab to industrial scale

Commercial enzyme production has gained popularity due to its extensive applications in traditional and modern industrial sectors. Rigorous research activities are being conducted worldwide to make the enzyme production system more efficient, cost-effective and hence, sustainable. To overcome the lacunae in earlier enzyme production methods, new engineering interventions are being introduced to meet the growing demand for industrial enzymes. This review focuses initially on the current global scenario of the enzyme market followed by a discussion on different bioreactor design approaches. The use of novel membrane based, airlift and reciprocating plate bioreactors along with the emergence of micro-reactors have also been discussed. Further, the review covers different modelling and optimization strategies for the enzyme production process including advanced techniques like neural networks, adaptive neuro-fuzzy inference systems and genetic algorithms. Finally, the required thrust areas in the enzyme production sector have been highlighted with directions for future research.

Recent advancements in the synthesis of novel thermostable biocatalysts and their applications in commercially important chemoenzymatic conversion processes

Thermostable enzymes are a field of growing interest in bioremediation, pharmaceuticals, food industry etc., due to their ability to catalyze bio reactions at high temperatures. This review aims to provide an overview on extremophiles with a special focus on thermophiles and enzymes produced from extremophilic bacteria. Novel thermostable catalysts, used in producing commercially important chemicals, are discussed in this review. Various classes of enzymes produced by microbes, synthesis of thermozymes and comparison with enzymes produced at optimal conditions are critically discussed. A detailed discussion on immobilized enzymes in comparisons with free enzymes, produced by extremozymes, is included. Different parameters which affect enzyme production are also discussed. The current industrial trends along with the future of biocatalysts in the production of chemicals using efficient methods are also discussed.

Cyclodextrin as a magic switch in covalent and non-covalent anticancer drug release systems

Cancer has been a threat to human health, so its treatment is a huge challenge to the present medical field. One of commonly used methods is the controlled release of anticancer drug to reduce the dose for patients, increase the stability of drug treatment and minimize side effects. Cyclodextrin is a kind of cyclic oligosaccharide produced by amylase hydrolysis. Because cyclodextrin contains a cavity structure and active hydroxyl groups, it has a positive effect on the study of the controlled release of anticancer drugs. This article reviews the controlled release of current anticancer drugs based on cyclodextrins as a "flexible switch", and discusses the classification of different types of release systems, highlighting their role in cancer treatment. Moreover, the opportunities and challenges of cyclodextrin as a magic switch in the controlled release of anticancer drugs are discussed.

Efficient continuous-flow aldehyde tag conversion using immobilized formylglycine generating enzyme

Immobilized formylglycine generating enzyme for efficient aldehyde tag conversion under continuous flow conditions.

Strategies and Challenges for the Development of Industrial Enzymes Using Fungal Cell Factories

Industrial enzymes have been produced from microorganisms for more than a century. Today, a large share of enzyme products is manufactured using recombinant microorganisms. This chapter focuses on major industrial fungal species belonging to the ascomycetes like Aspergillus niger, A. oryzae, and Trichoderma reesei. Many of the commercially available recombinant enzymes are manufactured using fungi. Examples of fungal enzymes used in food products are described. The enzyme industry is to a large extent cost-driven, so the enzyme product needs to meet strict COGS (cost of goods sold) targets. Therefore, the cell factory must be very efficient to produce the enzyme in high titers and efficiently utilize raw materials. Secondly, it must be designed for a robust and generic fermentation process. When developing fungal hosts for enzyme production, several properties of the system need to be considered relating to efficiency of the cell factory, purity of the product, and safety of both the cell factory and the product. Purity is secured by engineering of the cell factory, and properties related to safety must also be engineered into the fungal host. The methods used for strain improvement are continuously being developed to increase yields and are described herein. More automation using precision tools for modification of the genome (i.e., CRISPR) and low-cost sequencing have vastly expanded the possibilities and enabled fast strain development. Using systems biology approaches, better understanding of cellular processes is now possible enabling advanced engineering of fungal cell factories. Surprisingly, a survey of innovation in the field revealed a decrease in the number of patent applications in recent years. Finally, the requirements for enzyme approval, especially in food and feed, have increased significantly worldwide in the last few years. A description of the regulatory landscape and its challenges in food and feed is included.

State-of-the-art strategies and applied perspectives of enzyme biocatalysis in food sector - current status and future trends

With the recent progress in biotechnology, a wide variety of novel enzymes with unique physicochemical properties and diverse applications has been introduced, and new application list continues to extend in the future. Enzymes obtained from microorganisms, including bacteria, fungi, yeast are widely applied in numerous food formulations for intensifying their texture and taste. Owing to several desirable characteristics such as easy, cost-efficient and stable production, microbial-derived enzymes are preferred source in contrast to animals or plants. Enzymatic processes have a considerable impact in controlling the characteristics such as (1) physiochemical properties, (2) rheological functionalities, (3) facile process as compared to the chemical-based processing, (4) no or minimal consumption of harsh chemicals, (5) overall cost-effective ratio, (6) sensory and flavor qualities, and (7) intensifying the stability, shelf life and overall quality of the product, etc. in the food industry. Also, enzyme-catalyzed processing has also been designed for new food applications such as extraction of bioactive compounds, nutrient-rich and texture improved foods production, and eliminating food safety hazards. Herein, we reviewed recent applications of food-processing enzymes and highlighted promising technologies to diversify their application range in food industries. Immobilization technology enabled biocatalysts to be used cost-effectively due to reusability with negligible or no activity loss. Integrated progress in novel enzyme discovery, and recombinant DNA technology, as well as protein engineering and bioprocess engineering strategies, are believed to rapidly propagate biocatalysis at industrial-scale food processing or green and sustainable chemical manufacturing.

Effective incorporation of xylanase and phytase in lick blocks for grazing livestock

The addition of feed enzymes to livestock diets has contributed to significant increases in productivity over recent decades. The use of enzymes has been the most common in systems where enzyme delivery and diets can be easily managed, such as for poultry and pigs. Lick blocks supplement the forage diets of ruminants with nitrogen and minerals but not enzymes, due in part to concerns that block manufacturing temperatures would lead to unacceptable levels of enzyme degradation. The nutritional value of low quality pasture could be improved using enzyme supplemented lick blocks if enzymes remain active at the high lick block manufacturing temperatures. The aim of this study was to determine the extent of xylanase and phytase activity survival when exposed to the production of hot poured lick blocks. Lick block formulations and methods of manufacturing vary, so two enzyme containing molasses-based lick blocks were produced, one at 60°C and another at 100°C. The results showed that both the xylanase and phytase enzymes have high levels of survival at 60°C. In the 100°C lick block, the phytase displayed a half-life of ~10 min, whereas the xylanase retained 90% of the original activity after 30 min of exposure. The inherent thermostability of the enzymes were critical factors for enzyme survival and the enzymes were more stable in the lick blocks than in solution. The results indicate that it should be possible to add enzymes to lick blocks manufactured at elevated temperatures to enhance low quality pasture and thereby aid ruminant digestion and production.

Thermostable enzyme-immobilized magnetic responsive Ni-based metal–organic framework nanorods as recyclable biocatalysts for efficient biosynthesis of S-adenosylmethionine

A novel magnetic responsive Ni-based metal–organic framework material was developed to efficiently separate and immobilize thermal enzymes with high catalytic performance.

Ultrasound promotes enzymatic reactions by acting on different targets: Enzymes, substrates and enzymatic reaction systems

With the extensive application of enzyme-catalyzed reactions in numerous fields, improving enzymatic efficiency has attracted wide attention for reducing operating costs and increasing output. There are three targets throughout enzymatic reactions: the enzyme, substrate, and mixed reaction system. Ultrasound has been known to accelerate enzymatic reactions by acting on different targets. It can modify both enzyme and substrate macromolecules, which is helpful for enhancing enzyme activity and product yields. The synergistic effect of ultrasound and enzymes is widely reported to increase catalytic rates. The present review discusses the positive effect induced by ultrasound throughout the enzymatic process, including ultrasonic modification of enzymes, ultrasound assisted immobilization, ultrasonic pretreatment of substrates, and ultrasound assisted enzymatic reactions.

Case studies on the physical-chemical parameters' variation during three different purification approaches destined to treat wastewaters from food industry

The paper presents a set of three interconnected case studies on the depuration of food processing wastewaters by using aeration & ozonation and two types of hollow-fiber membrane bioreactor (MBR) approaches. A secondary and more extensive objective derived from the first one is to draw a clearer, broader frame on the variation of physical-chemical parameters during the purification of wastewaters from food industry through different operating modes with the aim of improving the management of water purification process. Chemical oxygen demand (COD), pH, mixed liquor suspended solids (MLSS), total nitrogen, specific nitrogen (NH₄⁺, NO₂^-, NO₃^-) total phosphorous, and total surfactants were the measured parameters, and their influence was discussed in order to establish the best operating mode to achieve the purification performances. The integrated air-ozone aeration process applied in the second operating mode lead to a COD decrease by up to 90%, compared to only 75% obtained in a conventional biological activated sludge process. The combined purification process of MBR and ozonation produced an additional COD decrease of 10-15%, and made the Total Surfactants values to comply to the specific legislation.

Cost-effective screening and isolation of xylano-cellulolytic positive microbes from termite gut and termitarium

In this study, screening and isolation of xylano-cellulolytic enzymes producing positive microbes from termitarium and termite gut microbiome were done using cost-effective agricultural wastes. The enrichment of xylano-cellulolytic microbes was done in three steps using wheat bran and waste paper. The qualitative screening of xylanase and cellulase producing micro-organisms was done on nutrient agar plates containing wheat bran and waste paper, respectively. Xylanase and cellulase positive colonies were analysed by observing the zone of substrate (wheat bran and waste paper) hydrolysis around the colonies. A total of 30 bacterial isolates were obtained from termite gut and termitarium, respectively. Xylan and cellulose degrading potential of the positive isolates was also quantitatively estimated using agro-wastes-based medium. All the bacterial isolates displayed cellulase and xylanase activities in the range of 0.45-6.80 and 51-380 IU/ml, respectively. This is the first report mentioning the isolation of xylano-cellulolytic microbes from termite gut and termitarium using very simple cost-effective methodology.

A new cold-adapted serine peptidase from Antarctic Lysobacter sp. A03: Insights about enzyme activity at low temperatures

Currently, there is a great interest for customized biocatalysts that can supply the ongoing demand of industrial processes, but also deal with the growing concern about the environment. In this scenario, cold-adapted enzymes have features that make them very attractive for industrial and biotechnological purposes. Here, we describe A03Pep1, a new cold-adapted serine peptidase isolated from Lysobacter sp. A03 by screening a genomic library. The enzyme is synthesized as a large inactive prepropeptidase that, after intramolecular processing, gives rise to the active form, of 35kDa. The heterologous expression of A03Pep1 was carried out in E. coli cells harboring the vector pGEX-4T-2-a0301. Its activity was optimal at pH 9.0 and 40°C, in the presence of 25mM Ca²⁺, which may contribute to the thermal stability of the enzyme. The 3D structure modelling predicted a less deep and more open binding pocket in A03Pep1 than that observed in the crystal structure of its mesophilic homologous AprV2, presumably as a way to enhance the probability of substrate binding at low temperatures. These results provide possible approaches in developing new biotechnologically relevant peptidases active at low to moderate temperatures.

Enzymatic Processes in Marine Biotechnology

In previous review articles the attention of the biocatalytically oriented scientific community towards the marine environment as a source of biocatalysts focused on the habitat-related properties of marine enzymes. Updates have already appeared in the literature, including marine examples of oxidoreductases, hydrolases, transferases, isomerases, ligases, and lyases ready for food and pharmaceutical applications. Here a new approach for searching the literature and presenting a more refined analysis is adopted with respect to previous surveys, centering the attention on the enzymatic process rather than on a single novel activity. Fields of applications are easily individuated: (i) the biorefinery value-chain, where the provision of biomass is one of the most important aspects, with aquaculture as the prominent sector; (ii) the food industry, where the interest in the marine domain is similarly developed to deal with the enzymatic procedures adopted in food manipulation; (iii) the selective and easy extraction/modification of structurally complex marine molecules, where enzymatic treatments are a recognized tool to improve efficiency and selectivity; and (iv) marine biomarkers and derived applications (bioremediation) in pollution monitoring are also included in that these studies could be of high significance for the appreciation of marine bioprocesses.

Mycotoxin Biotransformation by Native and Commercial Enzymes: Present and Future Perspectives

Worldwide mycotoxins contamination has a significant impact on animal and human health, and leads to economic losses accounted for billions of dollars annually. Since the application of pre- and post- harvest strategies, including chemical or physical removal, are not sufficiently effective, biological transformation is considered the most promising yet challenging approach to reduce mycotoxins accumulation. Although several microorganisms were reported to degrade mycotoxins, only a few enzymes have been identified, purified and characterized for this activity. This review focuses on the biotransformation of mycotoxins performed with purified enzymes isolated from bacteria, fungi and plants, whose activity was validated in in vitro and in vivo assays, including patented ones and commercial preparations. Furthermore, we will present some applications for detoxifying enzymes in food, feed, biogas and biofuel industries, describing their limitation and potentialities.

Induction, purification, and characterization of a thermo and pH stable laccase from Abortiporus biennis J2 and its application on the clarification of litchi juice

A fungus J2 producing laccase with high yield was screened in soils and identified as Abortiporus biennis. The production of laccase was induced by 0.1 mM Cu²⁺, 0.1 mM tannic acid, and 0.5 M ethanol. The laccase from Abortiporus biennis J2 was purified to electrophoretic homogeneity by a couple of steps. The N-terminal amino acid sequence of the enzyme was AIGPTADLNISNADI. The properties of the purified laccase were investigated. The result showed the laccase from Abortiporus biennis J2 is a thermo and pH stable enzyme. The laccase activity was inhibited by Hg²⁺, Cd²⁺, Fe²⁺, Ag⁺, Cu²⁺, and Zn²⁺, while promoted by Mg²⁺, Mn²⁺ at 10 mM level. Purified laccase was used to the clarification of litchi juice. After treatment with this laccase, the phenolic content of litchi juice had been found to be greatly reduced along with an increase in the clarity of the juice. The result indicated the potential of this laccase for application in juice procession.

Internet Databases of the Properties, Enzymatic Reactions, and Metabolism of Small Molecules-Search Options and Applications in Food Science

Internet databases of small molecules, their enzymatic reactions, and metabolism have emerged as useful tools in food science. Database searching is also introduced as part of chemistry or enzymology courses for food technology students. Such resources support the search for information about single compounds and facilitate the introduction of secondary analyses of large datasets. Information can be retrieved from databases by searching for the compound name or structure, annotating with the help of chemical codes or drawn using molecule editing software. Data mining options may be enhanced by navigating through a network of links and cross-links between databases. Exemplary databases reviewed in this article belong to two classes: tools concerning small molecules (including general and specialized databases annotating food components) and tools annotating enzymes and metabolism. Some problems associated with database application are also discussed. Data summarized in computer databases may be used for calculation of daily intake of bioactive compounds, prediction of metabolism of food components, and their biological activity as well as for prediction of interactions between food component and drugs.