Filamentous fungi (FF) are widely used as producers of enzyme complexes for the treatment of food raw materials contaminated with various pollutants, such as mycotoxins and pesticides. The composition of enzyme complexes produced by the same FF can be purposefully varied through the use of certain substrates as inductors of enzyme biosynthesis. In this study, immobilized fungal biocatalysts (IBCs) based on Aspergillus niger, Rhizopus oryzae, and Trichoderma viride were developed using poly(vinyl alcohol) cryogel as matrix carrier with incorporated substrate-inductors (wheat straw, aspen sawdust, potato processing waste, corn stalks, samples of seaweed biomass, or microalgae biomass) for biosynthesis of secreted enzymes. This approach enabled earlystage activation of enzyme biosynthesis and resulted in a 75-200% increase in enzymatic activity compared to IBCs without substrate incorporation. The developed IBCs demonstrated the ability to maintain the production of multienzyme complexes over five repeated cultivation cycles, significantly outperforming free-cell based systems. The resulting enzyme complexes were used to treat contaminated grain samples, and demonstrated detoxification efficiencies of more than 97% for mycotoxins (zearalenone, deoxynivalenol) and the organophosphate pesticide chlorpyrifos. The residual concentrations of toxins after enzymatic treatment did not exceed 2.5%. The results of this study demonstrate that substrate-integrated IBCs can serve as efficient and reusable biocatalysts for simultaneous enhancement of nutritional value and detoxification of food raw materials.

Environmental pollution continues to be an urgent global problem that requires innovative solution approaches, and biotechnology promises to address environmental problems and also serve as a scientific and practical basis for the remediation of various natural and artificial systems [...]

The current interest in microalgal biomass does not subside but continues to intensify due to the emergence of new trends in the use of this bioresource in various biotechnological and environmental processes. The rather slow growth rate of phototrophs compared to other microorganisms limits more active application of the biomass for various purposes. Stimulation of the Quorum Sensing formation in the cells due to the appearance of their own quorum molecules or those produced by other co-cultured microorganisms in the medium is one of the efficient approaches for overcoming this limitation. This review discusses the immobilization or co-immobilization of phototrophic cells with other microorganisms as an effective way to maintain accumulation of the target biomass for long-term period at improved rates. The 40% increase in the use of co-immobilized phototrophs for biomass obtaining and its use in wastewater treatment has been observed over the past five years. The level of investigations of co-immobilized microalgae cells is four times higher than that of the immobilized single cultures. Among the main trends in the new investigations of immobilized forms of microalgae, the predominant application of Chlorella genus cells in immobilized samples of individual cultures and the involvement of diatom microalgae and cyanobacteria, in addition to Chlorella cells, in co-immobilization with other microorganisms, was ascertained. The most significant increase in the rate of microalgal biomass accumulation uncovered in cases of co-immobilization of microalgae with bacteria. In several cases, in the presence of bacteria, co-immobilization has led to the emergence of new characteristics in microalgal cells (increased synthesis of pigments, polysaccharides, biofilm formation, etc.), which opens new directions for their further practical use as biopesticides, components of packaging and building materials, etc.

Mycotoxins are characterized by wide structural diversity and variety of origins.Various physical and chemical methods are tried for neutralization of mycotoxins.Enzymatic treatment looks like nature-like and efficient method of detoxification.Recombinant and fusion enzymes catalyze the detoxification of mixed mycotoxins.Relevance. Mycotoxins are easily produced by widely spread fungi and possess serious danger for life and wellbeing of humans, as well as farm animals and can be used for sabotage and terrorist acts.The purpose of the work is analysis of the main up-to-date trends in mycotoxin detoxification, paying special attention to biological (enzymatic) methods.The source base of the research is mainly English–language scientific literature available via the global Internet network, as well as the authors' own published experimental studies.The research method is analytical.Results. The current information on the structures of mycotoxins produced by microscopic fungi of the genera Aspergillus, Fusarium, and Penicillium, and the objects for their accumulation is summarized. The main investigated methods of physical and chemical effects on mycotoxins in media of various chemical composition are noted. The use of enzymes for the detoxification of mycotoxins is analyzed in more detail. Special attention is paid to individual enzymes capable of catalyzing the conversion of structurally diverse mycotoxins in their mixtures. It is indicated that in order to increase the effectiveness of neutralizing the toxic effects of mycotoxins, it is possible to successfully use different enzymes genetically combined into one molecule (creating fusion proteins) or using a mixture of enzymes.There is a great potential in the use of enzymes that catalyze the detoxification of mycotoxins, possesing different mechanisms of action, at pH values below neutral.Conclusions. For detoxification of the same mycotoxins, there are at least several different enzymes that can catalyze reactions with them. Among them are fusion proteins, oxidoreductases (glucose oxidase, peroxidase, laccase). The use of computer models and the application of molecular modeling methods will allow us to obtain enzyme preparations for detoxification of mycotoxins at different pH values.

The growing efforts towards preparation and investigation of supramolecular complexes formed by proteins and other polymers are determined by their promising biochemical and physical properties. In the current work, interaction of 6 enzymes, catalyzing transformation of various mycotoxins, with 8 polymers of variable structure and length was simulated to predict the best possible complex composition. The localization and portion of occupied areas on the enzyme surface varied widely, thus allowing the selection of those enzyme-polymer pairs for maximal retention of enzyme activity. Glucose oxidase (GOx) being active with a number of carbohydrates and mycotoxins was rationally selected to prepare complexes in vitro with some of these polyelectrolytes. Luckily, it was possible to determine enzymatic activity of these enzyme-polyelectrolyte complexes directly due to coupling reaction with horseradish peroxidase. A 180 nm-sized complex of GOx with Succinylated gelatin could be considered as a preferable one by its cumulative characteristics and especially by its turnover in the presence of methanol. This complex was active in patulin and zearalenone oxidation under low pH values and could be useful in practice for processes accompanied by acidification (like ensilaging, fermentation, etc.).

This work was undertaken in order to identify the presence of changes in the characteristics of poly(vinyl alcohol) (PVA) cryogels that can contribute to the degradation of such polymer matrices under the influence of their contact with various microorganisms used in immobilized form in different biotechnological processes using various complex media and conditions. Immobilized cells of bacteria, yeasts, microalgae, fungi, and microbial consortia were involved in the investigations. It was established that the presence of microorganisms can indirectly (through media transformed by them, in particular, containing lipids) or directly (through high rates of metabolite production, in particular, the fast accumulation of gases in the pores of polymer matrices, or due to the colonization of cryogels (self)immobilization by fungi with the growing mycelium) decrease rheological characteristics of PVA cryogel. Such weakening of PVA cryogels can be expected as a result of the first stage of further degradation of polymer matrices. The values of both the modulus of elasticity and the shear modulus of PVA cryogels confirmed this. The effect of high pressure accumulated in the reactors with PVA cryogel-immobilized cells, as well as their use in flow systems, was not revealed. These factors can be taken into account for the sustainable use of matrices based on PVA cryogels as biocatalysts with microorganisms or soil-structuring elements in artificial or natural environments.

Background: Various thiolactones are known as biologically active compounds, capable of stimulating the development of several human diseases and quorum sensing of Gram–positive bacteria. The enzymatic hydrolysis of thiolactones represents a promising approach to preventing their action. Methods: Thirteen enzymes, including various lactonases and serine hydrolases were studied in this work using several substrates including the homocysteine thiolactone (HTL), and its derivatives the N–acetylhomocysteine thiolactone (C2–HTL) and the isobutyryl–homocystein thiolactone (i–but–HTL). The potential interactions of the ligands with the surface of enzymes molecules were predicted in silico using computational modeling and checked in wet experiments in vitro. Results: Based on the data obtained several enzymes were selected with localization of the thiolactones near their active sites, indicating the possibility of effective catalysis. The lactonase (AiiA), metallo-β-lactamase (NDM-1) and the organophosphate hydrolase with hexahistidine tag (His6–OPH) were among them. Determination of catalytic characteristics of enzymes in the hydrolytic reactions with the HTL and the C2–HTL revealed the maximal value of catalytic efficiency constant for the NDM-1 in the hydrolysis of the HTL (826 M−1 s−1). The maximal activity in the hydrolysis of C2–HTL was established for AiiA (137 M−1 s−1). The polyaspartic (PLD50) and the polyglutamic (PLE50) acids were used to obtain polyelectrolyte complexes with enzymes. The further combination of these complexes with the clotrimazole and polymyxin B possessing antimicrobial properties resulted in notable improvement of their action in relation to Staphylococcus cells. Conclusions: It was revealed that the antimicrobial activity of the polymyxin B is enhanced by 9–10 times against bacteria and yeast when combined with the His6–OPH polyelectrolyte complexes. The antimicrobial activity of clotrimazole was increased by ~7 times against Candida tropicalis cells in the case of the AiiA/PLE50/Clotrimazole combination. These results make the obtained biology attractive and promising for their further advancement to practical application.

In recent years, the sustained and even increasing interest in the development and application of novel composite materials based on the polysaccharide bacterial cellulose (BC) has been driven by the accumulation of experimental data and the emergence of analytical reviews that narratively summarize these findings. This review presents a comparative and critical analysis of various approaches to the fabrication of BC-based composites. Among them, in situ biosynthesis is highlighted as the most promising strategy. In this approach, different additives are introduced directly into the culture medium of BC-producing microorganisms, enabling the formation of materials with different mechanical and physicochemical properties. Such a method also allows imparting to the composites a range of properties that BC itself does not possess, including antibacterial and enzymatic activity, as well as electrical conductivity. During the so-called “cell weaving” stage, performed by BC-producing microorganisms, diverse substances and microorganisms can be incorporated into the cultivation medium. By varying the concentrations of the introduced compounds, their ratios to the synthesized BC, and by employing different BC-producing strains and substrates, it becomes possible to regulate the characteristics of the resulting composites. Special attention is given to the role of various polysaccharides that are either introduced into the medium during BC biosynthesis or co-synthesized alongside BC within the same environment. Depending on the mode of incorporation of these additional polysaccharides, the resulting materials demonstrate variations in Young’s modulus and tensile strength. Nevertheless, they almost invariably exhibit a decreased degree of BC crystallinity within the composite structure and an enhanced water absorption capacity compared to the pure polymer.

Recently, we found that combining various antimicrobial polypeptides (AMPs) with enzymes exhibiting lactonase activity results in an antifungal agent with significantly enhanced stability and antimicrobial action efficiency. In this context, this study aims to investigate the catalytic and antifungal activity and physical-chemical properties of antifungal enzyme combinations hydrolyzing fungal cell wall components with various AMPs, comparing them with enzymes exhibiting lactonase activity (capable of hydrolyzing lactones by ring opening). Additionally, combinations of enzymes targeting the fungal cell wall and/or hydrolyzing fungal lactone-containing Quorum-sensing molecules with polyamino acids (PAAs) supplemented with fungicides (PAAF) were studied for comparison with AMP-containing combinations. Interaction models for these antifungal enzyme combinations were simulated in silico using the molecular docking method. The most promising variants, which were predicted to possess high catalytic activity, were selected, and their catalytic and physical-chemical characteristics were further evaluated in vitro. The antifungal activity of the selected combinations of enzymes with AMPs or PAAF was assessed against a number of fungi, leading to the identification of several combinations as potential candidates for inclusion in antifungals. Unexpectedly, antifungal enzyme combinations with lactonase activity were, in most cases, more effective than those with fungal-cell-wall-degrading enzymes.

The concentration of intracellular adenosine triphosphate (ATP) is one of the most important characteristics of the metabolic state of the cells of microorganisms and their viability. This indicator, monitored by bioluminescent ATP-metry, and accumulation of the suspension biomass in the medium were used to assess the effect of particles of different synthetic microplastics (MPs) (non-biodegradable and biodegradable) on the cells of yeast, filamentous fungi, bacteria and phototrophic microorganisms (microalgae and cyanobacteria) co-exposed with polymer samples in different environments and concentrations. It was found that the effect of MPs on microorganisms depends on the concentration of MPs (1–5 g/L), as well as on the initial concentration of cells (104 or 107 cells/mL) in the exposure medium with polymers. It was shown that the lack of a sufficient number of nutrition sources in the medium with MPs is not fatal for the cells. The study of the effect of MPs on the photobacteria Photobacterium phosphoreum, widely used as a bioindicator for assessing the ecotoxicity of various environments, demonstrated a correlation between the residual bioluminescence of these cells and the level of their intracellular ATP in media with biodegradable polycaprolactone and polylactide, which had an inhibitory effect on these cells. Marine representatives of phototrophic microorganisms showed the greatest sensitivity to the presence of MPs, which was confirmed by both a decrease in the level of intracellular ATP and the concentration of their biomass. Among the eight microorganisms studied, bacteria of the genus Pseudomonas turned out to be not only the most tolerant to the presence of the seven MP samples used in the work, but also actively growing in their presence.

Today, there is considerable interest in creating artificial microbial consortia to solve various biotechnological problems. The use of such consortia allows for the improvement of process indicators, namely, increasing the rate of accumulation of target products and enhancing the conversion efficiency of the original substrates. In this work, the prospects for creating artificial consortia based on anaerobic sludge (AS) with cells of different yeasts were confirmed to increase the efficiency of methanogenesis in glucose- and glycerol-containing media and obtain biogas with an increased methane content. Yeasts of the genera Saccharomyces, Candida, Kluyveromyces, and Pachysolen were used to create the artificial consortia. Their concentration in the biomass of consortium cells was 1.5%. Yeast cells were used in an immobilized form, which was obtained by incorporating cells into a cryogel of polyvinyl alcohol. The possibility of increasing the efficiency of methanogenesis by 1.5 times in relation to the control (AS without the addition of yeast cells) was demonstrated. Using a consortium composed of methanogenic sludge and yeast cells of the genus Pachysolen, known for their ability to convert glycerol into ethanol under aerobic conditions, the possibility of highly efficient anaerobic conversion of glycerol into biogas was shown for the first time. Analysis of the metabolic activity of the consortia not only for the main components of the gas phase (CH4, CO2, and H2) and metabolites in the cell culture medium, but also for the concentration of intracellular adenosine triphosphate (ATP), controlled by the method of bioluminescent ATP-metry, showed a high level of functionality and thus, prospects for using such consortia in methanogenesis processes. The advantages and the prospect of using the developed consortia instead of individual AS for the treatment of methanogenic wastewater were confirmed during static tests conducted with several samples of real and model waste.

Interest in enzymes capable of neutralizing various mycotoxins is quite high. The methods used for the screening and selection of enzymes that catalyze the detoxification of mycotoxins should be sensitive and fast. However toxic compounds can be generated under the action of such enzymes. Thus, the assessment of the overall reduction in the toxic properties of reaction media towards bioluminescent bacteria seems to be the most reasonable control method allowing a quick search for the effective enzymatic biocatalysts. The influence of a wide range of mycotoxins and glucanases, which hydrolyze toxins with different chemical structures, on the analytical characteristics of luminescent photobacteria as a biosensing element has been studied. Different glucanases (β-glucosidase and endoglucanase) were initially selected for reactions with 10 mycotoxins based on the results of molecular docking which was performed in silico with 20 mycotoxins. Finally, the biorecognizing luminescent cells were used to estimate the residual toxicity of reaction media with mycotoxins after their interaction with enzymes. The notable non-catalytic decrease in toxicity of media containing deoxynivalenol was revealed with luminous cells for both types of tested glucanases, whereas β-glucosidase provided a significant catalytic detoxification of media with aflatoxin B2 and zearalenone at pH 6.0.

The review analyzes recent advances, challenges, and practical applications in the field of enzymes within the framework of chemical enzymology and enzyme engineering. The achievements in the fundamental understanding of molecular mechanisms of the catalytic cycle of enzymatic reactions made using quantum mechanics/molecular mechanics methods with supercomputer technologies and bioinformatic approaches are considered. The design of protein biocatalysts with new properties is a fundamentally significant methodology of the bioengineering approach to solving practical problems, which is demonstrated by a number of examples. The increasing role of biocatalysis in medicine and biomedical research is illustrated by addressing the problems of antibiotic synthesis and overcoming antibiotic resistance of bacteria, mechanisms of neurodegenerative diseases and development of drugs to treat Alzheimer's disease, biocatalytic processes of DNA repair and the role of mechanisms of functioning of heme peroxidases in the human body. The use of enzymes to degrade endogenous and exogenous toxicants has been greatly developed in recent decades. The advances and problems of using enzymes in therapy and drug delivery are analyzed. The fundamental role of enzymes in modern analysis and diagnosis is noted. The review considers a new trend in the development of bioanalytical methods using aptamers, multi-analysis systems on biochips, surface-enhanced Raman scattering systems, and bioelectroanalysis. The bibliography includes 460 references.

Highlights. Peptide biotoxins are important problem for human health and as lethal agents due to their wild diversity of chemical structures and biological sources.Such peptide biotoxins and prion proteins can be effectively neutralized by different methods, including by protease treatment.Relevance – biological toxins containing peptides possess serious danger for life and well being of humans. There are a lot of reviews summarizing immunologic protective measures against these toxins. As opposed to that an enzymatic detoxification of biotoxins is, at best, considered superficially.The purpose of the work is analysis of the main up-to-date trends of development of protective remedies against biotoxins of peptide nature.The source base of the research is mainly English–language scientific literature available via the global Internet network, as well as the authors' own published experimental studies.The research method is analytical.Results. Currently the efficiency of detoxifying immunological drugs is surging due to highly productive methods of screening and selection of effective clones producing monoclonal antibodies. Special attention in the review is paid to application of hydrolytic enzymes which are considered in the work as alternative for immunobiological agents during detoxication of peptide biotoxins. The natural analogue of detoxifying enzymes is a system “toxin–antitoxin” of procaryotes. More than four types of inhibitors of biotoxins are know: blocking of their catalytic activity; hindering of their target receptors; inhibiting of toxin by acting on its structure; and allosterically modulating of biotoxin activity. There are encouraging data on application of detoxifying enzymes for neutralization of prions in soils and for treatment of prion complication.Conclusions. Application of proteases for detoxification of peptide biotoxins and prion peptides could be considered as viable alternative to detoxifying immunobiological agents.

Mycelial fungi are known by their biodestructive activity towards building material samples. In this work the possibility of using various derivatives of natural humic acids as antifungal agents was evaluated using the method of bioluminescent luciferase determination of the adenosine triphosphate intracellular concentration in the mycelial fungi cells. In order to prevent fungal lesions in rooms with high humidity the fungal biocide ACTICIDE (R) OTP 10 containing 2-octyl-4-isothiazoline-3-one is added to the tile grout; it was used as a comparison sample in our study. Aspergillus niger F-1057 and Stachybotrys chartarum F-993 spores were used as test cultures as the most frequently detected fungal contaminants of building materials. The samples of extracted from coal (leonardite) potassium humate modified with 2-methylhydroquinone, or 1,4-hydroquinone or 2-hydroxy-1,4-hydroxynaphthoquinone were the studied substances. The antifungal activity of potassium humate modified with 2-hydroxy-1,4-hydroxynaphthoquinone to both fungal test objects was confirmed in experiments aimed at studying the condition of intertile joints. The same compound at a concentration of 0.5-5.0 g/L showed noticeable antifungal effect when applied to a universal wallpaper adhesive containing carboxymethylcellulose. Antifungal activity of the same additive was comparable with the action of commercial biocide at the initial stage of the study, and after 32 days of exposure of fungi in contact with the studied additive at a final concentration of 5 g/kg of building material was superior to its action.

Recently, the lactonase activity of several enzymes (lactonase AiiA, organophosphate hydrolase (His6-OPH) and New Delhi metallo-β-lactamase (NDM-1)) was revealed in the hydrolysis of lactone-containing fungal Quorum Sensing molecules (FQSM). This study was aimed at the investigation of possible use of these enzymes as components of antifungal combinations with antimicrobial peptides (AMPs) to increase their action efficiency against various fungi. For this, the interaction of various AMPs with AiiA, NDM-1 or His6-OPH, as well as the effect of AMPs on the catalytic characteristics of these enzymes in the hydrolysis of FQSM in enzyme/AMP combinations, were studied using in silico computer modeling methods. Enzymes combinations with 3 AMPs Bacitracin, Colistin and Polymyxin B were selected as the most rational in terms of maintaining the effectiveness of AMP and the catalytic activity of enzymes. The antifungal action of the selected combinations against cells of mycelial fungi and yeast was studied in vitro. It was found that combinations of the enzymes AiiA, His6-OPH and NDM-1 with Bacitracin, Colistin and Polymyxin B provide a significant increase in the action efficiency (up to 5000 times) of both AMPs and enzymes against fungi. The most effective variants were obtained for Polymyxin B in multicomponent combinations with enzymes.

Waste from the production and use of synthetic polymers is a serious problem. The development of enzymatic and microbial biocatalysts capable of degrading hard-to-decompose polymers seems to be one of the promising and environmentally oriented solutions to this problem. A possibility of combining biocatalysts (BCs)—enzymes and microbial cells—with metal catalysts is considered as a promising basis for the development of new hybrid chemobiocatalytic processes intended for the effective degradation of synthetic polymers (SPs).

Information on the detection of the presence and potential for degradation of synthetic polymers (SPs) under various environmental conditions is of increasing interest and concern to a wide range of specialists. At this stage, there is a need to understand the relationship between the main participants in the processes of (bio)degradation of SPs in various ecosystems (reservoirs with fresh and sea water, soils, etc.), namely the polymers themselves, the cells of microorganisms (MOs) participating in their degradation, and humic substances (HSs). HSs constitute a macrocomponent of natural non-living organic matter of aquatic and soil ecosystems, formed and transformed in the processes of mineralization of bio-organic substances in environmental conditions. Analysis of the main mechanisms of their influence on each other and the effects produced that accelerate or inhibit polymer degradation can create the basis for scientifically based approaches to the most effective solution to the problem of degradation of SPs, including in the form of microplastics. This review is aimed at comparing various aspects of interactions of SPs, MOs, and HSs in laboratory experiments (in vitro) and environmental investigations (in situ) aimed at the biodegradation of polymers, as well as pollutants (antibiotics and pesticides) that they absorb. Comparative calculations of the degradation velocity of different SPs in different environments are presented. A special place in the analysis is given to the elemental chemical composition of HSs, which are most successfully involved in the biodegradation of SPs. In addition, the role of photo-oxidation and photoaging of polymers under the influence of the ultraviolet spectrum of solar radiation under environmental conditions on the (bio)degradation of SPs in the presence of HSs is discussed.

Alkaline hydrolysate of chicken manure (HCM) containing artificially formed humic-like substances (HLSs) was investigated in combination with specially loaded cells (bacteria and microalgae) for oil degradation in soil. After 7 days in the laboratory experiment, the oil biodegradation efficiency in the polluted soil (50 g oil/kg soil) was 5–78

There is currently growing interest in the creation of artificial microbial consortia, especially in the field of developing and applying various bioremediation processes. Heavy metals, dyes, synthetic polymers (microplastics), pesticides, polycyclic aromatic hydrocarbons and pharmaceutical agents are among the pollutants that have been mainly targeted by bioremediation based on various consortia containing fungi (mycelial types and yeasts). Such consortia can be designed both for the treatment of soil and water. This review is aimed at analyzing the recent achievements in the research of the artificial microbial consortia that are useful for environmental and bioremediation technologies, where various fungal cells are applied. The main tendencies in the formation of certain microbial combinations, and preferences in their forms for usage (suspended or immobilized), are evaluated using current publications, and the place of genetically modified cells in artificial consortia with fungi is assessed. The effect of multicomponence of the artificial consortia containing various fungal cells is estimated, as well as the influence of this factor on the functioning efficiency of the consortia and the pollutant removal efficacy. The conclusions of the review can be useful for the development of new mixed microbial biocatalysts and eco-compatible remediation processes that implement fungal cells.