Safety of the fungal workhorses of industrial biotechnology: update on the mycotoxin and secondary metabolite potential of Aspergillus niger, Aspergillus oryzae, and Trichoderma reesei

Safety evaluation of the food enzyme 3-phytase from the non-genetically modified Aspergillus niger strain PHY93-08

The food enzyme 3-phytase (myo-inositol-hexakisphosphate 3-phosphohydrolase EC 3.1.3.8) is produced with the non-genetically modified Aspergillus niger strain PHY93-08 by Shin Nihon Chemical Co., Ltd. The food enzyme is free from viable cells of the production organism. It is intended to be used in nine food manufacturing processes. Since residual amounts of food enzyme-total organic solids (TOS) are removed in two of the food manufacturing processes, dietary exposure was calculated only for the remaining seven processes. It was estimated to be up to 0.763 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not raise safety concerns. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 2560 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 3355. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no matches were found. The Panel considered that the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme lysophospholipase from the genetically modified Trichoderma reesei strain DP-Nyc81

The food enzyme lysophospholipase (2-lysophosphatidylcholine acylhydrolase, EC 3.1.1.5) is produced with the genetically modified Trichoderma reesei strain DP-Nyc81 by Genencor International B.V. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in the processing of cereals and other grains for the production of glucose syrups and other starch hydrolysates. Since residual amounts of food enzyme-total organic solids are removed during these food manufacturing processes, dietary exposure was not calculated and toxicological studies were considered unnecessary. A search for the identity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Advanced anaerobic digestion of household food waste pretreated by in situ-produced mixed enzymes via solid-state fermentation: Feasibility and application perspectives

Enzymatic pretreatment is an effective method which can improve the anaerobic digestion (AD) efficiency of household food waste (HFW). As an alternative to expensive commercial enzymes, mixed enzymes (MEs) produced in situ from HFW by solid-state fermentation (SSF) can greatly promote the hydrolysis rate of HFW and achieve advanced anaerobic digestion (AAD) economically sustainable. In this paper, strategies for improving the efficiency of the enzyme-production process and the abundance of MEs are briefly discussed, including SSF, fungal co-cultivation, and stepwise fermentation. The feasibility of using HFW as an applicable substrate for producing MEs (amylase, protease, and lignocellulose-degrading enzymes) and its potential advantages in HFW anaerobic digestion are comprehensively illustrated. Based on the findings, an integrated AAD process of HFW pretreated with MEs produced in situ was proposed to maximise bioenergy recovery. The mass balance results showed that the total volatile solids removal rate could reach 98.56%. Moreover, the net energy output could reach 2168.62 MJ/t HFW, which is 9.79% higher than that without in situ-produced MEs and pretreatment. Finally, perspectives for further study are presented.

Expression of microbial lipase in filamentous fungus Aspergillus niger: a review

Lipase has high economic importance and is widely used in biodiesel, food, detergents, cosmetics, and pharmaceutical industries. The rapid development of synthetic biology and system biology has not only paved the way for comprehensively understanding the efficient operation mechanism of Aspergillus niger cell factories but also introduced a new technological system for creating and optimizing high-efficiency A. niger cell factories. In this review, all relevant data on microbial lipase enzyme sources and general properties are gathered and updated. The relationship between A. niger strain morphology and protein production is discussed. The safety of A. niger strain is investigated to ensure product safety. The biotechnologies and factors influencing lipase expression in A. niger are summarized. This review focuses on various strategies to improve lipase expression in A. niger. The summary of these methods and the application of the gene editing technology CRISPR/Cas9 system can further improve the efficiency of constructing the engineered lipase-producing A. niger.

Safety evaluation of the food enzyme asparaginase from the genetically modified Aspergillus niger strain ASP

The food enzyme asparaginase (l-asparagine amidohydrolase; EC 3.5.1.1) is produced with the genetically modified Aspergillus niger strain ASP by DSM Food Specialties B.V. The genetic modifications do not give rise to safety concerns. The food enzyme was considered free from viable cells of the production organism and its DNA. The food enzyme is intended to be used in the prevention of acrylamide formation in foods and in the processing of yeast and yeast products. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.792 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level at the highest dose tested of 1038 mg TOS/kg bw per day, which when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 1311. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Exploration of Trichoderma reesei as an alternative host for erythritol production

BACKGROUND

Erythritol, a natural polyol, is a low-calorie sweetener synthesized by a number of microorganisms, such as Moniliella pollinis. Yet, a widespread use of erythritol is limited by high production costs due to the need for cultivation on glucose-rich substrates. This study explores the potential of using Trichoderma reesei as an alternative host for erythritol production, as this saprotrophic fungus can be cultivated on lignocellulosic biomass residues. The objective of this study was to evaluate whether such an alternative host would lead to a more sustainable and economically viable production of erythritol by identifying suitable carbon sources for erythritol biosynthesis, the main parameters influencing erythritol biosynthesis and evaluating the feasibility of scaling up the defined process.

RESULTS

Our investigation revealed that T. reesei can synthesize erythritol from glucose but not from other carbon sources like xylose and lactose. T. reesei is able to consume erythritol, but it does not in the presence of glucose. Among nitrogen sources, urea and yeast extract were more effective than ammonium and nitrate. A significant impact on erythritol synthesis was observed with variations in pH and temperature. Despite successful shake flask experiments, the transition to bioreactors faced challenges, indicating a need for further scale-up optimization.

CONCLUSIONS

While T. reesei shows potential for erythritol production, reaching a maximum concentration of 1 g/L over an extended period, its productivity could be improved by optimizing the parameters that affect erythritol production. In any case, this research contributes valuable insights into the polyol metabolism of T. reesei, offering potential implications for future research on glycerol or mannitol production. Moreover, it suggests a potential metabolic association between erythritol production and glycolysis over the pentose phosphate pathway.

A Whole-Process Visible Strategy for the Preparation of Rhizomucor miehei Lipase with Escherichia coli Secretion Expression System and the Immobilization

BACKGROUND

Rhizomucor miehei (RM) lipase is a regioselective lipase widely used in food, pharmaceutical and biofuel industries. However, the high cost and low purity of the commercial RM lipase limit its industrial applications. Therefore, it is necessary to develop cost-effective strategies for large-scale preparation of this lipase. The present study explored the high-level expression of RM lipase using superfolder green fluorescent protein (sfGFP)-mediated Escherichia coli secretion system.

RESULTS

The sfGFP(-15) mutant was fused to the C-terminus of RM lipase to mediate its secretion expression. The yield of the fusion protein reached approximately 5.1 g/L with high-density fermentation in 5-L fermentors. Unlike conventional secretion expression methods, only a small portion of the target protein was secreted into the cell culture while majority of the fusion protein was still remained in the cytoplasm. However, in contrast to intracellular expression, the target protein in the cytoplasm could be transported efficiently to the supernatant through a simple washing step with equal volume of phosphate saline (PBS), without causing cell disruption. Hence, the approach facilitated the downstream purification step of the recombinant RM lipase. Moreover, contamination or decline of the engineered strain and degradation or deactivation of the target enzyme can be detected efficiently because they exhibited bright green fluorescence. Next, the target protein was immobilized with anion-exchange and macropore resins. Diethylaminoethyl sepharose (DEAE), a weak-basic anion-exchange resin, exhibited the highest bind capacity but inhibited the activity of RM lipase dramatically. On the contrary, RM lipase fixed with macropore resin D101 demonstrated the highest specific activity. Although immobilization with D101 didn't improve the activity of the enzyme, the thermostability of the immobilized enzyme elevated significantly. The immobilized RM lipase retained approximately 90% of its activity after 3-h incubation at 80 °C. Therefore, D101 was chosen as the supporting material of the target protein.

CONCLUSION

The present study established a highly efficient strategy for large-scale preparation of RM lipase. This innovative technique not only provides high-purity RM lipase at a low cost but also has great potential as a platform for the preparation of lipases in the future.

Analysis of the Surface of Historic Fabric from the Auschwitz-Birkenau State Museum after Treatment with Ethanol Mist Used to Eliminate Microorganisms Harmful to Human Health

AIM

the aim of the work was to present the changes occurring on the model and historical cotton surface of cotton resulting from disinfection with 90% ethanol mist.

MATERIALS AND METHODS

Samples of historical materials consisted of fabric elements from suitcases stored in A-BSM. A mist of 90% ethanol was applied for 15 s at a distance of 16 cm from the surface. The spectra of cotton samples before and after ethanol application were recorded using Fourier transform infrared spectroscopy (FTIR-ATR). Analyses of the surface layers were performed using X-ray photoelectron spectroscopy (XPS).

RESULTS

the decontamination performed did not show any significant differences in the chemical composition and surface structure of cotton before and after the use of 90% ethanol mist.

CONCLUSIONS

Ethanol mist, which eliminates microorganisms from the historical surface, does not cause significant changes to the surface of historical objects.

Safety evaluation of the food enzyme inulinase from the non-genetically modified Aspergillus welwitschiae strain NZYM-KF

The food enzyme inulinase (1-β-d-fructan fructanohydrolase; EC 3.2.1.7) is produced with the non-genetically modified Aspergillus welwitschiae strain NZYM-KF by Novozymes A/S. The food enzyme is free from viable cells of the production organism. It is intended to be used in the processing of fructo-polysaccharides for the production of fructo-oligosaccharides. Since residual amounts of total organic solids (TOS) are removed during the food manufacturing process, toxicological studies other than allergenicity were considered unnecessary and dietary exposure was not calculated. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and two matches with tomato allergens were found. The Panel considered that the risk of allergic reactions upon dietary exposure to this food enzyme, particularly in individuals sensitised to tomato, cannot be excluded, but is expected not to exceed that of tomato. As the prevalence of allergic reactions to tomato is low, also the likelihood of such reactions to occur to the food enzyme is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Safety evaluation of a food enzyme with phospholipase A1 and lysophospholipase activities from the genetically modified Aspergillus niger strain PLN

The food enzyme with phospholipase A1 (phosphatidycholine 1-acylhydrolase, EC 3.1.1.32) and lysophospholipase (2-lysophosphatidylcholine acylhydrolase, EC 3.1.1.5) activities is produced with the genetically modified Aspergillus niger strain PLN by DSM. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used for the production of refined edible fats and oils by degumming. Since residual amounts of total organic solids are removed during this process, dietary exposure was not calculated and toxicological studies were considered unnecessary for the assessment of this food enzyme. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no matches were found. The Panel considered that the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Safety of the feed additive consisting of endo-1,4-β-xylanase (produced with Trichoderma reesei CBS 143953), subtilisin (produced with Bacillus subtilis CBS 143946) and α-amylase (produced with Bacillus amyloliquefaciens CBS 143954) (Avizyme® 1505) for all poultry species (Danisco (UK) Ltd.)

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety of the feed additive consisting of endo-1,4-β-xylanase (produced with Trichoderma reesei CBS 143953), subtilisin (produced with Bacillus subtilis CBS 143946) and α-amylase (produced with Bacillus amyloliquefaciens CBS 143954) (Avizyme® 1505) as a zootechnical feed additive for all poultry species. The additive is authorised in feed for chickens and turkeys for fattening, ducks and laying hens. In 2020, the FEEDAP Panel issued an opinion for the renewal of the authorisation of the additive for the species/categories for which there is an authorisation, a reduction of the minimum recommended level in turkeys for fattening and the extension of use to all poultry species. In that assessment, the Panel could not conclude on the safety of the additive due to uncertainties on the characterisation of the production strains and the possible presence of their viable cells and DNA in the final product. Moreover, limitations were identified in the xylanase specifications and xylanase method of analysis. The applicant submitted information to address the limitations previously identified. The Panel concluded that the additive is safe for the target species under the proposed conditions of use. The use of Avizyme® 1505 in animal nutrition is considered safe for the consumer and the environment. The additive is a mild irritant to skin and eyes; it is not a dermal sensitiser but should be considered a respiratory sensitiser. The additive is efficacious in ducks at 75 U endo-1,4-β-xylanase, 1000 U subtilisin and 100 U α-amylase/kg of complete feed. In other poultry species for fattening (including turkeys), reared for breeding and reared for laying, the additive is efficacious at 187.5 U endo-1,4-β-xylanase, 2500 U subtilisin and 250 U α-amylase per kg of complete feed and at 300 U endo-1,4-β-xylanase, 4000 U subtilisin and 400 U α-amylase per kg of complete feed for all poultry species for laying (except for ducks).

Safety evaluation of the food enzyme carboxypeptidase D from the genetically modified Aspergillus oryzae strain NZYM-MK

The food enzyme carboxypeptidase D (EC 3.4.16.6) is produced with the genetically modified Aspergillus oryzae strain NZYM-MK by Novozymes A/S. It is free from viable cells of the production organism and its DNA. The genetic modifications do not give rise to safety concerns. The food enzyme is intended to be used in five food manufacturing processes. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.908 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 2220 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 2445. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and two matches were found, one with a food allergen (wheat). The Panel considered that a risk of allergic reactions upon dietary exposure to this food enzyme, particularly in individuals sensitised to wheat, cannot be excluded, but will not exceed that of wheat consumption. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

A comprehensive review of mycotoxins: Toxicology, detection, and effective mitigation approaches

Mycotoxins, harmful compounds produced by fungal pathogens, pose a severe threat to food safety and consumer health. Some commonly produced mycotoxins such as aflatoxins, ochratoxin A, fumonisins, trichothecenes, zearalenone, and patulin have serious health implications in humans and animals. Mycotoxin contamination is particularly concerning in regions heavily reliant on staple foods like grains, cereals, and nuts. Preventing mycotoxin contamination is crucial for a sustainable food supply. Chromatographic methods like thin layer chromatography (TLC), gas chromatography (GC), high-performance liquid chromatography (HPLC), and liquid chromatography coupled with a mass spectrometer (LC/MS), are commonly used to detect mycotoxins; however, there is a need for on-site, rapid, and cost-effective detection methods. Currently, enzyme-linked immunosorbent assays (ELISA), lateral flow assays (LFAs), and biosensors are becoming popular analytical tools for rapid detection. Meanwhile, preventing mycotoxin contamination is crucial for food safety and a sustainable food supply. Physical, chemical, and biological approaches have been used to inhibit fungal growth and mycotoxin production. However, new strains resistant to conventional methods have led to the exploration of novel strategies like cold atmospheric plasma (CAP) technology, polyphenols and flavonoids, magnetic materials and nanoparticles, and natural essential oils (NEOs). This paper reviews recent scientific research on mycotoxin toxicity, explores advancements in detecting mycotoxins in various foods, and evaluates the effectiveness of innovative mitigation strategies for controlling and detoxifying mycotoxins.

Optimised Degradation of Lignocelluloses by Edible Filamentous Fungi for the Efficient Biorefinery of Sugar Beet Pulp

The degradation of the complex structure of lignocellulosic biomass is important for its further biorefinery to value-added bioproducts. The use of effective fungal species for the optimised degradation of biomass can promote the effectiveness of the biorefinery of such raw material. In this study, the optimisation of processing parameters (temperature, time, and s/w ratio) for cellulase activity and reducing sugar (RS) production through the hydrolysis of sugar beet pulp (SBP) by edible filamentous fungi of Aspergillus, Fusarium, Botrytis, Penicillium, Rhizopus, and Verticillium spp. was performed. The production of RS was analysed at various solid/water (s/w) ratios (1:10-1:20), different incubation temperatures (20-35 °C), and processing times (60-168 h). The Aspergillus niger CCF 3264 and Penicillium oxalicum CCF 3438 strains showed the most effective carboxymethyl cellulose (CMC) degrading activity and also sugar recovery (15.9-44.8%) from SBP biomass in the one-factor experiments. Mathematical data evaluation indicated that the highest RS concentration (39.15 g/100 g d.w.) and cellulolytic activity (6.67 U/g d.w.) could be achieved using A. niger CCF 3264 for the degradation of SBP at 26 °C temperature with 136 h of processing time and a 1:15 solid/water ratio. This study demonstrates the potential of fungal degradation to be used for SBP biorefining.

How Fungi Biosynthesize 3-Nitropropanoic Acid: The Simplest yet Lethal Mycotoxin

We uncovered the biosynthetic pathway of the lethal mycotoxin 3-nitropropanoic acid (3-NPA) from koji mold Aspergillus oryzae. The biosynthetic gene cluster (BGC) of 3-NPA, which encodes an amine oxidase and a decarboxylase, is conserved in many fungi used in food processing, although most of the strains have not been reported to produce 3-NPA. Our discovery will lead to efforts that improve the safety profiles of these indispensable microorganisms in making food, alcoholic beverages, and seasoning.

Safety evaluation of the food enzyme AMP deaminase from non-genetically modified Aspergillus sp. strain DEA 56-111

The food enzyme AMP deaminase (AMP aminohydrolase; EC 3.5.4.6) is produced with the non-genetically modified microorganism Aspergillus sp. strain DEA 56-111 by Shin Nihon Chemical Co., Ltd. The food enzyme was considered free from viable cells of the production organism. It is intended to be used in the processing of yeast and yeast products. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.005 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The Panel identified a no observed adverse effect level of 1984 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 396,800. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Reassessing the Etiology of Aspergillus Vine Canker and Summer Bunch Rot of Table Grapes in California

Fungal taxonomy is in constant flux, and the advent of reliable DNA barcodes has enabled the enhancement of plant pathogen identification accuracy. In California, Aspergillus vine canker (AVC) and summer bunch rot (SBR) are economically important diseases that affect the wood and fruit of grapevines, respectively, and their causal agents are primarily species of black aspergilli (Aspergillus section Nigri). During the last decade, the taxonomy of this fungal group has been rearranged several times using morphological, physiological, and genetic analyses, which resulted in the incorporation of multiple cryptic species that are difficult to distinguish. Therefore, in this study, we aimed to reassess the etiology of AVC and SBR using a combination of morphological observations with phylogenetic reconstructions based on nucleotide sequences of the calmodulin (CaM) gene. Results revealed that the isolates causing AVC from recent isolations corresponded to A. tubingensis, whereas the isolates obtained from initial surveys when the disease was discovered were confirmed as A. niger and A. carbonarius. Similarly, the isolates obtained from table grapes with SBR symptoms and from spore traps placed in those vineyards were identified primarily as A. tubingensis, followed by A. niger and A. carbonarius. Notably, the A. niger isolates formed a subclade with strains previously known as A. welwitschiae, which is a species that was recently synonymized with A. niger. Overall, the most prevalent species was A. tubingensis, which was associated with both AVC and SBR, and representative isolates recovered from AVC-symptomatic wood, berries SBR symptoms, and spore traps were equally pathogenic in healthy wood and berries of 'Red Globe' grapevines. This study also constitutes the first report of A. tubingensis causing AVC and SBR of grapes in California and in the United States.

Safety evaluation of the food enzyme leucyl aminopeptidase from the genetically modified Aspergillus oryzae strain NZYM-BU

The food enzyme leucyl aminopeptidase (EC 3.4.11.1) is produced with the genetically modified Aspergillus oryzae strain NZYM-BU by Novozymes A/S. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in five food manufacturing processes. Dietary exposure to the food enzyme TOS was estimated to be up to 1.508 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 4,928 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 3,268. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that the food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme oryzin from the non-genetically modified Aspergillus ochraceus strain AE-P

The food enzyme oryzin (EC 3.4.21.63) is produced with the non-genetically modified Aspergillus ochraceus strain AE-P by Amano Enzyme Inc. The food enzyme was considered free from viable cells of the production organism. It is intended to be used in nine food manufacturing processes. The dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.1 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1862 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 18,620. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and 31 matches were found, including one food allergen (melon). The Panel considered that the risk of allergic reactions upon dietary exposure to this food enzyme, particularly in individuals sensitised to melon, cannot be excluded, but would not exceed the risk from consumption of this food. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Aspergillus oryzae as a Cell Factory: Research and Applications in Industrial Production

Aspergillus oryzae, a biosafe strain widely utilized in bioproduction and fermentation technology, exhibits a robust hydrolytic enzyme secretion system. Therefore, it is frequently employed as a cell factory for industrial enzyme production. Moreover, A. oryzae has the ability to synthesize various secondary metabolites, such as kojic acid and L-malic acid. Nevertheless, the complex secretion system and protein expression regulation mechanism of A. oryzae pose challenges for expressing numerous heterologous products. By leveraging synthetic biology and novel genetic engineering techniques, A. oryzae has emerged as an ideal candidate for constructing cell factories. In this review, we provide an overview of the latest advancements in the application of A. oryzae-based cell factories in industrial production. These studies suggest that metabolic engineering and optimization of protein expression regulation are key elements in realizing the widespread industrial application of A. oryzae cell factories. It is anticipated that this review will pave the way for more effective approaches and research avenues in the future implementation of A. oryzae cell factories in industrial production.

Safety evaluation of the food enzyme asparaginase from the genetically modified Aspergillus niger strain AGN

The food enzyme asparaginase (l-asparagine amidohydrolase; EC 3.5.1.1) is produced with the genetically modified Aspergillus niger strain AGN by DSM Food Specialties B.V. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used to prevent acrylamide formation in food processing. The dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 1.434 mg TOS/kg body weight (bw) per day in European populations. The toxicity studies were carried out with an asparaginase from A. niger (strain ASP). The Panel considered this food enzyme as a suitable substitute for the asparaginase to be used in the toxicological studies, because the genetic differences between the production strains are not expected to result in a different toxigenic potential, and the raw materials and manufacturing processes of both food enzymes are comparable. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1038 mg TOS/kg bw per day, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 724. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Dietary mycotoxin exposure and human health risks: A protocol for a systematic review

BACKGROUND

Mycotoxins are toxic fungal secondary metabolites that contaminate a wide spectrum of essential foods worldwide, such as grain-based products, nuts and spices, causing adverse health effects pertaining to their carcinogenic, nephrotoxic and hepatotoxic nature, among others.

AIM

The aim of this systematic review (SR) is to systematically search for, appraise and synthesize primary research evidence to identify what is known about dietary mycotoxin-related health effects and what remains unknown, as well as the uncertainty around findings and the recommendations for the future.

SEARCH STRATEGY AND ELIGIBILITY CRITERIA

Search strategies, as well as eligibility criteria were structured according to a predefined PECO (population, exposure, comparison, and outcome) research question and developed in an iterative scoping process. Several bibliographic databases, including Embase, Cochrane Library, Pubmed, Web of Science Core Collection and Scopus, will be searched. Primary research on any measured or modelled dietary exposure to a single or multiple mycotoxins, and adverse human health outcomes (i.e. cancer, non-carcinogenic diseases, and reproductive & developmental adverse outcomes) will be included, and references will be imported into Covidence. In vitro, ex vivo, in silico, animal and review studies, as well as expert's opinions, secondary literature, conference abstracts, presentations, posters, book chapters, dissertations and studies involving non-dietary mycotoxin exposure, will be excluded.

STUDY SELECTION

Two independent reviewers will screen titles and abstracts, and review full-texts. Any disagreements will be resolved by a third reviewer based on two-third majority.

DATA EXTRACTION

Data from retained eligible studies will be extracted by the principal reviewer, and peer-checked by a second reviewer.

STUDY QUALITY ASSESSMENT

Eligible studies will be evaluated for risk of bias (Overall High-Quality Assessment Tool, OHAT) and certainty of evidence (Grading of Recommendations Assessment, Development and Evaluation, GRADE).

EVIDENCE SYNTHESIS

A detailed summary of the included studies will be provided within a tabular format and narratively discussed. Heat maps will be constructed to provide information on available knowledge (gaps), and a meta-analysis may be performed based on the variability in predefined PECO elements and depending on the heterogeneity of studies.

CONCLUSION

This protocol describes the methodology for the conduct of a SR on mycotoxin-related human health risks, that could guide future research and inform regulatory decisions, as emphasized by the European Commission within the field of regulatory risk assessment for emerging chemicals.

Cellulase with Bacillus velezensis improves physicochemical characteristics, microbiota and metabolites of corn germ meal during two-stage co-fermentation

Corn germ meal (CGM) is one of the major byproducts of corn starch extraction. Although CGM has rich fiber content, it lacks good protein content and amino acid balance, and therefore cannot be fully utilized as animal feed. In this study, we investigated the processing effect of cellulase synergized with Bacillus velezensis on the nutritional value of pretreated CGM (PCGM) in two-stage solid-state fermentation (SSF). High-throughput sequencing technology was used to explore the dynamic changes in microbial diversity. The results showed that compared with four combinations of B. velezensis + Lactiplantibacillus plantarum (PCGM-BL), cellulase + L. plantarum (PCGM-CL),control group (PCGM-CK), and cellulase + B. velezensis + L. plantarum (PCGM-BCL), the fourth combination of PCGM-BCL significantly improved the nutritional characteristics of PCGM. After two-stage SSF (48 h), viable bacterial count and contents of crude protein (CP) and trichloroacetic acid-soluble protein (TCA-SP) all were increased in PCGM-BCL (p < 0.05), while the pH was reduced to 4.38 ± 0.02. In addition, compared with PCGM-BL, the cellulose degradation rate increased from 5.02 to 50.74%, increasing the amounts of short-chain fatty acids (216.61 ± 2.74 to 1727.55 ± 23.00 µg/g) and total amino acids (18.60 to 21.02%) in PCGM-BCL. Furthermore, high-throughput sequencing analysis revealed significant dynamic changes in microbial diversity. In the first stage of PCGM-BCL fermentation, Bacillus was the dominant genus (99.87%), which after 24 h of anaerobic fermentation changed to lactobacillus (37.45%). Kyoto Encylopaedia of Genes and Genomes (KEGG) metabolic pathway analysis revealed that the pathways related to the metabolism of carbohydrates, amino acids, cofactors, and vitamins accounted for more than 10% of the enriched pathways throughout the fermentation period. Concisely, we show that cellulase can effectively improve the nutritional value of PCGM when synergized with B. velezensis in two-stage SSF.

Safety evaluation of the food enzyme leucyl aminopeptidase from the non-genetically modified Aspergillus sp. strain AE-MB

The food enzyme leucyl aminopeptidase (EC 3.4.11.1) is produced with the non-genetically modified Aspergillus sp. strain AE-MB by Amano Enzyme Inc. The food enzyme is considered free from viable cells of the production organism. It is intended to be used in five food manufacturing processes: processing of dairy products for the production of (1) flavouring preparations; processing of plant- and fungal-derived products for the production of (2) protein hydrolysates; processing of meat and fish products for the production of (3) protein hydrolysates, (4) modified meat and fish products and processing of (5) yeast and yeast products. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 2.273 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 183 mg TOS/kg bw per day. The calculated margin of exposure for each age group was 135 (infants), 81 (toddlers), 83 (children), 109 (adolescents), 160 (adults) and 184 (the elderly). A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no matches were found. The Panel considered that the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. The safety of the food enzyme could not be established given the derived margins of exposure. Therefore, the Panel concluded that this food enzyme could not be considered safe under the intended conditions of use.

Safety evaluation of the food enzyme 3-phytase from the genetically modified Aspergillus niger strain NPH

The food enzyme 3-phytase (myo-inositol-hexakisphosphate 3-phosphohydrolase EC 3.1.3.8) is produced with the genetically modified Aspergillus niger strain NPH by DSM Food Specialties. The genetic modifications do not give rise to safety concerns. The food enzyme was considered free from viable cells of the production organism and its DNA. It is intended to be used in three food manufacturing processes: processing of cereals and other grains for the production of (1) baked products and (2) distilled alcohol, and the processing of plant- and fungal-derived products for the production of (3) plant-based analogues of milk and milk products. Since no residual amounts of total organic solids (TOS) are carried over into distilled alcohol, dietary exposure was calculated only for the remaining two food manufacturing processes. It was estimated to be up to 0.553 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 833 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 1506. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that the risk of allergic reactions by dietary exposure cannot be excluded (except for distilled alcohol production), but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Safety evaluation of the food enzyme leucyl aminopeptidase from non-genetically modified Aspergillus oryzae strain NZYM-EX

The food enzyme leucyl aminopeptidase (EC 3.4.11.1) is produced with the non-genetically modified microorganism Aspergillus oryzae strain NZYM-EX by Novozymes A/S. The food enzyme is free from viable cells of the production organism. It is intended to be used in eight food manufacturing processes: processing of dairy products for the production of (1) flavouring preparations, (2) modified milk proteins; processing of plant- and fungal-derived products for the production of (3) protein hydrolysates, (4) soy sauce; processing of meat and fish products for the production of (5) protein hydrolysates; processing of cereals and other grains for the production of (6) baked products, (7) brewed products; (8) processing of yeast and yeast products. Dietary exposure to the food enzyme total organic solids (TOS) was estimated to be up to 0.577 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 440 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 763. A search for similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme catalase from the non-genetically modified Aspergillus tubingensis strain AE-CN

The food enzyme catalase (hydrogen-peroxide:hydrogen-peroxide oxidoreductase; EC 1.11.1.6) is produced with the non-genetically modified Aspergillus tubingensis strain AE-CN by Amano Enzyme Inc. The absence of viable cells of the production organism in the food enzyme was not demonstrated. The food enzyme is intended to be used in five food manufacturing processes: production of baked products, processing of egg and egg products, production of fruit and vegetable products other than juices, production of cheese and production of fish roes. The dietary exposure to the food enzyme total organic solids (TOS) was estimated to be up to 0.325 mg TOS/kg body weight (bw) per day in European populations. The results of the in vitro genotoxicity studies indicated the presence of a clastogenic agent in the food enzyme which could not be dismissed due to limitations in the in vivo studies. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 323 mg TOS/kg bw per day, the highest dose tested. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and one match was found. The Panel considered that the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Because of the results of the genotoxicity studies, and as the absence of viable cells from the production strain was not demonstrated, the Panel was unable to establish the safety of the food enzyme.

Safety evaluation of the food enzyme endo-1,4-β-xylanase from the non-genetically modified Trichoderma citrinoviride strain 278

The food enzyme endo-1,4-β-xylanase (4-β-d-xylan xylanohydrolase; EC 3.2.1.8) is produced with the non-genetically modified Trichoderma citrinoviride strain 278 by Kerry Ingredients & Flavours Ltd. The food enzyme was considered free from viable cells of the production organism. It is intended to be used in eight food manufacturing processes: processing of cereals and other grains for the production of baked products; production of cereal-based products other than baked, brewed products, starch and gluten fractions, distilled alcohol; processing of fruits and vegetables for the production of juices, wine and wine vinegar and processing of yeast and yeast products. Since residual amounts of total organic solids (TOS) are removed during two processes, dietary exposure was only calculated for the remaining six food manufacturing processes. Exposure was estimated to be up to 4.808 mg TOS/kg body weight (bw) per day in European populations. The Panel was unable to reach a conclusion on genotoxicity and systemic toxicity. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that a risk of allergic reactions upon dietary exposure cannot be excluded (except for distilled alcohol production), but the likelihood is low. In the absence of an acceptable full set of toxicological data, the Panel was unable to complete the safety assessment of the food enzyme.

Safety evaluation of the food enzyme endo-polygalacturonase from the non-genetically modified Aspergillus tubingensis strain MUCL 55013

The food enzyme endo-polygalacturonase ((1→4)-α-d-galacturonan glycanohydrolase (endo-cleaving); EC 3.2.1.15)) is produced with the non-genetically modified Aspergillus tubingensis strain MUCL 55013 by Soufflet Biotechnologies. The food enzyme is free from viable cells of the production organism. It is intended to be used in 10 food manufacturing processes: processing of fruits and vegetables for the production of juices, other fruit and vegetable products, wine, distilled spirits from wine, alcoholic beverages other than grape wine; processing of plant-derived products for the production of refined and unrefined sugar, edible oils from plants, green coffee beans by demucilation, coffee extracts and tea and other herbal and fruit infusions. Since residual amounts of total organic solids (TOS) are removed in three processes, dietary exposure was calculated only for the remaining seven food manufacturing processes. Exposure was estimated to be up to 7.834 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 2,097 mg TOS/kg bw per day, the highest dose tested, resulting in a margin of exposure of at least 268. A search for the similarity of the amino acid sequence of the food enzyme to known allergens found 14 matches, one of which was to a food allergen. The Panel considered that the risk of allergic reactions upon dietary exposure to this food enzyme cannot be excluded, in particular for individuals sensitised to papaya, but that the risk will not exceed that of consumption of papaya. In addition, oral allergy reactions cannot be excluded in pollen-sensitised individuals. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Safety evaluation of the food enzyme phospholipase A2 from the genetically modified Aspergillus niger strain PLA

The food enzyme phospholipase A2 (phosphatidylcholine 2-acylhydrolase, EC 3.1.1.4) is produced with the genetically modified Aspergillus niger strain PLA by DSM Food Specialties B.V. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in the processing of egg and egg products, in the processing of fats and oils by degumming and for the production of modified lecithins (lysolecithin). As residual total organic solids (TOS) are removed in the refined fats and oils during degumming, dietary exposure was calculated only for the remaining two food manufacturing processes. For egg processing, the dietary exposure was estimated to be up to 1.712 mg TOS/kg body weight (bw) per day in European populations. Wet gum can be used to produce lysolecithin with the highest dietary exposure of 1.61 mg TOS/kg bw per day in children at the 95th percentile when used as a food additive. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1350 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated overall dietary exposure, resulted in a margin of exposure of at least 851. A search for the similarity of the amino acid sequence of the food enzyme to those of known allergens was made and no match was found. The Panel considered that the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Fungal and mycotoxin contaminants in cannabis and hemp flowers: implications for consumer health and directions for further research

Medicinal and recreational uses of Cannabis sativa, commonly known as cannabis or hemp, has increased following its legalization in certain regions of the world. Cannabis and hemp plants interact with a community of microbes (i.e., the phytobiome), which can influence various aspects of the host plant. The fungal composition of the C. sativa phytobiome (i.e., mycobiome) currently consists of over 100 species of fungi, which includes phytopathogens, epiphytes, and endophytes, This mycobiome has often been understudied in research aimed at evaluating the safety of cannabis products for humans. Medical research has historically focused instead on substance use and medicinal uses of the plant. Because several components of the mycobiome are reported to produce toxic secondary metabolites (i.e., mycotoxins) that can potentially affect the health of humans and animals and initiate opportunistic infections in immunocompromised patients, there is a need to determine the potential health risks that these contaminants could pose for consumers. This review discusses the mycobiome of cannabis and hemp flowers with a focus on plant-infecting and toxigenic fungi that are most commonly found and are of potential concern (e.g., Aspergillus, Penicillium, Fusarium, and Mucor spp.). We review current regulations for molds and mycotoxins worldwide and review assessment methods including culture-based assays, liquid chromatography, immuno-based technologies, and emerging technologies for these contaminants. We also discuss approaches to reduce fungal contaminants on cannabis and hemp and identify future research needs for contaminant detection, data dissemination, and management approaches. These approaches are designed to yield safer products for all consumers.

Safety evaluation of the food enzyme triacylglycerol lipase from the genetically modified Aspergillus luchuensis strain FL105SC

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase; EC 3.1.1.3) is produced with the genetically modified Aspergillus luchuensis strain FL105SC by Advanced Enzyme Technologies Ltd. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in an immobilised form for the production of modified fats and oils by interesterification. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level (NOAEL) of 783 mg TOS/kg body weight per day. As the food enzyme is used in an immobilised form and as any residual amounts of the food enzyme-total organic solids (TOS) are removed during the food manufacturing process, dietary exposure was not calculated. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that a risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme triacylglycerol lipase from the genetically modified Aspergillus luchuensis strain FL108SC

The food enzyme triacylglycerol lipase (triacylglycerol acylhydrolase; EC 3.1.1.3) is produced with the genetically modified Aspergillus luchuensis strain FL108SC by Advanced Enzyme Technologies Ltd. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in an immobilised form for the production of modified fats and oils by interesterification. Genotoxicity tests did not raise safety concerns. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rodents. The Panel identified a no observed adverse effect level (NOAEL) at the highest dose of 774 mg TOS/kg body weight per day. As the food enzyme is used in an immobilised form and as any residual amounts of the food enzyme-total organic solids (TOS) are removed during the food manufacturing process, dietary exposure was not calculated. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that a risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme asparaginase from the genetically modified Aspergillus oryzae strain NZYM-SP

The food enzyme asparaginase (l-asparagine amidohydrolase, EC 3.5.1.1) is produced with the genetically modified Aspergillus oryzae strain NZYM-SP by Novozymes A/S. The genetic modifications do not give rise to safety concerns. The food enzyme is considered free from viable cells of the production organism and its DNA. It is intended to be used to prevent acrylamide formation in food processing. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.101 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 880 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 8,713. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that a risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Seven New Species of Eurotiales (Ascomycota) Isolated from Tidal Flat Sediments in China

Tidal flats have been reported to contain many microorganisms and play a critical role in maintaining biodiversity. In surveys of filamentous fungi from tidal flat sediments in China, seven new species of Eurotiales were discovered and described. Morphological characteristics and DNA sequence analyses of combined datasets of the BenA, CaM, and RPB2 regions support their placements and recognition as new species. Aspergillus liaoningensis sp. nov. and A. plumeriae sp. nov. belong to sections Candidi and Flavipedes of subgenus Circumdati, and A. subinflatus sp. nov. is a member of section Cremei of subgenus Cremei. Penicillium danzhouense sp. nov., P. tenue sp. nov., and P. zhanjiangense sp. nov. are attributed to sections Exilicaulis and Lanata-Divaricata of subgenus Aspergilloides. Talaromyces virens sp. nov. is in section Talaromyces. Detailed descriptions and illustrations of these novel taxa are provided. Their differences from close relatives were compared and discussed.

Molecular identification of Brazilian Fusarium strains: sources of proteases with milk-clotting properties

Fusarium is a genus of ubiquitous fungi that comprises mycotoxigenic animal and plant pathogens. These fungi have the ability to exploit a wide range of substrates and hosts, indicating their great potential for enzyme production; however, this aspect is understudied. Therefore, the present study aimed for revaluating the identity of twenty-three Fusarium strains maintained in the University Recife Mycology (URM) culture collection, Brazil, and to evaluate their potential for proteases production and the milk-clotting activity of these proteases. According to phylogenetic analysis of translation elongation factor 1-alpha (TEF1) gene partial sequences, these strains belonged to 12 species representing four species complexes: Fusarium concolor, F. fujikuroi, F. incarnatum-equiseti, and F. oxysporum. Four of these species are putatively novel to science. Notably, novel associations of Fusarium spp. with certain hosts/substrates were documented. The proteolytic activity ranged from 1.67 U ml-1 to 22.03 U ml-1 among the evaluated fungal isolates, with specific proteolytic activity reaching 205.86 U mg-1. The values for coagulant activity and specific activity were up to 157.14 U ml-1 and 1,424.11 U mg-1, respectively. These results indicate the potential of URM Fusarium strains as a source for the production of enzymes of industrial interest. Additionally, they reinforce the importance of applying DNA-based methods for reviewing the identification of fungal strains preserved in biodiversity repositories.

Strategies for the Development of Industrial Fungal Producing Strains

The use of microorganisms in industry has enabled the (over)production of various compounds (e.g., primary and secondary metabolites, proteins and enzymes) that are relevant for the production of antibiotics, food, beverages, cosmetics, chemicals and biofuels, among others. Industrial strains are commonly obtained by conventional (non-GMO) strain improvement strategies and random screening and selection. However, recombinant DNA technology has made it possible to improve microbial strains by adding, deleting or modifying specific genes. Techniques such as genetic engineering and genome editing are contributing to the development of industrial production strains. Nevertheless, there is still significant room for further strain improvement. In this review, we will focus on classical and recent methods, tools and technologies used for the development of fungal production strains with the potential to be applied at an industrial scale. Additionally, the use of functional genomics, transcriptomics, proteomics and metabolomics together with the implementation of genetic manipulation techniques and expression tools will be discussed.

Soil Aspergillus Species, Pathogenicity and Control Perspectives

Five Aspergillus sections have members that are established agricultural pests and producers of different metabolites, threatening global food safety. Most of these pathogenic Aspergillus species have been isolated from almost all major biomes. The soil remains the primary habitat for most of these cryptic fungi. This review explored some of the ecological attributes that have contributed immensely to the success of the pathogenicity of some members of the genus Aspergillus over time. Hence, the virulence factors of the genus Aspergillus, their ecology and others were reviewed. Furthermore, some biological control techniques were recommended. Pathogenic effects of Aspergillus species are entirely accidental; therefore, the virulence evolution prediction model in such species becomes a challenge, unlike their obligate parasite counterparts. In all, differences in virulence among organisms involved both conserved and species-specific genetic factors. If the impacts of climate change continue, new cryptic Aspergillus species will emerge and mycotoxin contamination risks will increase in all ecosystems, as these species can metabolically adjust to nutritional and biophysical challenges. As most of their gene clusters are silent, fungi continue to be a source of underexplored bioactive compounds. The World Soil Charter recognizes the relevance of soil biodiversity in supporting healthy soil functions. The question of how a balance may be struck between supporting healthy soil biodiversity and the control of toxic fungi species in the field to ensure food security is therefore pertinent. Numerous advanced strategies and biocontrol methods so far remain the most environmentally sustainable solution to the control of toxigenic fungi in the field.

Rapid and robust squashed spore/colony PCR of industrially important fungi

BACKGROUND

Fungi have been utilized for centuries in medical, agricultural, and industrial applications. Development of systems biology techniques has enabled the design and metabolic engineering of these fungi to produce novel fuels, chemicals, and enzymes from renewable feedstocks. Many genetic tools have been developed for manipulating the genome and creating mutants rapidly. However, screening and confirmation of transformants remain an inefficient step within the design, build, test, and learn cycle in many industrial fungi because extracting fungal genomic DNA is laborious, time-consuming, and involves toxic chemicals.

RESULTS

In this study we developed a rapid and robust technique called "Squash-PCR" to break open the spores and release fungal genomic DNA as a template for PCR. The efficacy of Squash-PCR was investigated in eleven different filamentous fungal strains. Clean PCR products with high yields were achieved in all tested fungi. Spore age and type of DNA polymerase did not affect the efficiency of Squash-PCR. However, spore concentration was found to be the crucial factor for Squash-PCR in Aspergillus niger, with the dilution of starting material often resulting in higher PCR product yield. We then further evaluated the applicability of the squashing procedure for nine different yeast strains. We found that Squash-PCR can be used to improve the quality and yield of colony PCR in comparison to direct colony PCR in the tested yeast strains.

CONCLUSION

The developed technique will enhance the efficiency of screening transformants and accelerate genetic engineering in filamentous fungi and yeast.

Safety evaluation of the food enzyme peroxidase from the genetically modified Aspergillus niger strain MOX

The food enzyme peroxidase (phenolic donor: hydrogen-peroxide oxidoreductase, EC 1.11.1.7) is produced with the genetically modified Aspergillus niger strain MOX by DSM Food Specialties B.V. The genetic modifications do not give rise to safety concerns. The food enzyme is considered free from viable cells of the production organism and its DNA. The food enzyme is intended to be used in whey processing. Dietary exposure to the food enzyme total organic solids (TOS) was estimated to be up to 0.635 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 2,162 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure resulted in a margin of exposure of at least 3,405. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that, under the intended conditions of use, the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Safety evaluation of the food enzyme ribonuclease P from the non-genetically modified Penicillium citrinum strain AE-RP-4

The food enzyme ribonuclease P (EC 3.1.26.5) is produced with the non-genetically modified Penicillium citrinum strain AE-RP-4 by Amano Enzyme Inc. It is intended to be used in yeast processing only for the production of yeast extract. Dietary exposure to the food enzyme total organic solids (TOS) was estimated to be up to 0.153 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not raise safety concerns. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level (NOAEL) of 134.7 mg TOS/kg bw per day, which when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 880. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that, under the intended conditions of use, the risk of allergic reactions upon dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme pectinesterase from the genetically modified Aspergillus niger strain PME

The food enzyme pectinesterase (pectin pectylhydrolase; EC 3.1.1.11) is produced with the genetically modified Aspergillus niger strain PME by DSM Food Specialties B.V. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its recombinant DNA. It is intended to be used in fruit and vegetable processing, for juice production and fruit and vegetable processing for products other than juices. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.095 mg TOS/kg body weight (bw) per day in European populations. The toxicity studies were carried out with a xylanase obtained from A. niger strain XEA. The Panel considered this food enzyme as a suitable substitute for the pectinesterase to be used in the toxicological studies, because both production strains are derived from the same recipient strain, the location of the inserts is comparable, no partial inserts were present and the production methods are essentially the same. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level (NOAEL) of 1,852 mg TOS/kg bw per day, the highest dose tested, resulting in a margin of exposure of at least 19,495. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and two matches with pollen allergens were found. The Panel considered that, under the intended conditions of use, the risk of allergic reactions upon dietary exposure to this food enzyme, particularly in individuals sensitised to pollen allergens, cannot be excluded. The Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme endo-1,4-β-xylanase from the non-genetically modified Aspergillus tubingensis strain LYX

The food enzyme endo-1,4-β-xylanase (4-β-d-xylan xylanohydrolase, EC 3.2.1.8) is produced with the non-genetically modified microorganism Aspergillus tubingensis strain LYX by DSM Food Specialties B.V. The food enzyme was considered free from viable cells of the production organism. It is intended to be used in baking processes and cereal-based processes. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.106 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 227 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 2,142. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that, under the intended conditions of use, the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Safety evaluation of the food enzyme inulinase from the genetically modified Aspergillus oryzae strain MUCL 44346

The food enzyme inulinase (1-β-d-fructan fructanohydrolase; EC 3.2.1.7) is produced with the genetically modified Aspergillus oryzae strain MUCL 44346 by PURATOS NV. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in the production of fructo-oligosaccharides (FOS) from inulin extracted from chicory roots. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.01 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level (NOAEL) of 100 mg TOS/kg bw per day, which when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 10,000. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and two matches were found with tomato allergens. The Panel considered that, under the intended conditions of use, the risk of allergic reactions upon dietary exposure to this food enzyme, particularly in individuals sensitised to tomato, cannot be excluded. However, the likelihood of allergic reactions is expected not to exceed the likelihood of allergic reactions to tomato. As the prevalence of allergic reactions to tomato is low, also the likelihood of such reactions to occur to the food enzyme is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Safety evaluation of the food enzyme cellulase from the non-genetically modified Aspergillus niger strain 294

The food enzyme cellulase (4-(1,3;1,4)-β-d-glucan-4-glucanohydrolase; EC 3.1.2.4) is produced with the non-genetically modified Aspergillus niger strain 294 by Kerry Ingredients & Flavours Ltd. The food enzyme is considered free from viable cells of the production organism. The enzyme is intended to be used in eight food manufacturing processes: baking processes, cereal-based processes, brewing processes, grain treatment for the production of starch and gluten fractions, fruit and vegetable processing for juice production, fruit and vegetable processing for products other than juices, distilled alcohol production and wine and wine vinegar production. Since residual amounts of total organic solids (TOS) are removed during distilled alcohol production and grain treatment for the production of starch and gluten fractions, dietary exposure was only calculated for the remaining six food manufacturing processes. It was estimated to be up to 5.706 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 794 mg TOS/kg bw per day, the highest dose tested. The calculated margin of exposure for each age group was 184 (infants), 146 (toddlers), 139 (children), 219 (adolescents), 305 (adults) and 441 (the elderly). A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and four matches were found. The Panel considered that, under the intended conditions of use (other than distilled alcohol production), the risk of allergic reactions by dietary exposure cannot be excluded, but the likelihood is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use for adolescents, adults and the elderly.

Safety evaluation of a food enzyme containing endo-polygalacturonase and pectin lyase activities from the non-genetically modified Aspergillus tubingensis strain NZYM-PE

The food enzyme with the declared activities endo-polygalacturonase ((1-4)-α-D-galacturonan glycanohydrolase; EC 3.2.1.15) and pectin lyase ((1-4)-6-O-methyl-α-D-galacturonan lyase; EC 4.2.2.10) is produced with the non-genetically modified Aspergillus tubingensis strain NZYM-PE by Novozymes A/S. It is intended to be used in four food manufacturing processes: fruit and vegetable processing for juice production, fruit and vegetable processing for products other than juices, refined olive oil production and wine and wine vinegar production. Since residual amounts of total organic solids (TOS) are removed during production, dietary exposure was not calculated for refined olive oil production. For the remaining three food processes, it was estimated to be up to 0.132 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level (NOAEL) of 1,430 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, resulted in a margin of exposure above 10,833. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and 13 matches were found, including one food allergen (papaya). The Panel considered that, under the intended conditions of use, the risk of allergic reactions upon dietary exposure to this food enzyme cannot be excluded, in particular for individuals sensitised to papaya, but that the risk will not exceed that of consumption of papaya. In addition, oral allergy reactions cannot be excluded in pollen-sensitised individuals. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns, under the intended conditions of use.

Antimicrobial Activity against Foodborne Pathogens and Antioxidant Activity of Plant Leaves Traditionally Used as Food Packaging

In accordance with Thai wisdom, indigenous plant leaves have been used as food packaging to preserve freshness. Many studies have demonstrated that both antioxidant and antimicrobial activities contribute to protecting food from spoilage. Hence, the ethanolic extracts of leaves from selected plants traditionally used as food packaging, including Nelumbo nucifera (1), Cocos nucifera (2), Nypa fruticans (3), Nepenthes mirabilis (4), Dendrocalamus asper (5), Cephalostachyum pergracile (6), Musa balbisiana (7), and Piper sarmentosum (8), were investigated to determine whether they have antioxidant and antimicrobial activities against spoilage microorganisms and foodborne pathogens that might be beneficial for food quality. Extracts 1-4 exhibited high phenolic content at 82.18-115.15 mg GAE/g and high antioxidant capacity on DPPH, FRAP and SRSA assay at 14.71-34.28 μg/mL, 342.92-551.38 μmol Fe²⁺/g, and 11.19-38.97 μg/mL, respectively, while leaf extracts 5-8 showed lower phenolic content at 34.43-50.08 mg GAE/g and lower antioxidant capacity on DPPH, FRAP, and SRSA at 46.70-142.16 μg/mL, 54.57-191.78 μmol Fe²⁺/g, and 69.05->120 μg/mL, respectively. Extracts 1-4 possessed antimicrobial activities against food-relevant bacteria, including Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, and Escherichia coli. Only N. mirabilis extract (4) showed antimicrobial activities against Salmonella enterica subsp. enterica serovar Abony and Candida albicans. Extracts 5-8 showed slight antimicrobial activities against B. cereus and E. coli. As the growth and activity of microorganisms are the main cause of food spoilage, N. fruticans (3) was selected for bioassay-guided isolation to obtain 3-O-caffeoyl shikimic acid (I), isoorientin (II) and isovitexin (III), which are responsible for its antimicrobial activity against foodborne pathogens. N. fruticans was identified as a new source of natural antimicrobial compounds I-III, among which 3-O-caffeoyl shikimic acid was proven to show antimicrobial activity for the first time. These findings support the use of leaves for wrapping food and protecting food against oxidation and foodborne pathogens through their antioxidant and antimicrobial activities, respectively. Thus, leaves could be used as a natural packaging material and natural preservative.

Safety and efficacy of a feed additive consisting of endo-1,4-beta-xylanase, endo-1,3(4)-beta-glucanase and endo-1,4-beta-glucanase produced by Trichoderma reeseiATCC 74444 (Ronozyme® Multigrain) for use in poultry for fattening, poultry for laying and piglets (weaned) (DSM Nutritional Products)

Ronozyme® Multigrain G/L is the trade name of the feed additive under assessment containing endo-1,4-beta-xylanase, endo-1,4-beta-glucanase and endo-1,3(4)-beta-glucanase produced by a non-genetically modified strain of Trichoderma reesei (ATCC 74444). It is authorised for use as a zootechnical additive (functional group: digestibility enhancer) in poultry for fattening, poultry for laying and weaned piglets. This scientific opinion concerns the request for the renewal of the authorisation of the additive for the species/categories for which there is an authorisation. The applicant provided evidence that the additive currently in the market complies with the conditions of the authorisation. There is no new evidence that would lead the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) to reconsider previous conclusions that the additive is safe for the animal species/categories, the consumer and the environment under the authorised conditions of use. Regarding the safety for the user, the additive should be considered a potential respiratory sensitiser. In absence of data, the Panel could not conclude on the potential of the additive to cause skin and eye irritation or dermal sensitisation. There was no need for assessing the efficacy of the additive in the context of the renewal of the authorisation for poultry for fattening, poultry for laying and weaned piglets.

Safety evaluation of the food enzyme pectinesterase from the genetically modified Trichoderma reesei strain RF6201

The food enzyme pectinesterase (pectin pectylhydrolase; EC 3.1.1.11) is produced with the genetically modified Trichoderma reesei strain RF6201 by AB Enzymes GmbH. The genetic modifications do not give rise to safety concerns. The food enzyme was considered free from viable cells of the production organism and its DNA. It is intended to be used in five food manufacturing processes: fruit and vegetable processing for juice production, fruit and vegetable processing for products other than juices, production of wine and wine vinegar, coffee demucilation and production of plant extracts as flavouring preparations. Since residual amounts of the total organic solids (TOS) are removed during the coffee demucilation and the production of flavouring extracts, dietary exposure was calculated only for the remaining three food processes. It was estimated to be up to 0.532 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 1,000 mg TOS/kg bw per day, the highest dose tested, which, when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 1,880. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and two matches were found with pollen allergens. The Panel considered that, under the intended conditions of use, the risk of allergic reactions upon dietary exposure, particularly in individuals sensitised to pollen allergens, cannot be excluded. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.