Risks associated with endotoxins in feed additives produced by fermentation

Responsible innovation: Mitigating the food safety aspects of cultured meat production

There is much interest in cultured (cultivated) meat as a potential solution to concerns over the ecological and environmental footprint of food production, especially from animal-derived food products. The aim of this critical review is to undertake a structured analysis of existing literature to (i) identify the range of materials that could be used within the cultured meat process; (ii) explore the potential biological and chemical food safety issues that arise; (iii) identify the known and also novel aspects of the food safety hazard portfolio that will inform hazard analysis and risk assessment approaches, and (iv) position a responsible innovation framework that can be utilized to mitigate food safety concerns with specific emphasis on cultured meat. Although a number of potential food safety hazards are identified that need to be considered within a food safety plan, further research is required to validate and verify that these food safety hazards have been suitably controlled and, where possible, eliminated. The responsible innovation framework developed herein, which extends beyond hazard analysis and traditional risk assessment approaches, can be applied in multiple contexts, including this use case of cultured meat production.

Safety and efficacy of a feed additive consisting of vitamin B12 (cyanocobalamin) produced by fermentation with Ensifer adhaerens CGMCC 21299 for all animal species (NHU Europe GmbH)

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of vitamin B12 (cyanocobalamin) produced by fermentation with a non-genetically modified strain of Ensifer adhaerens (CGMCC 21299), when used as a nutritional additive for all animal species. No viable cells or DNA of the production strain were detected in the additive. Therefore, cyanocobalamin produced by fermentation with E. adhaerens CGMCC 21299 does not raise safety concerns as regards to the production strain. The Panel on Additives and Products or Substances used in Animal Feed concluded that cyanocobalamin produced by fermentation with E. adhaerens CGMCC 21299 is considered safe for all animal species, for the consumers and the environment. Due to the presence of nickel, the additive is considered a skin and respiratory sensitiser. Inhalation and dermal exposure are considered a risk. Due to the lack of data, the Panel could not conclude on the potential of the additive to be an eye irritant. Cyanocobalamin produced by fermentation with E. adhaerens CGMCC 21299 is effective in meeting animal's nutritional requirements when administered via feed.

Safety and efficacy of a feed additive consisting of vitamin B12 (cyanocobalamin) produced by fermentation with Ensifer adhaerens CGMCC 19596 for all animal species (Hebei Huarong Pharmaceutical Co. ltd)

The vitamin B12 (in the form of cyanocobalamin) under assessment is produced by fermentation with Ensifer adhaerens CGMCC 19596 and it is intended to be used as a nutritional additive for all animal species. Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of cyanocobalamin, produced by fermentation with E. adhaerens CGMCC 19596. Cyanocobalamin produced by other strains of E. adhaerens is already authorised for use in animal species. ■■■■■ However no viable cells nor DNA of the production strain were detected in the additive. Therefore, cyanocobalamin produced by E. adhaerens CGMCC 19596 does not raise safety concerns as regards to the production strain. The FEEDAP Panel concluded that cyanocobalamin produced by fermentation with E. adhaerens CGMCC 19596 is considered safe for all animal species. The use of cyanocobalamin in animal nutrition is of no concern for consumer safety. Cyanocobalamin is non-irritant to skin and non-irritant to eyes. No conclusions could be drawn on the potential of the additive to be a skin sensitiser. The potential endotoxin activity of the additive is unlikely to represent a hazard for users. The use of the additive under assessment in animal nutrition is considered safe for the environment. Cyanocobalamin produced by E. adhaerens CGMCC 19596 is effective in meeting animal's nutritional requirements when administered via feed.

Endotoxin content in neonatal formulas, fortification, and lactoferrin products: association with outcomes and guidance on acceptable limits

While endotoxin (lipopolysaccharide) can be harmful and contribute to morbidity and mortality with Gram-negative sepsis or necrotizing enterocolitis in preterm infants, non-toxic amounts are produced as part of the neonatal microbiome and may be present in enteral nutrition and medications administered. The United States Food and Drug Administration has given guidance for endotoxin concentration limits for intravenous medications and fluids of 5 endotoxin units/kg/hour (120 endotoxin units/kg/day), but no guidance for amounts of endotoxin in enteral products. To determine baseline exposure to infants in the neonatal intensive care unit, we examined endotoxin content of enteral formulas and fortification used for preterm infants, as well as bovine lactoferrin products. We also examined endotoxin exposure and outcomes in very low birth weight infants. Endotoxin content was measured using kinetic chromogenic limulus amebocyte lysate analysis. Daily endotoxin exposure from enteral formulas ranged between < 75 to 7110 endotoxin units/kg and from lactoferrin products from 7 to 3720 endotoxin units/kg. In examining neonatal outcomes from a bovine lactoferrin product studied at three different escalating doses (100, 200, and 300 mg/kg/day), we measured endotoxin in the lactoferrin product and daily exposure was 1089 (N = 10), 2178 (N = 10) and 3287 (N = 11) endotoxin units/kg, respectively. There were no cases of necrotizing enterocolitis or mortality and no lactoferrin-related adverse effects in these patients. Enteral endotoxin daily exposures from lactoferrin products are similar to amounts in preterm enteral nutrition and appear safe and not associated with patient harm. Testing enteral products and establishing safety limits may improve care of high risk patients.

Spraying compound probiotics improves growth performance and immunity and modulates gut microbiota and blood metabolites of suckling piglets

One factor that shapes the establishment of early neonatal intestinal microbiota is environmental microbial exposure, and probiotic application has been shown to promote health and growth of piglets. Thus, this study hypothesized that environmental probiotic application in early days of life would be beneficial to newborn piglets. This study aimed to investigate the effect of spraying a compound probiotic fermented liquid (CPFL) into the living environment of piglets on their early growth performance and immunity. This work included 68 piglets, which were randomized into probiotic and control groups. Blood and fecal samples were collected at 0, 3, 7, 14, and 21 days of age. Spraying CPFL significantly reshaped the microbiota composition of the delivery room environment, increased piglets' daily weight gain and weaning weight (P<0.001), and modulated piglets' serum cytokine levels (increases in IgA, IgG, and IL-10; decrease in IFN-γ; P<0.05 in each case) in piglets. Additionally, spraying CPFL during early days of life modified piglets' gut microbiota structure and diversity, increased the abundance of some potentially beneficial bacteria (such as Bacteroides uniformis, Butyricimonas virosa, Parabacteroides distasonis, and Phascolarctobacterium succinatutens) and decreased the abundance of Escherichia coli (P<0.05). Interestingly, CPFL application also significantly enhanced the gut microbial bioactive potential and levels of several serum metabolites involved in the metabolism of vitamins (B2, B3, B6, and E), medium/long-chain fatty acids (caproic, tetradecanoic, and peptadecanoic acids), and dicarboxylic acids (azelaic and sebacic acids). Our study demonstrated that spraying CPFL significantly could improve piglets' growth performance and immunity, and the beneficial effects are associated with changes in the gut microbiota and host metabolism. Our study has provided novel data for future development of probiotic-based health-promoting strategies and expanded our knowledge of probiotic application in animal husbandry.

Post-endotoxin exposure-induced lung inflammation and resolution consequences beneficially impacted by lung-delivered IL-10 therapy

Although lung diseases typically result from long-term exposures, even a robust, one-time exposure can result in long-lasting consequences. Endotoxin is a ubiquitous environmental/occupational inflammatory agent often used to model airway inflammation. Using a murine model, the return to lung homeostasis following high dose inhalant lipopolysaccharide (LPS, 10-100 μg) exposure were delineated over 2 weeks. LPS-induced rapid weight loss, release of proinflammatory mediators, and inflammatory cell influx with prolonged persistence of activated macrophages CD11c⁺CD11b⁺ and recruited/transitioning CD11c^intCD11b⁺ monocyte-macrophages out to 2 weeks. Next, lung-delivered recombinant (r) interleukin (IL)-10 was intratracheally administered for 3 doses initiated 5 h following LPS (10 μg) exposure for 2 days. IL-10 therapy reduced LPS-induced weight loss and increased blood glucose levels. Whereas there was no difference in LPS-induced bronchoalveolar lavage airway fluid cellular influx, total lung cell infiltrates were reduced (37%) with rIL-10 treatment. Post-LPS exposure treatment with rIL-10 strikingly reduced lavage fluid and lung homogenate levels of tumor necrosis factor-α (88% and 93% reduction, respectively), IL-6 (98% and 94% reduction), CXCL1 (66% and 75% reduction), and CXCL2 (47% and 67% reduction). LPS-induced recruited monocyte-macrophages (CD11c^intCD11b⁺) were reduced (68%) with rIL-10. Correspondingly, LPS-induced lung tissue CCR2⁺ inflammatory monocyte-macrophage were reduced with rIL-10. There were also reductions in LPS-induced lung neutrophils, lymphocyte subpopulations, collagen content, and vimentin expression. These findings support the importance of studying resolution processes for the development of treatment after unintended environmental/occupational biohazard exposures. Short-term, lung-delivered rIL-10 favorably hastened inflammatory recovery processes following acute, high dose inhalant LPS exposure.

CRISPR-Cas systems mediated biosensing and applications in food safety detection

Food safety, closely related to economic development of food industry and public health, has become a global concern and gained increasing attention worldwide. Effective detection technology is of great importance to guarantee food safety. Although several classical detection methods have been developed, they have some limitations in portability, selectivity, and sensitivity. The emerging CRISPR-Cas systems, uniquely integrating target recognition specificity, signal transduction, and efficient signal amplification abilities, possess superior specificity and sensitivity, showing huge potential to address aforementioned challenges and develop next-generation techniques for food safety detection. In this review, we focus on recent progress of CRISPR-Cas mediated biosensing and their applications in food safety monitoring. The properties and principles of commonly used CRISPR-Cas systems are highlighted. Notably, the frequently coupled nucleic acid amplification strategies to enhance their selectivity and sensitivity, especially isothermal amplification methods, as well as various signal output modes are also systematically summarized. Meanwhile, the application of CRISPR-Cas systems-based biosensors in food safety detection including foodborne virus, foodborne bacteria, food fraud, genetically modified organisms (GMOs), toxins, heavy metal ions, antibiotic residues, and pesticide residues is comprehensively described. Furthermore, the current challenges and future prospects in this field are tentatively discussed.

Assessment of Indoor Air Quality for Group-Housed Macaques (Macaca spp.)

Indoor Air Quality (IAQ) is strongly associated with animal health and wellbeing. To identify possible problems of the indoor environment of macaques (Macaca spp.), we assessed the IAQ. The temperature (°C), relative humidity (%) and concentrations of inhalable dust (mg/m3), endotoxins (EU/m3), ammonia (ppm) and fungal aerosols were measured at stationary fixed locations in indoor enclosures of group-housed rhesus (Macaca mulatta) and cynomolgus macaques (Macaca fascicularis). In addition, the personal exposure of caretakers to inhalable dust and endotoxins was measured and evaluated. Furthermore, the air circulation was assessed with non-toxic smoke, and the number of times the macaques sneezed was recorded. The indoor temperature and relative humidity for both species were within comfortable ranges. The geometric mean (GM) ammonia, dust and endotoxin concentrations were 1.84 and 0.58 ppm, 0.07 and 0.07 mg/m3, and 24.8 and 6.44 EU/m3 in the rhesus and cynomolgus macaque units, respectively. The GM dust concentrations were significantly higher during the daytime than during the nighttime. Airborne fungi ranged between 425 and 1877 CFU/m3. Personal measurements on the caretakers showed GM dust and endotoxin concentrations of 4.2 mg/m3 and 439.0 EU/m3, respectively. The number of sneezes and the IAQ parameters were not correlated. The smoke test revealed a suboptimal air flow pattern. Although the dust, endotoxins and ammonia were revealed to be within accepted human threshold limit values (TLV), caretakers were exposed to dust and endotoxin levels exceeding existing occupational reference values.

Prevalence of Mycotoxins and Endotoxins in Total Mixed Rations and Different Types of Ensiled Forages for Dairy Cows in Lithuania

In this study, 119 samples of total mixed rations and different types of ensiled forage (maize and grass silage, and haylage) collected in 2019–2020 from dairy farms in Lithuania were analyzed to evaluate the quantitative occurrence of mycotoxins and endotoxins. Samples were analyzed using high-performance liquid chromatography (HPLC) with a fluorescent (FLD) and an ultraviolet detector (UV) of mycotoxins and a detection assay based on the ELISA technology for endotoxins. The study included toxins regulated within the European Union (aflatoxin B1 (AFB1), zearalenone (ZEA), deoxynivalenol (DON) and T-2 toxin) and nonregulated toxins (endotoxins). Mycotoxin analysis showed that 49.58% of the samples out of 119 were positive for AFB1, 52.11% for ZEA and DON, 55.47% for T-2 toxin and 84.04% for endotoxins. In the contaminated samples, the highest mean values of AFB1 and T-2 toxin were determined in the grass silage samples, while ZEA and DON–were determined in the maize silage samples. Maize silage samples had the highest ZEA and DON concentrations, exceeding the EU maximum permissible concentration limits. In the haylage samples, AFB1 mycotoxin exceeded the maximum concentration limits. The highest mean value of endotoxins was determined in the total mixed rations samples. This is the first study to provide information about the concentrations of mycotoxins and endotoxins in total mixed rations and different types of ensiled forages for dairy cows in Lithuania.

Safety and efficacy of a feed additive consisting of l-histidine monohydrochloride monohydrate produced using Escherichia coli NITE SD 00268 for all animal species (Kyowa Hakko Europe GmbH)

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on l-histidine monohydrochloride (HCl) monohydrate produced by fermentation with Escherichia coli  (NITE SD 00268) when used as a nutritional additive or as a feed flavouring compound in feed for all animal species. The active substance of the additive is l-histidine. The production strain has been modified by conventional mutagenesis and it does not raise safety concerns. The additive under assessment is safe for the target species when used as a nutritional additive to supplement the diet in appropriate amounts to cover the requirements, depending on the species, the physiological state of the animal, the performance level, the environmental conditions, the background amino acid composition of the unsupplemented diet and the status of some essential trace elements. This conclusion would cover its use as flavouring compound. l-Histidine HCl monohydrate produced by E. coli NITE SD 00268, when used at the proposed conditions of use, is safe for the consumer and for the environment. l-Histidine HCl monohydrate produced using E. coli NITE SD 00268 is not a skin irritant. In the absence of data, it is not possible to conclude on the potential of the additive to be toxic by inhalation, irritant to eyes or a skin sensitiser. The additive l-histidine HCl monohydrate is regarded as an effective source of the amino acid l-histidine when used as a nutritional additive. For the supplemental l-histidine to be as efficacious in ruminants as in non-ruminant species, it would require protection against degradation in the rumen. l-Histidine is efficacious as a flavouring compound.

Effect of Food Endotoxin on Infant Health

Endotoxin is a complex molecule derived from the outer membrane of Gram-negative bacteria, and it has strong thermal stability. The processing of infant food can kill pathogenic bacteria but cannot remove endotoxin. Because the intestinal structure of infants is not fully developed, residual endotoxin poses a threat to their health by damaging the intestinal flora and inducing intestinal inflammation, obesity, and sepsis, among others. This paper discusses the sources and contents of endotoxin in infant food and methods for preventing endotoxin from harming infants. However, there is no clear evidence that endotoxin levels in infant food cause significant immune symptoms or even diseases in infants. However, in order to improve the safety level of infant food and reduce the endotoxin content, this issue should not be ignored. The purpose of this review is to provide a theoretical basis for manufacturers and consumers to understand the possible harm of endotoxin content in infant formula milk powder and to explore how to reduce its level in infant formula milk powder. Generally, producers should focus on cleaning the milk source, securing the cold chain, avoiding long-distance transportation, and shortening the storage time of raw milk to reduce the level of bacteria and endotoxin. After production and processing, the endotoxin content should be measured as an important index to test the quality of infant formula milk powder so as to provide high-quality infant products for the healthy growth of newborns.

Safety of vitamin B12 (in the form of cyanocobalamin) produced by Ensifer adhaerensCNCM-I 5541 for all animal species

The vitamin B12 (in the form of cyanocobalamin) under assessment is produced by fermentation with a genetically modified strain of Ensifer adhaerens and it is intended to be used as a nutritional additive for all animal species. In 2018, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) of EFSA issued an opinion on the safety and efficacy of the product. In that assessment, the Panel could not conclude on the safety of the additive for the target species, consumers and the environment due to uncertainties on the safety of the production strain and the resulting product. Due to high endotoxin content, potential inhalation exposure when handling premixtures and reported irritancy for skin and eyes, the additive was considered to pose a risk to user safety. The applicant provided supplementary data on the identity of the production strain, its susceptibility to antibiotics and toxigenic potential, as well as on the absence of cells and recombinant DNA of the production strain in the final product. The production strain is not expected to produce any toxic compound during fermentation but harbours antimicrobial resistance genes. However, viable cells and recombinant DNA of the strain were not detected in the most concentrated form of the additive. With this new information, the FEEDAP Panel concluded that vitamin B12 produced by E. adhaerens CNCM I-5541 (identified as SCM 2034 in the previous opinion) is safe for all animal species, the consumers and the environment. The applicant did not provide new evidence that would lead the FEEDAP Panel to reconsider previous conclusions regarding the safety for the user.

Safety and Efficacy of l-histidine monohydrochloride monohydrate produced by fermentation using Escherichia coli KCCM 80212 as a feed additive for all animal species

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on l-histidine monohydrochloride (HCl) monohydrate produced by fermentation using Escherichia coli KCCM 80212 when used as a nutritional additive in feed for all animal species. The production strain is genetically modified. The production strain and its recombinant DNA were not detected in the final product. l-Histidine HCl monohydrate manufactured by fermentation using E. coli KCCM 80212 does not give rise to any safety concern regarding the genetic modification. The use of l-histidine HCl monohydrate produced by fermentation using E. coli KCCM 80212 is safe for the target species when used as a nutritional additive to supplement the diet in appropriate amounts to cover the requirements, depending on the species, the physiological state of the animal, the performance level, the environmental conditions, the background amino acid composition of the unsupplemented diet and the status of some essential trace elements such as copper and zinc. l-Histidine HCl monohydrate produced using E. coli KCCM 80212 supplemented at levels appropriate for the requirements of the target species is considered safe for the consumer. l-Histidine HCl monohydrate produced by E. coli KCCM 80212 is a skin sensitiser. There is a risk for persons handling the additive from the exposure to endotoxins by inhalation. The additive under assessment is not irritant to skin or eyes. The use of l-histidine HCl monohydrate produced using E. coli KCCM 80212 in animal nutrition is not expected to represent a risk to the environment. l-Histidine HCl monohydrate is considered an efficacious source of the essential amino acid l-histidine for non-ruminant animal species. For the supplemental l-histidine to be as efficacious in ruminants as in non-ruminant species, it would require protection against degradation in the rumen.

Safety and efficacy of l-valine produced by fermentation using Escherichia coli KCCM 80159 for all animal species

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of l-valine (≥ 98.0%) produced by fermentation using a genetically modified strain of Escherichia coli (KCCM 80159). It is intended to be used in feed for all animal species and categories. Species identity of the production organism E. coli KCCM 80159 was confirmed; the strain was sensitive to antibiotics at concentrations below or equal to thresholds specified by EFSA; and no viable cells or its recombinant DNA were detected in the final product. Therefore, the final product does not give raise to any safety concern with regard to the genetic modification of the production strain. The FEEDAP Panel concludes that l-valine produced by E. coli KCCM 80159 is safe for the target species when supplemented in appropriate amounts to the diet according to the nutritional needs of the target species, for the consumer, for the users and for the environment. The product l-valine produced by fermentation using E. coli KCCM 80159 is regarded as an efficacious source of the essential amino acid l-valine for non-ruminant nutrition. For the supplemental l-valine to be as efficacious in ruminants as in non-ruminant species, it requires protection against degradation in the rumen.

Occurrence of bacteria and endotoxins in fermented foods and beverages from Nigeria and South Africa

In Africa, fermented foods and beverages play significant roles in contributing to food security. Endotoxins are ubiquitous heat stable lipopolysaccharide (LPS) complexes situated in the outer cell membranes of Gram-negative bacteria. This study evaluated the microbiological quality of fermented foods (ogiri, ugba, iru, ogi and ogi baba) and beverages (mahewu and umqombothi) from selected Nigerian and South African markets. The bacterial diversity of the fermented foods was also investigated and the identity of the isolates confirmed by biochemical and molecular methods. Isolate grouping was established through hierarchal clustering and the samples were further investigated for endotoxin production with the chromogenic Limulus Amoebocyte Lysate assay. The total aerobic count of the samples ranged from 5.7 to 10.8 Log CFU/g. Fourteen bacteria genera were detected with most of the isolates being members of the Enterobacteriaceae family. Sphingomonas paucimobilis and Escherichia coli were the dominant Gram-negative bacterial species detected. There were considerable variations in the concentrations of endotoxins produced and the lowest endotoxin concentration was found in ogi (4.3 × 10 EU/g) and the highest in iru (5.5 × 10⁴ EU/g) while, 44% of umqombothi samples had endotoxins. Ogi baba samples had better microbial quality than other samples due to its reduced bacterial load and endotoxin levels. There was a strong positive (r = 0.714, r = 0.996) and significant (p < 0.01) correlation between the endotoxin levels and bacterial loads of the samples. Some previously unreported species of bacteria found in the fermented foods included Aeromonas haemolyticus and Rhizobium radiobacter. This is the first comprehensive report on endotoxins in fermented foods and beverages in Africa. Furthermore, the occurrence of pathogenic bacteria and toxins in the foods and beverages is of serious concern that calls for immediate action.

Safety and efficacy of l-tryptophan produced with Escherichia coli CGMCC 11674 for all animal species

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on l-tryptophan produced by fermentation with Escherichia coli CGMCC 11674 when used as a nutritional additive in feed and water for drinking for all animal species and categories. The production strain did not raise safety concerns. The FEEDAP Panel cannot conclude on the safety of l-tryptophan produced by E. coli CGMCC 11674 for the target species and for the consumer due to the tryptophan-related impurities such as 1,1'-ethylidene-bis-l-tryptophan (EBT). The FEEDAP Panel has concerns on the safety of the simultaneous oral administration of l-tryptophan via water for drinking and feed. Using unprotected forms of tryptophan in ruminants can be a risk. The FEEDAP Panel cannot conclude on the dermal or ocular irritation and skin sensitisation of l-tryptophan produced by E. coli CGMCC 11674. The additive poses a risk by inhalation from the exposure to endotoxins for people handling the additive. The use of l-tryptophan produced by E. coli CGMCC 11674 in animal nutrition does not pose a risk to the environment. The additive under assessment is regarded as an effective source of the amino acid l-tryptophan for all non-ruminant species. If the product l-tryptophan is intended for use in ruminants, it should be protected from ruminal degradation.

Dietary deoxynivalenol and oral lipopolysaccharide challenge differently affect intestinal innate immune response and barrier function in broiler chickens

Dietary deoxynivalenol (DON) impairs the intestinal immune system and digestive functions of broiler chickens. However, little is known whether increasing doses of DON similarly affect the intestinal functions in different segments of the small intestine in chickens and whether a second oral challenge may potentiate those effects. The present objective was to investigate the effect of increasing dietary DON concentrations on the relative expression of genes for tight junction proteins, mucins, toll-like receptors (TLR), and cytokines in duodenum and jejunum, jejunal mucosal permeability, as well as on α-1-acid glycoprotein and IgA in serum with or without an additional oral lipopolysaccharide (LPS) challenge. Eighty 1-d-old chickens were fed diets with increasing DON concentrations (0, 2.5, 5, and 10 mg DON/kg diet) for 5 wk. One day before sampling, half of the chickens received an oral challenge with 1-mg Escherichia coli O55:B5 LPS/kg BW. Ussing chambers were used to measure the jejunal permeability in birds receiving 10-mg DON/kg feed with or without LPS challenge and 0-mg DON/kg feed without LPS. Increasing DON concentrations of up to 5-mg DON/kg increased (P < 0.05) the duodenal expression of TLR2, IL6, and Claudin 1 (CLDN1) by up to 84%, 88%, and 48%, respectively, compared with the noncontaminated diet. Likewise, jejunal CLDN1 expression increased up to 23% in the chickens fed DON concentrations of up to 5-mg DON/kg diet (P < 0.05). Moreover, increasing DON concentrations linearly and quadratically decreased (P < 0.05) the jejunal expression of TLR2 and transforming growth factor-β 1, respectively. The additional LPS challenge increased (P < 0.040) duodenal occludin expression by 10% as well as the jejunal tissue conductance in chickens of the 10 DON group (P = 0.050). In conclusion, dietary DON differently affected the duodenal and jejunal expression of genes for tight-junction proteins and proinflammatory signaling pathways. The additional LPS challenge did not potentiate the DON effect but it seemed to induce a certain up-regulation of the proinflammatory response in the duodenum and enhanced the mucosal permeability in the jejunum.

Production of recombinant beta-amylase of Bacillus aryabhattai

In this study, the effects of carbon source, nitrogen source, and metal ions on cell growth and Bacillus aryabhattai β-amylase production in recombinant Brevibacillus choshinensis were investigated. The optimal medium for β-amylase production, containing glucose (7.5 g·L^-1), pig bone peptone (40.0 g·L^-1), Mg²⁺ (0.05 mol·L^-1), and trace metal elements, was determined through single-factor experiments in shake flasks. When cultured in the optimized medium, the β-amylase yield reached 925.4 U mL^-1, which was 7.2-fold higher than that obtained in the initial medium. Besides, a modified feeding strategy was proposed and applied in a 3-L fermentor fed with glucose, which achieved a dry cell weight of 15.4 g L^-1. Through this cultivation approached 30 °C with 0 g·L^-1 initial glucose concentration, the maximum β-amylase activity reached 5371.8 U mL^-1, which was 41.7-fold higher than that obtained with the initial medium in shake flask.

Effect of gelatin source and photoinitiator type on chondrocyte redifferentiation in gelatin methacryloyl-based tissue-engineered cartilage constructs

This work investigates neocartilage formation in bovine and porcine gelatin methacryloyl-based hydrogels photocrosslinked using ultraviolet or visible light photoinitiator systems.

Safety and efficacy of vitamin B12 (in the form of cyanocobalamin) produced by Ensifer spp. as a feed additive for all animal species based on a dossier submitted by VITAC EEIG

Cyanocobalamin is a synthetic form of vitamin B₁₂ used in pharmaceuticals, supplements and as a food additive. It is intended to be used in feed for all animal species and categories. The European Commission asked EFSA for an opinion on the safety for the target animals, consumer, user and the environment and on the efficacy of cyanocobalamin produced by fermentation with Ensifer adhaerens strains SCM 2034 or CICC 11008s or Ensifer fredii strain CMCC (B) 70000. Since relevant data were not provided by the applicant that would allow a proper identification and characterisation of the production strains, the Additives and Products or Substances used in Animal Feed (FEEDAP) Panel cannot conclude on the safety of the use of vitamin B₁₂ produced using E. adhaerens CICC 11008s and E. fredii CMCC (B) 70000 in animal nutrition for the target animals, the consumer, the user and the environment. Due to significant uncertainties on the identity and safety of the production strain E. adhaerens SCM 2034, including the presence of antibiotic resistance genes, the absence of viable cells of the production strain or their DNA in the product, the FEEDAP Panel cannot conclude on the safety of the use of vitamin B₁₂, produced by E. adhaerens SCM 2034 in animal nutrition for the target species, consumers and the environment. Due to high endotoxin content, potential inhalation exposure when handling premixtures and reported irritancy for skin and eyes, vitamin B₁₂ produced by E. adhaerens SCM2034 is considered to pose a risk to user safety. Vitamin B₁₂ additives produced by Ensifer spp. are regarded as effective in meeting animals' requirements.

Airborne bioaerosols and their impact on human health

Bioaerosols consist of aerosols originated biologically such as metabolites, toxins, or fragments of microorganisms that are present ubiquitously in the environment. International interests in bioaerosols have increased rapidly to broaden the pool of knowledge on their identification, quantification, distribution, and health impacts (e.g., infectious and respiratory diseases, allergies, and cancer). However, risk assessment of bioaerosols based on conventional culture methods has been hampered further by several factors such as: (1) the complexity of microorganisms or derivatives to be investigated; (2) the purpose, techniques, and locations of sampling; and (3) the lack of valid quantitative criteria (e.g., exposure standards and dose/effect relationships). Although exposure to some microbes is considered to be beneficial for health, more research is needed to properly assess their potential health hazards including inter-individual susceptibility, interactions with non-biological agents, and many proven/unproven health effects (e.g., atopy and atopic diseases).

Design of a Type-1 Diabetes Vaccine Candidate Using Edible Plants Expressing a Major Autoantigen

Type-1 diabetes (T1D) is a metabolic disease involving the autoimmune destruction of insulin-producing pancreatic beta cells. It is often diagnosed by the detection of autoantibodies, typically those recognizing insulin itself or the 65-kDa isoform of glutamic acid decarboxylase (GAD65). Oral insulin can be used to induce systemic immunological tolerance and thus prevent or delay the onset of T1D, suggesting that combination treatments with other autoantigens such as GAD65 could be even more successful. GAD65 has induced oral tolerance and prevented T1D in preclinical studies but it is difficult to produce in sufficient quantities for clinical testing. Here we combined edible plant systems, namely spinach (Spinacia oleracea cv Industra) and red beet (Beta vulgaris cv Moulin Rouge), with the magnICON^® expression system to develop a safe, cost-effective and environmentally sustainable platform for the large-scale production of GAD65. The superior red beet platform was extensively characterized in terms of recombinant protein yields and bioequivalence to wild-type plants, and the product was tested for its ability to resist simulated gastric digestion. Our results indicate that red beet plants are suitable for the production of a candidate oral vaccine based on GAD65 for the future preclinical and clinical testing of T1D immunotherapy approaches.

Safety of l-tryptophan technically pure, produced by fermentation with Escherichia coli DSM 25084, KCCM 11132P and SARI12091203 for all animal species based on a dossier submitted by FEFANA Asbl

In 2015, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) issued an opinion on the safety and efficacy of l-tryptophan produced by fermentation using three strains of Escherichia coli, when used as a nutritional additive for all animal species. The Panel concluded that the safety of l-tryptophan produced by E. coli SARI12091203 for target animals, consumers, users and the environment could not be assessed because the data submitted did not permit the identity and safety of the strain, and the purity of the additive, to be determined. During the current assessment, the applicant withdrew the application for l-tryptophan produced by E. coli SARI12091203. l-Tryptophan produced by E. coli DSM 25084 or KCCM 11132P was considered safe for non-ruminant target species, the consumer and the environment. For both products, the level of endotoxins and the possible dusting potential indicated a risk by inhalation for the user. In the absence of data, a potential for dermal sensitisation could not be excluded. The Commission gave the applicant the possibility of submitting complementary information to allow the FEEDAP Panel to complete its assessment. The additional data on the characterisation of the additives and on their potential for inhalation toxicity and as skin sensitisers are the subject of the current opinion. Due to improvements in the manufacturing process, the level of endotoxins present in the l-tryptophan produced by E. coli KCCM 11132P has been markedly reduced; consequently, the endotoxin content does not represent a health risk for the user. The additive has a low acute toxicity by inhalation and is not considered as a potential skin sensitiser. l-Tryptophan produced by E. coli DSM 25084 is not considered a skin sensitiser. The level of endotoxins in this product, however, represents a risk by inhalation for the user handling the additive.