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EFSA Journal. European Food Safety... Jul 2024The food enzyme -l-rhamnosidase (-l-rhamnoside rhamnohydrolase; EC 3.2.1.40) is produced with strain AE-HP by Amano Enzymes Inc. A safety evaluation of this food enzyme...
The food enzyme -l-rhamnosidase (-l-rhamnoside rhamnohydrolase; EC 3.2.1.40) is produced with strain AE-HP by Amano Enzymes Inc. A safety evaluation of this food enzyme was made previously, in which EFSA concluded that this food enzyme did not give rise to safety concerns when used in two food manufacturing processes. Subsequently, the applicant has requested to extend its use to include two additional processes. In this assessment, EFSA updated the safety evaluation of this food enzyme when used in a total of four food manufacturing processes. Dietary exposure to the food enzyme-total organic solids (TOS) was calculated to be up to 0.022 mg TOS/kg body weight (bw) per day in European populations. Using the no observed adverse effect level reported in the previous opinion (300 mg TOS/kg bw per day, the highest dose tested), the Panel derived a margin of exposure of at least 13,636. Based on the data provided for the previous evaluation and the revised margin of exposure in the present evaluation, the Panel concluded that this food enzyme does not give rise to safety concerns under the revised intended conditions of use.
PubMed: 38957750
DOI: 10.2903/j.efsa.2024.8871 -
Environment International Jun 2024Bioaerosols are more likely to accumulate in the residential environment, and long-term inhalation may lead to a variety of diseases and allergies. Here, we studied the...
Bioaerosols are more likely to accumulate in the residential environment, and long-term inhalation may lead to a variety of diseases and allergies. Here, we studied the distribution, influencing factors and diffusion characteristics of indoor and outdoor microbiota pollution in six residential buildings in Guangzhou, southern China over a period of one year. The results showed that the particle sizes of bioaerosol were mainly in the range of inhalable particle size (<4.7 μm) with a small difference among four seasons (74.61 % ± 2.17 %). The microbial communities showed obvious seasonal differences with high abundance in summer, but no obvious geographical differences. Among them, the bacteria were more abundant than the fungi. The dominant microbes in indoor and outdoor environments were similar, with Anoxybacillu, Brevibacillus and Acinetobacter as the dominant bacteria, and Cladosporium, Penicillium and Alternaria as the dominant fungi. The airborne microbiomes were more sensitive to temperature and particulate matter (PM, PM) concentrations. Based on the Sloan neutral model, bacteria were more prone to random diffusion than fungi, and the airborne microbiome can be randomly distributed in indoor and outdoor environments and between the two environments in each season. Bioaerosol in indoor was mainly from outdoor. The health risk evaluation showed that the indoor inhalation risks were higher than those outdoor. The air purifier had a better removal efficiency on 1.1-4.7 μm microorganisms, and the removal efficiency on Gram-negative bacteria was better than that on Gram-positive bacteria. This study is of great significance for the risk assessment and control of residential indoor bioaerosol exposure.
PubMed: 38954924
DOI: 10.1016/j.envint.2024.108857 -
PloS One 2024Mold infestations in buildings pose significant challenges to human health, affecting both private residences and hospitals. While molds commonly trigger asthma and...
Mold infestations in buildings pose significant challenges to human health, affecting both private residences and hospitals. While molds commonly trigger asthma and allergies in the immunocompetent, they can cause life-threatening diseases in the immunocompromised. Currently, there is an unmet need for new strategies to reduce or prevent mold infestations. Far-UVC technology can inactivate microorganisms while remaining safe for humans. This study investigates the inhibitory efficacy of far-UVC light at 222 nm on the growth of common mold-producing fungi, specifically Penicillium candidum, when delivered in low-dose on-off duty cycles, a configuration consistent with its use in real-world settings. The inhibitory effect of the low-dose duty cycles was assessed on growth induced by i) an adjacent spore-producing P. candidum donor and ii) P. candidum spores seeded directly onto agar plates. In both setups, the far-UVC light significantly inhibited both vertical and horizontal growth of P. candidum, even when the UV doses were below the Threshold Value Limit of 23 mJ/cm2. These results suggest that far-UVC light holds the potential to improve indoor air quality by reducing or preventing mold growth, also when people are present.
Topics: Ultraviolet Rays; Penicillium; Spores, Fungal; Fungi; Humans; Air Pollution, Indoor; Threshold Limit Values
PubMed: 38954713
DOI: 10.1371/journal.pone.0299421 -
Folia Microbiologica Jul 2024Bioethanol production from lignocellulosic materials is hindered by the high costs of pretreatment and the enzymes. The present study aimed to evaluate whether...
Bioethanol production from lignocellulosic materials is hindered by the high costs of pretreatment and the enzymes. The present study aimed to evaluate whether co-cultivation of four selected cellulolytic fungi yields higher cellulase and xylanase activities compared to the monocultures and to investigate whether the enzymes from the co-cultures yield higher saccharification on selected plant materials without thermo-chemical pretreatment. The fungal isolates, Trichoderma reesei F118, Penicillium javanicum FS7, Talaromyces sp. F113, and Talaromyces pinophilus FM9, were grown as monocultures and binary co-cultures under submerged conditions for 7 days. The cellulase and xylanase activities of the culture filtrates were measured, and the culture filtrates were employed for the saccharification of sugarcane leaves, Guinea grass leaves, and water hyacinth stems and leaves. Total reducing sugars and individual sugars released from each plant material were quantified. The co-culture of Talaromyces sp. F113 with Penicillium javanicum FS7 and of T. reesei F118 with T. pinophilus FM9 produced significantly higher cellulase activities compared to the corresponding monocultures whereas no effect was observed on xylanase activities. Overall, the highest amounts of total reducing sugars and individual sugars were obtained from Guinea grass leaves saccharified with the co-culture of T. reesei F118 with T. pinophilus FM9, yielding 63.5% saccharification. Guinea grass leaves were found to be the most susceptible to enzymatic saccharification without pre-treatment, while water hyacinth stems and leaves were the least. Accordingly, the study suggests that fungal co-cultivation could be a promising approach for the saccharification of lignocellulosic materials for bioethanol production.
PubMed: 38954242
DOI: 10.1007/s12223-024-01183-y -
Fitoterapia Jun 2024Four undescribed polyketides, beshanzones A (1) and B (2) as well as beshanhexanols A (3) and B (4), along with three known ones (5-7) were isolated from the rice...
Four undescribed polyketides, beshanzones A (1) and B (2) as well as beshanhexanols A (3) and B (4), along with three known ones (5-7) were isolated from the rice fermentation of two endophytic fungi associated with the critically endangered Chinese endemic conifer Abies beshanzuensis. γ-Butyrolactone derivatives 1, 2, and 5 were isolated from Phomopsis sp. BSZ-AZ-2, an interesting strain that drawn our attention this time. The cyclohexanol derivatives 3, 4, 6 and 7 were obtained during a follow-up investigation on Penicillium commune BSZ-P-4-1. The chemical structures including absolute configurations of compounds 1-4 were determined by spectroscopic methods, Mo(OAc) induced electronic circular dichroism (IECD), GIAO NMR calculations and DP4+ probability analyses. In particular, compound 2 contains a novel 5/5 bicyclic ring system, which might be biogenetically derived from the known compound 5 through hydrolysis followed by an Aldol reaction. All isolates were evaluated for their antimicrobial activities against a small panel of bacterial and fungal pathogens. Compounds 6 and 7 showed moderate inhibitory activities against Candida albicans, with MIC values of 16 and 32 μg/mL, respectively.
PubMed: 38950637
DOI: 10.1016/j.fitote.2024.106104 -
Natural Product Research Jul 2024Seven polyketides, including an undescribed depsidone () and six previously reported 3,6,8-trihydroxy-1-methylxanthone (), 7-hydroxy-2-(2-hydroxypropyl)-5-methylchromone...
Seven polyketides, including an undescribed depsidone () and six previously reported 3,6,8-trihydroxy-1-methylxanthone (), 7-hydroxy-2-(2-hydroxypropyl)-5-methylchromone (), methyl3-chloro-6-hydroxy-2-(4-hy-droxy-2-methoxy-6-methylphenoxy)-4- methoxybenzoate (), xylarianin A (), 4,5-dihydroxy-6-(6'-methylsalicyloxy)-2-hydro-xymethyl-2-cyclohexen-1-one () and alternariol (), have been isolated from cultures of the mangrove-derived fungus HNNU0006. The structure of compound was elucidated by extensive spectroscopic analysis and X-ray crystallography. Furthermore, all the compounds were evaluated their cytotoxic activities, and compounds and showed weak cytotoxicity against two cell lines Vero and A549 with IC values ranging from 95.6 and 296.5 M, relative to the positive control Etoposide phosphate with IC values of 24.5 and 18.7 M, respectively.
PubMed: 38949631
DOI: 10.1080/14786419.2024.2371100 -
Food Chemistry: X Oct 2024Honey is a natural product used since ancient times due to its taste, aroma, and therapeutic properties (antibacterial, antiviral, anti-inflammatory, and antioxidant... (Review)
Review
Honey is a natural product used since ancient times due to its taste, aroma, and therapeutic properties (antibacterial, antiviral, anti-inflammatory, and antioxidant activity). The purpose of this review is to present the species of microorganisms that can survive in honey and the effect they can have on bees and consumers. The techniques for identifying the microorganisms present in honey are also described in this study. Honey contains bacteria, yeasts, molds, and viruses, and some of them may present beneficial properties for humans. The antimicrobial effect of honey is due to its acidity and high viscosity, high sugar concentration, low water content, the presence of hydrogen peroxide and non-peroxidase components, particularly methylglyoxal (MGO), phenolic acids, flavonoids, proteins, peptides, and non-peroxidase glycopeptides. Honey has antibacterial action (it has effectiveness against bacteria, e.g. , , , and etc.), antifungal (effectiveness against spp., spp. spp. spp. and spp.), antiviral (effectiveness against SARS-CoV-2, Herpes simplex virus type 1, Influenza virus A and B, Varicella zoster virus), and antiparasitic action (effectiveness against and ) demonstrated by numerous studies that are comprised and discussed in this review.
PubMed: 38947342
DOI: 10.1016/j.fochx.2024.101524 -
Phytochemistry Jun 2024The genus Penicillium has provided us with the household antibiotic penicillin and the well-known lipid-lowering agent mevastatin. The strain Penicillium sp. SZ-1 was...
The genus Penicillium has provided us with the household antibiotic penicillin and the well-known lipid-lowering agent mevastatin. The strain Penicillium sp. SZ-1 was found to grow vigorously in an intact Pinus koraiensis seed, it is inferred that the strain may develop unique mechanisms associated with the biosynthesis of rare metabolites. Further fermentation of the strain on solid rice medium yielded thirteen undescribed compounds, including three andrastin-type meroterpenoids (1-3), two α- pyrone polyketides (4 and 5), and eight sesquicarane derivatives (6-13), along with seven known compounds (14-20). Their structures were determined by detailed analysis of the spectroscopic and spectrometric data (NMR and HRESIMS), in addition to comparisons of the experimental and calculated ECD data for absolute configurational assignments. The hemiacetal moiety in compounds 1 and 2 and the 3α-hydroxy group in compound 3 were rarely found in the andrastin-type meroterpenoid family. The sesquicaranes belong to a small group of sesquiterpenoid that are rarely reported. Bioassay study showed that compound 1 exhibited inhibitory effects against Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922 with MIC values of 64 and 32 μg/mL, respectively. In addition, compounds 1 and 3 displayed weak DPPH radical scavenging activities. The andrastins and sesquicaranes in this study enriched the structural diversity of these classes of terpenoids. Of note, this study is the first report on the metabolites of a fungus isolated from P. koraiensis seed.
PubMed: 38944099
DOI: 10.1016/j.phytochem.2024.114202 -
Microbial Ecology Jun 2024Plastic pollution poses a worldwide environmental challenge, affecting wildlife and human health. Assessing the biodegradation capabilities of natural microbiomes in...
Plastic pollution poses a worldwide environmental challenge, affecting wildlife and human health. Assessing the biodegradation capabilities of natural microbiomes in environments contaminated with microplastics is crucial for mitigating the effects of plastic pollution. In this work, we evaluated the potential of landfill leachate (LL) and estuarine sediments (ES) to biodegrade polyethylene (PE), polyethylene terephthalate (PET), and polycaprolactone (PCL), under aerobic, anaerobic, thermophilic, and mesophilic conditions. PCL underwent extensive aerobic biodegradation with LL (99 ± 7%) and ES (78 ± 3%) within 50-60 days. Under anaerobic conditions, LL degraded 87 ± 19% of PCL in 60 days, whereas ES showed minimal biodegradation (3 ± 0.3%). PE and PET showed no notable degradation. Metataxonomics results (16S rRNA sequencing) revealed the presence of highly abundant thermophilic microorganisms assigned to Coprothermobacter sp. (6.8% and 28% relative abundance in anaerobic and aerobic incubations, respectively). Coprothermobacter spp. contain genes encoding two enzymes, an esterase and a thermostable monoacylglycerol lipase, that can potentially catalyze PCL hydrolysis. These results suggest that Coprothermobacter sp. may be pivotal in landfill leachate microbiomes for thermophilic PCL biodegradation across varying conditions. The anaerobic microbial community was dominated by hydrogenotrophic methanogens assigned to Methanothermobacter sp. (21%), pointing at possible syntrophic interactions with Coprothermobacter sp. (a H-producer) during PCL biodegradation. In the aerobic experiments, fungi dominated the eukaryotic microbial community (e.g., Exophiala (41%), Penicillium (17%), and Mucor (18%)), suggesting that aerobic PCL biodegradation by LL involves collaboration between fungi and bacteria. Our findings bring insights on the microbial communities and microbial interactions mediating plastic biodegradation, offering valuable perspectives for plastic pollution mitigation.
Topics: Biodegradation, Environmental; Microbiota; Microplastics; Waste Disposal Facilities; Bacteria; Water Pollutants, Chemical; Polyesters; Geologic Sediments; RNA, Ribosomal, 16S; Estuaries; Polyethylene; Polyethylene Terephthalates
PubMed: 38943017
DOI: 10.1007/s00248-024-02399-8 -
Methods in Enzymology 2024Terpenes comprise the largest class of natural products and are used in applications spanning the areas of medicine, cosmetics, fuels, flavorings, and more. Copalyl...
Terpenes comprise the largest class of natural products and are used in applications spanning the areas of medicine, cosmetics, fuels, flavorings, and more. Copalyl diphosphate synthase from the Penicillium genus is the first bifunctional terpene synthase identified to have both prenyltransferase and class II cyclase activities within the same polypeptide chain. Prior studies of bifunctional terpene synthases reveal that these systems achieve greater catalytic efficiency by channeling geranylgeranyl diphosphate between the prenyltransferase and cyclase domains. A molecular-level understanding of substrate transit phenomena in these systems is highly desirable, but a long disordered polypeptide segment connecting the prenyltranferase and cyclase domains thwarts the crystallization of full-length enzymes. Accordingly, these systems are excellent candidates for structural analysis using cryo-electron microscopy (cryo-EM). Notably, these systems form hexameric or octameric oligomers, so the quaternary structure of the full-length enzyme may influence substrate transit between catalytic domains. Here, we describe methods for the preparation of bifunctional hexameric copalyl diphosphate synthase from Penicillium fellutanum (PfCPS). We also outline approaches for the preparation of cryo-EM grids, data collection, and data processing to yield two-dimensional and three-dimensional reconstructions.
Topics: Penicillium; Alkyl and Aryl Transferases; Cryoelectron Microscopy; Diterpenes; Fungal Proteins; Dimethylallyltranstransferase
PubMed: 38942500
DOI: 10.1016/bs.mie.2023.11.002