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Bampidis V, Azimonti G, Bastos MDL, Christensen H, Durjava M, Dusemund B, Kouba M, López‐Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M, Ramos F, Villa RE, Woutersen R, Martelli G, Yurkov A, Anguita M, Galobart J, Innocenti ML, Pettenati E, Ortuño J. Safety and efficacy of a feed additive consisting of endo-1,4-β xylanase, endo-1,4-β-glucanase and xyloglucan-specific-endo-β-1,4-glucanase produced by Trichoderma citrinoviride DSM 33578 (Huvezym® neXo) for all Suidae (Huvepharma EOOD). EFSA J 2024; 22:e8643. [PMID: 38450084 PMCID: PMC10915726 DOI: 10.2903/j.efsa.2024.8643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024] Open
Abstract
Following a request from the European Commission, the EFSA 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 Huvezym® neXo 100 G/L, a product containing endo-1,4-β-xylanase, endo-1,4-β-glucanase and xyloglucan-specific-endo-β-1,4-glucanase activities produced by a non-genetically modified strain of Trichoderma citrinoviride (DSM 33578), as a zootechnical additive for all Suidae. The applicant provided information confirming the taxonomic identification of the production strain. The batches used for the characterisation of the final formulations showed compliance with the minimum specifications of the additive in terms of enzyme activities (> 15,000 EPU, > 1000 CU, > 1000 XGU per g) but not for the ratio of the enzymes, which is lower (ca. 7:1:1) than the ones specified (15:1:1). The Panel could not conclude on the representativeness of the test item used in the toxicological and tolerance studies with respect to the final formulations. Therefore, the conclusions are limited to the product with a minimum enzyme activity of 15,000 EPU, 1000 CU, 1000 XGU per g and a xylanase:glucanase:xyloglucanase ratio of 15:1:1. The Panel concluded that the additive is safe for the target species, consumers and the environment. Huvezym® neXo 100 G is not an irritant to the skin and eyes but should be considered a skin sensitiser. Huvezym® neXo 100 L is neither an irritant to the skin and eyes nor a skin sensitiser. Due to the proteinaceous nature of the active substances, the additive is considered a respiratory sensitiser. The additive has the potential to be efficacious in all reproductive Suidae at the minimum proposed use level. Owing to the lack of sufficient data, the Panel could not conclude on the efficacy of the additive for Suidae for fattening or reared for reproduction.
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Lambré C, Barat Baviera JM, Bolognesi C, Cocconcelli PS, Crebelli R, Gott DM, Grob K, Lampi E, Mengelers M, Mortensen A, Rivière G, Steffensen I, Tlustos C, Van Loveren H, Vernis L, Zorn H, Herman L, Aguilera J, Andryszkiewicz M, Boinowitz E, Criado A, Kovalkovicova N, Liu Y, Nielsen E, Nørby K, di Piazza G, Chesson A. Safety evaluation of the food enzyme endo-1,4-β-xylanase from the non-genetically modified Trichoderma citrinoviride strain 278. EFSA J 2023; 21:e8399. [PMID: 38035144 PMCID: PMC10686006 DOI: 10.2903/j.efsa.2023.8399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023] Open
Abstract
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.
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Bampidis V, Azimonti G, Bastos MDL, Christensen H, Dusemund B, Durjava M, Kouba M, López‐Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M, Ramos F, Sanz Y, Villa RE, Woutersen R, Tosti L, Anguita M, Galobart J, Innocenti M, Pettenati E, Ortuño J. Safety and efficacy of a feed additive consisting of endo-1,4-β-xylanase produced by Trichoderma citrinovirideDSM 34663 (Hostazym® X) for use in all poultry species, ornamental birds, all growing Suidae and carp (Huvepharma NV). EFSA J 2023; 21:e08171. [PMID: 37547225 PMCID: PMC10401331 DOI: 10.2903/j.efsa.2023.8171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/08/2023] Open
Abstract
Following a request from the European Commission, the EFSA 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 a feed additive containing endo-1,4-β-xylanase produced by Trichoderma citrinoviride DSM 34663 (Hostazym® X). The product is authorised as a zootechnical additive (digestibility enhancers) for use in all poultry species for fattening, for laying and reared for laying, weaned piglets, pigs for fattening and carp. The current opinion concerns the request for the renewal of the authorisation for the use in those species/categories and the extension of use to all poultry species for breeding and reared for breeding, ornamental birds, suckling piglets and minor porcine species for fattening. The applicant provided evidence that the additive in the market complies with the conditions of the authorisation. There is no new evidence that would lead the Panel to reconsider previous conclusions that the additive is safe for the target species, the consumers and the environment under the authorised conditions of use. This conclusion also applies to the target species for which a request for extension of use is made. The additive is considered not a skin corrosive or skin sensitiser, but it is an eye irritant. The Panel cannot conclude on the potential of the additive to be a skin irritant. Due to the proteinaceous nature of the active substance, the additive is considered a respiratory sensitiser. The Panel considers that the additive has the potential to be efficacious in all poultry species, ornamental birds, all growing Suidae and carp at the proposed conditions of use.
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Zhao D, Shen D, Fan H, Zhu X, Wang Y, Duan Y, Chen L. Virulent and attenuated strains of Trichoderma citrinoviride mediated resistance and biological control mechanism in tomato. Front Plant Sci 2023; 14:1179605. [PMID: 37324719 PMCID: PMC10262999 DOI: 10.3389/fpls.2023.1179605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 05/03/2023] [Indexed: 06/17/2023]
Abstract
Introduction Root-knot nematode disease is one of the world's most serious vegetable crop diseases. In recent years, Trichoderma spp. has been widely used in root-knot nematode disease control as a biological control agent. Methods Virulent and attenuated strains of Trichoderma citrinoviride mediated resistance and biological control mechanism in tomato were determined. Results Preliminary experiments found differences in nematicidal virulence among Trichoderma citrinoviride. The 24-hour corrected mortality rate of the virulent strainT1910 was as high as 92.37%, with an LC50 of 0.5585 against the second juveniles (J2s) of Meloidogyne incognita. And the attenuated strain TC9 was 23.01%, the LC50 was 2.0615, so the virulent strain T1910 had a more substantial effect on the J2s than the attenuated strain. We found that the strong virulent strain T1910 have a good control effect on M. incognita by the pot experiment of tomato than that of the attenuated virulent strain TC9,especially the J2 and J4 numbers were inhibited inside the root knots of tomato. Theinhibition rates of virulent strains reached 85.22% and 76.91%, followed by attenuatedstrain TC9, which were 63.16% and 59.17%, respectively. To reveal the differences intomato defense pathways induced by different virulent strains, qRT-PCR was further usedto detect changes in the expression of inducement-related genes. The results showed thatthe TC9 was significantly upregulated at 5dpi, LOX1, PR1, and PDF1.2. The PR5 gene ofthe virulent strain T1910 was highly upregulated, and the JA pathway was activated laterbut weaker than the attenuated strain. The results of this study revealed that thebiocontrol mechanism of T. citrinoviride as poison killing through the virulent strain T1910 and induced resistance to M. incognita through attenuated strain, although virulence degradation also has an induced resistance effect. Moreover, the attenuated strain TC9 stimulated tomato immune response earlier than the virulent strain by nematode-associated molecular pattern-triggered (NAMP). Discussion Therefore, the research elucidated the mechanism of multiple control of Trichoderma spp. against M. incognita.
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Affiliation(s)
- Di Zhao
- Analysis and Testing Center, Shenyang Agricultural University, Shenyang, China
| | - Dan Shen
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Haiyan Fan
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Xiaofeng Zhu
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Yuanyuan Wang
- College of Life Science and Technology, Shenyang Agricultural University, Shenyang, China
| | - Yuxi Duan
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Lijie Chen
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
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Bampidis V, Azimonti G, Bastos MDL, Christensen H, Dusemund B, Durjava M, Kouba M, López‐Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M, Ramos F, Sanz Y, Villa RE, Woutersen R, Anguita M, Galobart J, Tarrés‐Call J, Pettenati E, Ortuño J. Safety and efficacy of a feed additive consisting of endo-1,4-β-glucanase produced by Trichoderma citrinoviride IMI 360748 (Hostazym C) for use in all poultry species for fattening and reared for laying/breeding, ornamental birds and piglets (weaned and suckling) (Huvepharma NV). EFSA J 2023; 21:e07954. [PMID: 37089170 PMCID: PMC10119908 DOI: 10.2903/j.efsa.2023.7954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023] Open
Abstract
Following a request from the European Commission, the EFSA 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 the feed additive containing endo-1,4-β-glucanase produced by Trichoderma citrinoviride IMI 360748 (Hostazym® C). The product is authorised as a zootechnical additive (functional group: digestibility enhancers) for use in chickens for fattening, minor poultry species for fattening and weaned piglets. This scientific opinion concerns the request for the renewal of the authorisation for the use in those species/categories, and the extension of use to chickens reared for laying, turkeys reared for breeding, minor poultry species reared for laying or breeding, ornamental birds and suckling piglets. 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 Panel to reconsider previous conclusions that the additive is safe for the target species, the consumers, and the environment under the authorised conditions of use. This conclusion also applies to the target species for which a request for an extension of use is made. The additive is considered not a skin corrosive or eye irritant, but it should be considered a skin sensitiser. The Panel cannot conclude on the potential of the additive to be a skin irritant. Due to the proteinaceous nature of the active substance, the additive is considered a respiratory sensitiser. The Panel considers that the additive has the potential to be efficacious at 500 CU/kg complete feed in all poultry for fattening, reared for laying or breeding, and ornamental birds, and at 350 CU/kg complete feed in piglets (weaned and suckling, for the period in which solid feed is given).
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Bampidis V, Azimonti G, Bastos MDL, Christensen H, Dusemund B, Fašmon Durjava M, Kouba M, López‐Alonso M, Puente SL, Marcon F, Mayo B, Pechová A, Petkova M, Ramos F, Sanz Y, Villa RE, Woutersen R, Aquilina G, Tosti L, Yurkov A, Anguita M, Galobart J, Ortuño J, Pizzo F, Tarrés‐Call J, Pettenati E. Safety and efficacy of a feed additive consisting of endo-1,4-beta xylanase, endo-1,4-beta-glucanase and xyloglucan-specific-endo-beta-1,4-glucanase produced by Trichoderma citrinovirideDSM 33578 (Huvezym® neXo 100 G/L) for all poultry species, ornamental birds and piglets (weaned and suckling) (Huvepharma EOOD). EFSA J 2022; 20:e07702. [PMID: 36545570 PMCID: PMC9761340 DOI: 10.2903/j.efsa.2022.7702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Following a request from the European Commission, the EFSA 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 the product Huvezym® neXo 100 G/L containing an endo-1,4-beta xylanase, an endo-1,4-beta-glucanase and a xyloglucan-specific-endo-beta-1,4-glucanase produced by a non-genetically modified strain of Trichoderma citrinoviride (DSM 33578) as a zootechnical additive for feed in all poultry species, ornamental birds and piglets (weaned and suckling). The information regarding the production strain did not allow to confirm its taxonomic identification. The batches used for the characterisation of the final formulations showed compliance with the minimum specifications of the additive in terms of enzyme activities but showed ratios between the enzymes lower than the ones specified for the additive. The FEEDAP Panel considered that the below-described conclusions would apply to the final formulations of the additive as per specifications with xylanase:glucanase, xylanase:xyloglucanase and glucanase:xyloglucanase ratios of 15, 15 and 1, respectively. Based on the data available, the Panel concluded that the additive is safe for the target species, consumers and the environment. Huvezym® neXo 100 G (granulated form) is neither skin corrosive nor eye irritant but should be considered a potential skin sensitiser. Huvezym® neXo 100 L (liquid) is neither skin corrosive nor sensitising and it is not an eye irritant. Due to lack of data, no conclusions can be drawn on the skin irritation of the final formulations of the additive. Due to the proteinaceous nature of the active substances, the additive is considered a respiratory sensitiser. The FEEDAP Panel concluded that the additive has the potential to be efficacious in chickens for fattening, chickens reared for laying and breeding, and all growing poultry and ornamental birds at the minimum intended level of 1,500 EPU, 100 CU and 100 XGU/kg complete feed. Owing to the lack of sufficient data, the Panel could not conclude on the efficacy of the additive for laying hens and weaned piglets.
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Kong X, Xu L, Ji X, Yang S, Zhang H. Investigation on bioactive metabolites produced by an endophytic fungus Trichoderma citrinoviride from the arils of Torreya grandis. Nat Prod Res 2022; 37:1-5. [PMID: 36239516 DOI: 10.1080/14786419.2022.2134999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 10/03/2022] [Accepted: 10/06/2022] [Indexed: 10/17/2022]
Abstract
An endophytic fungus Trichoderma citrinoviride capable of producing active substances was isolated from the arils of Torreya grandis. Seven compounds were separated from the ethyl acetate extract of fermentation broth and mycelium by chromatography, respectively identified as trichomerol (1), bisorbicillinolide (2), sohirnone A (3), emodin (4), stigmasterol (5), ergosterol (6), daidzein (7). This study is the first to report of the isolation of the endophytic fungus T. citrinoviride from the arils of T. grandis with complete assignments of 1-7. Compound 1 and 2 exhibited significant antioxidant activity of diphenyl picryl hydrazinyl with IC50 38.92 and 3.91 µg/mL, respectively. Compound 1, 2, 4 and 7 significantly inhibited the growth of Staphylococcus aureus with MIC 0.78; 0.39; 0.20 and 0.20 mg/mL, respectively. Current study indicated the presence of endophytic fungus in the arils of Torreya grandis that could be responsible for the bioactive metabolite synthesis.
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Affiliation(s)
- Xiaohui Kong
- The College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, People's Republic of China
| | - Lin Xu
- The Center for TCM Standardization, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, People's Republic of China
| | - Xiaokang Ji
- The College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, People's Republic of China
| | - Shengli Yang
- The College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, People's Republic of China
| | - Hui Zhang
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, People's Republic of China
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Yaosanit W, Rukachaisirikul V, Phongpaichit S, Preedanon S, Sakayaroj J. Sesquiterpenes from the soil-derived fungus Trichoderma citrinoviride PSU-SPSF346. Beilstein J Org Chem 2022; 18:479-485. [PMID: 35558648 PMCID: PMC9062651 DOI: 10.3762/bjoc.18.50] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 04/11/2022] [Indexed: 11/23/2022] Open
Abstract
Two new sesquiterpenes, trichocitrinovirenes A (1) and B (2), and five known compounds including four structurally related sesquiterpenes and one γ-lactone were isolated from the soil-derived fungus Trichoderma citrinoviride PSU-SPSF346. The structures were identified by analysis of their spectroscopic data. The relative configuration was assigned based on NOEDIFF data. The absolute configuration of compound 1 was established according to specific rotations and ECD data while that of compound 2 was proposed based on biosynthetic considerations. Compound 2 possesses a rare bicyclic sesquiterpene skeleton. The antimicrobial and cytotoxic activities of the isolated compounds were evaluated.
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Affiliation(s)
- Wiriya Yaosanit
- Division of Physical Science and Center of Excellence for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand
| | - Vatcharin Rukachaisirikul
- Division of Physical Science and Center of Excellence for Innovation in Chemistry, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand
| | - Souwalak Phongpaichit
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90110, Thailand
| | - Sita Preedanon
- National Biobank of Thailand (NBT), National Science and Technology for Development Agency (NSTDA), Thailand Science Park, Klong Luang, Pathumthani 12120, Thailand
| | - Jariya Sakayaroj
- School of Science, Walailak University, Thasala, Nakhonsithammarat 80160, Thailand
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Piegza M, Pietrzykowska J, Trojan-Piegza J, Łaba W. Biosurfactants from Trichoderma Filamentous Fungi-A Preliminary Study. Biomolecules 2021; 11:biom11040519. [PMID: 33808486 PMCID: PMC8067329 DOI: 10.3390/biom11040519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 11/17/2022] Open
Abstract
Biosurfactants represent a structurally diverse group of secondary metabolites produced by bacteria, yeasts, and filamentous fungi. Their character is often associated with numerous additional properties. The observation of Trichoderma fungi of various species used as a source of bioinhibitors against pathogenic plants fungi focuses attention to the often quite specific behavior of preparations in contact with, among others, plant leaves, dependent on strain. Thus, an evaluation of the selected strains belonging to the species: T. atroviride, T. citrinoviride,T. reesei and T. harzianum was conducted towards their capability of the extracellular secretion of surfactants, with a simultaneous attempt to pre-determine their chemical nature. Two mineral-organic media were used for this purpose, and the culture fluid was extensively tested using a variety of methods. A decrease in surface tension was observed in culture fluid of each tested strain, especially T. citrinoviride HL and C1. The results strongly depended on medium composition, of which Saunders 1 and MGP 1 were most beneficial. The secreted compounds were further analyzed to pre-determine their chemical nature using IR, GC, and NMR. In the case of most efficient biosurfactant producers, a lipopeptide structure of the surfactants was concluded.
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Affiliation(s)
- Michał Piegza
- Department of Biotechnology and Food Microbiology, Wroclaw University of Environmental and Life Sciences, 37 Chelmonskiego Street, 51-630 Wroclaw, Poland; (J.P.); (W.Ł.)
- Correspondence:
| | - Joanna Pietrzykowska
- Department of Biotechnology and Food Microbiology, Wroclaw University of Environmental and Life Sciences, 37 Chelmonskiego Street, 51-630 Wroclaw, Poland; (J.P.); (W.Ł.)
| | - Joanna Trojan-Piegza
- Faculty of Chemistry, University of Wroclaw, 14 F. Joliot-Curie Street, 50-383 Wroclaw, Poland;
| | - Wojciech Łaba
- Department of Biotechnology and Food Microbiology, Wroclaw University of Environmental and Life Sciences, 37 Chelmonskiego Street, 51-630 Wroclaw, Poland; (J.P.); (W.Ł.)
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Vornanen-Winqvist C, Salonen H, Järvi K, Andersson MA, Mikkola R, Marik T, Kredics L, Kurnitski J. Effects of Ventilation Improvement on Measured and Perceived Indoor Air Quality in a School Building with a Hybrid Ventilation System. Int J Environ Res Public Health 2018; 15:E1414. [PMID: 29976864 PMCID: PMC6068750 DOI: 10.3390/ijerph15071414] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 07/03/2018] [Indexed: 11/24/2022]
Abstract
Ventilation system design and operation may significantly affect indoor air quality (IAQ). The aims of this case study were to investigate the functionality of a supply air fan-assisted hybrid ventilation system in a newly built school building with reported IAQ problems and to determine the effects of ventilation improvement on measured and perceived IAQ. The ventilation system function was researched simultaneously with IAQ measurements, with an analysis of total volatile organic compounds (TVOC), single volatile organic compounds (VOCs), and indoor mycobiota, and with questionnaires about perceived IAQ. At the baseline, an operational error of the ventilation system was found, which prevented the air from coming into the classrooms, except for short periods of high carbon dioxide (CO₂) concentrations. After the ventilation operation was improved, a significant change in indoor mycobiota was found; the dominant, opportunistic human pathogenic species Trichoderma citrinoviride found in settled dust in the classroom before the improvement was no longer detected. In addition, the concentrations of CO₂, TVOC, and some single VOCs, especially toluene and decamethylcyclopentasiloxane, decreased. The analysis of the questionnaire results indicated that the perceptions of unpleasant odors and stuffy air decreased, although a statistically significant improvement in perceived IAQ was not observed. The results provided evidence that the properly controlled hybrid ventilation system operating in mechanical supply mode provided adequate ventilation and was effective in decreasing the concentrations of some indoor-generated pollutants. With simple ventilation adjustments, microbiological exposure from building structures might be prevented.
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Affiliation(s)
| | - Heidi Salonen
- Department of Civil Engineering, Aalto University, Rakentajanaukio 4, 02150 Espoo, Finland.
| | - Kati Järvi
- Department of Civil Engineering, Aalto University, Rakentajanaukio 4, 02150 Espoo, Finland.
| | - Maria A Andersson
- Department of Civil Engineering, Aalto University, Rakentajanaukio 4, 02150 Espoo, Finland.
| | - Raimo Mikkola
- Department of Civil Engineering, Aalto University, Rakentajanaukio 4, 02150 Espoo, Finland.
| | - Tamás Marik
- Department of Microbiology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
| | - László Kredics
- Department of Microbiology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary.
| | - Jarek Kurnitski
- Department of Civil Engineering, Aalto University, Rakentajanaukio 4, 02150 Espoo, Finland.
- Department of Civil Engineering and Architecture, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia.
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