Extracellular Enzymatic Activities of Oceanic Pelagic Fungal Strains and the Influence of Temperature
Although terrestrial and aquatic fungi are well-known decomposers of organic matter, the role of marine fungi remains largely unknown. Recent studies based on omics suggest that marine fungi potentially play a major role in elemental cycles. However, there is very limited information on the diversit...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-05-01
|
| Series: | Journal of Fungi |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2309-608X/8/6/571 |
| _version_ | 1797485689697206272 |
|---|---|
| author | Katherine Salazar Alekseyeva Gerhard J. Herndl Federico Baltar |
| author_facet | Katherine Salazar Alekseyeva Gerhard J. Herndl Federico Baltar |
| author_sort | Katherine Salazar Alekseyeva |
| collection | DOAJ |
| description | Although terrestrial and aquatic fungi are well-known decomposers of organic matter, the role of marine fungi remains largely unknown. Recent studies based on omics suggest that marine fungi potentially play a major role in elemental cycles. However, there is very limited information on the diversity of extracellular enzymatic activities performed by pelagic fungi in the ocean and how these might be affected by community composition and/or critical environmental parameters such as temperature. In order to obtain information on the potential metabolic activity of marine fungi, extracellular enzymatic activities (EEA) were investigated. Five marine fungal species belonging to the most abundant pelagic phyla (Ascomycota and Basidiomycota) were grown at 5 °C and 20 °C, and fluorogenic enzymatic assays were performed using six substrate analogues for the hydrolysis of carbohydrates (β-glucosidase, β-xylosidase, and <i>N</i>-acetyl-β-<span style="font-variant: small-caps;">D</span>-glucosaminidase), amino acids (leucine aminopeptidase), and of organic phosphorus (alkaline phosphatase) and sulfur compounds (sulfatase). Remarkably, all fungal strains were capable of hydrolyzing all the offered substrates. However, the hydrolysis rate (V<sub>max</sub>) and half-saturation constant (K<sub>m</sub>) varied among the fungal strains depending on the enzyme type. Temperature had a strong impact on the EEAs, resulting in Q<sub>10</sub> values of up to 6.1 and was species and substrate dependent. The observed impact of temperature on fungal EEA suggests that warming of the global ocean might alter the contribution of pelagic fungi in marine biogeochemical cycles. |
| first_indexed | 2024-03-09T23:22:27Z |
| format | Article |
| id | doaj.art-6bae624bf6924bff869afd4c027680ad |
| institution | Directory Open Access Journal |
| issn | 2309-608X |
| language | English |
| last_indexed | 2024-03-09T23:22:27Z |
| publishDate | 2022-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Journal of Fungi |
| spelling | doaj.art-6bae624bf6924bff869afd4c027680ad2023-11-23T17:24:18ZengMDPI AGJournal of Fungi2309-608X2022-05-018657110.3390/jof8060571Extracellular Enzymatic Activities of Oceanic Pelagic Fungal Strains and the Influence of TemperatureKatherine Salazar Alekseyeva0Gerhard J. Herndl1Federico Baltar2Department of Functional and Evolutionary Ecology, University of Vienna, 1030 Vienna, AustriaDepartment of Functional and Evolutionary Ecology, University of Vienna, 1030 Vienna, AustriaDepartment of Functional and Evolutionary Ecology, University of Vienna, 1030 Vienna, AustriaAlthough terrestrial and aquatic fungi are well-known decomposers of organic matter, the role of marine fungi remains largely unknown. Recent studies based on omics suggest that marine fungi potentially play a major role in elemental cycles. However, there is very limited information on the diversity of extracellular enzymatic activities performed by pelagic fungi in the ocean and how these might be affected by community composition and/or critical environmental parameters such as temperature. In order to obtain information on the potential metabolic activity of marine fungi, extracellular enzymatic activities (EEA) were investigated. Five marine fungal species belonging to the most abundant pelagic phyla (Ascomycota and Basidiomycota) were grown at 5 °C and 20 °C, and fluorogenic enzymatic assays were performed using six substrate analogues for the hydrolysis of carbohydrates (β-glucosidase, β-xylosidase, and <i>N</i>-acetyl-β-<span style="font-variant: small-caps;">D</span>-glucosaminidase), amino acids (leucine aminopeptidase), and of organic phosphorus (alkaline phosphatase) and sulfur compounds (sulfatase). Remarkably, all fungal strains were capable of hydrolyzing all the offered substrates. However, the hydrolysis rate (V<sub>max</sub>) and half-saturation constant (K<sub>m</sub>) varied among the fungal strains depending on the enzyme type. Temperature had a strong impact on the EEAs, resulting in Q<sub>10</sub> values of up to 6.1 and was species and substrate dependent. The observed impact of temperature on fungal EEA suggests that warming of the global ocean might alter the contribution of pelagic fungi in marine biogeochemical cycles.https://www.mdpi.com/2309-608X/8/6/571marine fungitotal extracellular enzymatic activitykineticsmaximum velocityhalf-saturation constant |
| spellingShingle | Katherine Salazar Alekseyeva Gerhard J. Herndl Federico Baltar Extracellular Enzymatic Activities of Oceanic Pelagic Fungal Strains and the Influence of Temperature Journal of Fungi marine fungi total extracellular enzymatic activity kinetics maximum velocity half-saturation constant |
| title | Extracellular Enzymatic Activities of Oceanic Pelagic Fungal Strains and the Influence of Temperature |
| title_full | Extracellular Enzymatic Activities of Oceanic Pelagic Fungal Strains and the Influence of Temperature |
| title_fullStr | Extracellular Enzymatic Activities of Oceanic Pelagic Fungal Strains and the Influence of Temperature |
| title_full_unstemmed | Extracellular Enzymatic Activities of Oceanic Pelagic Fungal Strains and the Influence of Temperature |
| title_short | Extracellular Enzymatic Activities of Oceanic Pelagic Fungal Strains and the Influence of Temperature |
| title_sort | extracellular enzymatic activities of oceanic pelagic fungal strains and the influence of temperature |
| topic | marine fungi total extracellular enzymatic activity kinetics maximum velocity half-saturation constant |
| url | https://www.mdpi.com/2309-608X/8/6/571 |
| work_keys_str_mv | AT katherinesalazaralekseyeva extracellularenzymaticactivitiesofoceanicpelagicfungalstrainsandtheinfluenceoftemperature AT gerhardjherndl extracellularenzymaticactivitiesofoceanicpelagicfungalstrainsandtheinfluenceoftemperature AT federicobaltar extracellularenzymaticactivitiesofoceanicpelagicfungalstrainsandtheinfluenceoftemperature |