TY - JOUR
T1 - Hydrophobin gene deletion and environmental growth conditions impact mechanical properties of mycelium by affecting the density of the material
AU - Appels, Freek V. W.
AU - Dijksterhuis, Jan
AU - Lukasiewicz, Catherine E.
AU - Jansen, Kaspar
AU - Wösten, Han A.B.
AU - Krijgsheld, Pauline
PY - 2018
Y1 - 2018
N2 - Filamentous fungi colonize substrates by forming a mycelium. This network of hyphae can be used as a bio-based material. Here, we assessed the impact of environmental growth conditions and deletion of the hydrophobin gene sc3 on material properties of the mycelium of the mushroom forming fungus Schizophyllum commune. Thermogravimetric analysis showed that Δsc3 mycelium retained more water with increasing temperature when compared to the wild type. The Young's modulus (E) of the mycelium ranged between 438 and 913 MPa when the wild type strain was grown in the dark or in the light at low or high CO2 levels. This was accompanied by a maximum tensile strength (σ) of 5.1-9.6 MPa. In contrast, E and σ of the Δsc3 strain were 3-4- fold higher with values of 1237-2727 MPa and 15.6-40.4 MPa, respectively. These values correlated with mycelium density, while no differences in chemical composition of the mycelia were observed as shown by ATR-FTIR. Together, genetic modification and environmental growth conditions impact mechanical properties of the mycelium by affecting the density of the mycelium. As a result, mechanical properties of wild type mycelium were similar to those of natural materials, while those of Δsc3 were more similar to thermoplastics.
AB - Filamentous fungi colonize substrates by forming a mycelium. This network of hyphae can be used as a bio-based material. Here, we assessed the impact of environmental growth conditions and deletion of the hydrophobin gene sc3 on material properties of the mycelium of the mushroom forming fungus Schizophyllum commune. Thermogravimetric analysis showed that Δsc3 mycelium retained more water with increasing temperature when compared to the wild type. The Young's modulus (E) of the mycelium ranged between 438 and 913 MPa when the wild type strain was grown in the dark or in the light at low or high CO2 levels. This was accompanied by a maximum tensile strength (σ) of 5.1-9.6 MPa. In contrast, E and σ of the Δsc3 strain were 3-4- fold higher with values of 1237-2727 MPa and 15.6-40.4 MPa, respectively. These values correlated with mycelium density, while no differences in chemical composition of the mycelia were observed as shown by ATR-FTIR. Together, genetic modification and environmental growth conditions impact mechanical properties of the mycelium by affecting the density of the mycelium. As a result, mechanical properties of wild type mycelium were similar to those of natural materials, while those of Δsc3 were more similar to thermoplastics.
UR - http://www.scopus.com/inward/record.url?scp=85044268095&partnerID=8YFLogxK
UR - http://resolver.tudelft.nl/uuid:8265668f-6994-409f-bf17-86307d135b01
U2 - 10.1038/s41598-018-23171-2
DO - 10.1038/s41598-018-23171-2
M3 - Article
SN - 2045-2322
VL - 8
SP - 1
EP - 7
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 4703
ER -