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A microscopy study of hyphal growth of Penicillium rubens on gypsum under dynamic humidity conditions.

van Laarhoven KA, Huinink HP, Adan OC - Microb Biotechnol (2016)

Bottom Line: It was found that hyphal tips ceased to extend when exposed to any tested decrease in RH.However, new hyphal growth always emerges, seemingly from the old mycelium, suggesting that this indoor fungus does not rely only on conidia to survive the humidity patterns considered.These findings are a fundamental step in unravelling the effect of RH on indoor fungal growth.

View Article: PubMed Central - PubMed

Affiliation: Department of Applied Physics, Eindhoven University of Technology, Eindhoven, the Netherlands.

No MeSH data available.


Related in: MedlinePlus

The RH on the position of the sample, measured as a function of time with a humidity sensor (continuous line). (A) Glycerol solutions of alternatingly aw = 0.8 and aw = 0.5 are brought into the chamber, imposing a switching equilibrium RH (dotted line). The dashed line is the sensor response when transferred from dry air into a container pre‐equilibrated at RH = 80%. (B) Glycerol solutions of alternatingly aw = 0.76 and aw = 0.53 are brought into the chamber, replacing each other every 6 h.
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mbt212357-fig-0002: The RH on the position of the sample, measured as a function of time with a humidity sensor (continuous line). (A) Glycerol solutions of alternatingly aw = 0.8 and aw = 0.5 are brought into the chamber, imposing a switching equilibrium RH (dotted line). The dashed line is the sensor response when transferred from dry air into a container pre‐equilibrated at RH = 80%. (B) Glycerol solutions of alternatingly aw = 0.76 and aw = 0.53 are brought into the chamber, replacing each other every 6 h.

Mentions: Equilibration of the RH throughout the incubation chamber after each change of glycerol solutions was driven by vapour diffusion; no additional stirring was applied. This was done to keep hyphae on the surface unperturbed by moving air, making it possible to follow hyphal extension with video microscopy. A control measurement during a change of solutions from RH = 97% to RH = 97% indicated that hyphae indeed remained undisturbed by the mechanical process of changing solutions. To confirm that diffusion facilitated sufficiently fast equilibration of the chamber, the RH at the location of the sample was measured as a function of time with a RH sensor (SHT71; Sensirion, Staefa, Switzerland) after switching between glycerol solutions (Fig. 2A). Equilibrium is reached within approximately 15 min and possibly faster, since the measurement is limited by the response time of the sensor (bold dashed line). The RH was also measured during cyclic replacement of two solutions for several periods to confirm that the same RH value was reached every time (Fig. 2B).


A microscopy study of hyphal growth of Penicillium rubens on gypsum under dynamic humidity conditions.

van Laarhoven KA, Huinink HP, Adan OC - Microb Biotechnol (2016)

The RH on the position of the sample, measured as a function of time with a humidity sensor (continuous line). (A) Glycerol solutions of alternatingly aw = 0.8 and aw = 0.5 are brought into the chamber, imposing a switching equilibrium RH (dotted line). The dashed line is the sensor response when transferred from dry air into a container pre‐equilibrated at RH = 80%. (B) Glycerol solutions of alternatingly aw = 0.76 and aw = 0.53 are brought into the chamber, replacing each other every 6 h.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835577&req=5

mbt212357-fig-0002: The RH on the position of the sample, measured as a function of time with a humidity sensor (continuous line). (A) Glycerol solutions of alternatingly aw = 0.8 and aw = 0.5 are brought into the chamber, imposing a switching equilibrium RH (dotted line). The dashed line is the sensor response when transferred from dry air into a container pre‐equilibrated at RH = 80%. (B) Glycerol solutions of alternatingly aw = 0.76 and aw = 0.53 are brought into the chamber, replacing each other every 6 h.
Mentions: Equilibration of the RH throughout the incubation chamber after each change of glycerol solutions was driven by vapour diffusion; no additional stirring was applied. This was done to keep hyphae on the surface unperturbed by moving air, making it possible to follow hyphal extension with video microscopy. A control measurement during a change of solutions from RH = 97% to RH = 97% indicated that hyphae indeed remained undisturbed by the mechanical process of changing solutions. To confirm that diffusion facilitated sufficiently fast equilibration of the chamber, the RH at the location of the sample was measured as a function of time with a RH sensor (SHT71; Sensirion, Staefa, Switzerland) after switching between glycerol solutions (Fig. 2A). Equilibrium is reached within approximately 15 min and possibly faster, since the measurement is limited by the response time of the sensor (bold dashed line). The RH was also measured during cyclic replacement of two solutions for several periods to confirm that the same RH value was reached every time (Fig. 2B).

Bottom Line: It was found that hyphal tips ceased to extend when exposed to any tested decrease in RH.However, new hyphal growth always emerges, seemingly from the old mycelium, suggesting that this indoor fungus does not rely only on conidia to survive the humidity patterns considered.These findings are a fundamental step in unravelling the effect of RH on indoor fungal growth.

View Article: PubMed Central - PubMed

Affiliation: Department of Applied Physics, Eindhoven University of Technology, Eindhoven, the Netherlands.

No MeSH data available.


Related in: MedlinePlus