ATP assay for the determination of mould activity on wood at different moisture conditions
To determine fungal responses to fungicides and environmental conditions and for detection of microbial activity in wood, sensitive and objective methods are needed. We have developed a suitable assay based on analysis of adenosine triphosphate (ATP) by using the luciferin-luciferase reaction. With the aid of this assay the activity of Penicillium brevicompactum on wood at different RH levels was studied. The ATP content in a two week old culture responded quite rapidly to changes in humidity. The ATP content in the colony moved to 70% or lower RH for one week was 10 times lower than the ATP content in the colony kept at 100% relative humidity for the same time period. Increasing the humidity level to 100% RH one week before the ATP determination from a period at lower humidities did not result in a significant increase in the ATP content. This probably indicates that the mycelia of the fungus did not survive the low humidity treatment.