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Microbial growth in stored dust samples as a function of the relative humidity

Li, Yujing LU ; Wadsö, Lars LU and Larsson, L. (2005) 10th International Conference on Indoor Air Quality and Climate (Indoor Air 2005) In Indoor Air 2005: Proceedings of the 10th International Conference on Indoor Air Quality and Climate, Vols 1-5 p.2435-2438
Abstract
House dusts, collected for detection of microorganisms in buildings, sometimes have to be stored before measurement. It is possible that continued growth of microorganisms in the stored samples will increase the levels of CFU, chemical marker, biomass etc. The aim of this investigation was to assess the influence of relative humidity on microbial growth in dust samples. We have exposed dust samples to different RH and measured their thermal activity with isothermal microcalorimetry. We also measured concentrations of the three microbial markers ergosterol (fungi), 3-OH fatty acids (Gram-negative bacterial), and muramic acid (Gram-positive bacteria) by GC-MS-MS. The calorimetric results showed that there were a significant biological... (More)
House dusts, collected for detection of microorganisms in buildings, sometimes have to be stored before measurement. It is possible that continued growth of microorganisms in the stored samples will increase the levels of CFU, chemical marker, biomass etc. The aim of this investigation was to assess the influence of relative humidity on microbial growth in dust samples. We have exposed dust samples to different RH and measured their thermal activity with isothermal microcalorimetry. We also measured concentrations of the three microbial markers ergosterol (fungi), 3-OH fatty acids (Gram-negative bacterial), and muramic acid (Gram-positive bacteria) by GC-MS-MS. The calorimetric results showed that there were a significant biological activity in samples kept at 75 and 94% RH, but not at 54% RH. The marker for Gram-positive bacteria only showed an increase at the highest RH (94%). No changes were seen in the marker for Gram-negative bacteria. We conclude that at least fungi will continue to grow in dust which is kept at 75% RH and higher. Significantly higher amounts of ergosterol and other measures of fungal growth may be found in such samples after storage with higher humidity. (Less)
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author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
relative humidity, house dust, microorganism, isothermal calorimetry, ergosterol
in
Indoor Air 2005: Proceedings of the 10th International Conference on Indoor Air Quality and Climate, Vols 1-5
pages
2435 - 2438
publisher
Tsinghua University Press
conference name
10th International Conference on Indoor Air Quality and Climate (Indoor Air 2005)
external identifiers
  • WOS:000233831203092
ISBN
7-89494-830-6
language
English
LU publication?
yes
id
07e13801-f34c-4291-90a1-5ff2d719a298 (old id 715608)
date added to LUP
2007-12-10 12:11:47
date last changed
2016-07-11 14:43:59
@misc{07e13801-f34c-4291-90a1-5ff2d719a298,
  abstract     = {House dusts, collected for detection of microorganisms in buildings, sometimes have to be stored before measurement. It is possible that continued growth of microorganisms in the stored samples will increase the levels of CFU, chemical marker, biomass etc. The aim of this investigation was to assess the influence of relative humidity on microbial growth in dust samples. We have exposed dust samples to different RH and measured their thermal activity with isothermal microcalorimetry. We also measured concentrations of the three microbial markers ergosterol (fungi), 3-OH fatty acids (Gram-negative bacterial), and muramic acid (Gram-positive bacteria) by GC-MS-MS. The calorimetric results showed that there were a significant biological activity in samples kept at 75 and 94% RH, but not at 54% RH. The marker for Gram-positive bacteria only showed an increase at the highest RH (94%). No changes were seen in the marker for Gram-negative bacteria. We conclude that at least fungi will continue to grow in dust which is kept at 75% RH and higher. Significantly higher amounts of ergosterol and other measures of fungal growth may be found in such samples after storage with higher humidity.},
  author       = {Li, Yujing and Wadsö, Lars and Larsson, L.},
  isbn         = {7-89494-830-6},
  keyword      = {relative humidity,house dust,microorganism,isothermal calorimetry,ergosterol},
  language     = {eng},
  pages        = {2435--2438},
  publisher    = {ARRAY(0xbf75c20)},
  series       = {Indoor Air 2005: Proceedings of the 10th International Conference on Indoor Air Quality and Climate, Vols 1-5},
  title        = {Microbial growth in stored dust samples as a function of the relative humidity},
  year         = {2005},
}