title: Starch in plasterboard sustains Streptomyces californicus growth and bioactivity of spores.
abstract: OBJECTIVE
  The effects of plasterboard composition on Streptomyces californicus growth and bioactivity of spores were studied.
  
  
  RESULTS
  Streptomyces californicus was grown on 13 modified plasterboards under saturated humidity conditions. The total content of fatty acid methyl esters was used for quantifying S. californicus biomass, while the spore-induced cytotoxicity and production of nitric oxide (NO), tumour necrosis factor-alpha, and interleukine-6 (IL-6) in mouse macrophages was used to assess the bioactivity of spores. Removal of starch completely from the plasterboard or only from the core reduced significantly the biomass production and the biological activity of spores in comparison with reference board. The biocide added into the core or on the liner decreased the growth markedly and inhibited the sporulation totally. The biomass production correlated positively with the spore number, cytotoxicity, and production of NO and IL-6.
  
  
  CONCLUSIONS
  Streptomyces californicus grew under nutrient limitation on all studied plasterboards. The starch is the major factor enabling S. californicus to grow and to produce biologically active metabolites on plasterboard.
  
  
  CONCLUSIONS
  The composition of building material has an impact on microbial growth and bioactivity of spores which may be involved in complex mechanisms leading to respiratory symptoms in the occupants in moisture damaged buildings.
authors.affiliation: Department of Environmental Health, National Public Health Institute, Kuopio, Finland. timo.murtoniemi@ktl.fi
authors.forename: T
authors.initials: T
authors.lastname: Murtoniemi
authors.forename: M M
authors.initials: MM
authors.lastname: Keinänen
authors.forename: A
authors.initials: A
authors.lastname: Nevalainen
authors.forename: M-R
authors.initials: MR
authors.lastname: Hirvonen
mesh_terms: D002244:Carbon; D003252:Construction Materials; D004783:Environmental Microbiology; D015850:Interleukin-6 / Q000096:biosynthesis; D009569:Nitric Oxide / Q000378:metabolism; D013170:Spores; D013213:Starch / Q000378:metabolism*; D013302:Streptomyces / Q000254:growth & development* / Q000378:metabolism; D014867:Water
chemical_list: D015850:Interleukin-6; D014867:Water; D009569:Nitric Oxide; D002244:Carbon; D013213:Starch