title: Effect of sample thickness on the extracted near-infrared bulk optical properties of Bacillus subtilis in liquid culture.
abstract: In order to determine the bulk optical properties of a Bacillus subtilis culture during growth phase we investigated the effect of sample thickness on measurements taken with different measurement configurations, namely total diffuse reflectance and total diffuse transmittance. The  bulk optical properties were extracted by inverting the measurements using the radiative transfer theory. While the relationship between reflectance and biomass changes with sample thickness and the intensity (absorbance) levels vary significantly for both reflectance and transmittance measurements,  the extracted optical properties show consistent behavior in terms of both the relationship with biomass and magnitude. This observation indicates the potential of bulk optical properties for building models that could be more easily transferable compared to those built using raw measurements.
authors: School of Chemical Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne, United Kingdom.
authors: Elitsa
authors: E
authors: Dzhongova
authors: Colin R
authors: CR
authors: Harwood
authors: Suresh N
authors: SN
authors: Thennadil
mesh_terms: D000042:Absorption; D001412:Bacillus subtilis / Q000737:chemistry* / Q000254:growth & development; D004058:Diffusion; D005285:Fermentation; D008027:Light; D012542:Scattering, Radiation; D013057:Spectrum Analysis / Q000379:methods*