title: Simple and Versatile Turbidimetric Monitoring of Bacterial Growth in Liquid Cultures Using a Customized 3D Printed Culture Tube Holder and a Miniaturized Spectrophotometer: Application to Facultative and Strictly Anaerobic Bacteria.
abstract: Here we introduce a novel strategy for turbidimetric monitoring of bacterial growth in liquid culture. The instrumentation comprises a light source, a customized 3D printed culture tube holder and a miniaturized spectrophotometer, connected through optical cables. Due to its small footprint and the possibility to operate with external light, bacterial growth was directly monitored from culture tubes in a simple and versatile fashion. This new portable measurement technique was used to monitor the growth of facultative (Escherichia coli ATCC/25922, and Staphylococcus aureus ATCC/29213) and strictly (Butyrivibrio fibrisolvens JW11, Butyrivibrio proteoclasticus P18, and Propionibacterium acnes DSMZ 1897) anaerobic bacteria. For E. coli and S. aureus, the growth rates calculated from normalized optical density values were compared with those ones obtained using a benchtop spectrophotometer without significant differences (P = 0.256). For the strictly anaerobic species, a high precision (relative standard deviation < 3.5%) was observed between replicates up to 48 h. Regarding its potential for customization, this manifold could accommodate further developments for customized turbidimetric monitoring, such as the use of light-emitting diodes as a light source or flow cells.
authors.affiliation: REQUIMTE, LAQV, ICBAS, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do PortoPorto, Portugal; REQUIMTE, LAQV, DGAOT, Faculdade de Ciências, Universidade do PortoPorto, Portugal.
authors.forename: Margarida R G
authors.initials: MR
authors.lastname: Maia
authors.affiliation: CIBIO, InBIO-Research Network in Biodiversity and Evolutionary Biology, Universidade do PortoVairão, Portugal; Departamento Clinicas Veterinárias - ICBAS, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do PortoPorto, Portugal.
authors.forename: Sara
authors.initials: S
authors.lastname: Marques
authors.affiliation: REQUIMTE, LAQV, ICBAS, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto Porto, Portugal.
authors.forename: Ana R J
authors.initials: AR
authors.lastname: Cabrita
authors.affiliation: Rowett Institute of Nutrition and Health, University of Aberdeen Aberdeen, UK.
authors.forename: R John
authors.initials: RJ
authors.lastname: Wallace
authors.affiliation: CIBIO, InBIO-Research Network in Biodiversity and Evolutionary Biology, Universidade do PortoVairão, Portugal; Departamento Clinicas Veterinárias - ICBAS, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do PortoPorto, Portugal.
authors.forename: Gertrude
authors.initials: G
authors.lastname: Thompson
authors.affiliation: REQUIMTE, LAQV, ICBAS, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto Porto, Portugal.
authors.forename: António J M
authors.initials: AJ
authors.lastname: Fonseca
authors.affiliation: REQUIMTE, LAQV, ICBAS, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto Porto, Portugal.
authors.forename: Hugo M
authors.initials: HM
authors.lastname: Oliveira
keywords: 3D print; bacterial growth; liquid culture; miniaturized spectrophotometer; optical density