Volume: 5, 2026
5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: H014
DOI: https://doi.org/10.24326/ICDSUPL5.H014
Published online: 22 April 2026
Isolation and characterization of biofilm-forming environmental isolates
Konrad Niedźwiadek*1, 2 and Magdalena Polak-Berecka2
1 Margomed S.A., R&D Department, 16 Erazm Plewiński St., 20-270 Lublin, Poland
2 Department of Biotechnology, Microbiology and Human Nutrition, University of Life Sciences in Lublin, 8 Skromna St., 20-704, Lublin, Poland
Corresponding author: konrad.niedzwiadek@up.lublin.pl
Biofilms formed by environmental microorganisms in medical device manufacturing facilities represent a persistent source of microbial contamination and may compromise product quality and patient safety. This study aimed to isolate environmental microorganisms (bacteria and fungi) from a medical device production environment and to characterize their biofilm-forming capacity using a standardized microtiter plate crystal violet assay.
Environmental samples were collected from selected high-risk surfaces within the production area and transferred to the laboratory under controlled conditions. Isolates, including both bacterial and fungal strains, were obtained by conventional microbiological methods and identified to the genus or species level using 16S rRNA gene sequencing for bacteria and ITS region sequencing for fungi, both performed by Sanger sequencing. Representative isolates were grown in 96-well polystyrene microplates under static conditions, and biofilm formation was quantified after crystal violet staining and solubilization of the bound dye followed by spectrophotometric measurement at approximately 595 nm. Assay conditions, including inoculum density, incubation time and washing steps, were optimized to minimize variability and to obtain reproducible quantification of total biofilm biomass.
Among the seven environmental isolates tested, one strain produced a moderate biofilm, three strains were classified as strong biofilm formers, and three strains were categorized as non-producers within the tested conditions, with absorbance values spanning approximately one order of magnitude. These findings demonstrate that environmental microorganisms isolated from a medical device manufacturing setting can differ markedly in their ability to form biofilms on abiotic surfaces and highlight the importance of using site-specific isolates for the development and validation of cleaning and disinfection strategies. The implemented crystal violet assay provides a simple, low-cost and scalable tool for routine screening of biofilm formation by environmental isolates and will be further applied to evaluate practical anti-biofilm interventions relevant to the production process.
This research was conducted as part of an Industrial Doctorate programme funded by the Ministry of Science and Higher Education (MNiSW) in Poland
Keywords: biofilm; crystal violet assay; environmental microorganisms; fungi; medical devices
How to cite
Niedźwiadek K., Polak-Berecka M., 2026. Isolation and characterization of biofilm-forming environmental isolates. In: 5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL5.H014