title: Identification of bacterial contaminants from calcium carbonate filler production lines and an evaluation of biocide based decontamination procedures.
abstract: The aim of this study was to analyze the bacterial community in the production line of a calcium carbonate filler production company and to investigate possible causes for bacterial presence. Throughout 2012, 24 carbonate slurry and six groundwater samples were analyzed. Pseudomonas and Microbacterium were the most frequent contaminants in the slurry, whereas Pseudomonas and Brevundimonas dominated the groundwater samples. Of the 43 different bacterial strains isolated, only five were found both in the slurry and the groundwater, indicating that the latter was not a major source of contamination. The efficacy of 54 commercial biocidal formulations was tested against an artificial bacterial consortium composed of selected slurry isolates. A formulation containing 7.5-15% (v v-1) bronopol and 1.0-2.5% (v v-1) [chloroisothiazolinone (CIT) + methylisothiazolinone (MIT)] exhibited the highest efficacy. Of the possible causes for bacterial presence, sporogenesis and biocide adsorption to carbonate particles were found to be less probable compared to bacterial adsorption to particles, and the acquisition of resistance to biocides.
authors.affiliation: a Microbiology and Microbial Biotechnology, Zootechnical Department, Biotechnical Faculty , University of Ljubljana , Domžale , Slovenia.
authors.forename: Duško
authors.initials: D
authors.lastname: Odić
authors.affiliation: a Microbiology and Microbial Biotechnology, Zootechnical Department, Biotechnical Faculty , University of Ljubljana , Domžale , Slovenia.
authors.forename: Jana
authors.initials: J
authors.lastname: Prah
authors.affiliation: a Microbiology and Microbial Biotechnology, Zootechnical Department, Biotechnical Faculty , University of Ljubljana , Domžale , Slovenia.
authors.forename: Gorazd
authors.initials: G
authors.lastname: Avguštin
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D003252:Construction Materials / Q000032:analysis / Q000382:microbiology*; D003666:Decontamination / Q000379:methods*; D004202:Disinfectants / Q000494:pharmacology*; D060587:Groundwater / Q000032:analysis / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D011549:Pseudomonas / Q000187:drug effects / Q000302:isolation & purification*
chemical_list: D004202:Disinfectants; D002119:Calcium Carbonate
keywords: Industrial microbiology; antimicrobials; bacterial contamination; biocides; carbonate products