title: Bioreactor study employing bacteria with enhanced activity toward cyanobacterial toxins microcystins.
abstract: An important aim of white (grey) biotechnology is bioremediation, where microbes are employed to remove unwanted chemicals. Microcystins (MCs) and other cyanobacterial toxins are not industrial or agricultural pollutants; however, their occurrence as a consequence of human activity and water reservoir eutrophication is regarded as anthropogenic. Microbial degradation of microcystins is suggested as an alternative to chemical and physical methods of their elimination. This paper describes a possible technique of the practical application of the biodegradation process. The idea relies on the utilization of bacteria with a significantly enhanced MC-degradation ability (in comparison with wild strains). The cells of an Escherichia coli laboratory strain expressing microcystinase (MlrA) responsible for the detoxification of MCs were immobilized in alginate beads. The degradation potency of the tested bioreactors was monitored by HPLC detection of linear microcystin LR (MC-LR) as the MlrA degradation product. An open system based on a column filled with alginate-entrapped cells was shown to operate more efficiently than a closed system (alginate beads shaken in a glass container). The maximal degradation rate calculated per one liter of carrier was 219.9 µg h-1 of degraded MC-LR. A comparison of the efficiency of the described system with other biological and chemo-physical proposals suggests that this new idea presents several advantages and is worth investigating in future studies.
authors.affiliation: Department of Plant Physiology and Development, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Kraków, Poland. dariusz.dziga@uj.edu.pl.
authors.forename: Dariusz
authors.initials: D
authors.lastname: Dziga
authors.affiliation: Department of Plant Physiology and Development, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30387 Kraków, Poland. magdalena.sworzen@uj.edu.pl.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Lisznianska
authors.affiliation: Department of Analytical Biochemistry, Jagiellonian University, Gronostajowa 7, 30387 Kraków, Poland. wladykab@interia.pl.
authors.forename: Benedykt
authors.initials: B
authors.lastname: Wladyka
mesh_terms: D000464:Alginates; D001427:Bacterial Toxins / Q000378:metabolism*; D019149:Bioreactors; D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D008387:Marine Toxins; D052998:Microcystins / Q000378:metabolism*
chemical_list: D000464:Alginates; D001427:Bacterial Toxins; D029968:Escherichia coli Proteins; D006603:Hexuronic Acids; D008387:Marine Toxins; D052998:Microcystins; C451279:MlrA protein, E coli; D020723:Glucuronic Acid; C057862:cyanoginosin LR