title: A generally applicable cryopreservation method for nitrite-oxidizing bacteria.
abstract: Nitrite-oxidizing bacteria are key members of the global nitrogen cycle but their study is hampered by their limited availability in culture, mostly due to laborious cultivation procedures and the lack of stable preservation methods. In this study, it was demonstrated that long-term cryopreservation of nitrite-oxidizing bacteria assigned to the genera Nitrobacter, Nitrospina, Nitrococcus, Nitrotoga and Nitrospira was possible using a simple and rapid protocol. Their survival was tested with different cryoprotecting agents, DMSO and Hatefi, and in various carbon-rich preservation media, ten-fold diluted TSB, and ten-fold diluted TSB supplemented with 1% trehalose, and 1% sucrose. Optimal preservation conditions were strain-dependent and marine strains appeared to be more sensitive to freezing than non-marine strains. Nevertheless, a general cryopreservation protocol using 10% dimethyl sulfoxide with or without ten-fold diluted trypticase soy broth as a preservation medium allowed successful preservation of all tested strains.
authors: Laboratory of Microbiology (LM-UGent), Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium.
authors: Bram
authors: B
authors: Vekeman
authors: Sven
authors: S
authors: Hoefman
authors: Paul
authors: P
authors: De Vos
authors: Eva
authors: E
authors: Spieck
authors: Kim
authors: K
authors: Heylen
mesh_terms: D001419:Bacteria / Q000378:metabolism / Q000528:radiation effects*; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology; D050296:Microbial Viability / Q000528:radiation effects*; D008828:Microbiological Techniques / Q000379:methods*; D009573:Nitrites / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D003451:Cryoprotective Agents; D009573:Nitrites
keywords: Carbon; Dimethyl sulfoxide; Freezing; Nitrification; Nitrite oxidizers; Storage