Growth of silicone-immobilized bacteria on polycarbonate membrane filters, a technique to study microcolony formation under anaerobic conditions.
A technique was developed to study microcolony formation by silicone-immobilized bacteria on polycarbonate membrane filters under anaerobic conditions. A sudden shift to anaerobiosis was obtained by submerging the filters in medium which was depleted for oxygen by a pure culture of bacteria. The technique was used to demonstrate that preinduction of nitrate reductase under low-oxygen conditions was necessary for nonfermenting, nitrate-respiring bacteria, e.g., Pseudomonas spp., to cope with a sudden lack of oxygen. In contrast, nitrate-respiring, fermenting bacteria, e.g., Bacillus and Escherichia spp., formed microcolonies under anaerobic conditions with or without the presence of nitrate and irrespective of aerobic or anaerobic preculture conditions.
Højberg
O
O
Department of Ecology and Molecular Biology, Royal Veterinary and Agricultural University, Frederiksberg C, Copenhagen, Denmark. ole.hoejberg@ecol.kvl.dk
Binnerup
S J
SJ
Sørensen
J
J
D000693:Anaerobiosis; D001407:Bacillus / Q000254:growth & development* / Q000378:metabolism; D001431:Bacteriological Techniques; D004926:Escherichia coli / Q000254:growth & development* / Q000378:metabolism; D050901:Nitrate Reductase; D009565:Nitrate Reductases / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D011076:Polycarboxylate Cement; D011549:Pseudomonas / Q000254:growth & development* / Q000378:metabolism; D012828:Silicones / Q000494:pharmacology
D011076:Polycarboxylate Cement; D012828:Silicones; C005506:polycarbonate; D009565:Nitrate Reductases; D050901:Nitrate Reductase; D010100:Oxygen