Geranic acid formation, an initial reaction of anaerobic monoterpene metabolism in denitrifying Alcaligenes defragrans.
Monoterpenes with an unsaturated hydrocarbon structure are mineralized anaerobically by the denitrifying beta-proteobacterium Alcaligenes defragrans. Organic acids occurring in cells of A. defragrans and culture medium were characterized to identify potential products of the monoterpene activation reaction. Geranic acid (E,E-3,7-dimethyl-2,6-octadienoic acid) accumulated to 0.5 mM in cells grown on alpha-phellandrene under nitrate limitation. Cell suspensions of A. defragrans 65Phen synthesized geranic acid in the presence of beta-myrcene, alpha-phellandrene, limonene, or alpha-pinene. Myrcene yielded the highest transformation rates. The alicyclic acid was consumed by cell suspensions during carbon limitation. Heat-labile substances present in cytosolic extracts catalyzed the formation of geranic acid from myrcene. These results indicated that a novel monoterpene degradation pathway must be present in A. defragrans.
Heyen
U
U
Department of Microbiology, Max-Planck-Institute for Marine Microbiology, D-28359 Bremen, Germany.
Harder
J
J
D000421:Alcaligenes / Q000254:growth & development / Q000378:metabolism*; D000693:Anaerobiosis; D003470:Culture Media / Q000737:chemistry; D005227:Fatty Acids / Q000032:analysis; D009566:Nitrates / Q000378:metabolism*; D013729:Terpenes / Q000378:metabolism*
D003470:Culture Media; D005227:Fatty Acids; D009566:Nitrates; D013729:Terpenes; C043081:decaprenoic acid