Influence of iron on growth, production of siderophore compounds, membraneproteins, and lipase activity in Acinetobacter calcoaceticus BD 413

Acinetobacter calcoaceticus BD413 was examined for production of siderophor es and iron-repressible outer membrane proteins following growth in iron-re stricted media. The iron-scavenging phenotype was associated with the secre tion of iron-repressible catechol and the induction of a group of six outer membrane proteins with molecular weights ranging from 34 to 85 kDa. The am ount of catechol produced was dependent on medium composition and iron stri ngency. The relation between iron limitation and lipase production was stud ied at the level of lipA transcription and extracellular lipase activity. I n minimal medium, iron limitation slightly affected lipA expression but dec reased exo-lipase activity significantly. However, if iron limitation and r ich nitrogen sources were simultaneously present in the culture media, the production of lipase was increased approximately 4 times.