| ythium ultimum causes seed rots of many plant species. P. ultimum sporangia require stimulation to germinate. Unsaturated long chain fatty acids (LCFA) are the predominant sporangium germination stimulatory molecules in cotton seed exudate (CSE), with linoleic acid being the most abundant. E. cloacae strain EcCT-501R3, an effective seed protectant, is capable of inactivating the germination stimulatory activity (GSA) of CSE and linoleic acid. To test whether bacterial metabolism of LCFA was important in biological control, two mutants of E. cloacae EcCT-501R3 were isolated, Ec31 and ECL1, that are affected in LCFA metabolism. Ec31 was isolated by random Tn5phoA mutagenesis and has an insertion in a gene that shows high sequence identity with fadB from Escherichia coli. fadB encodes a component of a multienzyme complex involved in fatty acid... |
