Table 1.

Strains and plasmids used in this study

Strain or plasmidDescriptionReference or source
Strains
P. profundum
  SS9Wild type 10
  DB110LacRifr SS9 derivative 6
  EA2Oleic acid-auxotrophic mutant; DB110 derivativeThis study
  EA3Oleic acid-auxotrophic mutant; DB110 derivativeThis study
  EA10EPA-deficient mutant; DB110 derivativeThis study
E. coli
  DH5α recA strain used in maintaining plasmids 16
  ED8654Strain in which pRK2073 is maintained 33
Plasmids
 pRK2073Helper plasmid carrying the tra genes necessary for conjugal transfer 3
 pAMP1Plasmid containing an 885-bp internal fragment of SS9 EPA ORF3/4; Ampr This study
 pMUT100Mobilizable suicide plasmid; Kmr 5
 pEA30710-bp internal fragment of SS9 ORF3/4 in pMUT100; Kmr This study