TABLE 2.
Expression of glycosyl transferase genes in Sphingomonas, X. campestris, and R. leguminosarum
| Recipient strain (phenotype) | Donor plasmid (genotype)a | Exconjugants
|
|
|---|---|---|---|
| Frequency | Morphologyb | ||
| Sphingomonas S88 | |||
| m265 (SpsB−) | pB215 (spsB) | Normal | + |
| pB554 (spsKB) | Normal | + | |
| pB599 (pssDE spsB) | Normal | + | |
| pB610 (gumM spsB) | Normal | − | |
| pB611 (gumM) | Normal | − | |
| pB597 (pssCDE spsB) | Normal | Tiny | |
| pB609 (pssC spsB) | Normal | Tiny | |
| pMP3030 (pssCDE) | Normal | − | |
| m302 (SpsK−B−) | pB554 (spsKB) | Normal | + (S-88) |
| pS88c3 (spsQIKLB) | Normal | + | |
| pY976 (spsQI::TnKLB) | Normal | + | |
| pY872 (spsQIKL::TnB) | Normal | + | |
| pY882 (spsQIK::TnLB) | Normal | − | |
| pB599 (pssDE spsB) | Normal | + (S-88) | |
| pB610 (gumM spsB) | Normal | − | |
| pB611 (gumM) | Normal | − | |
| pB597 (pssCDE spsB) | Normal | Tiny | |
| pB609 (pssC spsB) | Normal | Small | |
| pMP3030 (pssCDE) | Normal | − | |
| X. campestris X59 m31 (GumD−) | pSY1483 (gumDEF) | Normal | + |
| pS88c1Δ3 (spsB) | Normal | + | |
| pS88c2 (spsQIKLB) | Zero | ND | |
| pS88c3 (spsQIKLB) | Zero | ND | |
| pZ206 (spsQ::TnIKLB) | Zero | ND | |
| pY976 (spsQI::TnKLB) | Zero | ND | |
| pY872 (spsQIKL::TnB) | Zero | ND | |
| pY882 (spsQIK::TnLB) | Normal | + (XG) | |
| pB610 (gumM spsB) | Normal | + | |
| pB608 (spsK) | Normal | − | |
| pB554 (spsKB) | Zero | ND | |
| pB599 (pssDE spsB) | Zero | ND | |
| pB609 (pssC spsB) | Normal | + (XG) | |
| R. leguminosarum | |||
| RBL5833 (PssDE−) | pMP3030 (pssCDE) | Normal | + (rhEPS) |
| pMP2642 (pssA) | Normal | − | |
| pB608 (spsK) | Normal | Intermediate (rhEPS) | |
| pS88c3 (spsQIKLB) | Low | Intermediate/− (1/9) | |
| pY872 (spsQIKL::TnB) | Normal | Intermediate (rhEPS) | |
| pY882 (spsQIK::TnLB) | Normal | − | |
| pB610 (gumM spsB) | Zero | ND | |
| pB611 (gumM) | Zero | ND | |
| RBL5523 (Pss+) | pMP3030 (pssCDE) | Normal | + |
| pMP2642 (pssA) | Normal | + | |
| pS88c3 (spsQIKLB) | Low | + | |
| pY872 (spsQIKL::TnB) | Normal | + | |
| pY882 (spsQIK::TnLB) | Normal | +, Small | |
| RBL5807 (PssA−) | pMP3030 (pssCDE) | Normal | − |
| pMP2642 (pssA) | Normal | + | |
| pB608 (spsK) | Normal | − | |
| pB554 (spsKB) | Normal | + | |
| pS88c3 (spsQIKLB) | Low | +/− (1/9) | |
| pY872 (spsQIKL::TnB) | Normal | + | |
| pY882 (spsQIK::TnLB) | Normal | +/− (9/1) | |
| pB610 (gumM spsB) | Zero | ND | |
| pB611 (gumM) | Normal | − | |
Only the relevant genes are listed; see Table 1 for a complete list of genes on plasmids.
EPS-producing colonies of Sphingomonas, X. campestris, and R. leguminosarum are denoted as +, and nonproducers are denoted as −; intermediate for R. leguminosarum indicates a colonial appearance between smooth (+) and rough (−). XG, rhEPS, and S-88 indicate the sugar compositions typical of xanthan gum, rhizobial EPS, and sphingan S-88, respectively. Tiny and small refer to reduced colony sizes. The relative frequency of colony types is given in parentheses. Zero means that no exconjugants were observed. ND, not determinable by visual inspection. The position of each mini-Tn10kan insertion was determined by digestion with restriction endonucleases and comparison to the DNA sequence of segment S88c3 (37).