TABLE 3.
Percentage of chitinolytic bacteria in coastal and estuarine samples inferred from the frequency of clones hydrolyzing MUF-diNAG
| Environment | Plaques or phagemids screened | Observed frequency of MUF-diNAG-positive clones | Expected frequency of MUF-diNAG-positive clonesa | Chitinolytic bacteriab (%) |
|---|---|---|---|---|
| Estuary | Plaques | 1/8,333 | 1/460 | 5.5 |
| Coastal | Plaques | 1/750,000 | 1/920 | 0.12 |
| Coastal | Phagemids | 1/533 | 1/920 | 170 |
a
The reciprocal of the number of clones that must be screened to find a single-copy gene (equation 1) divided by 5 (number of chitinase genes per bacterium). The numbers of clones to screen for the coastal sample were multiplied by 2 because this sample contained total plankton DNA, which typically contains only 50% bacterial DNA (22).
b
That is, the observed frequency of MUF-diNAG-positive clones divided by the expected frequency of MUF-diNAG-positive clones multiplied by 100.