TABLE 2.
MPN counts of phenanthrene-, fluoranthene-, and pyrene-degrading bacteria from two PAH-contaminated soils
| PAH | Soil | Replicatea | MPN (95% confidence limits) (103 cells g−1)
|
|
|---|---|---|---|---|
| WST-1b | 14C-PAHc | |||
| Phenanthrene | B&W | 1 | 1,700 (240-5,700) | 270 (28-1,300) |
| B&W | 2 | 460 (79-1,500) | 140 (22-680) | |
| B&W | 3 | 560 (120-1,800) | 270 (28-1,300) | |
| Ringe | 1 | 6,400 (1,100-20,000) | 1,300 (120-6,500) | |
| Ringe | 2 | 16,000 (1,700-48,000) | 4,300 (420-22,000) | |
| Ringe | 3 | 22,000 (3,000-68,000) | 3,600 (380-18,000) | |
| Fluoranthene | B&W | 1 | 3.4 (0.33-10) | 9.3 (1.4-44) |
| B&W | 2 | 2.5 (0.26-7.8) | 3.5 (0.39-16) | |
| B&W | 3 | 6.9 (0.84-23) | 2.6 (0.35-12) | |
| Ringe | 1 | 600 (60-1,900) | 840 (90-4,100) | |
| Ringe | 2 | 950 (98-2,900) | 220 (23-1,000) | |
| Ringe | 3 | 510 (54-1,600) | 300 (28-1,600) | |
| Pyrene | B&W | 1 | 56 (5.4-170) | 150 (22-700) |
| B&W | 2 | 55 (5.3-160) | 36 (5.4-170) | |
| B&W | 3 | 93 (13-280) | 67 (7.0-320) | |
| Ringe | 1 | 4,700 (550-14,000) | 1,300 (120-6,500) | |
| Ringe | 2 | 6,300 (770-22,000) | 1,600 (140-7,900) | |
| Ringe | 3 | 4,900 (600-15,000) | 1,100 (110-5,600) | |
a
The two soil samples (B&W and Ringe) were MPN enumerated three times for each PAH.
b
MPN estimates were obtained by using a WST-1 microtiter plate MPN method developed in this study (fourfold dilution series, six-row MPN).
c
MPN estimates were obtained by using a radiotracer method (fourfold dilution series, three-row MPN).