TABLE 1.
Soil characteristics and screening results
| Soil type/location (sample no.) | Contamination | Texture | TOCa or OMb (%) | CFU/g of soilc | No. of isolates screenedd | Biosurfactant- producing isolatese |
|---|---|---|---|---|---|---|
| Undisturbed | ||||||
| Tucson, Ariz. (1) | None | Sandy | 0.43a | (9.9 ± 3.8) × 105 | 88 | 2 |
| Tucson, Ariz. (2) | None | Sandy loam | 4.59a | (7.1 ± 57.7) × 106 | 72 | 1 |
| Tucson, Ariz. (3) | None | Loamy sand | 1.27a | (3.4 ± 38.0) × 107 | 77 | 1 |
| Tucson, Ariz. (4) | None | Sandy loam | 0.12a | (5.3 ± 34.2) × 106 | 82 | 4 |
| Elgin, Ariz. (5) | None | Loam | 1.88a | (2.9 ± 11.4) × 106 | 72 | 1 |
| Tucson, Ariz. (6) | None | Sandy loam | 0.2a | (1.2 ± 17.4) × 106 | 75 | 4 |
| Hydrocarbon contaminated | ||||||
| Tucson, Ariz. (7) | Motor oil | NDh | ND | (1.6 ± 23.0) × 107 | 91 | 4 |
| Blythe, Calif. (8) | Waste oil | ND | ND | (8.1 ± 64.3) × 107 | 81 | 0 |
| Layton, Utah (9) | JP4,f PAHg | Fine to coarse sand w/ interbedded gravel | ND | (1.5 ± 22.0) × 106 | 42 | 0 |
| Layton, Utah (10) | JP4, chlorinated solvents, PAH | Fine to coarse sand w/ interbedded gravel | ND | (1.6 ± 42.8) × 107 | 36 | 0 |
| Tucson, Ariz. (11) | Gasoline | Silty clay | ND | (4.9 ± 81.3) × 106 | 43 | 0 |
| Willcox, Ariz. (12) | Mineral oil | Sandy clay | ND | (4.4 ± 39.6) × 106 | 64 | 3 |
| Metal contaminated | ||||||
| Green Valley, Ariz. (13) | Pb, Cd | Sandy loam | 0.55a | (4.1 ± 40.5) × 105 | 71 | 7 |
| Wickenburg, Ariz. (14) | Cr, Hg | Sandy loam | 0.30b | (3.7 ± 51.6) × 106 | 54 | 0 |
| Tucson, Ariz. (15) | Pb | Sandy loam | ND | (2.0 ± 30.1) × 107 | 47 | 0 |
| Tucson, Ariz. (16) | Pb, Cd, Cr | Sandy loam | ND | (3.6 ± 33.1) × 107 | 53 | 0 |
| Bellemount, Ariz. (17) | As, Ba, Be, Cd, Cr, Pb | Sandy loam | 3.78a | (2.0 ± 21.9) × 106 | 54 | 1 |
| Cocontaminated | ||||||
| Tucson, Ariz. (18) | Pb, waste oil | Sandy loam | ND | (8.9 ± 2.5) × 106 | 83 | 2 |
| San Manuel, Ariz. (19) | Flue dust, hydrocarbon waste | ND | ND | (3.4 ± 26.1) × 106 | 63 | 1 |
| San Manuel, Ariz. (20) | Flue dust, diesel fuel | Alluvial fill | ND | (7.1 ± 75.7) × 106 | 57 | 14 |
a
TOC, total organic carbon.
b
OM, organic matter.
c
Plate counts were not significantly different in the day 3, 7, 14, and 21 soil slurries.
d
Total number of colonies screened from day 3, 7, 14, and 21 soil slurries.
e
Total number of biosurfactant-producing isolates obtained from the day 3, 7, 14, and 21 soil slurries.
f
JP4, jet fuel.
g
PAH, polyaromatic hydrocarbon.
h
ND, not determined.