TABLE 4.
Arsenic metabolisms selected in groundwater microbial communities: arsenic transformation analyzed spectrophotometrically and microbial growth measured at optical density OD600 nm.
| Sample | As(V)-respiring bacteria | Aerobic As(V)-resistant bacteria | Nitrate-reducing As(III) oxidizers | Heterotrophic As(III) oxidizers | Autotrophic As(III) oxidizers |
| LO | − | − | − | − | + |
| CR1 | − | − | + | − | + |
| MN | + | − | − | − | + |
| VA | − | + | − | − | + |
| BS | + | − | − | + | + |
| CR2 | + | + | − | + | + |
−, negative growth and absence of arsenic transformation; +, positive growth and presence of arsenic transformation.