| distribution of purple photosynthetic bacteria in wetland and woodland habitats of central and northern minnesota. | enrichment cultures for purple nonsulfur and sulfur photosynthetic bacteria were prepared from soil samples collected in central and northern minnesota. the purple nonsulfur bacteria were found in most wetland soils sampled but were uncommon in woodland and grassland soils. the ph range of the soils in which these bacteria occurred was 3.8 to 7.8, and the oxidation-reduction potential (e(h)) range was +510 to -65 mv. soils with a ph below 5.0 or an e(h) above +370 mv had few purple nonsulfur bac ... | 1974 | 4590487 |