Relationship between soluble forms of iron and manganese and the presence of oxidizing bacteria of both elements in the dam Riogrande II-Don Matías (Antioquia, Colombia)

Abstract

From August 2006 to March 2008 presence of bacteria associated with the oxidation of iron and manganese was determined in the euphotic zone limit (LZF) and in the bottom of the hipolimnio (HF) in seven seasons of Riogrande II Dam reservoir depending on the availability of these metals. A water temperature, dissolved oxygen, pH, redox potential and electrical conductivity were measured in situ. At the bottom of hipolimnio with levels of dissolved oxygen ≤ 4 mgL-1 only were found iron oxidizing bacteria compatible with Gallionella sp, and Sphaerotilus sp, Beggiatoa sp . Final estimates for the bacterial population were conducted in culture media and the selective and specific recognition through morphological observations on wet mounts and colors. The largest number of these bacteria was found on the arm of Rio Grande (E4) in which levels of soluble iron were above 1.4 mgL-1. We found no presence of manganese-oxidizing bacteria.

Keywords

• iron
• Manganese
• oxidation
• Gallionella sp
• Sphaerotilus sp
• Beggiatoa sp euphotic zone limit