Pyruvic Oxime Nitrification and Copper and Nickel Resistance by a Cupriavidus pauculus, an Active Heterotrophic Nitrifier-Denitrifier

Figure 2

Growth (a) and nitrification (b) of C. pauculus UM1 in PO-mineral salts medium with or without either 1.0 mM Cu²⁺ or 0.5 mM Ni²⁺. (The inoculum for the cultures was grown in 0.2% PO-mineral salts medium until mid-to-late logarithmic growth and used at 0.5% (v/v). The growth curves for C. pauculus UM1 either with 1.0 mM Cu²⁺ () or 0.5 mM Ni²⁺ () or without Cu²⁺ or Ni²⁺ () were significantly different from their corresponding uninoculated controls. Similarly, the synthesis curves either with 1.0 mM Cu²⁺, 0.5 mM Ni²⁺ or without either Cu²⁺ or Ni²⁺ were significantly different () from their corresponding uninoculated controls. At the and 72 hours, growth of all inoculated C. pauculus UM1 cultures was significantly different () than the corresponding uninoculated controls. In addition, at and 167 hours, C. pauculus UM1 cultures grown either without Cu²⁺ or Ni²⁺ or with 0.5 mM Ni²⁺ were significantly different () than their corresponding uninoculated controls. At hours, the growth of C. pauculus UM1 with 0.5 mM Ni²⁺ was significantly less () than C. pauculus UM1 grown without Cu²⁺ or Ni²⁺. At and 167 hours, the growth of all C. pauculus UM1 cultures was not significantly different than the uninoculated 1 mM Cu²⁺ control. At all measurements, concentrations were significantly different () between the inoculated cultures and their corresponding uninoculated controls. It is presumed that, at the early time points ( and perhaps 6 hours), this was due to carryover with the inocula. At hours, concentrations were significantly different () between the inoculated PO-0.5 mM Ni⁺ cultures and inoculated PO cultures without either Cu²⁺ or Ni²⁺.) Error bars represent the standard deviation of a point.

(a) PO-dependent C. pauculus growth with or without 1 mM Cu²⁺ or 0.5 mM Ni²⁺

(b) PO-dependent C. pauculus synthesis with or without 1 mM Cu²⁺ or 0.5 mM Ni²⁺