The present invention relates in part to methods for screening for novel enzymatic pathways in environmental samples using metabolic selection strategies, and the isolation of the genes and proteins that make up these pathways. Portions of the first metal pattern may be between the substrate and the first insulating layer, and the first insulating layer may have a first opening therein exposing a portion of the first metal pattern. The sacrificial anode assembly includes a sacrificial metal element and an activator to maintain an activity of the sacrificial metal element and at least one spacer. A marker is disposed on the fixation support at one or more of the plurality of fixation points.