Figure 6. TEM images of (a) non-reduced control (NC) suspensions, (b) bioreduced smectite (BS) suspensions, and (c) aerobically inoculated smectite (AIS) suspensions showing the evolution in floc architecture associated with microbial Fe(III) reduction: note pore areas (p) in NC and AIS and clusters of biopolymers (see arrow) secreted by S. oneidensis (S) and smectite particles.