Combination of a membrane bioreactor with a rotating biological contactor holding several diverse metazoans can reduce excess sludge with fouling mitigation.

In a membrane bioreactor (MBR) system, in situ sludge reduction techniques induce membrane fouling. To address this challenge, we incorporated a rotating mesh carrier, which can adsorb organic matter and provide a habitat for metazoans, into the anoxic tank of a conventional anoxic/oxic-MBR (A/O-MBR) system, termed rotating biological contactor-MBR (RBC-MBR), and evaluated treatment performance. Over 151 days, lab-scale RBC-MBR and A/O-MBR were used to treat municipal sewage.

Selective expression of light-harvesting complexes alters phospholipid composition in the intracytoplasmic membrane and core complex of purple phototrophic bacteria.

Phospholipid-protein interactions play important roles in regulating the function and morphology of photosynthetic membranes in purple phototrophic bacteria. Here, we characterize the phospholipid composition of intracytoplasmic membrane (ICM) from Rhodobacter (Rba.) sphaeroides that has been genetically altered to selectively express light-harvesting (LH) complexes.

Phospholipid distributions in purple phototrophic bacteria and LH1-RC core complexes.

In contrast to plants, algae and cyanobacteria that contain glycolipids as the major lipid components in their photosynthetic membranes, phospholipids are the dominant lipids in the membranes of anoxygenic purple phototrophic bacteria. Although the phospholipid compositions in whole cells or membranes are known for a limited number of the purple bacteria, little is known about the phospholipids associated with individual photosynthetic complexes. In this study, we investigated the phospholipid distributions in both membranes and the light-harvesting 1-reaction center (LH1-RC) complexes purified from several purple sulfur and nonsulfur bacteria.