Mark Martin returns to TWiM for a discussion of the frightening global burden of bacterial antibiotic resistance, and a solution to the problem of daylight nitrogen fixation in a cyanobacterium, despite the incompatibility of nitrogenase with oxygen produced during photosynthesis.

Mark Martin returns to TWiM for a discussion of the observation that Gram’s stain does not cross the bacterial cytoplasmic membrane, and suppression of gingival inflammation and bone loss through host modulation caused by episymbiotic Saccharibacteria.