Nitrate assimilation by bacteria/Janine T. Lin and Valley Stewart -- Physiology of carbohydrate to solvent conversion by clostridia/Wilfred J. Mitchell -- The envelope layers of mycobacteria with reference to their pathogenicity/Mamadou Daffe and Philip Draper -- The effects of fermentation acids on bacterial growth/James. B. Russell and Francisco Diez-Gonzalez -- Physiology and genetics of sulfur-oxidizing bacteria/Cornelius G. Friedrich -- Circadian and ultradian clock-controlled rhythms in unicellular microorganisms/David Lloyd -- Biodegradation and metabolism of unusual carbon compounds by anoxygenic phototrophic bacteria/Ch. Sasikala and Ch. V. Ramana