The objectives will include: (1) further characterization of glycolate excretion by R. rubrum, (2) preparation of mutants of R. rubrum with altered RuBP carboxylase/oxygenase, (3) characterization of the effect of histidine modification upon RuBP oxygenase, (4) elucidation of the role of small subunits in activation and catalysis by RuBP carboxylase/oxygenase and (5) separation of diastereomeric salts and lactones present in 2-carboxyhexitol-6-phosphate and -1,6-bisphosphate followed by studies of the effect of each compound upon growth of P. oxalaticus on formate.