The purification of glycerate kinase from Hyphomicrobium sp. and Pseudomonas AM1: product identification.

Aerobic bacteria grown on methanol can utilize one of two pathways for carbon assimilation , either the serine pathway or the pentose phosphate cycle of formaldehyde fixation. utilize the serine pathway. During work on the carbon assimilation pathway of methanol-grown Hjlphomicrobium sp. the relative rates of conversion of glycerate, a-phosphoglycerate and 3-phosphoglycerate into phosphoenol-pyruvate indicated that 2-phosphoglycerate was the product of the glycerate kinase. The conversion of a-phosphoglycerate into 3-phosphoglycerate may be the first step in the biosynthesis of cellular material (Harder, Attwood & Quayle, 1973). Glycerate kinase has been purified from both methanol-grown Hyphomicrobium x and Pseudomonas A M I and the product of the reaction identified. Organisms. The maintenance of H~lphonzicrobiirt?z x and growth in liquid inorganic salts medium with methanol (0.5 O , , , v,'v) was as described by Harder et a/. (1973). Pseudomonas A M I (~crsg133) was maintained and grown in liquid culture as described by Salem, Hacking & Quayle (1973) using methanol (0.5 y;, v/v) as carbon source. Preparation of cell-jiee extracts. Bacteria were disrupted using an ultrasonic disintegrator (Harder et a/. 1973). The supernatant fluids after centrifugation at 15000g for 15 min at o "C were used as the crude extracts.