Growth of Bacillus fastidiosus on glycerol and the enzymes of ammonia assimilation

The level of enzymes involved in the allantoin metabolism of Bacillus fastidiosus grown under different conditions

Bacillus fastidiosus was cultivated in batch and continuous culture on various carbon and nitrogen sources. The enzymes involved in allantoin degradation (allantoinase, urease, carboligase) of B. fastidiosus were hardly affected by either carbon or nitrogen source. In contrast, the enzymes involved in glycerol utilization (glycerol kinase, glycerol 3-phosphate dehydrogenase) were induced during growth on glycerol, but were not affected by the amount of allantoin present.

Purification and characterization of the NADP-dependent glutamate dehydrogenase from Bacillus fastidiosus

Ammonia assimilation in Bacillus fastidiosus proceeds via the NADP-dependent glutamate dehydrogenase. The enzyme, purified to homogeneity, is composed of identical subunits with a molecular weight of about 48,000 dalton. Presumably the enzyme is a hexamer. The enzyme is specific for NADP(H). The pH optima for the amination and deamination reactions are 7.7 and 8.6, respectively. The temperature optimum is 60 degrees C. Furthermore, temperature stability and apparent Km values for substrates of both the amination and deamination reactions were determined. Several metabolites were tested for their effect on the enzyme activity. Only malate and fumarate showed some inhibitory effect.