NH + 4 -N recovery from ammonia-treated straw-whey ensilage and cell biomass formation by Rhodobacter capsulatus ATCC 23782 on silage filtrates

Summary Growth of Rhodobacter capsulatus ATCC 23782 on silage filtrates under both axenic and non-axenic conditions was evaluated. Under both conditions, 96% assimilation of NH ₊ ⁴ -N at rates of about 0.1 g/l·d was attained. Assimilation was complete when the C/N ratio was adjusted to ca. 5. Thus assimilation rates of 0.2 g/l·d were achieved for an acid-C and NH ₊ ⁴ -N concentration of 2.0 and 0.4 g/l respectively. The corresponding biomass production amounted about 104 mg/g silage, dry matter.