title: Macromolecular composition of a Cellulomonas sp. cultivated in continuous culture under glucose and zinc limitation.
abstract: The mutant strain of Cellulomonas sp. (ATCC 21399) was cultivated under glucose and zinc limitation at a variety of growth rates in continuous culture. The growth characteristics and macromolecular composition of the population varied with the limitation imposed and the growth rate. Glucose- and zinc-limited cultures maintained a constant relative protein content. The relative ribonucleic acid content increased, whereas the carbohydrate and deoxyribonucleic acid contents decreased with an increase in the population growth rate in glucose-limited cultures. Free unbound lipid remained constant. The maximum population growth rate in zinc-limited cultures was directly proportional to the zinc concentration and demonstrated a traditional steady-state function. The nucleic acid content increased with increased growth rate; however, the relative nucleic acid content was significantly depressed when compared to glucose limited cells. This manner of cultivation may prove to be a useful tool for the production of single cell protein with lowered nucleic acid content and the elucidation of micronutrient involvement in growth-related processes.
mesh_terms: D000192:Actinomycetales / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D001426:Bacterial Proteins / Q000096:biosynthesis*; D004269:DNA, Bacterial / Q000096:biosynthesis*; D004044:Dietary Proteins; D005285:Fermentation; D005947:Glucose / Q000378:metabolism*; D009154:Mutation; D012329:RNA, Bacterial / Q000096:biosynthesis*; D015032:Zinc / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004044:Dietary Proteins; D012329:RNA, Bacterial; D005947:Glucose; D015032:Zinc