Abstract: A biologically pure culture of cellulase-elaborating bacteria of mutant microorganisms of Cellulomonas (ATCC-21399) which have the ability to excrete L-glutamic acid or L-lysine, or both, when the mutant microorganisms are grown in a fermentation medium in the substantial absence of yeast extract on an assimilable source of carbon, and supplied with nitrogen and mineral nutrients, in the presence of oxygen at temperatures ranging from about 20.degree. C. to about 40.degree. C. The preferred mutant microorganisms are selected from the group consisting of: Cellulomonas sp. ATCC-21399 strain LC-10 (ATCC-31230), Cellulomonas sp. ATCC-21399 strain A.sup.r -1 (ATCC-31231) and Cellulomonas sp. ATCC-21399 strain A.sup.r -156 (ATCC-31232).

Abstract: A process for the production, by spontaneous or induced mutations from a parent microorganism of the genus Cellulomonas (ATCC-21399), of selected mutants which have the ability to excrete L-glutamic acid or L-lysine, or both, inclusive particularly of certain of the mutant strains produced by the mutagenesis, to wit: Cellulomonas sp. ATCC-21399 strain LC-10, Cellulomonas sp. ATCC-21399 strain A.sup.r -1, and Cellulomonas sp ATCC-21399 strain A.sup.r -156. In a preferred process comestible, digestible protein is produced from these strains in an aqueous culture medium, or broth, which contains an assimilable source of carbon, particularly cellulose, nitrogen and mineral nutrients. The mutant strains are comparable with the parent organism in cellulolytic activity and growth rate, but the nutritional requirements, notably the need of a yeast extract, are far less exacting than for the parent microorganism, or microorganisms.

Abstract: A process for biosynthetically producing cells in a liquid fermentation media comprised of a carbon source, and a growth medium containing oxygen and other essential cell nutrients, to obtain a biomass for harvesting. The carbon source and each of the other essential cell nutrients are added, incrementally or continuously, to the fermentation media, and each required nutrient is maintained at essentially the minimum level needed for efficient assimilation by the growing cells, in accordance with a predetermined cell growth curve based on the metabolic or respiratory function of the cells which convert the carbon source to a biomass. The process constitutes a marked improvement in accelerating and increasing cell production in a given fermentation system. In its preferred aspects, the nutrients are added within the fermentation media below the foam level which forms on top of the fermentation broth.