Abstract: Cellulose fermentation by cellulose-digesting microorganisms is increased by conducting the fermentation in the presence of a minor amount of a compound of the formula ##STR1## wherein R' is haloalkyl and the carbocyclic ring has from 0 to 3 sites of olefinic unsaturation.

Abstract: In vivo and in vitro cellulose fermentation by cellulose-digesting microorganisms is increased by conducting the fermentation in the presence of a minor amount of a compound of the formula ##STR1## wherein R' is haloalkyl and R is H or alkyl.

Abstract: A method of increasing yield of yeast cells on a carbon source of crude methanol or crude ethanol is given.

Abstract: A fermentation vessel is used to grow a cell mass and maintain it in a maintenance energy state. In this state the mass of the cell material is maintained substantially constant, and fresh medium containing an energy source is introduced to the vessel at a rate sufficient to sustain cell viability but insufficient to support growth of the cell mass. Fluid with suspended cells is pumped from the vessel to a separator which separates a fraction of the fluid from the cells and discharges the fraction, the unfiltered portion of the fluid and substantially all of the cells being returned to the vessel, the discharged fraction containing useful secondary metabolites.

Abstract: This invention is concerned with the use of fluorocarbon and silicone oil greases or gels to stimulate the growth of various microorganisms. More particularly, the instant invention contemplates the addition of a peroxide compound, preferably hydrogen peroxide (H.sub.2 O.sub.2), to fluorocarbon and silicone oil greases or gels to further stimulate the growth of anaerobes and facultative anaerobes in liquid or solid nutrient media.