Abstract: A process for producing cellulolytic and/or hemicellulolytic enzymes uses the residue from the ethanolic fermentation of enzymatic hydrolyzates of cellulosic or ligno-cellulosic materials. This process may be integrated into a process for the production of ethanol from cellulosic or ligno-cellulosic materials which comprises the following steps: 1) chemical and/or physical pre-treatment of a cellulosic or ligno-cellulosic substrate; 2) enzymatic hydrolysis of the pre-treated substrate using cellulolytic and/or hemicellulolytic enzymes; 3) ethanolic fermentation, by a suitable alcohologenic microorganism, of the hydrolyzate from step (2) and production of a fermentation must; and 4) separation of the alcohologenic microorganism used in step (3), separation/purification of the ethanol and production of an aqueous phase constituting a residue; and in which said residue serves for the production of the cellulolytic and/or hemicellulolytic enzymes used in step 2).

Abstract: A process for producing cellulolytic and/or hemicellulolytic enzymes uses the residue from the ethanolic fermentation of enzymatic hydrolyzates of cellulosic or ligno-cellulosic materials. This process may be integrated into a process for the production of ethanol from cellulosic or ligno-cellulosic materials which comprises the following steps: 1) chemical and/or physical pre-treatment of a cellulosic or ligno-cellulosic substrate; 2) enzymatic hydrolysis of the pre-treated substrate using cellulolytic and/or hemicellulolytic enzymes; 3) ethanolic fermentation, by a suitable alcohologenic microorganism, of the hydrolyzate from step (2) and production of a fermentation must; and 4) separation of the alcohologenic microorganism used in step (3), separation/purification of the ethanol and production of an aqueous phase constituting a residue; and in which said residue serves for the production of the cellulolytic and/or hemicellulolytic enzymes used in step 2).

Abstract: The present invention relates to a process for controlling the permeability of the walls of the geologic formations drilled. The circulating drilling fluid includes a determined amount of gellan used as a filtrate reducer.In the process, the viscosity of the fluid is mainly controlled by polymers, such as xanthan, scleroglucan or wellan.The invention further relates to a drilling fluid including gellan.

Abstract: The invention relates to a decontamination process for a porous medium polluted by hydrocarbons according to a composition containing a surface active agent as glycolipids in their crude or modified form is introduced, for example by at least one input well, in the optional presence of hydrocarbon-destroying bacteria and at least one part of the composition containing at least one part of the hydrocarbons is collected, for example by a production well.

Abstract: Process for treating a xanthan gum in order to improve the filterability of its aqueous solutions, comprising an enzymatic treatment of an aqueous solution of xanthan gum containing, as dissolved salts, a proportion of alkali and/or alkaline-earth metals of at least 10.sup.-2 equivalent/liter, said treatment being performed by means of two enzyme extracts of different types, a so-called PG enzyme having as main activity a polygalacturonase activity and a so-called P enzyme extract whose main activity is a protease activity, in conditions compatible with the activity of said enzyme extracts. The obtained xanthan gum powder or solution can be used as enhanced oil recovery agent.

Abstract: A process for producing glucose dehydrogenase consists of cultivating a mutant strain (ATCC 39 118) of Bacillus megaterium in a culture medium and recovering the resultant glucose dehydrogenase. The latter can be used in the enzymatic production of L-carnitine consisting of subjecting 3-dehydrocarnitine to the simultaneous action of carnitine dehydrogenase, nicotinamide adenine dinucleotide and glucose and glucose dehydrogenase.

Abstract: An aqueous composition is provided, suitable for direct use in waterflood oil recovery processes, which comprises the clarified fermentation fluid obtained by(a) culturing a polysaccharide-producing microorganism in an aqueous culture medium to produce an aqueous culture containing dissolved polysaccharide therein; and(b) clarifying the resultant aqueous culture from (a) by at least one of centrifugation and filtration, introducing therein at least one bactericidal agent, and recovering the resultant clarified fermentation fluid;said aqueous composition being obtained without precipitation and recovery of a solid polysaccharide and dissolution thereof in an aqueous medium.The above composition can be pumped into oil formations without substantial clogging thereof.