Abstract: The invention relates to a process for drying out rock containing immobile formation water in the intake radius of natural gas wells and gas storage wells which deliver less than 50 l of water per 1000 m.sup.3 (S.T.P.) of natural gas produced, in which a dispersion comprising the componentsA) a water-repellent active compound,B) hydrophilic water-miscible dispersion medium, with or withoutC) a dispersant renders the water-containing rock hydrophobic.

Abstract: The microbial decontamination of soils contaminated with hydrocarbons, in particular with mineral oils, by microbial oxidation is improved by a process in which in addition to supplying the oxygen necessary for degradation, by aeration, soluble nutrients, water and soluble or dispersed biosurfactants as such or mixed with chemical surfactants are metered into the contaminated soils directly or into the removed contaminated soil layers, in one or more batches at time intervals, in an amount such that the formation of toxic intermediates which slow down or block microbial degradation in prevented, the accessibility of mineral oils and their products for the microorganisms is simultaneously increased and, as a result, accelerated, virtually complete mineralization by respiration to CO.sub.2 and H.sub.2 O is effected.

Abstract: Solid particles of various sizes are separated from viscous liquids, for example biomass from liquids of biotechnological processes, by pressure filtration by subjecting the inhomogeneous or homogenized suspension, without or after only a little dilution, to a pressure filtration whereby the solid particles of various sizes are retained according to size in a plurality of, in particular in from 1 to 3, superposed or juxtaposed filter stages on filter layers of various depths and on filter surfaces and are separated from the viscous liquid.

Abstract: Rhamnolipids with high surface activity are produced micro iologically in high yield per g of dry cell substance using Pseudomonas spec. DSM 2874 in the form of growing, resting and immobilized cell mass in an aqueous medium containing at least one assimilable carbon source at a pH of 6.7 to 7.3 and a temperature of 30.degree. to 37.degree. C. Two new rhamnolipids with only one .beta.-hydroxydecanoic acid residue in the molecule and defined as .alpha.-L-rhamnopyranosyl- and 2-O-.alpha.-L-rhamnopyranosyl-.alpha.-L-rhamnopyranosyl-.beta.-hydroxydeca noic acid with a molecular weight of 334 and 480, respectively, are obtained.

Abstract: Anionic, surface-active trehalose lipids, in which different organic acids are bound to a trehalose molecule by an ester linkage, are prepared by aerobically cultivating trehalose-producing microorganisms, capable of assimilating hydrocarbons, under growth-limiting conditions, but without limiting the oxygen.