Abstract: A mixing device, especially for a fermenter, capable of dispersing gas in a broth therein, in which a number of propeller mixers are provided on a vertically extending shaft. The lower propeller mixer is a gas dispersing mixer having a hollow hub and open channels on the blades extending from this hub and tapering outwardly. At least one intermediate propeller mixer has some blades shorter than others and of reverse flow direction, some blades having baffle bars on trail edges thereof. The upper propeller mixer has the longer blades without channels and flow modifying elements.

Abstract: The invention relates to acaricidal compositions containing as active ingredient: the fermentation broth or cell-free fermentation broth, of a concentrate of the fermentation broth or cell-free fermentation broth, or a solidified form of the fermentation broth or cell-free fermentation broth of one or two bacterium strains deposited at the National Collection of Agricultural and Industrial Microorganisms, Budapest, Hungary under the identification Nos. 001083 and 001086 or of their mixed micropopulation, if desired, in a sterilized state, optionally together with the metabolism products arising during the fermentation and inutilized nutriments, as well as one or more solid and/or liquid carrier(s) (preferably sugar or a grist of natural minerals), or an inert solvent (e.g. water) and, if desired, with surface active (preferably anionic or nonionic emulsifying or dispersing) agents.

Abstract: Complex mixing system with stages consisting of propeller mixers of high diameter ratio, where the blades are provided with flow modifying elements, whereby the energy proportions spent on dispersion of the amount of gas injected into the reactor, homogenization of the multi-phase mixtures, suspension of solid particles, etc. and the properties corresponding to the rheological properties of the gas-liquid mixtures and to the special requirements of the processes can be ensured even in extreme cases. Open channels (5) opposite to the direction of rotation are on the blades (4) of the dispersing stage (2a) of the propeller mixers (2) fixed to a common shaft, where the channels (5) are interconnected with gas inlet (7). The angle of incidence of a certain part of the blades (4) of mixing stages (2b, 2d) used for homogenization and suspension is of opposite direction and the length is shorter and/or the angle of incidence is smaller than those of the other blades.

Abstract: The invention relates to a new method for controlling the level and distribution of alkaloids produced by Claviceps purpurea variant strains capable of producing primarily ergocornine, .alpha.-ergocryptine and .beta.-ergocryptine under saprophytic conditions. According to the invention a compound of the biosynthesis path of isoleucine or a compound which promotes the formation of isoleucine by biochemical control is added to the fermentation broth. In other respects fermentation is performed under conditions known per se.By the method of the invention the ratio of .alpha.- and .beta.-ergocryptine formed in the fermentation broth can be adjusted to the optimum value.

Abstract: The invention relates to a new process for the preparation of ergot alkaloids, primarily ergocornine and .beta.-ergocryptine, by subjecting a Claviceps purpurea strain to fermentation under aerobic conditions in a culture medium which contains carbon and nitrogen sources, mineral salts and optionally other additives, too. According to the invention a Claviceps purpurea variant strain deposited under No. MNG 00186 is applied as alkaloid-producing strain.