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: 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 microbiological process for the preparation of clavine alkaloids of the general formula (I), ##STR1## wherein R stands for hydroxymethyl or methyl group, by cultivation of a Claviceps fusiformis strain in liquid submerged culture medium containing sources of carbon, nitrogen, mineral salts and optionally other additives, under aerobic conditions, in which a Claviceps fusiformis variant strain deposited under No. 00211 is used as alkaloid-producing strain. The invention further relates to a biologically pure culture of the Claviceps fusiformis variant strain No. 00211 obtained in a process in which a Claviceps fusiformis strain No. 00164 is grown in a solid culture medium containing sources of carbon, nitrogen, mineral salts and agar as well as an additive promoting the formation of cytochrome P-450, followed by the selective isolation of the new strain No. 00211.