Kvasny Prumysl, 1990 (vol. 36), issue 6
Volatile N-nitrosamines in malt. III. Effect of barley germination on the formation of natural precursors of N-nitrosodimethylamine in green malt and final malt.Peer-reviewed article
J. ČULÍK, V. KELLNER, B. ©PINAR, J. PROKE©, G. BASAŘOVÁ
Kvasny Prum. 1990; 36(6): 162-165 | DOI: 10.18832/kp1990020 
The effect of various conditions of germination and kilning on changes of the level of free DMA, i. e. one of the main precursors of NDMA in malt were tested in experiments performed on the pilot and the production scales. The results proved no dominant role of the tree DMA on the NDMA formation. The lower level of NDMA in final malt was obtained under condition of the lower temperature or in the atmosphere with higher content of carbon dioxide during the germination.(In Czech, English summary only)
Reaction of spring barley varieties on fertilization with nitrogen and protein accumulation.Peer-reviewed article
F. DUDÁ©
Kvasny Prum. 1990; 36(6): 165-168 | DOI: 10.18832/kp1990021
Reactions of varieties and the improvement of spring barley reflecting the fertilization with nitrogen and the protein accumulation in grains using classical and minimum culture techniques were tested. The results proved a different reaction of genotypes to the nitrogen together with a protein accumulation in grains. With increasing addition of nitrogen the protein content in grains significantly increased. Using a minimum nitrogen addition a lower protein content was observed in comparison to the classical culture techniques. The improvement of KM-1192 resulted in the significantly higher protein level in comparison to the average of other genotypes...
Effect of quantitative and qualitative changes of inoculum on the activity of α-amylase produced by Aspergillus oryzae CCM 8005.Peer-reviewed article
V. VOLLEK, B. ©KÁRKA
Kvasny Prum. 1990; 36(6): 169-171 | DOI: 10.18832/kp1990022
The production of α-amylase formed by Aspergillus oryzae CCM 8005 was measured with the different quantity of different inoculum types. The different inoculum used were: the vegetative one and spores. Using spores for the inoculation a higher quantity of α-amylase was achieved. The difference in the quantity of α-amylase observed with the maximum or minimum inoculation after 96 h of the culture was 1,4 %. The best results obtained with the vegetative inoculum were achieved in the YD medium after 72 h of the culture. The inoculum proper was cultured three days. The quantity of α-amylase was 87,6 % of the standard value. In other...
Nitrogen metabolism in production strains of streptomycetes.Peer-reviewed article
I. VANČUROVÁ, A. VANČURA, V. BĚHAL
Kvasny Prum. 1990; 36(6): 171-172 | DOI: 10.18832/kp1990023
A production of many industrially produced antibiotics is negatively affected by the presence of ammonia ions (nitrogen source) in the culture medium. The mechanism includes the repression and inhibition of enzymes taking part in the biosynthesis of secondary metabolites and the inhibition on the level of precursor formations. The negative effect oft ammonia ions can be eliminated in three ways: 1. Keeping a low concentration of ammonia ions in the medium by their gradual addition. 2. Using mutants with the decreased sensitivity to the inhibitory effect of these ions. 3. Using sorbents in the culture medium for the adsorption of these ions.(In...