OATS AND FAT-FREE MILK BASED FUNCTIONAL FOOD PRODUCT

The present study addresses problems and solutions related to new functional bio-active food product creation. Commercial rolled oats and fat-free milk were used as raw materials. Limited enzymatic hydrolysis of oat starch was carried out by α-amylase. The lactic acid bacteria strains Lactobacillus acidophilus, Bifidobacterium sp., and commercial starter cultures ABT-1 were cultivated in enzymatically hydrolysed oat mash. Lactobacillus acidophilus was a more active producer of lactic acid, while Bifidobacterium sp. improved the taste properties. A fat-free milk additive was applied to stabilise the texture of the oat mash, and increase the protein content of the final product. All procedure…

Cultivation ofZymomonas mobilis 113 S at Different Mixing Regimes and their Influence on the Levan Formation

The Zymomonas mobilis I 13 S strain was cultivated in a bioreactor with a working volume of 1.4 I at different stirring regimes in a 15% initial sucrose medium The levan obtained in the fermentation process was analyzed by gel filtration. Because the sucrose/biomass ratio in the fermentation broth decreased to below 300 g/g, the insufficient concentration of sucrose might have decreased the concentration of levan. Besides the growth characteristics of the population, the mixing intensity and flow structure were also found to influence the molecular mass of levan. At 600 rpm, the microorganisms produced levan with a molecular mass lower than at 300 rpm. The stirring of a fermentation broth w…

The effect of mixing on glucose fermentation by Zymomonas mobilis continuous culture

Abstract The influence of mixing (in the range from 300 to 1100 rpm) on the performance of Zymomonas mobilis anaerobic continuous culture was studied. Biomass yield and ethanol productivity were improved at higher stirring intensities, in parallel with a decrease in byproduct synthesis. A mixing-dependent formation of minor amounts of fructose was first demonstrated in Z. mobilis anaerobic culture on glucose. The rate of fructose synthesis and the specific activity of the key enzyme in the pathway to fructose, phosphoglucose isomerase (EC 5.3.1.9), had a maximum at 700 rpm.

The Knowledge Flow and Commercialisation along the Continuous Chain: Education– Research– Implementation by Innovative Methods

Biofiltration System for Purification of Composting Waste Gases

The biofiltration technique for the purification of polluted air from composting facility volatile compounds was studied. Two different biowaste composting techniques were compared with regard to emission of NH3 and H2S. The ammonia removal was observed in aerobic phase of active composting period, respectively H2S in anaerobic phase. Biofiltration process was realized in modified solid- state fermentation system (SSF). The biodegradation of volatile compounds was investigated in one and two stage systems with inert packing material and hemoautotrofic microorganisms designed DN-1 (Pseudomonas sp.), DN-2 (Nitrisomonas sp.), DN-3 (Nitrobacter sp.) and DN-13 (Sarcina sp.) and Thiopharus-3. The…

Sugar Beet Juice Fermentation byZymomonas mobilis Attached to Stainless Steel Wire Spheres

The fermentation of sugar beet juice as well as juice syrup medium by Zymomonas mobilis inoculum attached to stainless steel wire spheres was investigated. A semi-synthetic sucrose medium enriched with mineral salts and yeast extract was used as the control. It was established that raw sugar beet juice ensured good Zymomonas mobilis culture growth and slightly decreased ethanol synthesis applying both flame-burned and TiCl 4 -treated wire spheres as carriers (Q x = 0.05-0.06 g/l × h: Q eth = 1.02-1.22 g/l × h). High ethanol yield was also observed in juice medium (Y = 0.45-0.46 g/g), however, levan synthesis with this medium decreased. The application of juice syrup brought about less growt…

Influence of Micromixing on Microorganisms and Products

The influence of mixing intensity as well as physical and chemical parameters on the cells of different microorganisms and the biosynthesis process is examined in this paper. Some reactions of cells effecting mixing intensity are described, such as retarded biomass growth, changes in aggregation and mutual arrangement of cells, morphological changes of cells and decreasing of biological activity, caused by an increased intensity of turbulence (turbohypobiosis). Several methods for investigating the local energy in reactors are compared. It is concluded that conventional methods of hydrodynamic analysis do not always allow valid results for the optimization of the mixing regime to be obtaine…

Effect of Inoculum on the Survival of Pathogenic Agents in Different Composts

Fructooligosaccharide and levan producing activity of Zymomonas mobilis extracellular levansucrase

Abstract The present work was devoted to investigations of the fructooligosaccharide (FOS) and levan forming activity of ethanol producing bacteria Zymomonas mobilis and their extracellular levansucrase. After cell separation the culture liquid was treated with ethanol to precipitate levan together with extracellular levansucrase. Levan–levansucrase sediment can be used as biocatalyst for fructooligosaccharide (FOS) production in sucrose syrup and levan sediment as soluble fibre source. The dynamics of sucrose conversion and glucose, fructose, and FOS formation by extracellular levansucrase showed that the fructose content increased only during the first 6 h, while the glucose content conti…