Russian Article pp. 309–318

It is demonstrated that aliphatic hydrocarbons (alkanes) penetrate into bacteria cells by the way of passive diffusion. The mechanism of this process is different for several bacteria species. A hydrophobic cell wall is essential for that process. In saprophytic Mycobacteria hydrocarbons are solubilized in the thick hydrophobic cell wall. During the process of absorption hydrocarbons pass through the whole cell wall up to the membrane. In the case of Arthrobacteria the hydrocarbons might pass not through the whole cell wall, but through special lipophilie canals. Mobile hydrocarbon-oxidizing bacteria g. Pseudomonas form peptidoglycolipid and excrete it into the medium. The peptidoglycolipid emulsifies hydrocarbon substrate.     

Russian Article pp. 195–200

The influence of flow rate on the cell shape of the yeast Candida hydrocarbofumarica cultivated continuously within a wide range of flow rates (D = 0.05–2.0 h^?1) was studied. The cell shape was heterogenic at growth rates from 0.05–0.8 h^?1. In some cases the cell size varied depending on the growth rate, evidently due to osmotic phenomena which do not pertain to the growth proper.     

Russian Article pp. 125–136

Transformation of mass indexes of microbial growth efficiency (the maximal yield and maintenance coefficient) into energetic ones is desribed. Energetic yield is expressed in terms of ATP expenditures for constructive metabolism, cell maintenance and other physiologo-energetic coefficients. From experimental data obtained during H. polymorpha cultivation on glucose, ethanol and methanol, it has been found that the growth-independent fraction of ATP expendditure for cell maintenance and futile dissipation (CMFD) is the same in all the three cases. The coefficient of the growth-dependent CMFD on glucose and methanol is approximately the same. Maximal energetic biomass yields on these substrates have been measured and the background of their differences is discussed.     

Russian Article pp. 139–146

The task of multicriterial optimization is solved for column bioreactors. The alternative criteria are the minimum of expense and the maximum of productivity of the bioreactor. The local criteria are calculated for evenly distributed nonrandom points in the space of variable parameters. A compromise evaluation of the column reactor efficiency is given.     

Russian Article pp. 213–225

The kinetics of assimilation of hydrocarbons having a different structure by Candida yeasts was studied. The rates of oxidation of various carbon atoms in the molecules of isoalkanes, alkylaromatic hydrocarbons and n-alkanes were evaluated in the range of C₁₁ to C₂₈. Metabolic inhomogeneity of carbon atoms in the molecules of isolakanes and alkylaromatic hydrocarbons was observed. A competition in the assimilation of the called hydrocarbons and n-alkanes and also a competition in the assimilation of n-alkanes of a different molecular weight, i.e. metabolic inhomogeneity of carbon atoms of n-dodecane and n-tetracosane was found out for yeasts.     

Russian Article pp. 055–069

The authors studied the action of inhibitor oxidation (antioxidant) reaction in the processes of cell proliferation. The data represented here concerned with the stimulating influence of antioxidants on the growth of microorganisms. Special consideration is given to the increase of biomass yield, productivity and yeast amount per substrate. This work established that synthetic antioxidants are able to carry out functions of natural antioxidants in growing cells.     

Russian Article pp. 151–158

Carrier facilitated transport of oxygen by hemoglobin in blood helps biotechnologists to create aeration systems using the phenomenon of labile bonds of oxygen for the intensification of the fermentation processes. This paper discusses the mechanism and the kinetics of oxygen mass transfer in the presence of carriers. For the modelling of the oxygen transport the corresponding system of differential equations of oxygen balance is used. The results presented here show the utility of carriers for the intensification of the production of SCP, enzymes and antibiotics.     

Russian Article pp. 191–195

Three cellulase components and one xylanase of Trichoderma sp. M-17 have been immobilzed on a soluble high molecular weight polymer (PVA), using carbodiimide. The immobilized enzymes retained about 80% of the cellulase, cellulose 1,4-β-cellobiosidase, β-glucosidase and 60% endo-1,4-β-xylanase activities. The bound enzymes catalyzed the hydrolysis of alkali-treated cornstalks with a higher efficiency than the free cellulase. The potential for reutilization of the immobilized enzymes was studied using membrane filters and the system was found to be active for three cycles.     

Russian Article pp. 207–211

During the submerged cultivation of Trichoderma sp. 414 on a medium with 2% cellulose containing plant substrats an enzyme system – exocellobiohydrolase (C₁-enzyme), endogluconase (C_x-enzyme), β-glucosidase and xylase – catalizing the cellulose hydrolysis was synthesized. The process of enzyme biosynthesis by the microbial strain under the conditions of two-step cultivation in flasks was optimized. The influence of different sources of carbohydrate – avicel, micricel, maize stalk and straw – on the activity of the synthesized enzymes was studied. This activity depends on induction properties and the concentration of the used substrats. During the cultivation of Trichoderma sp. 414 on a medium containing avicel and wheat bran the activity of cellobiohydrolase reaches 40 U/ml and this of endogluconase – 520 U/ml. When the cultivation was performed on a medium containing wheat bran and straw the activity of xylanase reaches 240 U/ml.     

Russian Article pp. 255–266

The growth of the yeast Candida utilis VKM-Y-2332 was investigated during the cultivation on a mineral medium with addition of ethanol in the regime of the chemostat and the pH-auxostat. The composition of the macroelements of the biomass produced by Candida utilis VKM-Y-2332 was studied. Stoichiometric equations of the growth process of the examined yeast strain on ethanol were presented. The growth of Candida utilis on ethanol and glucose was also characterized by the way of comparision.     

Russian Article pp. 51–58

This paper considers techniques of measurement of the curves of oxygen consumption by microorganisms. The widely applied method of obtaining the value of the critical oxygen concentration (COC) using these curves has been analysed. The experimental conditions necessary for the adequate measurement of the culture respiration rate in a fermenter have been found. It has been shown that in the case when the respiration rate within the considered range of pO₂ is determined by one and the same enzyme, the COC value is not an apropriate characteristic of the mode of the respiration rate dependence on oxygen concentration.     

Russian Article pp. 241–249

In this review are described results of the research in the Soviet Union in the field of selection and physiology of yeast strains for the production of SCP on the base of petroleum hydrocarbons. The most efficient yeast strains were selected by cultivation on enrichment medias. Most of them belong to a limited number of the species of the genus Candida. The stability of the industrial interesting properties of yeasts also was demonstrated during a continuous long-time cultivation.     

Russian Article pp. 335-340

Industrial processes of cultivation of aerobic microorganisms are characterized by too small transportation rates of oxygen from a gas into a cell. The search for new ways of productivity increase by means of intensification of oxygen mass transfer in the fermentation process is of great importance. The possibilities for use of chelate transition metal complexes (CTMC) capable of binding oxygen in biosynthetic processes have been studied. The formation of labial complex of the studied substances with oxygen is shown by spectrophotometry. The increase of the oxygen delution rate in water in the presence of CTMC is shown by physical absorbtion method. The rate increase of oxygen mass transfer from gas into liquid is calculated on the base of the sulphite method. The use of CTMC in the role of oxygen carriers in the yeast cultivation leads to the biomass increase up to 20%.     

Russian Article pp. 279-284

The accumulation of nucleic and protein (amino nitrogen) components as decomposition products of the process of autolysis of Saccharomyces cerevisiae yeast cells was studied at 50°C under the effect of various membranotropic additives. The influence of the added n-alcohols, n-fatty acids and several peptides was investigated in the range of concentration of 0.1–0.5 M. The maximal acceleration of the autolysis has been demonstrated under the effect of additives with a hydrophobicity of 7.5–8.5 ccal/M. In all the investigated concentrations stearic acid and octadecyl alcohol have an inhibitory influence. The role of the hydrophobic influences and the mechanism of autolysis are discussed.     

Russian Article pp. 499–505

The authors studied the influence of the pancreatic desoxyribonucleasa enzyme preparation on the growth of microorganisms and the biosynthesis of some essential amino acids. Kinetic data of amino acid biosynthesis with stimulator and without it are presented. The splain-approximation method for the estimation of the principal physiological characteristics of the fermentation process is used.