The increased population of the Wild Boar (Sus scrofa L.) in Europe

In this paper the recent population changes of the Wild Boar in different European countries is analysed through the study of hunting statistics. A simultaneous increase in numbers is observed throughout the whole area during the period 1965–1975. From 1975 onwards the population stabilizes itself apart from in peripheral areas like Finland. Potentially favourable factors which play a part in this process are discussed and certain reproductive and dispersive characteristics which favour its invasive behaviour are discussed.     

Production of an extracellular proteinase and α-amylase byBacillus subtilis in chemostat

The formation of two extracellular enzymes (α-amylase and a proteinase) ofB. subtilis was investigated in batch and continuous cultures. Differences were observed in the production of both enzymes in batch culture when studied in flasks and in a fermentor. The values of proteinase activity from continuous cultivation never reached those obtained during batch cultivation. The optimal dilution rate for proteinase synthesis was 0.1 – 0.2/h. The optimal dilution rate for the production of α-amylase was 0.2 –0.3/h.     

Selection of a community of acidochemolithotrophic microorganisms with a high oxidation rate of pyrrhotite-containing sulphide ore flotation concentrate

A community of acidochemolithotrophic microorganisms with a high oxidation rate of pyrrhotite-containing sulphide ore flotation concentrate was selected. The Acidithiobacillus caldus OP-1 and Ferroplasma acidiphilum OP-2 cultures were identified to be dominating members. The presence of the Acidithiobacillus ferrooxidans OP-3, Leptospirillum ferriphilum OP-4, and Sulfobacillus thermosulfidooxidans OP-5 cultures in the community’s composition was also mentioned. The analysis results of solid residues of the process showed a greater elemental sulfur oxidation level and gold recovery when the initial pH value in tank I was maintained at a level of 1.8–2.0 (90.5%) rather than 1.6–1.8 (86.3%).     

Effect of cultivation conditions on the growth and activities of sulfur metabolism enzymes and carboxylases of Sulfobacillus thermosulfidooxidans subsp. asporogenes strain 41

The moderately thermophilic acidophilic bacterium Sulfobacillus thermosulfidooxidans subsp. asporogenes strain 41 is capable of utilizing sulfides of gold-arsenic concentrate and elemental sulfur as a source of energy. The growth in the presence of S0 under auto- or mixotrophic conditions was less stable compared with the media containing iron monoxide. The enzymes involved in oxidation of sulfur inorganic compounds--thiosulfate-oxidizing enzyme, tetrathionate hydrolase, rhodonase, adenylyl sulfate reductase, sulfite oxidase, and sulfur oxygenase--were discovered in the cells of Sulfobacillus grown in the mineral medium containing 0.02% yeast extract and either sulfur or iron monoxide and thiosulfate. Cell-free extracts of the cultures grown in the medium with sulfur under auto- or mixotrophic conditions displayed activity of the key enzyme of the Calvin cycle--ribulose bisphosphate carboxylase--and several other enzymes involved in heterotrophic fixation of carbonic acid. Activities of carboxylases depended on the composition of cultivation media.     

Effects of exogenous factors on the activity of enzymes involved in carbon metabolism in thermoacidophilic bacteria of the genus Sulfobacillus

Aerobic thermoacidophilic chemolithotrophic bacteria Sulfobacillus thermosulfidooxidans 1269T and Sulfobacillus thermosulfidooxidans subsp. asporogenes 41 were shown to be resistant to stress factors, including high concentrations of Zn2+ (0.8 M) and H+ (pH 1.2) that exceeded the optimum values. The growth and biomass gain rates decreased, but bacteria retained their functions. The activity of nearly all enzymes involved in carbon metabolism decreased. Glucose was primarily metabolized via the Entner--Doudoroff pathway. The activity tricarboxylic acid cycle enzymes decreased compared to that in cells grown under normal conditions. After saturation of the growth medium with 5 vol % CO2, sulfobacteria utilized glucose by the Embden-Meyerhof and pentose phosphate pathways under mixotrophic conditions.     

Effect of the Medium Composition and Cultivation Conditions on Sporulation in Chemolithotrophic Bacteria

The possibility of regulating endospore formation by changing cultivation conditions was for the first time shown in acidophilic chemolithotrophic bacteria Sulfobacillus thermosulfidooxidans type strain 1269 and the thermotolerant strain K1 formerly described as S. thermosulfidooxidans subsp. thermotolerans. Suppression of sporulation occurred when these strains were cultured in Manning's liquid medium with yeast extract. This medium was optimized by gradually reducing the concentrations of ferrous iron salts (the source of energy), phosphorous, nitrogen, and yeast extract and simultaneously increasing the concentrations of calcium, magnesium, and manganese (the elements important for sporogenesis) to attain higher yields of endospores by strains 1269 and K1. As a result, a new medium A was proposed, in which, under aeration, the life cycle of the strains studied culminated in sporulation at a level of 45 and 60%, respectively, of the total cell number. In a series of additional tests, the growth temperature and medium pH were adjusted to obtain the maximum yield of endospores. The optimal ranges found were 40–50°C and pH 1.8–2.2 for strain 1269 and 35–40°C and pH 2.5–2.7 for strain K1. An even higher yield of endospores, amounting to 55 and 75% for strains 1269 and K1, respectively, was obtained when the above growth conditions were combined (growth on medium A at optimal temperatures and pH under static conditions). Our results suggest a new approach to optimizing sporulation by acidophilic chemolithotrophs, which consists in limiting the energy and nutrient sources and using temperature and pH values within the tolerance bounds of these cultures but outside their growth optimum ranges.     

The enzyme of carbon metabolism in the thermotolerant sulfobacillus strain K1

To determine enzymatic activities in the thermotolerant strain K1 (formerly "Sulfobacillus thermosulfidooxidans subsp. thermotolerans"), it was grown in a mineral medium with (1) thiosulfate and Fe2+ or pyrite (autotrophic conditions), (2) Fe2+, thiosulfate, and yeast extract or glucose (mixotrophic conditions), and (3) yeast extract (heterotrophic conditions). Cells grown mixo-, hetero-, and autotrophically were found to contain enzymes of the tricarboxylic acid (TCA) cycle, as well as malate synthase, an enzyme of the glyoxylate cycle. Cells grown organotrophically in a medium with yeast extract exhibited the activity of the key enzymes of the Embden-Meyerhof-Parnas and Entner-Doudoroff pathways. An increased content of carbon dioxide (up to 5 vol%) in the auto- and mixotrophic media enhanced the activity of the enzymes involved in the terminal reactions of the TCA cycle and the enzymes of the pentose phosphate pathway. Carbon dioxide was fixed in the Calvin cycle. The highest activity of ribulose bisphosphate carboxylase was detected in cells grown autotrophically at the atmospheric content of CO2 in the air used for aeration of the growth medium. The activities of pyruvate carboxylase, phosphoenolpyruvate carboxylase, phosphoenolpyruvate carboxykinase, and phosphoenolpyruvate carboxytransphosphorylase decreased with the increasing content of CO2 in the medium.     

Effects of Exogenous Factors on Enzymes of Carbon Metabolism in Thermoacidophilic Bacteria of the GenusSulfobacillus

Aerobic thermoacidophilic chemolithotrophic bacteria Sulfobacillus thermosulfidooxidans1269^Tand Sulfobacillus thermosulfidooxidanssubsp. asporogenes41 were shown to be resistant to stress factors, including high concentrations of Zn²⁺(0.8 M) and supraoptimal concentrations of H⁺(pH 1.2). The growth and biomass gain rates decreased, but bacteria retained their functions. The activity of nearly all enzymes involved in carbon metabolism decreased. Glucose was primarily metabolized via the Entner–Doudoroff pathway. The activity of tricarboxylic acid cycle enzymes decreased compared to that in cells grown under normal conditions. After saturation of the growth medium with 5 vol % CO₂, sulfobacteria utilized glucose by the Embden–Meyerhof and pentose phosphate pathways under mixotrophic conditions.