Olena Tigunova

As a result of analytical studies, the main types of lignocellulose raw materials of communal origin were established (using the example of the city of Kyiv). It was found that the most common and promising for use in biofuel technologies are the following types of lignocellulose raw materials in groups: 1) lawn grass; roadside grass; 2) green trimmings of maple, linden, poplar, chestnut, oak, birch; 3) fallen leaves of maple, linden, poplar, chestnut, oak, birch. These types of trees make up 91.6% of the number of all perennial plantations, excluding coniferous trees (based on the analysed data of municipal enterprises of Kyiv). The largest share of fallen leaves (92.9%) is formed by three types of trees - poplar, maple and chestnut. Chemical studies were conducted on the composition of these types of raw materials, as well as three types of miscanthus and sugar sorghum, as plants that can take a promising place in urban landscapes. As a result of chemical studies, it was found that the highest ash content (mineral component) was observed in the dry matter of roadside grass (31.63%), fallen birch leaves (31.17%) and lawn grass (17.53%), the highest content of lignin is in fallen poplar leaves (30.29%), oak trimmings (29.41%) and fallen oak leaves (27.63%), the highest cellulose content is in miscanthus plants of all species (42.23-46.00%), sugar sorghum (34.07%) and fallen birch leaves (31.79%), hemicelluloses – in fallen maple leaves (36.66%), roadside grass (33.97%) and sugar-flowering miscanthus (33.96%), water soluble substances – in plants of sugar sorghum (33.62%), trimmings of linden (22.81%) and poplar (22.57%), pitches and fats – in fallen birch leaves (14.71%), fallen oak leaves (9.82%) and trimmings of birch (8.73%). The obtained results allow us to determine the most promising types of raw materials of communal origin for use in technologies of liquid and gaseous biofuels.

Background: The global energy challenge has recently prompted biotechnological research to explore new non-food substrates of plant origin for obtaining liquid biofuels. One of the important areas of research is the process of pretreatment and further use of non-grain biomass (lignocellulose) as a substrate for bioconversion to higher alcohols. Objective: The aim of this work was to determine the macrocomponent composition and biochemical characteristics of sweet sorghum [Sorghum saccharatum (L.) Moench], select an effective bacterial culture for fermentation of the non-grain part of sorghum biomass as a substrate for obtaining biobutanol, and elaborate the best protective medium and storage temperature for lyophilization of the producer. Methods: This work was conducted using butanol producing strains Clostridium sp. UCM B-7570, Clostridium acetobutylicum UCM B-7407, and C. tyrobutylicum IFBG C4B from the “Collection of Microorganism Strains and Plant Lines for Agricultural and Industrial Biotechnology” of the Institute of Food Biotechnology and Genomics of the National Academy of Sciences of Ukraine. The bacterial cultures were cultivated on the sweet sorghum biomass provided by the National Botanical Garden named after M. M. Gryshko of the National Academy of Sciences of Ukraine. A gas chromatograph was used to determine the presence of ethanol, acetone, and butanol in the cultural liquid. Results: It has been established that the proposed improvement of the biobutanol production process made it possible to obtain 8 g/dm³ of the target product from 60 g of dry green biomass of sweet sorghum of the Energodar variety. The composition of the protective medium for drying the Clostridium sp. UCM B-7570 culture and its storage period in the lyophilic form have been optimized. Conclusion: The obtained results demonstrate the possibility of using the biomass of different varieties of sweet sorghum as a substrate for obtaining biobutanol, and the optimized storage conditions of the Clostridium sp. UCM B-7570 culture can minimize the possibility of its degradation.

Butanol-producing strains Clostridium sp. UCM B-7570 and C. acetobutylicum UCM B-7407 were used for research from “Collection of strains of microorganisms and plant lines for food and agricultural biotechnology” of the Institute of Food Biotechnology and Genomics of the National Academy of Sciences of Ukraine, glycerol (BASF, Germany) and apple pomace (total moisture 4%) after apple juice production. The aim of this work was to study the possibility of using apple pomace by domestic butanol-producing strains of Clostridium sp. UCM B-7570 and C. acetobutylicum UCM B-7407 as a substrate. Producers were cultured on medium with different concentrations of apple pomace, glycerol was used for the inoculation. The presence of ethanol, acetone, and butanol in the culture liquid was determined using a gas chromatograph. It was determined that a significant part of the macrocomponent composition of the extracts can be used in bioconversion by producing strains of the genus Clostridium. It was determined that the highest concentration of butanol (10 g/dm³) was at a concentration of 120 g/dm³ in the extracts. The obtained data showed the possibility of using apple pomace as a substrate in biobutanol technology.

Butanol-producing strains Clostridium sp. UCM B-7570 and C. acetobutylicum UCM B-7407 were used for research from "Collection of strains of microorganisms and plant lines for food and agricultural biotechnology" of the Institute of Food Biotechnology and Genomics of the National Academy of Sciences of Ukraine, glycerol (BASF, Germany) and apple pomace (total moisture 4%) after apple juice production. The aim of this work was to study the possibility of using apple pomace by domestic butanol-producing strains of Clostridium sp. UCM B-7570 and C. acetobutylicum UCM B-7407 as a substrate. Producers were cultured on medium with different concentrations of apple pomace, glycerol was used for the inoculation. The presence of ethanol, acetone, and butanol in the culture liquid was determined using a gas chromatograph. It was determined that a significant part of the macrocomponent composition of the extracts can be used in bioconversion by producing strains of the genus Clostridium. It was determined that the highest concentration of butanol (10 g/dm³) was at a concentration of 120 g/dm³ in the extracts. The obtained data showed the possibility of using apple pomace as a substrate in biobutanol technology.

The rapid development of new molecular methods and approaches, sequencing technologies, has provided new insights into genetic and structural features of bacterial genomes. Information about the genetic organization of metabolic pathways and their regulatory elements has greatly contributed to the increase in the number of studies related to the construction of new bacterial strains with improved characteristics. In this study, the entire genome of the producing strain Clostridium sp. UCM В-7570 from the “Collection of producing strains of microorganisms and plant lines for food and agricultural biotechnology” of Institute of Food Biotechnology and Genomics of the National Academy of Sciences of Ukraine was sequenced and characterized. The genome was assembled into the scaffold with a total size of 4,470,321 bp and a GC content of 29.7%. The total number of genes identified was 4262, of which 4057 encoded proteins, 10 were rRNA operons, and 80 were tRNA genes. The genes of the sequenced genome encoding enzymes involved in butanol fermentation were found and analyzed. They were organized into cluster structures, and their protein sequences were found to be similar to the corresponding strains of C. acetobutylicum, C. beijerinckii, and C. pasteurianum type strains with the highest similarity to the latter. Thus, Clostridium sp. UCM В-7570 producing strain was identified as C. pasteurianum and suggested for metabolic engineering purposes.