In the Republic of Kazakhstan (one of the top 10 oil-producing countries in the world), the remediation of oil pollution found in unproductive soils under the conditions of a sharply continental arid climate is a highly relevant problem. The aims of this work are to study the biodegradation capacity of the gray soil of the ‘Daulet Asia’ landfill, assess the degradative potential of indigenous oil-degrading strains and changes in the composition of the soil microbial community. Analytical chemistry methods, distillation and chromatographic mass spectrometry were used for oil analysis; gravimetry and IR spectroscopy were used to evaluate oil degradation. Standard microbiological techniques were employed to isolate and cultivate microorganisms and metagenomic sequencing was carried out using Oxford Nanopore technology. Raw data processing and subsequent analysis were performed using modern software packages. Three isolated strains of interest were identified based on the analysis of 16S rRNA gene fragment sequences. The studied soil has low biodegradation capacity (oil loss was 6.2% on day 60), possibly due to the low abundance and weak activity of indigenous hydrocarbon-oxidizing microorganisms. The taxonomic composition of the microbiome in the studied soil suggests some potential for oil degradation. Assessment of the effectiveness of oil degradation by the indigenous microbiome indicates that this potential can be realized only marginally in situ. Isolated oil-degrading strains were identified as belonging to the Rhodococcus and Kocuria genera. Effective oil removal from the studied soil requires the introduction of active microorganisms (e.g., as part of biopreparations). Considering the characteristics of the hot arid climate, for bioremediation of contaminated sierozems of Southern Kazakhstan, it is advisable to use halotolerant oil-degrading microorganisms with a wide temperature range that are capable of degrading hydrocarbons under moisture deficiency.

Annotation. With the help of modern methods of physico-chemical analysis, the physicochemical properties, origin and fractional compositionof the Akshabulak oil field were studied. Using adsorption column chromatography, the oil was purified from asphaltenes and resins contained in it. The full composition of oil was determined by chromatography-mass spectrometry and the content of compounds in it was calculated by internal normalization. The NIST-08 database was used as a library of Mass spectra. The origin of the oil was discovered, studied by the ratio of 2,6,10,14-tetramethylpentadecane to 2,6,10,14-tetramethylhexadecane on the obtained chromatogram. The proven oil was formed at the seabed off the coast by origin. The fractional composition of oil and the products obtained from it was studied by the method of simulated distillation. The heat of combustion of the products obtained and the octane number of gasoline obtained from oil were determined. The results obtained as a result of the study can be used in oil refining.

The article presents the results of research on the development of a dry form of the new biopreparation, the technology of production, and application for the reclamation of oil-contaminated soils in the extreme continental arid climate. A previously patented association of active crude oil degrader strains was used to develop the biopreparation (Pseudomonas putida KZ3 and two strains Rhodococcus KZ1 and KZ2). Microorganisms were cultured on a semi-synthetic medium to achieve maximum abundance, and the genes for the biodegradation of petroleum hydrocarbons were induced by additives at the end of fermentations. The microbial abundance at the end of cultivation with the addition of salicylate reached 7×109, with the addition of glucose – 1×109 CFU/ml, and with the addition of diesel fuel – 3.2×109 CFU/ml. Lyophilization at 35°C and a pressure of 4 μm Hg yielded a dry preparation with a microbial abundance of 8.0×1010 CFU/g. After storage for 6 months at 4-8°C, there was no loss of viability of microorganisms. Field tests conducted at the Akshabulak oil waste landfill of Company-Daulet Asia LLP showed the effectiveness of the control sample of the biopreparation. The degree of soil purification from petroleum products in 4 weeks was 70%, and in twelve weeks – 89.67%.

В работе рассматривается переработка многотоннажного сельскохозяйственного отхода – рисовой соломы в целлюлозу, которая может найти применение для производства бумажных изделий. Процесс десиликации рисовой соломы проводили в условиях сверхвысокочастотного облучения при мощностях 100 и 180 Вт в течение 5-40 мин раствором гидроксида натрия. Делигнификацию полученного продукта после процесса десиликации также проводили в условиях сверхвысокочастотного облучения при мощностях 100 и 180 Вт в течение 5- 40 мин смесью уксусной кислоты и пероксида водорода в соотношении 1:1 в присутствии молибдата аммония (0-5 мас. % от целлюлозной массы). Для отбелки полученной массы использовали концентрированный раствор гипохлорита натрия. Выход целевого продукта – целлюлозы составил 42,7-70,3 мас.%. Целлюлоза, полученная при десиликации и делигнификации сверхвысокочастотным облучением при мощности 180 Вт в течение 15 мин в присутствии молибдата аммония (5% от сухой обескремненной целлюлозной массы) и без добавления гипохлорита натрия является оптимальным, содержание альфа-целлюлозы в конечном продукте составил 74,45 мас. %, данная продукция соответствует №2 марки А (целлюлоза, применяемая для изготовления белой офисной бумаги). Полученные результаты могут найти применение для изготовления бумажных изделий.