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Biosurfactants are one of the promising biotechnological products applied in agriculture. Their use, however, is currently far from economically viable, due to the expensive feedstock for the growth of microorganisms. The solution to this problem can be to reduce the cost of production by using organic waste as a nutrient substrate. In this study, oil-containing wastes were considered as substrates - waste frying sunflower oil and petroleum-contaminated soil. At the first stage of research, we screened native waste microorganisms capable of synthesizing biosurfactants. As a result of the study, strains with the ability to form biosurfactants were isolated. Six strains (A, B, C, D, E, F) were isolated from waste frying sunflower oil, two strains (A1, B1) were isolated from petroleum-contaminated soil. The highest yield of biosurfactants is typical for strains A and A1 - 0.429 and 0.502 mg ml-1, while the best ratio of biosurfactant mass to cell biomass is typical for strains A1 and E - 0.9 and 0.6. The most effective producer of biosurfactants turned out to be strain E with an emulsifying activity of E24 equal to 80% and a surface tension of the culture liquid of 27.1 mN m-1.

Biochar is a product of oxygen-free thermal decomposition of biomass and refers alternative fertilizers. Data on the carbon footprint of agricultural products obtained using different types of biochars are not enough to date. The purpose of this study was to compare the carbon footprint of wheat of the grade "Yoldyz-Elita", grown using mineral fertilizers "Diamofoska" and biochar. Biochar was received from chicken manure, the pyrolysis process was at 400ºC, for 2 hours. Biochar was added in an amount of 30 t/ha, mineral fertilizers "Diamofoska" in an amount of 300 kg/ha, respectively. Calculations the carbon footprint included data on fuel consumption and N2O emission from mineral fertilizers, CO2 emission from soil (respiration activity), data on C fixation in biomass of wheat plants and in biochar. It was demonstrated that the use of biochar led to an increase in total soil carbon by 28% by the end of the field experiment. The application of biochar led to an increase in wheat yield by 2.5 times that was similar to the yield with application of mineral fertilizers. It was found that the main contribution to the carbon footprint of wheat was the respiration activity of the soil (up to 95%). The volume of CO2 from fuel used by agricultural machinery was insignificant (0.5% of the total CO2 emissions), soil cultivation with mineral fertilizers increased CO2 emissions by 3%. The use of biochar as an organomineral fertilizer led to a 79% decrease in the carbon footprint of wheat. Thus, biochar from chicken manures may be recommended to reduce the carbon footprint of wheat.

Amendment of soil with biochar instead of mineral or organic fertilizers might be one of techniques wich reduce carbon dioxide emissions into the atmosphere. The effect of biochar based on chicken manure on the biomass and respiratory activity of agricultural soil microorganisms was evaluated in lab conditions at normal (average climatic norm for the vegetation season in central Russia, 15 °C) and elevated (25 and 35 °C) temperatures. It was shown that the introduction of 10% biochar by mass did not lead to an increase emission of CO2 from the soil relative to the control at 15 °C for 60 days of the experiment. An increase in temperature caused an increase in carbon dioxide emissions from the control soil by 35% and 91% and a decrease in moisture by 24% and 42% at 25 and 35°C, respectively. Microbial biomass increased in the control soil by 32% at 25°C and decreased by 34% at 35°C. Soil amendment with biochar led to the leveling of the effect of elevated temperatures on all three parameters. Thus, biochar made from chicken manure allowed one of the characteristics of soil fertility to be preserved and did not lead to the loss of greenhouse gases.

The emission of carbon dioxide from the soil is an urgent problem, as it not only contributes to climate change, but also affects the reduction of the carbon pool in the soil, which negatively affects its fertility. Cultivation of crops with fast growth, high biomass and atmospheric carbon fixation capacity is effective in terms of reducing soil carbon dioxide emissions and organic carbon storage. The purpose of this work was to evaluate greenhouse gas emissions from the cultivation of industrial hemp (Cannabis sativa L., 1753) in different temperature regimes – 15ºС, 20ºС and 30ºС. Soil without plants was used as a control. The respiration activity of the soil microbial community was assessed on the 1st, 7th, 14th, 28th, 42nd, 56th, 70th, 84th and 98th days of incubation. Biomass of plants was measured on the 98th day. It was established that there were no differences in the respiration activity of the control soil and the soil under industrial hemp (Cannabis sativa L., 1753) at the beginning of the experiment, however, from the 14th day, the respiration activity was significantly lower in the soil without plants. The influence of the temperature regime on respiration activity was established after 56 days of the experiment. The influence of the temperature regime of vegetation on the morphometric parameters of hemp has been established: the largest biomass of plants was found at a colder incubation temperature (15ºС). It has been established that the emission of greenhouse gases from the soil during the cultivation of industrial hemp (Cannabis sativa L., 1753) is higher compared to pure soil and depends on the temperature regime.

Biosurfactants are amphiphilic substances with a wide range of uses. Biosurfactants are being researched in various areas of biotechnology. They are especially widely used in the development of new environmentally friendly methods for increasing oil production, as well as in agriculture as an effective biocontrol agent. However, the possibility of finding strains producing biosurfactants and the efficiency of their production is a separate task for research. The aim of this work was to evaluate the dynamics of biosurfactant production by the Bacillus amyloliquefaciens VKMA B-12464 strain, as well as to evaluate its chemical nature. During the research, the resulting biosurfactant was characterized by TLC and IR spectroscopy. It has been established that the biosurfactant produced by Bacillus amyloliquefaciens belongs to lipopeptides, and its highest yield is observed on the 7th day of cultivation.

The search for new biodegradable fertilizers to increase the productivity of agricultural plants is an urgent task. In this study, a complex microfertilizer was developed based on a chelating agent—glutamic-N,N-diacetic acid (GLDA). The evaluation encompassed assessments of biodegradability and effectiveness in fostering lettuce plant growth in hydroponic and conventional soil settings. The impact on endospheric bacteria, a sensitive indicator, was also examined. Results indicated a 59.8% degradation rate of the GLDA complex on the 28th day. The most notable positive effects were observed in above-ground plant biomass, with a 4.6-fold increase for hydroponics and 1.5 to 1.8-fold increases for root and foliar treatments in soil. In hydroponics, GLDA-treated plants showed 24 and 45 operational taxonomic units (OTUs) for leaves and 272 and 258 for roots (GLDA-treated and control plants). In soil, the OTU counts were 270 and 101, 221 and 111, and 198 and 116 in the leaves and roots of GLDA-treated and control plants (under root and foliar treatments), respectively. Non-metric multidimensional scaling (NMDS) and Indicator Species Analysis (ISA) demonstrated significant distinctions in endospheric communities between substrates (hydroponics and soil) in the presence of GLDA. Importantly, GLDA use simplified the composition of endospheric bacterial communities. [ABSTRACT FROM AUTHOR]

Despite the many papers published on oilfield ecosystems, there is a lack of data about microbial community structure and functioning in many crude oils or oilfields and wells. One of such poorly studied oilfields is supergiant Romashkino situated in Tatarstan (Russia). In the present study, prokaryotic community composition and abundance of functional genes encoding sulfate reduction and rhamnolipid production, was investigated in enrichment cultures of four samples from Romashkino oilfield production wells with different oil/water ratios. The enrichment was conducted under anaerobic conditions, sulfate and nitrate were used as electron acceptors, and acetate – as an electron donor. In enrichment culture A and enrichment culture B, bacteria of the Pseudomonadaceae family predominated with 99% and 93% relative abundance, respectively. In enrichment culture C (obtained on the basis of initial sample contained oil with medium water content) and D (obtained on the basis of initial sample contained oil with very high water content), Pseudomonadaceae were one of the two predominating families, along with Micrococcaceae (enrichment culture C) and Dietziaceae (enrichment culture D). The proportion of dsrA and apsA genes encoding sulfate reduction to 16S rRNA gene copy numbers was quite low and ranged between 0.003% (enrichment cultures A, B) and 0.027% (enrichment culture D). The proportion of rhlB gene encoding rhamnolipid production from the total 16S rRNA gene copy number was 1.10% in sample A and 0.06% in sample B. In enrichment cultures C and D the rhlB gene was not found. [ABSTRACT FROM AUTHOR]

Pyrolysis processes and products have yet to be studied fully, and information about chicken‐manure (CM) pyrolysis is especially poor. In the present study, biochar obtained from two CM samples at different residence times (1–4 h) and peak temperatures (400–800°C) was investigated. It was found that pH ranged between 6.8–10.3 and 6.6–11.6; EC between 1.8–3.9 and 1.2–11.9 mSm/cm; CEC between 30.0–65.6 and 15.2–146.9 cmol/kg; C, N, P, and K contents between 9.5–25.6% and 15.7–61.2%, 0.7–2.8% and 1.5–6.4%, 1.7–2.7% and 2.5–5.6%, 0.9–2.1% and 1.3–3.6%, respectively; ecotoxicity (LID10) towards aquatic organisms between 1–40 and 1–66; germination indices between 189–353% and 54–265%; and surface areas between 0.1–0.7 and 0.1–0.3 m2/cm3 for the second and first samples of CM, correspondingly. The multiobjective optimization method was used to analyse the results obtained and to choose the pyrolysis regimes that result in the biochar with the highest fertilizing ability. [ABSTRACT FROM AUTHOR]

Long-term field observations of the natural vegetation cover in industrial and adjacent areas has revealed that the Boraginaceae was one of the main plant family representatives of which were noted in oil-contaminated area. In this study against the background of the previously well characterized plant families Poaceae and Fabaceae, the phytoremediation potential of Boraginaceae plants was investigated under the field conditions and described. Among the members of this family, Lithospermum arvense, Nonea pulla, Asperugo procumbens, Lappula myosotis, and Echium vulgare were the most common in oil-contaminated areas. N. pulla was the most tolerant to hydrocarbons and, along with L. arvense and E. vulgare, actively stimulated the soil microorganisms, including hydrocarbon-oxidizing ones, in their rhizosphere. A comparative assay confirmed that the plants of the Fabaceae family as a whole more efficiently enrich the soil both with available nitrogen and with pollutant degradation genes. Nevertheless, the comparatively high ammonium nitrogen content in the rhizosphere of N. pulla and E. vulgare allows these species to be singled out to explain their high rhizosphere effect, and to suggest their remediation potential for oil-contaminated soil. Novelty statement Against the background of the previously well characterized plant families Poaceae and Fabaceae, the remediation potential of Boraginaceae plants was described for the first time. Overall, this study contributes to understanding the differences in remediation potential of plants at the family level and suggests the monitoring pollutant degradation genes as an informative tool to the search for plant promising for use in the cleanup of oil-contaminated soil. [ABSTRACT FROM AUTHOR]