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POTENTIAL OF BIOSURFACTANT PRODUCTION IN BACTERIA ISOLATED FROM OIL POLLUTED SOILS
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L. Biktasheva; P. Galitskaya; S. Selivanovskaya
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1314-2704
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English
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21
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7.2
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• Prof. DSc. Oleksandr Trofymchuk, UKRAINE
• Prof. Dr. hab. oec. Baiba Rivza, LATVIA |
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It is widely known that oil production processes do not usually achieve maximum efficiency. One method of increasing production is microbial enhanced oil recovery (MEOR). MEOR methods can clean oil, increase production and clean oil-contaminated soils by not only introducing the microorganisms themselves but also the substances they produce. Among the advantages of these methods are their relative efficiency and the absence of negative impact on the environment. MEOR methods are divided into two groups the first group - ex situ - includes the injection of nutrients into a well with few or no microbes and the stimulation of their growth in the oil reservoir, the second group - in situ - includes the cultivation of microbes outside the wells to obtain microbial products (for example, biosurfactants) and the injection of these products. Biosurfactants are amphiphilic compounds that can simultaneously interact with hydrophilic and hydrophobic molecules, since they are composed of polar (carbohydrates) and non-polar (fatty acids) sites. There are biosurfactants of different groups, such as surfactin, rhamnolipid, viscosin, lichenysin and others which are encoded by different groups of genes.
We have carried out a screening of microorganisms capable of producing biosurfactants isolated from oil-contaminated soils. Oil-contaminated soils were sampled in the oil-producing regions of the Republic of Tatarstan (Russia). 50 strains of microorganisms were isolated, of which 15 had surfactant production capabilities. Using 16S rRNA gene sequencing, these bacteria were identified. It was found that three strains belonged to the Pseudomonas genus, two strains to the Rhodococcus genus, and ten strains to the Bacillus genus. Biosurfactant activity was estimated on the basis of bacterial ability to produce substances that can emulsify an oil-water mixture (E24 index). The highest E24 was registered for B. amyloliquefaciens (47.6%) while the lowest was found to be for R. erythropolis (15.6%). Furthermore, the presence of genes encoding biosurfactant production in bacteria was screened in all the fifteen strains: srfA3 and srfAA (encoding surfactin production) and rhlB (encoding rhamnolipid production). It was revealed, that srfA3 and srfAA genes were present in all ten strains of Bacillus genus (both genes in each strain). The rhlB gene was present in Pseudomonas gessardii, Pseudomonas fluorescens, and Pseudomonas punonensis strains. It can be concluded that the isolates possess high potential for biosurfactant production and can be successfully used in MEOR. |
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conference
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21st International Multidisciplinary Scientific GeoConference SGEM 2021
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21st International Multidisciplinary Scientific GeoConference SGEM 2021, 16 - 22 August, 2021
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Proceedings Paper
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STEF92 Technology
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SGEM International Multidisciplinary Scientific GeoConference
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SWS Scholarly Society; Acad Sci Czech Republ; Latvian Acad Sci; Polish Acad Sci; Serbian Acad Sci & Arts; Natl Acad Sci Ukraine; Natl Acad Sci Armenia; Sci Council Japan; European Acad Sci, Arts & Letters; Acad Fine Arts Zagreb Croatia; Croatian Acad Sci
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225-232
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16 - 22 August, 2021
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website
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cdrom
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8273
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biosurfactants; oil polluted soils; surfactin; rhamnolipid
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