Streptomyces luridus So3.2 from Antarctic soil as a novel producer of compounds with bioemulsification potential

Abstract

The present study aimed to identify novel microbial producers of bioemulsificant compounds from Antarctic soils. Fifty-nine microbial strains were isolated from five different locations at South Shetland Islands, Antarctica, and screened for biosurfactant production by β-hemolytic activity. Strain So 3.2 was determined as bioemulsifier-producer and identified by phenotypic and molecular characterization as Streptomyces luridus. Emulsification activity, oil displacement method and drop-collapsing test were performed to evaluate the biosurfactant activity with different oils and hydrocarbons using two different culture media (Luria Bertani and Bushnell Haas in the presence of different carbon sources: glucose, glycerol, olive oil and n-Hexadecane). Cell free supernatant of Bushnell Haas culture supplemented with n-Hexadecane showed the best results for all tests. Emulsification of hydrocarbons exceeded 60%, reaching up to 90% on oil with high API grade, while displacement tests ranged from 8 cm to 4 cm in diameter according the culture media and tested oils. Our results revealed that Streptomyces luridus So3.2 is able to produce bioemulsifiers capable of emulsifying hydrocarbons and oils, which could be used in different biotechnological applications, particularly for bioremediation of environments contaminated by oil leaks.

Caracterización del potencial de degradación de compuestos xenobióticos por la rizobacteria Azospirillum brasilense

“…A pesar de obtener crecimiento de cada una de los 17 biotipos de Azospirillum brasilense en medio base sangre, ninguna de ellas presentó beta hemolisis. Existen estudios en los cuales se ha asociado la actividad hemolítica y la producción de biosurfactantes (Plaza et al, 2006, Lamilla et al, 2018. Sin embargo, ésta no es una prueba contundente debido a que, otros autores como Pacwa-Płociniczak et al (2014) reportaron que una cepa de Pseudomonas sp la cual resultó positiva para la actividad hemolítica fue insuficiente para confirmar la producción de biosurfactantes, debido a que esta cepa posee además de biotensioactivos, βhemolisinas, resultan positivas en la actividad hemolítica, por lo cual se requiere de la aplicación de pruebas adicionales.…”

The Variety and Inscrutability of Polar Environments as a Resource of Biotechnologically Relevant Molecules

“…Other studies have been performed starting from Antarctic soil samples instead of marine samples, as described above, as a direct source of new bacterial producers. Lamilla et al [12] screened for BS production 59 bacterial strains isolated from soil samples collected in five different sites (i.e., Peninsula Byers, Fildes Bay, Robert Island, Doumer Island, and Fildes Bay-Escudero Base). Among them, Streptomyces luridus So3.2 produced surface biomolecules in the presence of n-hexadecane, which emulsified and displaced different oils and hydrocarbons at high levels.…”

“…The main Antarctic areas on which bioprospecting research was focused are represented by water, soil and marine sediments nearby the most active research stations, where several authors have detected a greater bacterial diversity, attributed to the influence of human activities [ 9 , 10 , 11 ]. Therefore, studies are mainly focused in the areas of King George Island (Arctowski Base), Livingston Island (Byers Peninsula) and Budd Shore (Casey Station) [ 12 ].…”

“…Data on BS-producing bacteria are mainly derived from Antarctic areas and, at a lesser extent, from the Arctic. As it is shown in Table 1 , a number of bacterial genera from abiotic Antarctic matrices have been reported as BS producers, including mainly Pseudomonas , Pseudoalteromonas and Idiomarina [ 35 ], Bacillus [ 34 , 35 , 36 , 37 , 38 ], Rhodococcus [ 35 , 39 ], Halomonas [ 40 ], Pantoea [ 41 ], Oceanobacillus [ 42 ], Streptomyces [ 12 ].…”

Living at the Frontiers of Life: Extremophiles in Chile and Their Potential for Bioremediation

“…The Antarctic soil strain Streptomyces sp. So3.2 is able to produce a biosurfactant, which may be useful for hydrocarbon bioremediation ( Lamilla et al, 2018 ).…”