Study of exopolysaccharids production and antimicrobial activity in Actinobacteria strains isolated from saline soils

Ould Mohamed Imane, Serbah Assia

dc.contributor.author	Ould Mohamed Imane, Serbah Assia
dc.date.accessioned	2023-12-06T08:35:59Z
dc.date.available	2023-12-06T08:35:59Z
dc.date.issued	2023
dc.identifier.uri	http://dspace.univ-djelfa.dz:8080/xmlui/handle/123456789/5787
dc.description	This study focused on the isolation and characterization of Actinobacteria strains from saline soils, with a specific emphasis on their exopolysaccharide (EPS) production and antimicrobial activity. The research successfully isolated and purified 20 Actinobacteria strains from the soil samples collected in 'sabkha' area in Mosran, Djelfa. The morphological and cultural characteristics of these strains were analyzed using various culture media, including ISP1, ISP2, ISP3, and ISP4. The investigation into EPS production revealed that three selected strains (H3, H8, and H13) exhibited notable EPS production, with a yield of approximately 2.02 g/L .EPS production is a crucial trait exhibited by bacteria, including Actinobacteria, and the findings contribute to our understanding of the biological activities and potential applications of these microorganisms in biotechnology. Moreover, the antimicrobial activity of the isolated Actinobacteria strains was evaluated against pathogenic bacteria (Staphylococcus aureus and Escherichia coli) and non-pathogenic microorganisms (Penicillium sp. And Saccharomyces cerevisiae). The results demonstrated varying degrees of antimicrobial activity, with some strains exhibiting broad-spectrum activity and inhibiting the growth of multiple pathogens. These findings highlight the potential of Actinobacteria as a source of novel antimicrobial agents, contributing to the ongoing search for effective treatments against pathogenic bacteria and fungi, including yeast. The study also explored the tolerance of the isolated Actinobacteria to salinity, pH, and temperature. The Atinobacteria strains displayed adaptability to high salt concentrations and exhibited diverse responses to different pH levels and temperature conditions. These findings enhance our understanding of the ecological adaptations and survival mechanisms of Actinobacteria in extreme environments. The isolation and characterization of Actinobacteria from saline soils provide valuable insights into their diversity and adaptability in extreme environments. The observed morphological, physiological, and biochemical characteristics confirmed the identification of the isolated strains as Actinobacteria. The variation in cultural characteristics, EPS production, and antimicrobial activity highlighted the metabolic versatility and potential biotechnological applications of Actinobacteria.This study contributes to the growing body of research on Actinobacteria derived from extreme environments and their potential for biotechnological applications. The findings expand our knowledge of these microorganisms and their bioactive compounds, opening avenues for further exploration in fields such as biotechnology, agriculture, and pharmaceutical sciences.	en_EN
dc.description.abstract	This study aimed to isolate and characterize Actinobacteria strains from saline soils, focusing on their exopolysaccharide (EPS) production and antimicrobial activity against four microorganism, including Escherichia coli and Staphylococcus aureus, as well as fungal (mold) strains such as Penicillium.sp and the yeast strain Saccharomyces cerevisiae. The research was conducted at the microbiology laboratory of Zian Achour University of Djelfa, using standard methods for Actinobacteria isolation, characterization, and antimicrobial testing. Soil samples were collected from a saline site 'sabkha' area in Mosran, Djelfa, and Actinobacteria were isolated using a dilution series and selective media. The isolated strains were purified and subjected to salt, temperature, and pH tolerance tests. Cultural and morphological characteristics were analyzed, and the antibacterial activity of the strains was determined. One of the key objectives of this study was to investigate the production of extracellular polysaccharides (EPS) in the chosen isolated Actinobacteria strains H3, H8, and H13. EPS production is a crucial trait exhibited by many bacteria, including Actinobacteria, and it serves various biological functions. To assess EPS production, the Actinobacteria strains were cultivated in specific media (ISP2 liquid media) known to promote EPS production, and the amount of EPS produced was quantified. The yield of EPS production for all three samples (H3, H8, and H13) was approximately 0.202%. In terms of antimicrobial activity, the isolated Actinobacteria strains were evaluated against four microorganism. Antimicrobial testing was performed using the perpendicular streak method and the agar well diffusion method. The results revealed different degrees of antimicrobial activity exhibited by the Actinobacteria strains. Some strains demonstrated antimicrobial activity against all four tested microorganisms, inhibiting the growth of pathogens, while other strains showed activity specific to certain microorganisms. The antimicrobial activity of the Actinobacteria strains was observed through the formation of inhibition zones around the perpendicular streaks and agar wells. The findings of this study shed light on the potential of Actinobacteria from saline soils for biotechnological applications. By elucidating their antimicrobial activity against four microorganisms, the Actinobacteria show promise as a source of novel antimicrobial agents. Furthermore, the investigation of EPS production in the Actinobacteria strains contributes to our understanding of their biological activities and opens avenues for further research in the field of microbial biotechnology. This research emphasizes the significance of studying Actinobacteria from saline soils, which represent a unique ecological niche with untapped microbial diversity. The implications of this study extend to various fields, including biotechnology, agriculture, and pharmaceutical sciences, where the search for novel bioactive compound and antimicrobial agents is of paramount importance.	en_EN
dc.language.iso	en	en_EN
dc.publisher	Université Ziane Achour/Faculté des Sciences de la Nature et de la Vie	en_EN
dc.subject	Actinobacteria, Saline soils, Exopolysaccharides, Antimicrobial activity	en_EN
dc.title	Study of exopolysaccharids production and antimicrobial activity in Actinobacteria strains isolated from saline soils	en_EN
dc.title.alternative	Applied Microbiology	en_EN
dc.type	Thesis	en_EN