Study of the taxonomic diversity and bioactivity potential of Actinomycetota associated with Ruta graveolens

Ferreira, Sílvia Filipa da Silva

http://hdl.handle.net/10400.22/29575

Use this identifier to reference this record.

Name:	Description:	Size:	Format:
DISSERTAÇÃO_MBS_SílviaFerreira_V.final.pdf		16.95 MB	Adobe PDF	Download

Send Feedback

Authors

Ferreira, Sílvia Filipa da Silva

Advisor(s)

Carvalho, Maria de Fátima

Oliveira, Rui S.

Vieira, Mónica

Abstract(s)

The medicinal plant, Ruta graveolens, possesses various bioactive properties, including antibacterial, anti-inflammatory, and cytotoxic activities. Bactéria from the phylum Actinomycetota are well-known for their excellent ability to produce bioactive compounds. They can live in association with a wide diversity of organisms, including plants, and display significant potential for the bioprospecting of new compounds with biomedical and industrial applictaions, including cytotoxic compounds and biosurfactants. Bacterial biosurfactants are compounds with surfatant and emulsifying properties, characterised by hydrophilic and hydrophobic groups that reduce surface tension between two phases. The discovery of new compounds is na importante factor in the development of new drugs. This work aimed to explore the cytotoxic and antimicrobial activity and biosurfactant production in Actinomycetota strains isolated from R. graveolens. In antimicrobial activity tests, Actinomycetota strains did not show activity against the microorganisms tested: staphylococcus aureus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium and one yeast, Candida albicans. Thirty-six Actinomycetota starins were evaluated for their cytotoxic properties against the human liver cancer cell line (HepG2) and the non-cancerous brain endothelial cell line (hCMEC/D3). Additionally, these strains were also assessed for their biosurfactant production capabilities through emulsification, dispersion, drop colapse, and interfacial tension assays. Nine crude extracts showed the ability to reduce the viability of the HepG2 cancer cell line (liver cancer) after 48h of exposure, with reductions between 20-30%, and one extract with a 60% reduction. One extract was the most promising, showing no toxocity to the non-tumor cell line but reducing viability in the cancer cell line. Regarding biosurfactant production, 29 extracts demonstrated potential in various assays. Among these, nine showed high biosurfactant activity, eight exhibited moderate activity, and 12 showed low to moderate activity. In the dereplication analysis of the Actinomycetota extracts, the presence of some metabolities associated with known natural products was observed, but four potential new molecules were also identified. Furthermore, through molecular networking, the presence of two clusters associated with known compounds such as surfactins and amphibactins was confirmed, both amphiphilic molecules that had never before been reported in association with Actinomycetota strains.