Assessing the effects of antibiotic selectivity and temperature on the antimicrobial activity of isolates derived from the deep-sea sponge Pheronema capenteri

Authors

Lex L. Hilario

Document Type

Biomedical and Healthcare Sciences Articles

Abstract

The rapid increase of antibiotic resistance necessitates the discovery of novel antibiotic compounds capable to tackle these resistant bacteria. Deep-sea sponges accommodate a diverse and dense microbiome filled with an array of bacterial communities that have the potential to produce novel antimicrobials. Some discovered novel strains have already shown their capability in producing secondary metabolites that are effective against clinically relevant strains. This study aims to evaluate the impacts of different culture conditions; antibiotic selectivity and temperature, on the antimicrobial activity of isolates recovered from three different Pheronema carpenteri deep-sea sponges. Using culture-dependant methods, a total of 59 bacterial isolates were obtained, and their antimicrobial activity was tested against 6 different indicator strains using both solid and liquid assays. The results indicate that 42 (71.2%) of the 59 tested exhibited antimicrobial activity against at least one of the indicator strains. A larger distribution of isolates cultured with no antibiotics showed activity in both the simultaneous antagonism and well-diffusion assays. Similarly, a higher number of active isolates culture under a lower temperature (20°C) showed activity in both the simultaneous antagonism and well-diffusion assays. Whilst a negligible difference in isolate activity was observed using the cross-streak method on either culture condition, a larger portion of isolates grown under the higher temperature (28°C) showed greater inhibition strengths. The 2 isolates that showed great antimicrobial activity in all assays were selected for further phylogenetic analysis using 16S rRNA gene sequencing.

Publication Date

2025-07-29

Publication Title

The Plymouth Student Scientist

Volume

18

Issue

1

ISSN

1754-2383

Deposit Date

2025-07-30

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Recommended Citation

Hilario, Lex L. (2025) "Assessing the effects of antibiotic selectivity and temperature on the antimicrobial activity of isolates derived from the deep-sea sponge Pheronema capenteri," The Plymouth Student Scientist: Vol. 18: Iss. 1, Article 3.
DOI: https://doi.org/10.70156/1754-2383.1511
Available at: https://pearl.plymouth.ac.uk/tpss/vol18/iss1/3