Resumen de Chilean benthic species identified as a new source of antibiotic substances

Erwin Strahsburger, Jessica Pizarro, Alex Zúñiga, Sergio Ocares, Camila Vallejos, Michael McClelland

• Benthic marine organisms are a natural source of bioactive substances with applications in medicine to treat infections, cancer and other diseases. In Chile, this community possesses rich biodiversity that has been scarcely studied as a producer of bioactive substance so far. For that reason, we studied the potential production of antibiotic substances in 28 benthic species that inhabit the coast of the Tarapacá region in northern Chile, and belong to phylum Porifera, Cnidaria, Mollusca, Sipuncula, Annelida, Echinodermata and Chordata. The antibiotic activity was evaluated on ethanol extract obtained from their entire body or dissected tissues and was tested against Staphylococcus aureus ATCC 25923 with the diffusion agar method. According to the halo diameter, the antibiotic potency was classified as mild, regular or high. In this way, we could identify 21 benthic species as a producer of antibiotic substances with different antibiotic potency. This activity was found in more than one tissue and with regular or high antibiotic activity in the species; Acanthopleura echinata, Chiton cumingsii, Aulacomya atra, Fissurella crassa, Fissurella latimarginata, Luidia magellanica, Stichaster striatus, Arbacia spatuligera, and Loxechinus albus. The extracts obtained from the entire body and showed regular and high antibiotic activity were from the species; Phymanthea pluvia, Abarenicola affinis, Glycera americana, and Ophiactis kroyeri. In conclusion, northern Chile possesses a rich biodiversity of benthic species producer of antibiotic substances, and more research is encouraged to identify these substances with application in medicine.