Bioprospecting Antiproliferative Marine Microbiota From Submarine Volcano Tagoro

Abstract

Marine ecosystems are unique and rich reservoirs of biodiversity with high potential toward improving the quality of human life. The extreme physical–chemical conditions of the oceans have favored marine organisms to produce a great variety of new molecules as a mechanism to ensure their survival, and such compounds possess great biopharmaceutical interest. In particular, marine microbiota represent a promising and inexhaustible source for the development of new drugs. This work presents the taxonomic study of the samples obtained from the underwater volcano Tagoro, which has allowed us to develop a collection of 182 marine bacterial strains. On October 10th, 2011, at La Restinga–El Mar de Las Calmas Marine Reserve, an underwater eruption gave rise to a novel shallow submarine volcano at 1.8 km south of the island of El Hierro, Canary Islands, Spain. During the first 6 months, extreme physical–chemical perturbations, comprising thermal changes, water acidification, deoxygenation, and metal enrichment, resulted in significant alterations of the marine ecosystem. After March 2012, the submarine volcano Tagoro entered an active hydrothermal phase that involved a release of heat, gases, metals, and micronutrients that continues till our present. During 2016, our research team had the opportunity to participate in one of the monitoring oceanographic cruises carried out in the area in order to isolate microorganisms associated with both rock samples and deep-sea invertebrates over Tagoro submarine volcano. In this study, Proteobacteria revealed as the most abundant Phylum with 70.2% among all isolated strains, followed by Firmicutes 19%, Actinobacteria 9.5%, and Bacteroidetes 1.2%. Furthermore, we present the results of the antiproliferative assays of the extracts obtained from small-scale cultures of selected bacterial strains. An analysis of the effects of culture conditions in the antiproliferative activity showed that strains grown in Marine Broth (MB) presented lower GI50 values than those cultured in a modified medium (MM1). This effect is improved when the strains are incubated under agitation conditions. The antiproliferative potential of genera such as Halobacillus, Kangiella, Photobacterium, and Halomonas is revealed. Their biotechnological development provides an excellent starting point to access novel secondary metabolites and enzymes with potential for pharmaceutical and industrial applications.

Microbial ecology of a shallow alkaline hydrothermal vent: Strýtan Hydrothermal Field, Eyjafördur, northern Iceland

“…The best hit for ASV sq4, which made up 18–21% of the vent fluid community, was Pseudoalteromonas carrageenovora , isolated from extremely deep marine sediments from the Challenger Deep ( Chen et al, 2021 ; Table 2 ). ASV sq11, classified as Pseudoalteromonas and comprising 5–7% of the vent fluids, had a best hit from a recently formed, circumneutral hydrothermal vent ( García-Davis et al, 2021 ; Table 2 ). There were five ASVs belonging to the Pseudomonadales in Big Strýtan vent fluids ( Supplementary Table 3 ).…”

“…Two other ASVs belonging to the Pseudomonadales were classified at least the genus level and their best hits were also from hydrothermal vents: ASV sq63 (3.3%) is 100% similar to Psychrobacter sp. found at the recently formed vent referenced above (García-Davis et al, 2021) and ASV sq113 (2.2%) is 99.6% similar to Acinetobacter johnsonii (unpublished; Supplementary Table 3). The two ASVs of Flavobacterium spp.…”

Phenolic Fingerprinting and Bioactivity Profiling of Extracts and Isolated Compounds from Gypothamnium pinifolium Phil.

“…As part of our interest in the bioprospection of microorganisms [ 37 , 38 , 39 ] and native plants [ 40 , 41 , 42 , 43 , 44 ], we tested the antiproliferative activity of the n -hexane extract of G. pinifolium against a panel of six representative human solid tumor cell lines: A549 and SW1573 (lung), HBL-100 and T-47D (breast), HeLa (cervix) and WiDr (colon). The GI 50 values showed growth inhibition in all cell lines in the range of 7.6–20 µg/mL.…”

Bioprospecting for Novel Bacterial Sources of Hydrolytic Enzymes and Antimicrobials in the Romanian Littoral Zone of the Black Sea

“…The screening for extracellular hydrolytic activities (i.e., protease, lipase, amylase, cellulase, xylanase, and pectinase) was carried out by culturing the bacterial strains on enriched seawater agar supplemented with one of the following substrates at indicated concentrations (g•L −1 ): casein (10), Tween-80 (10), starch (10), carboxymethyl cellulose (CMC) (5), xylan (10), or pectin (10). The strains were spot-inoculated onto the surface of agar plates using fresh solid inocula and incubated at 30 • C for 7 days.…”

“…Besides their ecological roles, marine microorganisms provide great opportunities for biotechnological exploitation as sources of enzymes (e.g., hydrolases, DNA polymerases, and oxidoreductases), bioactive molecules (e.g., antimicrobials and nutraceuticals), polymers (e.g., polysaccharides and polyhydroxyalkanoates), and biofuels (e.g., microalgae) which can be used in industries, medicine, and research [1,[3][4][5]. Among the numerous marine-derived products, enzymes feature prominently due to their continuously increasing demand on the global market.…”