Reduction of RBL–2H3 cells degranulation by nitroaromatic compounds from a Bacillus strain associated to the Amazonian sponge Metania reticulata

Abstract

Symbionts in sponges must interact with the host immune system, and this can be mediated by immunomodulators. As the bases of the immune system in sponges resemble those of higher metazoans, it is possible that compounds from this microbiota show similar effects in other phyla. It is also known that several antibiotics, in special macrolides, can modulate many components of the immune response and sponges and their associated microorganisms are a rich source of these compounds. Therefore, we tested the immunosuppressive capacity of antibiotic substances produced by bacterial and fungal strains isolated from the Amazon freshwater sponge Metania reticulata. Fourteen bacterial and six fungal strains were obtained from samples of M. reticulata collected in the Negro River (Amazon Central Basin region), during the dry season. These cultures were monitored for natural antimicrobial activity, and two Bacillus strains (MERETb.761 and MERETb.762) and one fungus (MERETf.010) were selected. One Bacillus strain, MERETb.762, showed strong and specific antibiosis on Staphylococcus aureus and two fractions of its extract inhibited the degranulation of RBL–2H3 cells. The predicted formulas of these fractions were C12H6N4O8 and C25H4N2O6, both corresponding to nitroaromatic compounds.

A Mini Review on Analysis of Potential Antibacterial Activity of Symbiotic Bacteria from Indonesian Freshwater Sponge: An Unexplored and A Hidden Potency

“…Furthermore, bacillus could also produce compounds with anti-bacterial properties. According to Rozas et al (2015) reported the antibacterial activity of Bacillus sp. isolated from the Amazonian freshwater sponge Metania reticulata.…”

Freshwater Sponges as a Neglected Reservoir of Bacterial Biodiversity

“…Among fourteen bacterial strains isolated from the freshwater sponge Metania reticulata (Bowerbank, 1863) from the Negro River (Brazil), Rozas et al [ 27 ] individuated two bacterial strains (namely, MERETb.761 and MERETb.762) showing antimicrobial activity. Both bacterial strains inhibited the fungus Aspergillus sp., whereas MERETb.762 also inhibited Staphylococcus aureus .…”

“…The production of immunosuppressants is commonly considered a bacterial strategy to avoid expulsion from their hosts [ 45 ]. Rozas et al [ 27 ] supposed that MERETb.762 might utilize such a strategy to maintain its relationship with the host. The authors also suggested that performing immunosuppressive assays on isolated compounds could enhance the discovery of novel bioactive molecules.…”

“…Different from marine sponges, our current knowledge on this aspect in inland water sponges remains poorly investigated. It is noteworthy that more than 100 distinct bioactive compounds, that can be useful for humans, have been detected in freshwater sponges and some of them might originate from symbiotic bacteria [ 26 , 27 ].…”

Communality in microbial stress response and differential metabolic interactions revealed by time‐series analysis of sponge symbionts

“…The highest amino acid sequence identity is to NfnB (44%) and CnbA (43%), which are nitroreductases involved in the degradation of nitroaromatic and chlorinated nitroaromatic compounds (Wu et al, 2006;Manina et al, 2010). Sponge holobionts are known producers of various nitroaromatic compounds (Rozas et al, 2016) and Ca. P. multivorans might use the nitroreductase to utilize them as nutrition.…”