Discovery of chitin in skeletons of non-verongiid Red Sea demosponges

Abstract

Marine demosponges (Porifera: Demospongiae) are recognized as first metazoans which have developed over millions of years of evolution effective survival strategies based on unique metabolic pathways to produce both biologically active secondary metabolites and biopolymer-based stiff skeletons with 3D architecture. Up to date, among marine demosponges, only representatives of the Verongiida order have been known to synthetize biologically active substances as well as skeletons made of structural polysaccharide chitin. This work, to our knowledge, demonstrates for the first time that chitin is an important structural component within skeletons of non-verongiid demosponges Acarnus wolffgangi and Echinoclathria gibbosa collected in the Red Sea. Calcofluor white staining, FTIR and Raman analysis, ESI-MS, SEM, and fluorescence microscopy as well as a chitinase digestion assay were applied in order to confirm, with strong evidence, the finding of α-chitin in the skeleton of both species. We suggest that, the finding of chitin within these representatives of Poecilosclerida order is a promising step in the evaluation of these sponges as novel renewable sources for both biologically active metabolites and chitin, which are of prospective application for pharmacology and biomedicine.

Microbe‐Mediated Extracellular and Intracellular Mineralization: Environmental, Industrial, and Biotechnological Applications

“…Sponges produce various minerals including calcite, aragonite (i.e., calcareous sponges), [ 32 ] and/or amorphous silica (siliceous sponges) in the form of spicules around a collagenous or chitinous skeleton to provide strength and flexibility. [ 33,34 ]…”

Naturally Prefabricated Marine Biomaterials: Isolation and Applications of Flat Chitinous 3D Scaffolds from Ianthella labyrinthus (Demospongiae: Verongiida)

“…After differentiation, iPSC-CMs were maintained in standard cardiomyocyte medium (RPMI1640 medium (Thermo Fisher Scientific) with 2% B27 supplement (Thermo Fisher Scientific) at 37 • C, 5% CO 2 . After one month of maturation (days [28][29][30][31][32][33][34][35], beating iPSC-CMs were detached using collagenase B (1 mg/ml) for 30-60 min at 37 • C and transferred into fresh reaction tubes. iPSC-CMs were singularized by digestion in trypsin/EDTA (Thermo Fisher Scientific, 0.25% Trypsin-EDTA) for 8 min at 37 • C. Subsequently, iPSC-CMs were resuspended in digestion medium (RPMI1640, 2% B27 supplement, 15% FBS, 2 µM thiazovivin) in a density of 3 million cells/mL.…”

“…Since 2007, scientific interest in simultaneous extraction strategies of demosponges has focused on sponge representatives of the order Verongiida within the class Demospongiae [4]. These sponges are known to synthesize naturally prefabricated three-dimensional (3D) chitin scaffolds [4][5][6]8,[28][29][30][31] and contain highly biologically active bromotyrosines [2,[32][33][34]. Biological reasons to produce bromotyrosines, which are localized within spherulocytes [35,36] in skeletal chitinous fibers of verongiids, are likely to be related to the inhibitory activity of these metabolites against microbial chitinases [37].…”

Electrochemical method for isolation of chitinous 3D scaffolds from cultivated Aplysina aerophoba marine demosponge and its biomimetic application

“…A major drawback of the chemical isolation is caused by the use of hazardous to the environmental extraction agents. Moreover, these chemicals are used in great excess, generating effluents that must be neutralized prior to disposal [28][29][30]. To prevent this negative environmental effect, the biological/enzymatic treatment was developed as an alternative method of chitin isolation [31][32][33].…”