Biological activities and chemical compositions of slime tracks and crude exopolysaccharides isolated from plasmodia of Physarum polycephalum and Physarella oblonga

Abstract

BackgroundThe myxomycetes derive their common name (slime molds) from the multinucleate trophic stage (plasmodium) in the life cycle, which typically produces a noticeable amount of slimy materials, some of which is normally left behind as a “slime track” as the plasmodium migrates over the surface of a particular substrate. The study reported herein apparently represents the first attempt to investigate the chemical composition and biological activities of slime tracks and the exopolysaccharides (EPS) which cover the surface of the plasmodia of Physarum polycephalum and Physarella oblonga.ResultsChemical analyses indicated that the slime tracks and samples of the EPS consist largely of carbohydrates, proteins and various sulphate groups. Galactose, glucose and rhamnose are the monomers of the cabohydrates present. The slime tracks of both species and the EPS of Phy. oblonga contained rhamnose, but the EPS of Ph. polycephalum had glucose as the major monomer. In term of biological activities, the slime tracks displayed no antimicrobial activity, low anticancer activity and only moderate antioxidant activity. However, EPSs from both species showed remarkable antimicrobial activities, especially toward Candida albicans (zone of inhibition ≥20 mm). Minimum inhibitory concentrations of this fungus were found to be 2560 μg/mL and 1280 μg/mL for EPS from Phy. oblonga and Ph. polycephalum, respectively. These EPS samples also showed moderate antioxidant activities. However, they both displayed cytotoxicity towards MCF-7 and HepG2 cancer cells. Notably, EPS isolated from the plasmodium of Phy. oblonga inhibited the cell growth of MCF-7 and HepG2 at the half inhibitory concentration (IC50) of 1.22 and 1.11 mg/mL, respectively.ConclusionsEPS from Ph. polycephalum plasmodium could be a potential source of antifungal compounds, and EPS from Phy. oblonga could be a potential source of anticancer compounds.

Antioxidant, Oxidant and Antimicrobial Capacities of Physarum album (Bull.) Chevall

“…In previous antioxidant studies, it was reported that crude extracts isolated from the plasmodia of Physarum polycephalum and Physarella oblonga exhibited DPPH activities. 22 In the present study, it was determined that P. album had antioxidant capacity. Mushroom species were also used in previous TAS, TOS and OSI studies.…”

“…Antimicrobial studies conducted on myxomycetes reported that Physarum polycephalum and Physarella oblonga had antimicrobial effects on S. aureus, Salmonella typhi and C. albicans. 22 Furthermore, it was reported that different concentrations of the ethanol and chloroform extracts of Lycogala epidendrum exhibited antimicrobial activities against 19 different microorganisms. 23 In the present study, EtOH, MeOH and DCM extracts of P. album were used, and it was determined that it had antimicrobial activities on S. aureus, S. aureus MRSA, E. faecalis, E. coli, P. aeruginosa, K. pneumoniae, A. baumannii, C. albicans, C. krusei and C. glabrata.…”

Cytotoxicity activities and chemical characteristics of exopolysaccharides and intracellular polysaccharides of Physarum polycephalum microplasmodia

“…Slime molds (myxomycetes) are a group of unique protozoans for which the common name (i.e., “slime molds”) most often used is based on the fact that they excrete noticeable amounts of slimy materials in both liquid and solid culture [ 14 ]. Among the myxomycetes, those members of the order Physarales (e.g., P. polycephalum ) often form large plasmodia and are relatively easy to culture on synthetic media.…”

“…Among the myxomycetes, those members of the order Physarales (e.g., P. polycephalum ) often form large plasmodia and are relatively easy to culture on synthetic media. When cultured in liquid media, microplasmodia are formed instead of plasmodia [ 14 ]. Plasmodia and microplasmodia possess several important characteristics, including having no cell walls, rapid growth, and probably sharing the same set of metabolites.…”

Mixomicetos associados a coqueiro (Cocos nucifera L.) na Estação Experimental de Itapirema (Goiana, Pernambuco, Brasil)

“…Os esporocarpos dos mixomicetos e os resíduos do plasmódio podem servir como locais de postura e fontes de alimento para coleópteros e outros insetos (HUYNH et al, 2017). Diferentes grupos de fungos atuam como saprófitos ou parasitas dos mixomicetos, na maioria das vezes inviabilizando a dispersão dos esporos (MUELLER; BILLS; FOSTER, 2004).…”