RT Journal Article
T1 Production of bioactive lichen compounds by alginate-immobilized bionts isolated from Cladonia verticillaris: an in vitro study
A1 Santiago, Rocío
A1 Martins, Mônica C.B.
A1 Nascimento, Tais
A1 Filipe de Barros, Luis
A1 Vilaça, Matheus
A1 Emerson, Peter Falcão
A1 Henriques da Silva, Nicácio
A1 Legaz González, María Estrella
AB Bionts isolated from thalli of Cladonia verticillaris, immobilized in calcium alginate, produce two depsidones, fumarprotocetraric and protocetraric acids, and the depside atranorin, that exhibit antimicrobial activity against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae. Organic lichen extract (acetone/ether/chloroform) shows the highest antimicrobial activity due to a possible synergism between these substances. Antioxidant capacity of soluble metabolites secreted from the immobilisates to the bath medium of incubation during the first 12 days of immobilization has been found (˃80% oxidation inhibition). The concentration of soluble phenolic substances depends on the immobilization time (during 32 days), exogenous supply of acetate (1.0m mM sodium or calcium acetate) and on the type of isolated biont (phycobionts, mycobionts, whole thallus or immobilized phycobionts co-incubated with the mycobionts ones). The role of phycobionts in phenol production has been interpreted as a possible modification of the polymalonyl pathway; for example, atranorin is actively produced and secreted during immobilization while it is not detected in thallus in natura. Co-incubated bionts secrete higher amounts of atranorin to the media during the first 12 days of immobilization. Immobilization of isolated bionts could be used as a biotechnological technique to obtain a potential source of biological active compounds. On the other hand, the physiological state detected of C. verticillaris in the Cerrado is much better for experimentation than that of the specimens collected in Caatinga since, in this case, the thalli showed the fragility that the extreme environmental conditions of the semi-arid region of NE Brazil impose on this lichen species. To date, no priority has been defined for lichen conservation in Brazilian ecosystems. It is therefore suggested that it imust important to include lichen ecophysiology studies in public conservation policies.
PB Canadian Center of Science and Education
SN 1927-0461, ESSN 1927-047X
YR 2020
FD 2020-03-19
LK https://hdl.handle.net/20.500.14352/6600
UL https://hdl.handle.net/20.500.14352/6600
LA eng
NO Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
DS Docta Complutense
RD 6 may 2024