Production of an antimicrobial substance against Cryptococcus neoformans by Paenibacillus brasilensis Sa3 isolated from the rhizosphere of Kalanchoe brasiliensis.
An antifungal substance produced by Paenibacillus brasilensis strain Sa3 was preliminary characterized and showed to be stable after treatment with different enzymes and organic solvents and at a wide range of pH, and presented a molecular weight between 3 and 10 kDa. In vitro antagonism of this strain towards Cryptococcus neoformans was investigated by optical and electronic microscopic analyses and a fungicidal effect on C. neoformans was observed. Ultrastructural analysis showed intense changes on the fungus when it was paired cultured with strain Sa3, mainly the detachment of the capsule from the cell wall and the presence of altered organelles in the cytoplasm. This novel antifungal substance produced by P. brasilensis Sa3 may represent a new insight in antifungal therapy mainly against emergent fungi. Also, prospective studies on rhizobacteria of plants as Kalanchoe brasiliensis may offer a potential source for the discovery of bioactive compounds with medical value.
Fortes
Tiago Oliveira
TO
Laboratório de Genética Microbiana, Centro de Ciências da Saúde, Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro, Bloco I, Ilha do Fundão, CEP 21941-590 Rio de Janeiro, RJ, Brasil.
Alviano
Daniela Sales
DS
Tupinambá
Gleiser
G
Padrón
Thaís Souto
TS
Antoniolli
Angelo Roberto
AR
Alviano
Celuta Sales
CS
Seldin
Lucy
L
D000898:Antibiosis; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification; D001407:Bacillus / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism; D001938:Brazil; D003453:Cryptococcosis / Q000382:microbiology; D003455:Cryptococcus neoformans / Q000254:growth & development* / Q000648:ultrastructure; D005658:Fungi / Q000254:growth & development; D006801:Humans; D031962:Kalanchoe / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission; D018517:Plant Roots / Q000382:microbiology
D000935:Antifungal Agents