Persistência limitada de fungos endofíticos em jardins de formigas cortadeiras

Fungi that are known foliar endophytes have often been isolated from leaf-cutting ant fungal gardens. Recent in vitro growth trials showed that endophytic fungal growth was suppressed by the Lepiotaceous fungi cultivated by leaf-cutting ants. Here we conducted experiments with laboratory ant colonies to assess how long one strain of a common endophytic fungus persisted in the ants’ fungal garden after incorporation by worker ants. We observed that after 72 hours our focal strain could no longer be cultured from the incorporated leaf material or surrounding garden tissues. Moreover, we were unable to culture our focal strain from the ants’ garbage dumps. The limited persistence of an endophyte in ant fungal gardens may be due to ant hygiene behaviors and/or antagonism from the ants’ fungal cultivar.Key words: Atta colombica, Colletotrichum tropicale, endophyte, Leucocoprinus gongylophorus, mutualism.Fungos endofíticos foliares têm sido frequentemente isolados em jardins de formigas cortadeiras. Recentes observações de crescimento in vitro mostraram que fungos endofíticos foram suprimidos pelos fungos Lepiotaceous cultivados pelas formigas cortadeiras. Neste trabalho nós conduzimos experimentos usando colônias de formigas cultivadas em laboratório para avaliar quanto tempo a cepa de um fungo endofítico comum persistiu em jardins de fungos de formigas após a introdução de formigas operárias. Nós observamos que após 72 horas, a principal cepa introduzida não podia ser mais cultivada com material de folhas introduzidas ou com tecidos de jardins vizinhos. Também não foi possível cultivar a cepa principal a partir de materiais descartados  pelas formigas. A persistência limitada de endófitos em jardins de fungos cultivados pelas formigas pode ocorrer devido ao comportamento higiênico das formigas e/ou antagonismo dos cultivares de fungos das formigas.Palavras-chave: Atta colombica, Colletotrichum tropicale, endófito, Leucocoprinus gongylophorus,mutualismo

Antibacterial Activity of Volatile Organic Compounds Produced by the Octocoral-Associated Bacteria Bacillus sp. BO53 and Pseudoalteromonas sp. GA327

The present research aimed to evaluate the antibacterial activity of volatile organic compounds (VOCs) produced by octocoral-associated bacteria Bacillus sp. BO53 and Pseudoalteromonas sp. GA327. The volatilome bioactivity of both bacteria species was evaluated against human pathogenic antibiotic-resistant bacteria, methicillin-resistant Staphylococcus aureus, Acinetobacter baumanni, and Pseudomonas aeruginosa. In this regard, the in vitro tests showed that Bacillus sp. BO53 VOCs inhibited the growth of P. aeruginosa and reduced the growth of S. aureus and A. baumanni. Furthermore, Pseudoalteromonas sp. GA327 strongly inhibited the growth of A. baumanni, and P. aeruginosa. VOCs were analyzed by headspace solid-phase microextraction (HS-SPME) joined to gas chromatography-mass spectrometry (GC-MS) methodology. Nineteen VOCs were identified, where 5-acetyl-2-methylpyridine, 2-butanone, and 2-nonanone were the major compounds identified on Bacillus sp. BO53 VOCs; while 1-pentanol, 2-butanone, and butyl formate were the primary volatile compounds detected in Pseudoalteromonas sp. GA327. We proposed that the observed bioactivity is mainly due to the efficient inhibitory biochemical mechanisms of alcohols and ketones upon antibiotic-resistant bacteria. This is the first report which describes the antibacterial activity of VOCs emitted by octocoral-associated bacteria

Appendix D. Logistic regression results for the effect of phylogenetic distance (My), joint relative abundance (JRA), or the interaction (MyxJRA) on the probability that two plant species shared epifoliar fungal symbionts, from radial transects at San Lorenzo, Panama, and Cape Tribulation, Australia.

Logistic regression results for the effect of phylogenetic distance (My), joint relative abundance (JRA), or the interaction (MyxJRA) on the probability that two plant species shared epifoliar fungal symbionts, from radial transects at San Lorenzo, Panama, and Cape Tribulation, Australia

Appendix A. Canopy openness as a measure of microclimate at canopy and understory sample sites for radial transects in Cape Tribulation, Australia.

Canopy openness as a measure of microclimate at canopy and understory sample sites for radial transects in Cape Tribulation, Australia

Appendix B. Indentification and frequency of collection of epifoliar fungi in canopy or understory radial transects from Cape Tribulation, Australia, or San Lorenzo, Panama.

Indentification and frequency of collection of epifoliar fungi in canopy or understory radial transects from Cape Tribulation, Australia, or San Lorenzo, Panama

Appendix E. Logistic regression results for the effect of canopy fungi (presence/absence of fungi on nearest mature conspecific), juvenile density (number of juveniles in 3-m radius around adult), and percentage of canopy openness on the proportion of juvenile Cleistanthus myrianthus colonized by epifoliar fungi at Cape Tribulation, Australia.

Logistic regression results for the effect of canopy fungi (presence/absence of fungi on nearest mature conspecific), juvenile density (number of juveniles in 3-m radius around adult), and percentage of canopy openness on the proportion of juvenile Cleistanthus myrianthus colonized by epifoliar fungi at Cape Tribulation, Australia