Effects of Culture Conditions on Antimicrobial Activity of Ganoderma resinaceum (Agaricomycetes) Extracts.

Among many sources of natural bioactive substances, mushrooms constitute a huge and mostly unexplored group. Biologically active secondary metabolites of Ganoderma, a group of wood-degrading mushrooms, have recently been reviewed. Our previous study revealed the antimicrobial activity of extracts from G. resinaceum grown in submerged culture against phytopathogens. Different factors can influence the production of secondary metabolites, including nutritional factors. In this study we evaluated the influence of different culture conditions on the antimicrobial activity of extracts from liquid cultures of G. resinaceum, through use of a factorial design. Minimum inhibitory concentrations for extracts produced under different culture conditions were determined against Staphylococcus aureus and Xanthomonas vesicatoria. Based on the results of these assays, larger-scale cultures in malt extract broth supplemented with 20 g/L glucose and a 15-day incubation time should be performed in order to isolate from G. resinaceum antibiotic compound(s) that are potentially useful against S. aureus. In addition, pH 5 should be considered for the production of antimicrobial metabolites against X. vesicatoria from supernatant broths or extracts from G. resinaceum.

Anti-MRSA Activity of Fruiting Body Extracts of Spectacular Rustgill Mushroom, Gymnopilus junonius (Agaricomycetes).

Despite the great advances in chemotherapeutics, infectious diseases are still one of the leading causes of death worldwide. Among some of the clinically relevant pathogens, methicillin-resistant Staphylococcus aureus (MRSA) ranks as one of the most difficult bacteria to treat. It is a common cause of skin, soft-tissue, and endovascular infections, as well as pneumonia, septic arthritis, endocarditis, osteomyelitis, and sepsis. The research on Basidiomycota is extensive; many species show a broad spectrum of pharmacological activities, including antimicrobial activity. The vast majority of the literature to date generally focuses on screening the antibacterial properties of mushroom extracts. A gap still exists in the identification of the individual compounds responsible for these properties, and few low molecular weight compounds have been described. Gymnopilus junonius, the big laughter mushroom, grows wild in Uruguay, especially on Eucalyptus spp. plantations; it is known as the "eucalyptus fungus." In this work, we report the bioguided isolation, structural elucidation, and antistaphylococcal activity of the main antimicrobial components of fresh basidiocarps of G. junonius.

Screening for Antimicrobial Activity of Wood Rotting Higher Basidiomycetes Mushrooms from Uruguay against Phytopathogens.

In this work, the antimicrobial activity of extracts of wood rotting higher Basidiomycetes mushrooms isolated from Eucalyptus plantations in Uruguay was studied using bacterial and fungal phytopathogens as targets. Fifty-one extracts from mycelia and growth broth were prepared from higher Basidiomycetes mushrooms, from which eight extracts (from Ganoderma resinaceum, Laetiporus sulphureus, Dictyopanus pusillus, and Bjerkandera adusta) showed antimicrobial activity against Xanthomonas vesicatoria, Aspergillus oryzae, Penicillium expansum, Botrytis cinerea, and Rhizopus stolonifer as assayed in the qualitative test. The minimum inhibitory concentration (MIC) for those fungal extracts was determined and the results showed that L. sulphureus deserved further study, with low MIC values against X. vesicatoria. The antimicrobial activity of L. sulphureus culture broth extracts grown under different culture conditions was evaluated against X. vesicatoria. From the results of these assays, larger-scale cultures for the production of the compound(s) with antimicrobial activity should be performed using malt extract broth, at pH 5, at 20°C and static culture conditions.

Prospección química y microbiológica del bosque de galería del Río Uruguay / Chemical and microbiological prospecting woodland along the Uruguay River / Prospecção química e microbiológica do bosque de galeria do Rio Uruguai

La bioprospección es la búsqueda de información a partir de especies biológicas para su uso posterior en procesos de producción en diversos sectores. Ejemplos de esa información es la contenida en el material genético de todos los seres vivos, en los compuestos químicos que producen, en sus interacciones o en el conocimiento de las personas que de una manera u otra han estudiado a esos seres vivos. En este trabajo se presentan los resultados de la prospección botánica, química y microbiológica del bosque de galería del río Uruguay en la zona del rio Queguay, ecosistema con gran biodiversidad (comprende unas 200 especies) y de características poco comunes en el país dado su carácter subtropical. Se estudiaron 75 extractos provenientes de 31 especies pertenecientes a quince familias cubriendo de esa forma una gran biodiversidad.

Bioprospecting is the search for information from biological species for later use in production processes in various sectors. Examples of this information is contained in the genetic material of all living beings in the chemicals they produce, in their interactions or the knowledge of people who in one way or another, have studied these living beings. This paper presents the results of botanical, chemical and microbiological study of the gallery forest of the Uruguay River in the area of the Queguay river. This ecosystem presents great biodiversity (comprising about 200 species) and unusual features in the country given its subtropical character. We studied 75 extracts from 31 species belonging to fifteen families covering therefore a large biodiversity.

A bioprospecção é a bisca de informações a partir de espécies biológicas para seu uso posterior em processos de produção em diversos setores. Exemplos dessa informação está contida no material genético de todos os seres vivos, nas substâncias químicas que produzem, nas suas interações ou n o conhecimento das pessoas que, de uma maneira ou de outra, estudam os seres vivos. Neste trabalho é apresentado os resultados da prospecção botânica, química e microbiológica do bosque de galeria do Rio Uruguai na zona do Rio Queguay, ecosistema com grande biodiversidade, com cerca de duzentas espécies, e de características pouco comum no país dado seu caráter subtropical. Foram estudados 75 extratos provenientes de 31 espécies pertencentes a quinze famílias, cobrindo, assim, uma grande biodiversidade.