Daldinia eschscholtzii (Ascomycota, Xylariaceae) isolated from the Brazilian Amazon: taxonomic features and mycelial growth conditions

Abstract

The Amazon has a high diversity of fungi, including species of the genus Daldinia (Ascomycota, Xylariaceae), which produce secondary metabolites with recognized nematicidal and antimicrobial activity. The ecological role of Daldinia is important, as stromata serve as refuges to many insects and arthropodes, and the fungi contribute to the degradation of vegetable organic matter. The aim of this study was to analyze the taxonomic features and mycelial growth conditions in vitro of a Daldinia specimen collected in the Brazilian Amazon. Morphological and molecular studies of the fungus identified it as D. eschscholtzii. To evaluate mycelial growth, we cultivated the fungus at 20, 25, 30, 35, and 40 ºC in malt extract-peptone agar (MEPA), malt extract-peptone (MEP), potato dextrose (PD), and minimum medium (MM). The best mycelial growth occurred at 35 ºC, although the greatest amount of biomass was obtained at 25 ºC and 30 ºC. PD proved to be the best medium for biomass production. KEYWORDS: Daldinia eschscholzii, fungal diversity, macrofungus, occurrence. Daldinia eschscholzii (Ascomycota, Xylariaceae) isolado na Amazônia brasileira: características taxonômicas e condições de crescimento micelial RESUMOA Amazônia apresenta alta diversidade de fungos, incluindo Daldinia (Ascomycota, Xylariaceae), cujas espécies produzem metabólitos secundários com reconhecida atividade antimicrobiana e nematicida. O papel ecológico é importante, visto que estromas servem de abrigo para muitos insetos e artrópodes, além de contribuir na degradação da matéria orgânica vegetal. O objetivo desse estudo foi analizar as características taxonômicas e as condições do crescimento micelial in vitro de um espécime de Daldinia coletado na Amazônia brasileira. Estudos morfológicos e moleculares do fungo o indetificaram como D. eschscholtzii. Para avaliação do crescimento micelial o fungo foi cultivado nas temperaturas de 20, 25, 30, 35 e 40 ºC e nos meios de cultura extrato de malte-peptona ágar (EMPA), extrato de malte-peptona (EMP), batata dextrose (BD) e meio mínimo (MM). O melhor crescimento micelial ocorreu a 35 ºC, entretanto, a maior quantidade de biomassa foi obtida a 25 e 30 ºC. O meio BD provou ser o melhor meio para produção de biomassa.

Identification and characterization ofDaldinia eschscholtziiisolated from skin scrapings, nails, and blood

“…Thus, PCR-based ITS sequence analysis has been widely used to identify D. eschscholtzii (Chan et al, 2015; Hu et al, 2014; Tarman et al, 2012; Yuyama et al, 2013). Despite recent studies reporting limitations of the ITS region in distinguishing between the species complexes of Daldinia spp., this region has the broadest taxa covered in Daldinia (Stadler et al, 2014).…”

Peer Review #1 of "Identification and characterization of Daldinia eschscholtzii isolated from skin scrapings, nails, and blood (v0.2)"

“…ITS region of the nuclear rDNA can be used to examine species level relationship in fungi due to its higher degree of variation. Thus, PCR-based ITS sequence analysis has been widely used to identify D. eschscholtzii (Chan et al 2015, Hu et al 2014, Tarman et al 2012, Yuyama et al 2013. Despite recent studies reporting limitations of the ITS region in distinguishing between the species complexes of Daldinia spp., this region has the broadest taxa covered in Daldinia (Stadler et al 2014).…”

Molecular characterization of endophytic fungi-Daldinia eschscholtzii from Aloe vera plants in Bangladesh

“…The first significant addition to the Daldinia taxonomy that included molecular data was made by Johannesson et al (2000) who surveyed the genus across northern Europe and eastern Russia and described a preliminary phylogeny based on ITS sequencing of rDNA for a number of wellcharacterized specimens. Later, ITS sequence analysis was used extensively to identify D. eschscholtzii (Tarman et al, 2012;Yuyama et al, 2013;Hu et al, 2014;Chan et al, 2015). Chutulo & Chalannavar (2020) used molecular techniques based on ITS rDNA sequences to identify the endophyte fungus D. eschscholtzii from Psidium guajava.…”