Banca de QUALIFICAÇÃO: ALDECI FRANCA ARAUJO DOS SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ALDECI FRANCA ARAUJO DOS SANTOS
DATE: 26/05/2022
TIME: 14:00
LOCAL: ICBS/UFAL
TITLE:

The sea distance effect: How does proximity to the sea affect the yeasts community from mangrove sediments?

KEY WORDS:

Ascomycota, new species, molecular taxonomy, fungi, mangroves.

PAGES: 27
BIG AREA: Ciências Biológicas
AREA: Microbiologia
SUBÁREA: Biologia e Fisiologia dos Microorganismos
SPECIALTY: Micologia
SUMMARY:

Mangroves are unique environments with particular physical and chemical characteristics responsible for maintaining and subsidizing a complex diversity of macro and microorganisms. Salinity variation acts as a determining environmental bottleneck in microbial diversity. However, the influences on yeast communities and the phylogenetic rearrangements along a longitudinal gradient of this ecotope are poorly understood. This work aimed to study the diversity of yeasts associated with mangrove sediments in northeastern Brazil. In Santo Antônio River, we carried out four collections and sampled three different points, starting from a spot closer to the interface between freshwater and seawater and moving towards a point further into the river, to evaluate how the yeast community is influenced by the longitudinal gradient and the biotic and abiotic factors, and in each location two samples were collected, totaling 24 samples. A total of 132 isolated were identified by sequencing of the D1/D2 region of the LSU rDNA gene. Sequence analyzes and identification revealed 32 species, which 68.8% belong to the phylum Ascomycota and 31.2% to the phylum Basidiomycota, associated with 18 genera. Most species (53.1%) were singletons (species with a single occurrence record). The prevalence of Candida tropicalis and Pichia pseudolambica species, both already known as cosmopolitan species, are generally associated with human samples. Among the isolates, we report the presence of a possible new species belonging to the genus Barnettozyma, besides the presence of two recently isolated species from leaves and zoanthids, contributing new information on the habitats of these species. Yeast communities associated with mangrove sediment showed high homogeneity in the sampled locations, as seven species occurred in all sampled locations. Yeast communities showed high homogeneity at the sampled sites. The beta diversity metrics did not diverge significantly between the points. The alpha diversity indicators varied between the sites, as also both taxonomic diversity and richness (p=0.0096), Shannon index (p=0.05), and dominance (p=0.05), as well as phylogenetic diversity indicators, AvTD (p=0.04) and TTD (p=0.02). In addition, observed abundance also increased as the sampling point moved away from the sea (p=0.05). Our results highlight a longitudinal salinity gradient compositional stability of yeast species between sampled sites and gradual patterns, where alpha diversity decreases as the collection site approaches the sea, causing the sea to act as an environmental bottleneck for the species.

BANKING MEMBERS:
Presidente - 2024367 - MELISSA FONTES LANDELL
Interno - 1916144 - GILBERTO COSTA JUSTINO
Externa à Instituição - VANIA MARIA MACIEL MELO - UFC
Externa à Instituição - PATRICIA VALENTE - UFRGS