Banca de DEFESA: ADRIELY VITAL DE SOUZA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ADRIELY VITAL DE SOUZA SILVA
DATE: 09/09/2021
TIME: 14:00
LOCAL: Online, em link a ser enviado
TITLE:

Solubilization of inorganic phosphate by filamentous fungi isolated from lichens and sediment from Antarctica

KEY WORDS:

Extremophiles. Plant growth promoting fungi. Phosphate-solubilizing fungi.

PAGES: 75
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Fitossanidade
SPECIALTY: Microbiologia Agrícola
SUMMARY:

Antarctic shelter environments can different life forms adapted to physical conditions and extreme areas such as cold temperature, water availability, high UV radiation, strong winds, different pH and salinity ranges. Given this information, it is suspected that filamentous fungi adapted to such conditions develop the activity of solubilizing insoluble phosphate from the soil to release soluble phosphorus (P) and make it available to plants. In this context, the aim of this study was to isolate and identify new strains of filamentous fungi from lichens and sediments from Antarctica with the ability to solubilize inorganic phosphate. Lichens and sediments from Antarctica were collected during the OPERANTAR XXXVI expedition, in the austral summer of 2017/18. The 6 lichens of different colors were collected in King George Island - Punta Ullmann and Punta Hanequin, and the 4 from sediments collected in Deception Island, Whalers Bay, due to the South Shetlands (Maritime Antarctica). A collection of 82 fungal strains were selected and evaluated for an inorganic phosphate solubilization activity. Make the total of 82 fungi tested, 3 lichen and 8 sediment grant, dissipation activity for phosphate solubilization in solid NBRIP culture medium containing tricalcium phosphate (TCP) at 15 °C. 6 isolates were selected during screening in solid medium with larger solubilization halos and tested in temperature ranges, varying between 15.0, 25.0 and 30.0 °C. In solid medium, the fungi were able to solubilize in the three temperature ranges, with a solubilization index (IS) ranging from 1.4 to 3.63 mm subjected to a temperature of 15 °C, from 1.3 to 3.57 mm to 25 °C and from 1.3 to 1.4 mm at 30 °C. One of the largest IS was found in isolates 1EM.P1 at 15 °C and 5Y.P4 at 25 °C with 3.63 and 3.57 mm, respectively. In a liquid medium, the 1EM.P1 isolate was the only one to present significant values for solubilization, with an average release of soluble P of 106.14 mg/L-1 and with a pH reduction from 7.0 to 4.38 to 15 °C, and at 25 °C with soluble P release of 80.89 mg/L-1 and pH reduction from 7.0 to 5.40. For tests under stress conditions, the 1EM.P1 isolate showed better solubilization when subjected to 0.5 M NaCl. Regarding the pH variation, it showed greater release of soluble P at pH 8.0. As for the carbohydrate source, it presented better solubilization in the presence of glucose. The 1EM.P1 isolate, when subjected to different sources of inorganic phosphate, showed better solubilization in the presence of TCP, with a maximum peak in 15 days of incubation. In general, the results showed that Antarctic fungi are able to solubilize phosphate in solid medium, as well as through the release of soluble P in the liquid medium, especially those isolated from sediment.

BANKING MEMBERS:
Presidente - 1506475 - ALYSSON WAGNER FERNANDES DUARTE
Interna - 2187545 - FLAVIA DE BARROS PRADO MOURA
Interno - 2626313 - VALDEVAN ROSENDO DOS SANTOS
Externo à Instituição - MICHEL RODRIGO ZAMBRANO PASSARINI - UFPR