Bioprospecção de microrganismos autóctones e diversidade microbiana em solo cultivado com cana-de-açúcar e avaliação do seu potencial de biodegradação de tebuthiuron

• Grant number: 21/06952-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2021
• End date: June 07, 2023
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Paulo Renato Matos Lopes
• Grantee: Letícia Barbosa Jorososki
• Host Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil

Abstract

Brazil has an outstanding participation in the world production of sugarcan, and tebuthiuron is widely used in sugarcane fields to control weeds. However, due to its continuous use, high persistence and high toxicity, this herbicide has great potential to cause environmental damage. Thus, this study proposes to isolate and identify microorganisms with potential for biodegradation of tebuthiuron in sugarcane soils with a history of this herbicide application. Soil samples will be collected in a conventional sugarcane crop with tebuthiuron use. Bioprospecting of microbial strains will be performed in a mineral medium containing the herbicide molecule as carbon source in a rotating system for 12 days in continuous cultivation. Subsequently, isolates will be cultivated in a culture medium using the streak depletion technique and then cold stored for further morphological analysis and molecular identification. The evaluation of tebuthiuron biodegradation potential by microbial strains will be based on colorimetric assays using the redox indicator 2,6-dichlorophenol-indophenol - DCPIP. Two forms of analysis will be proposed: qualitative by photographic record and quantitative by UV-Vis spectrophotometry. These results will be expressed by the indicator discoloration time and thus statistically analyzed. The molecular identification of isolates and the soil microbial diversity analysis are associated with a BEPE request for a scientific exchange at "The University of Texas Rio Grande Valley - UTRGV", USA. (AU)