New sources of phytosanitary products from extracts of the algae Kappaphycus alvarezii for use in organic farming.

• Grant number: 25/13798-8
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: October 01, 2025
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Biology
• Principal Investigator: Regildo Márcio Gonçalves da Silva
• Grantee: Felipe Augusto Rigonatto Brandão
• Supervisor: Francisco A. Macias
• Host Institution: Faculdade de Ciências e Letras (FCL-ASSIS). Universidade Estadual Paulista (UNESP). Campus de Assis. Assis , SP, Brazil
• Institution abroad: Universidad de Cádiz, Puerto Real (UCA), Spain
• Associated to the scholarship: 24/21128-0 - Green biosynthesis of metal nanoparticles using Kappaphycus alvarezii biomass extract as a bioreductant and subsequent fungicidal evaluation on Fusarium sp., BP.IC

Abstract

This research project proposes the study of the red macroalga Kappaphycus alvarezii as a source of bioactive compounds with potential application in organic agriculture. In response to the growing demand for natural and sustainable crop protection agents, the study aims to investigate the physiological effects of aqueous extracts and metal nanoparticles synthesized from this alga on seeds and seedlings of various plant species. Besides its well-known use in carrageenan production, K. alvarezii contains secondary metabolites such as terpenoids, flavonoids, alkaloids, and phytosterols, which exhibit promising allelopathic and physiological activities. The proposal includes the preparation of aqueous extracts and the green synthesis of nanoparticles using metal salts such as silver nitrate. Physiological activity will be assessed through bioassays on seeds of weed species (including Lolium rigidum, Portulaca oleracea, and Plantago lanceolata), measuring their effects on germination and root growth. The project will be carried out at the Allelopathy Research Group of the University of Cádiz (Spain), with support from FAPESP through a BEPE fellowship. This initiative aims to generate new knowledge on allelopathic interactions among plant species and expand the potential use of natural compounds and nanomaterials in sustainable agriculture. The results are expected to be transferable to companies interested in developing plant-based bioproducts, directly benefiting the organic farming sector and promoting environmentally responsible practices. (AU)