Exploring the production of bioactive cyanopeptides by isolated Dolichospermum, Raphidiopsis and Microcystis strains under varying light, temperature and pH conditions

• Grant number: 25/10635-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: July 01, 2025
• End date: May 31, 2027
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Mathias Ahii Chia
• Grantee: Elizabeth Abdulmalik
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 23/00798-4 - Elucidating and predicting the ecological roles of cyanopeptides in four Sao Paulo State Public water supply reservoirs, AP.JP

Abstract

Cyanobacteria such as Dolichospermum, Raphidiopsis, and Microcystis are prolific producers of cyanopeptides-bioactive secondary metabolites with diverse ecological functions and potential health risks. While microcystins have been extensively studied, the broader spectrum of cyanopeptides remains poorly understood, particularly in relation to environmental factors that influence their production. This study investigates the effects of varying pH levels, temperatures, and light conditions on cyanopeptide production by Brazilian strains of Dolichospermum, Raphidiopsis, and Microcystis cultured under laboratory conditions. Strains will be isolated, identified using morphological and molecular techniques, and grown in ASM-1 medium under controlled gradients of pH (5-10), temperature (23-30¿°C), and light (PAR and UV combinations). Cyanopeptides will be extracted using solvent and solid-phase methods and analyzed by LC-MS/MS to determine their profiles. The biological activities of crude and purified extracts will be assessed using protease inhibition, antimicrobial, and cytotoxicity assays. The study aims to expand understanding of environmental regulation of cyanopeptide biosynthesis and contribute to public health, biodiversity conservation, and water resource management in the context of global environmental change. (AU)