Identification and production of bacteriophage lytic enzymes that mimic the effect of ionophores for use in cattle

• Grant number: 24/22254-9
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2025
• End date: April 30, 2028
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Genetics and Improvement of Domestic Animals
• Principal Investigator: Heidge Fukumasu
• Grantee: Camila Aparecida Faleiros
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil

Abstract

The ruminal microbiota of cattle influences phenotypic traits such as feed efficiency and methane production, which are crucial aspects for sustainability and economics in livestock farming. Among the strategies used to achieve feed efficiency and reduce methane production, the use of ionophores stands out, which selectively modulate the ruminal microbiota; despite the effectiveness of this strategy, its use is restricted in some countries, which restricts the global market for beef produced in Brazil. This project aims to develop lytic enzymes encoded by bacteriophages of bacteria that are targets of ionophores and methanogens. To this end, the lytic enzymes will be identified in viral genomes available in databases and in results from previous studies carried out by the group. After identifying the sequences that encode the enzymes, cloning, expression and purification of the enzymes will be carried out. In vitro tests will be conducted to verify the lytic activity, as well as to establish the ideal conditions of temperature, pH and concentration of the enzymes. Subsequently, evaluations of the activity and effectiveness of the enzymes will be conducted under ex situ and in vivo conditions. These steps will allow the analysis of parameters associated with ruminal fermentation, such as fatty acid production, methane production, pH and the dynamics of bacterial populations. In addition, it will be possible to associate these parameters with phenotypes including weight gain, conversion and feed efficiency. It is expected that the lytic enzymes developed in this study can be used as feed additives for cattle, mimicking the effect of ionophores in the rumen and expanding opportunities for the Brazilian meat market. (AU)