Congresso Brasileiro de Microbiologia 2023

Congresso Brasileiro de Microbiologia 2023

Resumo: 1072-1

1072-1

ISOLATION AND CHARACTERIZATION OF A LYTIC BACTERIOPHAGE FOR PSEUDOMONAS SYRINGAE PV. GARCAE, THE CAUSAL AGENT OF COFFEE CANKER

Autores:

Luan Mota (PHAGELAB UNISO - PHAGELAB – BIOFILMS AND BACTERIOPHAGES LABORATORY UNISO) ; Bruna Guerrero (PHAGELAB UNISO - PHAGELAB – BIOFILMS AND BACTERIOPHAGES LABORATORY UNISO) ; Stephen Emencheta (UNN NSUKKA - DEPARTMENT OF PHARMACEUTICAL MICROBIOLOGY AND BIOTECHNOLOGY,, PHAGELAB UNISO - PHAGELAB – BIOFILMS AND BACTERIOPHAGES LABORATORY UNISO) ; Erica Silva (PHAGELAB UNISO - PHAGELAB – BIOFILMS AND BACTERIOPHAGES LABORATORY UNISO) ; Arthur Pereira (PHAGELAB UNISO - PHAGELAB – BIOFILMS AND BACTERIOPHAGES LABORATORY UNISO) ; Marta Vila (PHAGELAB UNISO - PHAGELAB – BIOFILMS AND BACTERIOPHAGES LABORATORY UNISO) ; Victor Balcão (PHAGELAB UNISO - PHAGELAB – BIOFILMS AND BACTERIOPHAGES LABORATORY UNISO, UNIVERSIDADE AVEIRO - DEPARTMENT OF BIOLOGY AND CESAM, UNIVERSITY OF AVEIRO)

Resumo:

ABSTRACT: Coffee is of great importance in the history of Brazil., both from an economic and social perspective. However, coffee farming faces constant threats due to the increasing resistance of phytopathogens. One of the main bacterial diseases that directly affect coffee plantations is caused by the bacterium Pseudomonas syringae pv. garcae (Psg), which causes coffee canker. This disease results in the appearance of aureole spots on the plants and, eventually, leads to plant death. The available treatments for this disease are scarce and usually involve the application of copper-based products, such as copper oxychloride and copper hydroxide. Therefore, it is essential to develop new approaches that allow the control of Psg to reduce the emergence of resistant bacteria and, at the same time, enable more sustainable agricultural production without the use of toxic substances for the environment. A promising approach for controlling this bacterium is the use of bacteriophages or phages, which are viruses that specifically infect target bacteria. Phages have proven to be a promising tool for the biocontrol of phytopathogenic diseases due to their targeted and sustainable approach. Thus, the objective of the research was to isolate and characterize a specific lytic bacteriophage to combat the phytopathogenic agent Pseudomonas syringae pv. garcae from coffee plants of the Catuai Vermelho variety. For this, the steps of enrichment, propagation and purification were followed. For the characterization it was determined: phage title; one-step curve; adsorption curve; abiotic factors (pH, temperature and solar radiation); and transmission electron microscopy (TEM). The isolated bacteriophage was named vB_PsgS_Uniso1F. The titre obtained was 1.60x10^13 plaque-forming units per milliliter (PFU/mL). The one-step curve showed a burst size (number of viral particles released per host cell) of 45.19 virions/host cell. The adsorption curve revealed that the bacteriophage had a phage particle adsorption rate of 5.00x10-10 PFU-1 CFU-1 mL-1 h-1, indicating the ability of the bacteriophage to bind and infect bacterial cells. During the abiotic factor assays, the vB_PsgS_Uniso1F phage remained stable and showed lytic activity in the vast majority of tests, an important factor to ensure the phage's effectiveness in different environmental conditions. Through transmission electron microscopy (TEM) it was possible to observe the morphology, and the phage considered belongs to the order Caudoviricetes and the family Siphoviridae. Based on the results obtained, the bacteriophage vB_PsgS_Uniso1F demonstrated high specific lytic activity against the phytopathogenic agent P. syringae pv. garcae, being promising for use in the biocontrol of coffee canker.

Palavras-chave:

Bacteriophage, Biological control, Coffee canker, Phytopathogens, Pseudomonas syringae pv. garcae

Agência de fomento:

Project funding by FAPESP (São Paulo, Brazil) (Refs. No. 2022/10775-9 (Project PsgPhageKill) and 2018/05522-9 (Project PsaPhageKill)), is hereby gratefully acknowledged. This work also received support from CNPq, (Ref. No. 301978/2022-0).