| Congresso Brasileiro de Microbiologia 2023 | Resumo: 340-1 | ||||
Resumo:ABSTRACT
Actinomycetota are known for their ability to produce antibiotics and bioactive compounds. In addition to these products with biotechnological potential, actinomycetota are becoming increasingly important in plant growth promoting (PGP) and biological control of diseases. Target spot disease, caused by Corynespora cassiicola, is a common fungal disease in soybean
that can affect yield throughout the cycle and result in significant economic losses. Harnessing
the potential of microorganisms is an attractive and sustainable alternative to the use of
chemical products, which can be harmful to human health and the environment. Therefore, the
objective of this study was to evaluate the potential of the isolate Kribbella sp. from the soil for
PGP and the ability to control C. cassiicola through the production of volatile organic
compounds (VOCs). Specifically, the following parameters were evaluated for PGP traits:
nitrogen fixation, indole-3-acetic acid (IAA) production, ammonia production, phosphate
solubilization, and siderophore production. Different specific growth media were employed for
each PGP indicator, and positive results were qualitatively assessed by observing distinct
characteristics. For some indicators, the color changes of the growth medium after bacterial
culturing were examined, while for others, the formation of halos around bacterial colonies
indicated positive results. The antagonistic effect of VOCs was evaluated using the sealed plate
method. Kribbella sp. showed positive results in all tests, nitrogen fixation, IAA, phosphate
solubilization, ammonia and siderophore production, demonstrating the potential of this
bacterium to promote growth by several mechanisms. Ammonia production plays a key role in
stimulating root and shoot growth, contributing to an overall increase in plant biomass. This
essential compound can be sourced through various means, one of which involves the
conversion of atmospheric nitrogen via the process of nitrogen fixation. The synthesis of IAA
helps increase cellular differentiation as it is an auxin-class phytohormone that controls several
processes of vegetative growth, including xylem and root development. In addition, the strain
also showed potential for phosphate solubilization, which can help make this mineral available
to the plant, providing an alternative to chemical fertilizers. Kribbella sp. demonstrated
remarkable siderophore production capability, enabling it to effectively sequester iron from the
surrounding environment. This mechanism plays a pivotal role in enhancing iron bioavailability
for plants and serves as a potent tool for biological control against phytopathogens. The
percentage of inhibition of fungal growth by VOCs was 77.42%, demonstrating the potential of
Kribbella sp. for biological control of the target spot. In general, actinomycetota members have
great potential to produce VOCs, most of which are derived from terpenoids that possess
antifungal properties and biological control efficacy. The results demonstrated that Kribbella
sp. has great potential for PGP and biological control of C. cassiicola through the production
of volatile compounds. Future work aims at optimizing the results obtained through in vivo tests
in a greenhouse. Palavras-chave: Actinobacteria, PGP, volatile organic compound, target spot Agência de fomento:CNPq, CAPES, Fapemig | |||||