Bacillus thuringiensis (Bt)

Santos, S. R. N., Soares-da-Silva, J., Oda-Souza, M., Souza, H. A. & Pinheiro, V. C. S., 2022, Relations between soil attributes and the abundance of Bacillus thurigiensis in the Cerrado of Maranhão state, Brazil, Brazilian Journal of Biology (e 261840) 82, pp. 1-9 : 1-2

Bacillus thuringiensis (Bt) is a ubiquitous, gram-

positive, spore-forming bacterium, which has one or more insecticidal proteins used to control insect pests of the orders Lepidoptera, Diptera , and Coleoptera ( Jouzani et al., 2017; Rabinovitch et al., 2017). Early research on the ecology of this bacterium worked with the hypothesis that Bacillus thuringiensis had its natural habitat within certain insect species ( Prasertphon et al., 1973; Suzuki et al., 2004).

Soil is still noted today as one of the environments in which there is the greatest amount of Bt spores ( Dagga et al., 2016; Khodyrev et al., 2020). This environment has the ability to provide microhabitats that vary in their nutrient availability, in their physicochemical characteristics, in the characteristics of soil aggregates (Moreira and Siqueira, 2006), in intraspecific,interspecific interactions, and among the abiotic factors of the external environment and the soil itself ( Cotta, 2016; Fierer, 2017; Rahman et al., 2024).

The classic article byBernhard et al. (1997) that analyzed 2363 soils from 80 countries showed the local and world variation in the population density of Bt. Bt is known to easily adapt to the conditions of a number of different soils ( Mishra et al., 2017), which can only support a minimal amount for each bacterial population due to the limited nutritional resources that each microhabitat provides.

However, the influence of these factors on the abundance of soil microorganism populations is poorly known, in part because most microbes and their interactions cannot be directly observed or measured ( Karimi et al., 2019). However, new Bacillus thuringiensis strains with high toxicity rate to A. aegypti have been found in Atlantic Forest soils ( Santos et al., 2012). Similarly, other authors have collected them in Cerrado, Amazon and Caatinga soils ( Soares-da-Silva et al., 2015), in restinga and mangrove soils (Vieira-Neta et al., 2021) and continue to raise questions about the characteristics and the influence of abiotic factors of the environment and the soil in obtaining Bacillus thuringiensis isolates.

Thus, the objective was to analyze the relationship between the chemical and textural characteristics of soil from areas of native Cerrado forest on the abundance of Bacillus thuringiensis .