Bt Research 2024, Vol.15, No.3, 154-163 http://microbescipublisher.com/index.php/bt 160 7.3 Evolutionary implications The evolutionary implications of Bt's genomic variability are profound, influencing its adaptability, host range, and biocontrol efficacy. The coevolution of Bt with its hosts, such as Caenorhabditis elegans, has been shown to favor high virulence, with specific cry toxin genes sweeping to fixation in coevolving populations (Hollensteiner, 2017). This adaptive evolution is facilitated by the presence of mobile genetic elements and the ability to acquire new genetic material through horizontal gene transfer. Additionally, the genetic diversity among Bt strains allows for the development of specialized biocontrol agents with tailored properties for different agricultural applications. For example, the genomic analysis of Bt strain MORWBS1.1 has identified genes for the biosynthesis of biopesticidal metabolites, highlighting its potential as a candidate biocontrol agent (Adeniji et al., 2021). Overall, the genomic architecture of Bt underscores its evolutionary potential and versatility as a biocontrol organism. 8 Biotechnological Applications 8.1 Use in biopesticides Bacillus thuringiensis (Bt) is widely recognized for its use as a biopesticide due to its ability to produce insecticidal crystal proteins (ICPs) that are toxic to a variety of insect pests. The genomic exploration of various Bt strains has revealed a plethora of pesticidal protein genes that contribute to its effectiveness as a biopesticide. For instance, the complete genome sequencing of Bt strain GR007 identified multiple pesticidal protein genes, including 10 cry genes and two vip genes, which are crucial for its toxicity against Spodoptera frugiperda and Manduca sexta larvae (Pacheco et al., 2021). Similarly, the genome of Bt serovar galleriae strain HD-29 harbors ten plasmids, with three large ones carrying eight insecticidal protein genes, making it highly toxic to Lepidoptera insect pests (Zhu et al., 2015). The novel Bt strain BLB406, with its unique combination of cry and vip genes, also shows potential as a bioinsecticide against Aedes aegypti larvae (Zghal et al., 2018). These findings underscore the significant role of Bt in sustainable pest management and its widespread use in agriculture (Gutiérrez et al., 2019; Lechuga et al., 2020a). 8.2 Genetic engineering for enhanced traits Genetic engineering has been employed to enhance the traits of Bt strains, making them more effective and versatile in pest control. The genomic characterization of Bt strains has facilitated the identification and cloning of specific pesticidal protein genes for targeted expression. For example, the proteomic analysis of Bt GR007 revealed the expression of seven Cry proteins, each displaying differential toxicity against specific insect larvae (Pacheco et al., 2021). Additionally, the complete genome sequence of Bt HER1410 highlighted the presence of a unique cry gene located in a genomic island near the chromosome replication origin, which could be exploited for genetic engineering purposes (Lechuga et al., 2020b). Comparative genomic and proteomic analyses have also provided insights into the expression patterns of various insecticidal proteins, enabling the construction of highly virulent engineered bacteria (Rang et al., 2015). These advancements in genetic engineering hold promise for developing Bt strains with enhanced pesticidal properties and broader insecticidal spectra (Lechuga et al., 2020b). 8.3 Potential for industrial applications Beyond its use in biopesticides, Bt has potential applications in various industrial sectors. The production of antimicrobial compounds by Bt strains, such as zwittermicin A, has been documented, indicating its potential use in the pharmaceutical industry (Adeniji et al., 2021). The complete genome sequence of Bt YBT-1518, which displays effective toxicity to nematodes, suggests its application in controlling nematode infestations in agriculture (Wang et al., 2014). Furthermore, the novel Bt strain YC-10, with its high toxicity to plant-parasitic nematodes, could be utilized in developing biocontrol agents for nematode management (Cheng et al., 2015). The unique combination of toxins in Bt strains, such as those found in BLB406, also points to potential anti-cancer activities, opening avenues for biomedical applications (Zghal et al., 2018). These diverse biotechnological applications of Bt highlight its versatility and potential for contributing to various industrial processes (Gutiérrez et al., 2019). 9 Concluding Remarks The genomic architecture of Bacillus thuringiensis (Bt) has been extensively studied, revealing significant insights into its functional elements. Key findings include the identification of genes responsible for the biosynthesis of
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