AUTHOR=Duraisamy Kalaiselvi , Yu Nan Hee , Kim Seon Hwa , Baek Jong Hwi , Son Ji Yeon , Choi Euna , Park Min Gu , Kim Jiwon , Choi Jae Young , Sang Mee Kyung , Je Yeon Ho , Kim Jin-Cheol 

TITLE=Development of a new broad-spectrum microencapsulation-based spray drying formulation of Bacillus thuringiensis subsp. kurstaki IMBL-B9 for the control of moths

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1273725

DOI=10.3389/fmicb.2023.1273725

ISSN=1664-302X

ABSTRACT=<p>Certain <italic>Bacillus thuringiensis</italic> (Bt) strains such as Bt subsp. <italic>kurstaki</italic> and Bt subsp. <italic>aizawai</italic> have been widely used for pest management in agricultural practices. However, each strain only shows high specificity for pest control against a narrow range of lepidopteran species, and numerous lepidopteran pests have developed resistance to commercialized Bt strains. Therefore, there is a need for the development of novel Bt bioinsecticides which allow for potent and broad-spectrum insecticidal activity against lepidopteran species, including <italic>Spodoptera</italic> spp. (Noctuidae) and <italic>Plutella xylostealla</italic> (Plutellidae). In order to develop a novel bioinsecticide using Bt subsp. <italic>kurstaki</italic> IMBL-B9 (Btk IMBL-B9) that exhibits excellent insecticidal activity against three different lepidopteran species, we have developed a viable microencapsulation-based spray drying Btk IMBL-B9 formulation. The spore-crystal complex of Btk IMBL-B9 was microencapsulated using coating materials such as gum arabic, maltodextrin, and corn starch via spray drying. The encapsulated formulation of Btk IMBL-B9 presented an increased survival rate and storage stability at 54 ± 2°C for up to 6 weeks. The formulation showed similar insecticidal activity as the commercial bioinsecticide XenTari<sup>®</sup> against <italic>P. xylostella</italic>. Under controlled greenhouse conditions, the Btk IMBL-B9 formulation was more effective against Lepidoptera spp. <italic>S. frugiperda</italic> and <italic>P. xylostella</italic>, than XenTari<sup>®</sup>. These results suggest that the microencapsulation-based spray drying formulation of Btk IMBL-B9 can be used effectively for the control of a wide range of moths.</p>