Can (We Make) Bacillus thuringiensis Crystallize More Than Its Toxins?

Abstract

The development of finely tuned and reliable crystallization processes to obtain crystalline formulations of proteins has received growing interest from different scientific fields, including toxinology and structural biology, as well as from industry, notably for biotechnological and medical applications. As a natural crystal-making bacterium, Bacillus thuringiensis (Bt) has evolved through millions of years to produce hundreds of highly structurally diverse pesticidal proteins as micrometer-sized crystals. The long-term stability of Bt protein crystals in aqueous environments and their specific and controlled dissolution are characteristics that are particularly sought after. In this article, I explore whether the crystallization machinery of Bt can be hijacked as a means to produce (micro)crystalline formulations of proteins for three different applications: (i) to develop new bioinsecticidal formulations based on rationally improved crystalline toxins, (ii) to functionalize crystals with specific characteristics for biotechnological and medical applications, and (iii) to produce microcrystals of custom proteins for structural biology. By developing the needs of these different fields to figure out if and how Bt could meet each specific requirement, I discuss the already published and/or patented attempts and provide guidelines for future investigations in some underexplored yet promising domains.

Sporulation, Structure Assembly, and Germination in the Soil Bacterium Bacillus thuringiensis: Survival and Success in the Environment and the Insect Host

“…Another examples of this is the B. thuringiensis strains GBA46 and NMTD81, and the strain FZB42, Of toxic against the phytopathogen Aphelenchoides besseyi and cause severe damage to various crops of plants and vegetables [37,71,239]. Of relevance is that the progress and the development of novel and improved biological technologies for the bioremediation of heavy metals and other pollutants [249,250], B. thuringiensis is a model for hijacking the process of the synthesis of crystal proteins in order to generate diverse proteins with applications in biotechnology and medicine (nanoparticle delivery system) [251]. B. thuringiensis is a potential and suitable cell factory for different novel, valuable bioproducts [249][250][251].…”