Bacillus thuringiensis as microbial biopesticide: uses and application for sustainable agriculture

Background: Bacillus thuringiensis (Bt) has been used in agriculture for a long time because of its insecticidal proteins which make it a valuable environment-friendly biopesticide. However, its use is not only limited to insecticidal properties. Current and previous studies indicate its potential as a biofertilizer for promoting plant growth, the development of transgenic plants, and others. It is the presence of δ-endotoxins, especially cry protein, which attributes the insecticidal property to the bacteria. Besides, there are some vegetative and secreted insecticidal proteins that exert their toxic activity towards specific species. Main body of abstract: The present review briefly provides an overview of the Bt uses and application as a biocontrol agent against insect pest for sustainable agriculture. Historical development of Bt as biocontrol, classification of various cry proteins, their mechanisms of actions against different insect-pest, and incorporation of cry genes in the plant for developing transgenic Bt plants such as Bt cotton, potato, and maize. Applications of Bt as biofertilizer and the various bioformulations as biopesticide are also described. Short conclusion: Uses of harmful pesticides and chemical cause various health issues and environmental problem; therefore, the Bt served as the best alternative to overcome the above issue. Also, we aim to explore the potential as plant growth-promoting potential and solubilization of minerals and the uses as a biofertilizer, keeping the high specificity and environmental safety of Bt. Its various formulations are commercially available and considered an efficient alternative to chemical pesticides.