Exploration of Bacillus thuringiensis Berl. from soil and screening test its toxicity on insects of Lepidoptera order

Abstract

Abstract.Bacillus thuringiensis is a gram-positive bacterium that produces crystal proteins toxic (ᴕ-endotoxin) specific to the target insect, but is not toxic to humans and non-target organisms. This study aims to explore the origin of the soil bacterium B. thuringiensis subdistrict Sekayu, Banyuasin, South Sumatra and toxicity to larvae of lepidoptera. Fifty soil samples were taken from Musi Banyuasin District, namely 15 from Kayuare strip 2, 20 from Kayuare and 15 from Lumpatan. Isolation, characterization, identification and screening test were conducted in the laboratorium of Pest and Disease, Agricultural Faculty, Sriwijaya University. Isolat codes were given based on the area origin of the samples. Results of the study showed that from 50 isolates of bacteria that had been isolated, there were 15 bacterial isolates, characterized by morphology and physiology the same as B. thuringiensis, which has round colonies, white, wrinkled edges, slippery, elevation arise, aerobic and gram-positive. Of the 15 codes that contain positive isolates of B. thuringiensis, we have obtained several isolates of the following codes: KJ

Insecticidal, genotoxic and biochemical effects of Shewanella sp. (SS4) and Thauera sp. (M9) on Spodoptera litura

“…and Thauera sp., stopped feeding, turned black and became sluggish before death. Similar symptoms have earlier been reported in P. xylostella and S. litura larvae due to infection of B. thuringiensis , Lysinibacillus sphaericus , Klebsiella pneumonia and Pseudomonas paralactis (Astuti et al, 2018; Bravo et al, 2017; Devi et al, 2022). Pathogenicity of Shewanella sp.…”

“…and Thauera sp., stopped feeding, turned black and became sluggish before death. Similar symptoms have earlier been reported in P. xylostella and S. litura larvae due to infection of B. thuringiensis, Lysinibacillus sphaericus, Klebsiella pneumonia and Pseudomonas paralactis (Astuti et al, 2018;Bravo et al, 2017;Devi et al, 2022) Andrejko & Mizerska-Dudka, 2012;Maciel-Vergara et al, 2018;Matsumoto, 2004;Ng et al, 2015;OztasGulmus & Gormez, 2020;Tarhriz et al, 2011;Vallet-Gely et al, 2008). These hydrolytic enzymes are known to aid in disrupting the cuticle, peritrophic matrix and hydrolyzing their lipoproteins, fats and other molecules present in the integument, causing its degradation (Lopes et al, 2021).…”

Short Communication: Biological control agent for Spodoptera litura on vegetable plants

“…The protein toxin attached to the receptor protein located on the surface of epithelial cells of the intestine destroys the structure and function of epithelial cells in the insect's digestive tract, resulting in lysis and decreased appetite, and insect death (Schünemann et al 2014). Bacillus thuringiensis at a density of 106/mL spore density can result in high mortality on target insects because B. thuringiensis has high virulence (Afriani et al 2017;Astuti 2017;Ghazwan et al 2017;Pujiastuti et al 2018;Sayid et al 2020). The results of the deadline of insect mortality (LT50) applied by bacterial isolates of B. thuringiensis showed that the ability to kill insects of each isolate tested varied between an average of 2.94 to 7.43 days.…”