Biological characteristics of Bacillus thuringiensis strain Bt11 and identification of its cry-type genes

Abstract

A novel strain of Bacillus thuringiensis Bt11, isolated from soil samples in China, was classified and characterized in terms of its crystal proteins, cry genes content. The Bt11 strain showed high toxicity against Spodoptera exigua and Helicoverpa armigera neonates. Bt11 strain shares morphological and biochemical characteristics with the previously described Bacillus thuringiensis subsp. kurstaki. SDS-polyacrylamide gel electrophoresis revealed that crystals were composed of several polypeptides ranging from 20 to 130 kDa, of which the 35, 80, and 130 kDa proteins were the major components. PCR-RFLP with total DNA from strain Bt11 and specific primers for cry1, cry2, cry3, cry4/10, cry7, cry8, cry9, and cry11 genes revealed that cry1Aa, cry1Ab, cry1Ia, and cry9Ea genes were present.

Molecular characterization of indigenous Bacillus thuringiensis strains isolated from Kashmir valley

“…In this study, we tested the susceptibility of our Bt strains towards Spodoptera litura using an artificial diet. Modified diet overlay assay method was used by Liu et al (2009) to test the susceptibility of Helicoverpa armigera and Spodoptera exigua neonates to Bt11 and showed 100% mortality of these two pests at the concentration of 5.9 9 10 7 spores/ml. Thaphan et al (2008) screened toxicities of various Bt strains primarily on second-instar larvae of Plutella xylostella and on neonate larvae of Spodoptera litura and S. exigua with highly concentrated spore-crystal suspension and observed mortality after 3 days.…”

Identificação e caracterização de genes vip e cry coleóptero‑específicos em isolados de Bacillus thuringiensis

“…Embora seja uma técnica importante para avaliar a composição gênica de coleções de B. thuringiensis e para prever toxicidade (Thuler et al, 2007;Costa et al, 2010), a PCR permite apenas a identificação da classe do gene amplificado e não da subclasse a qual o gene em estudo pertence. Portanto, a técnica de PCR-RFLP vem sendo utilizada para auxiliar na detecção e na caracterização de diferentes subclasses de genes cry e vip (Beard et al, 2008;Liu et al, 2009;Hernández-Rodríguez et al, 2009). Contudo, essa técnica não permite diferenciar genes intimamente relacionados, com perfis semelhantes (Hernández-Rodríguez et al, 2009).…”

“…A PCR também tem sido utilizada em combinação com a técnica de polimorfismo de comprimento dos fragmentos de restrição (RFLP), na qual o produto de amplificação é clivado com enzimas de restrição e o padrão de bandas obtido em géis determina os tipos de genes cry e vip presentes nos isolados bacterianos, dentro de uma mesma classe, o que também pode indicar a presença de novos genes (diferentes alelos) (Sauka et al, 2006;Liu et al, 2009).…”

Draft Genome Sequence of Bacillus thuringiensis var. thuringiensis Strain T01-328, a Brazilian Isolate That Produces a Soluble Pesticide Protein, Cry1Ia

“…These parasporal bodies harbor the crystal (Cry) protein, which acts as a defense system against pests that cause enormous losses in crop production (2). At the same time, this bacterium has an array of other genetic information which codes for vegetative insecticidal proteins, which control pests in a different fashion (3).…”