Cloning and expression of Bacillus thuringiensis cry11 crystal protein gene in Escherichia coli

Effect of probiotics on hematological parameters of male and female Wistar rats

In the present study, the effect of probiotics on the hematology of Wistar rats was examined. Locally isolated Lactobacillus plantarum MZ707748 (Pro 1), L. plantarum MZ710117 (Pro 2), Weisella confusa MZ727611 (Pro 3), and L. plantarum MZ735961 (Pro 4) were used. One strain of probiotic, L. acidophilus-14 (Pro 5), was purchased commercially. Different groups were designed as G1, G2, G3, G4, and 5, G5/PC consisting only pro 5 and NC & 0 day were untreated. Different groups have different probiotics like G1 containing Pro 1 and Pro 2, G2 comprising Pro 3 and Pro 4, G3 containing Pro 2, Pro 3 and Pro 5, G4 having Pro 1-5, and G5 containing Pro 5. A complete count of blood, serum chemistry, fecal analysis, and histopathological examination of the thymus and liver were done. Statistical differences were seen in the complete blood count parameters (p < 0.05). No difference was observed in AST, ALT, bilirubin, albumin, IL-6, and IgA (p > 0.05) except for TP, creatinine, and globulin (p < 0.05). Fecal strains of probiotic groups were antibiotic-resistant. In males, Lactobacillus helveticus OQ152020, Enterococcus lactis OQ1519891, E. faecium OQ152017, L. gasseri OQ152017, and E. lactis OQ152019 were isolated from positive control, G1, G2, G3, and G4 respectively. In females, Enterococcus sp. OP800231, Limosilactobacillus fermentum OQ151985, E. lactis OP800267, L. plantarum OP800244, and E. faecium OQ151988 were isolated from positive control, G1, G2, G3 and G4, respectively. It was concluded that all probiotic strains were safe to use and had beneficial effects on the hematology of Wistar rats.

Biotoxicity comparison of Bacillus thuringiensis to control vector borne diseases against mosquito fauna

The current study was designed to evaluate the biotoxicity of screened echo-friendly Bacillus thuringiensis strains from different areas of Pakistan. Out of 50 samples, 36% Bt. isolates were quarantined from soil containing cattle waste after morphological, biochemical, and molecular characterization. The toxicity bioassays with Bt. spores and protein diet proved that 11 Bt. isolates were utmost noxious to 3rd instar larvae of mosquitoes Aedes aegypti, Anopheles stephensi, and Culex pipiens. The entopathogenic activity of first 4 Bt. toxins against A. aegypti was highly lethal as compared to the other dipteran larvae. The toxicity (LC₅₀) of spore diet of Bt. strains GCU-DAB-NF4 (442.730 ± 0.38 μg/ml), NF6 (460.845 ± 0.29 μg/ml), NF3 (470.129 ± 0.28 μg/ml), and NF7 (493.637 ± 0.70 μg/ml) was quite high against A. aegypti as compared to the C. pipiens after 24 h of incubation. The highest toxicity of total cell protein was shown by GCU-DAB-NF4 (LC₅₀ = 84.10 ± 50 μg/ml), NF6 (95.122 ± 0.40 μg/ml), NF3 (100.715 ± 06 μg/ml), and NF5 (103.40 ± 07 μg/ml) against A. aegypti after 24 h. So, these strains a have great potential to be used as biological control especially against A. aegypti as compared to the C. pipiens.

Biotoxicity assessment of cloned cry 11 protein gene from Bacillus thuringiensis 9NF

The current investigation describes the isolation and characterization of toxic Bt. local isolates harboring 99% homology with Bti. prototoxin Bacillus thuringiensis (AXJ97553.1 and novel OUB27301.1) which contains full length cry11 gene (1.9 kb). Initially, it was cloned in pTZ57R/T and then sub-cloned in pET30a(+) for expression. The optimized conditions for good expression were found 1 mM IPTG, 3.5–4 h incubation time, and 37 °C. Toxicological assays were determined against 3rd instar larvae of Aedes aegypti with expressed partially purified and crude recombinant protein using recombinant E. coli BL21, DE3 transformed with cry11 gene. It was found that partially purified Bt. protein is highly toxic against A. aegypti larvae with LC₅₀ value of 42.883 ± 6 µg/ml. B. thuringiensis strains producing Cry 11 toxic protein can be used as biopesticide to control resistance in insects.

Potential for Bacillus thuringiensis and Other Bacterial Toxins as Biological Control Agents to Combat Dipteran Pests of Medical and Agronomic Importance

The control of dipteran pests is highly relevant to humans due to their involvement in the transmission of serious diseases including malaria, dengue fever, Chikungunya, yellow fever, zika, and filariasis; as well as their agronomic impact on numerous crops. Many bacteria are able to produce proteins that are active against insect species. These bacteria include Bacillus thuringiensis, the most widely-studied pesticidal bacterium, which synthesizes proteins that accumulate in crystals with insecticidal properties and which has been widely used in the biological control of insects from different orders, including Lepidoptera, Coleoptera, and Diptera. In this review, we summarize all the bacterial proteins, from B. thuringiensis and other entomopathogenic bacteria, which have described insecticidal activity against dipteran pests, including species of medical and agronomic importance.

Production and characterization of the 13 C/15 N single-labeled insecticidal protein Cry1Ab/Ac using recombinant Escherichia coli

Synthetic Cry1Ab/Ac proteins expressed by genetically modified (GM) crops have a high potential to control insect pests without utilizing large amounts of chemical insecticides. Before these crops are used in agriculture, the environmental fate and interactions in the soil must be understood. Stable isotope-labeled Cry1Ab/Ac protein is a highly useful tool for collecting such data. We developed a protocol to produce ¹³ C/¹⁵ N single-labeled Cry proteins. The artificially synthesized gene Cry1Ab/Ac of Bt rice Huahui No. 1, which has been certified by the Chinese government to be safe for human consumption, was subcloned into pUC57, and the expression vector pET-28a-CryAb/Ac was constructed and transformed into Escherichia coli BL21 (DE3) competent cells. Next, 0.2 mM isopropyl thiogalactoside (IPTG) was added to these cells and cultured at 37°C for 4 h to induce the synthesis and formation of inclusion bodies in M9 growth media containing either [U-¹³ C] glucose (5% ¹³ C-enriched) or [¹⁵ N] ammonium chloride (5% ¹⁵ N-enriched). Then, Cry inclusion bodies were dissolved in urea and purified by affinity chromatography under denaturing conditions, renatured by dialysis, and further detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. The purities of ¹³ C/¹⁵ N-labeled Cry proteins reached 99% with amounts of 12.6 mg/L and 8.8 mg/L, respectively. The δ ¹³ C and ä ¹⁵ N values of ¹³ C-labeled Cry protein and ¹⁵ N-labeled Cry protein were 3,269‰ and 2,854‰, respectively. A bioassay test revealed that the labeled Cry1Ab/Ac proteins had strong insecticidal activity. The stable isotope-labeled insecticidal Cry proteins produced for the first time in this study will provide an experimental basis for future metabolic studies on Cry proteins in soil and the characteristics of nitrogen (N) and carbon (C) transformations. Our findings may also be employed as a reference for elucidating the environmental behavior and ecological effects of BT plants and expressed products.

Transgenic tetraploid Isatis indigotica expressing Bt Cry1Ac and Pinellia ternata agglutinin showed enhanced resistance to moths and aphids

Co-expression of multiple genes encoding different kinds of insect resistant proteins has been developed to confer a broader spectrum of pest control. Tetraploid Isatis indigotica Fort was transformed with a plasmid, p3300BP, containing Bacillus thuringiensis Cry1Ac gene (Bt) and Pinellia ternata agglutinin gene (Pta) and the selectable marker herbicide resistance gene (Bar) driven by the CaMV35S promoter via Agrobacterium tumefaciens-mediated transformation. The integration and expression of introduced genes in regenerated transgenic plants were confirmed by PCR and Western blot assays. Insect bioassay test demonstrated transgenic lines had significant inhibition to diamondback moths (Plutella xylostella L.) and peach potato aphids (Myzus persicae Sulzer) simultaneously. Our study reported here would be a great motivation for field culture of tetraploid I. indigotica, also providing an efficient molecular breeding strategy to provide insect tolerant plants.