Optimization of Fermentation Parameters and In Vitro Efficacy of Native Bacillus thuringiensis Isolates Against Spodoptera litura

2016 ◽  
pp. 415-435
Author(s):  
Rahul Amin ◽  
Kuldeep Khatri ◽  
Deepak Panpatte ◽  
Leena Pathak ◽  
Ankit Patel ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Spodoptera Litura ◽  
Fermentation Parameters ◽  
Optimization Of Fermentation

scholarly journals Identification and Functional Analysis of Apoptotic Protease Activating Factor-1 (Apaf-1) from Spodoptera litura

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 64
Author(s):  
Haihao Ma ◽  
Xiumei Yan ◽  
Lin Yan ◽  
Jingyan Zhao ◽  
Jiping Song ◽  
...  
Keyword(s):  
Spodoptera Litura ◽  
Actinomycin D ◽  
Titration Calorimetry ◽  
Apoptosis Pathway ◽  
Downstream Effector ◽  
Lepidopteran Insects ◽  
Evolutionarily Conserved ◽  
Effector Caspases ◽  
And Function

Apoptotic protease activating factor-1 (Apaf-1) is an adaptor molecule, essential for activating initiator caspase and downstream effector caspases, which directly cause apoptosis. In fruit flies, nematodes, and mammals, Apaf-1 has been extensively studied. However, the structure and function of Apaf-1 in Lepidoptera remain unclear. This study identified a novel Apaf-1 from Spodoptera litura, named Sl-Apaf-1. Sl-Apaf-1 contains three domains: a CARD domain, as well as NOD and WD motifs, and is very similar to mammalian Apaf-1. Interference of Sl-apaf-1 expression in SL-1 cells blocked apoptosis induced by actinomycin D. Overexpression of Sl-apaf-1 significantly enhances apoptosis induced by actinomycin D in Sf9/SL-1/U2OS cells, suggesting that the function of Sl-Apaf-1 is evolutionarily conserved. Furthermore, Sl-Apaf-1 could interact with Sl-caspase-5 (a homologue of mammalian caspase-9) and yielded a binding affinity of 1.37 × 106 M–1 according isothermal titration calorimetry assay. Initiator caspase (procaspase-5) of S. litura could be activated by Sl-Apaf-1 (without WD motif) in vitro, and the activated Sl-caspase-5 could cleave Sl-procaspase-1 (a homologue of caspase-3 in mammals), which directly caused apoptosis. This study demonstrates the key role of Sl-Apaf-1 in the apoptosis pathway, suggesting that the apoptosis pathway in Lepidopteran insects and mammals is conserved.

scholarly journals Bacillus thuringiensis Bel Protein Enhances the Toxicity of Cry1Ac Protein to Helicoverpa armigera Larvae by Degrading Insect Intestinal Mucin

2009 ◽  
Vol 75 (16) ◽  
pp. 5237-5243 ◽  
Author(s):  
Shangling Fang ◽  
Li Wang ◽  
Wei Guo ◽  
Xia Zhang ◽  
Donghai Peng ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Armigera ◽  
Trichoplusia Ni ◽  
Knockout Mutant ◽  
Gene Encoding ◽  
In Vitro Degradation ◽  
Intestinal Mucin ◽  
Helicoverpa Armígera ◽  
Cry1ac Protein

ABSTRACT Bacillus thuringiensis has been used as a bioinsecticide to control agricultural insects. Bacillus cereus group genomes were found to have a Bacillus enhancin-like (bel) gene, encoding a peptide with 20 to 30% identity to viral enhancin protein, which can enhance viral infection by degradation of the peritrophic matrix (PM) of the insect midgut. In this study, the bel gene was found to have an activity similar to that of the viral enhancin gene. A bel knockout mutant was constructed by using a plasmid-free B. thuringiensis derivative, BMB171. The 50% lethal concentrations of this mutant plus the cry1Ac insecticidal protein gene were about 5.8-fold higher than those of the BMB171 strain. When purified Bel was mixed with the Cry1Ac protein and fed to Helicoverpa armigera larvae, 3 μg/ml Cry1Ac alone induced 34.2% mortality. Meanwhile, the mortality rate rose to 74.4% when the same amount of Cry1Ac was mixed with 0.8 μg/ml of Bel. Microscopic observation showed a significant disruption detected on the midgut PM of H. armigera larvae after they were fed Bel. In vitro degradation assays showed that Bel digested the intestinal mucin (IIM) of Trichoplusia ni and H. armigera larvae to various degrading products, similar to findings for viral enhancin. These results imply Bel toxicity enhancement depends on the destruction of midgut PM and IIM, similar to the case with viral enhancin. This discovery showed that Bel has the potential to enhance insecticidal activity of B. thuringiensis-based biopesticides and transgenic crops.

scholarly journals Plasmid Transfer between the Bacillus thuringiensis Subspecies kurstaki andtenebrionis in Laboratory Culture and Soil and in Lepidopteran and Coleopteran Larvae

2000 ◽  
Vol 66 (1) ◽  
pp. 118-124 ◽  
Author(s):  
D. John I. Thomas ◽  
J. Alun W. Morgan ◽  
John M. Whipps ◽  
Jon R. Saunders
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacterial Population ◽  
Laboratory Culture ◽  
Plasmid Transfer ◽  
Donor Strain ◽  
Lepidopteran Insect ◽  
Lepidopteran Insects ◽  
Rapid Formation ◽  
Coleopteran Insect

ABSTRACT Plasmid transfer between Bacillus thuringiensis subsp.kurstaki HD1 and B. thuringiensis subsp.tenebrionis donor strains and a streptomycin-resistantB. thuringiensis subsp. kurstaki recipient was studied under environmentally relevant laboratory conditions in vitro, in soil, and in insects. Plasmid transfer was detected in vitro at temperatures of 5 to 37°C, at pH 5.9 to 9.0, and at water activities of 0.965 to 0.995, and the highest transfer ratios (up to 10−1 transconjugant/donor) were detected within 4 h. In contrast, no plasmid transfer was detected in nonsterile soil, and rapid formation of spores by the introduced strains probably contributed most to the lack of plasmid transfer observed. When aB. thuringiensis subsp. kurstaki strain was used as the donor strain, plasmid transfer was detected in killed susceptible lepidopteran insect (Lacanobia oleracea) larvae but not in the nonsusceptible coleopteran insect Phaedon chocleriae. When a B. thuringiensis subsp.tenerbrionis strain was used as the donor strain, no plasmid transfer was detected in either of these insects even when they were killed. These results show that in larger susceptible lepidopteran insects there is a greater opportunity for growth of B. thuringiensis strains, and this finding, combined with decreased competition due to a low initial background bacterial population, can provide suitable conditions for efficient plasmid transfer in the environment.

PSVII-15 Effects of electrolyzed reduced water on intake, digestion and ruminal fermentation parameters in beef cattle

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 446-447
Author(s):  
Natasha L Bell ◽  
Daisy A Gonzalez ◽  
Kendrah DeLeon
Keyword(s):  
Transition Period ◽  
Rumen Fluid ◽  
Phase 1 ◽  
Analysis Data ◽  
Phase 2 ◽  
Ruminal Fermentation ◽  
Fermentation Parameters ◽  
Reduced Water ◽  
Electrolyzed Reduced Water

Abstract The effect of electrolyzed reduced water consumption by cattle is not well defined. The objective of this study was to evaluate the effect of electrolyzed reduced water on intake, in vitro true digestibility (IVTD), ORP and pH in four ruminally cannulated steers (4 Bos taurus; 317 kg BW). Steers were subjected to a two period (14 d), two treatment crossover design. Treatment included: 1) standard water (CON; pH = 7.0 ± 1.0) or 2) electrolyzed reduced water (ERW; pH = 9.0 ± 1.0). The project comprised of two studies where the effects of ERW were observed for steers consuming a roughage diet (phase 1) or concentrate diet (phase 2). During Phase 1, animals were provided bermudagrass hay ad libitum. A 14 d transition period followed phase 1 to allow transition of diets. In phase 2, animals were maintained on a concentrate diet. During each period, d 1–8 served as a treatment adaptation phase, d 9–13 allowed for measures of intake and digestion, and rumen fluid was collected at h 0, 2, 4, 8, and 12 after feeding on d 14 for VFA, pH and ORP analysis. Data were analyzed using the MIXED procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC). Intake, digestion, and ruminal fermentation parameters were not different for CON vs ERW steers (P ≥ 0.06). Analysis of VFA data have not been finalized and will be reported later. Results indicate that ERW has no effect on intake, digestion or ruminal fermentation parameters of steers consuming roughage or concentrate diets.

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