Limits...
Proteomic analysis of the influence of Cu(2+) on the crystal protein production of Bacillus thuringiensis X022.

Liu X, Zuo M, Wang T, Sun Y, Liu S, Hu S, He H, Yang Q, Rang J, Quan M, Xia L, Ding X - Microb. Cell Fact. (2015)

Bottom Line: However, the molecular mechanisms of the effects caused by mineral elements have yet to be reported.Bacillus thuringiensis X022 mainly expresses Cry1Ca, Cry1Ac, and Cry1Da.Cu(2+) increases the expression of Cry1Da, Cry1Ca, and also enhances the toxicity of fermentation broth to S. exigua and H. armigera.

View Article: PubMed Central - PubMed

Affiliation: College of Life Science, Hunan Provincial Key Laboratory of Microbial Molecular Biology-State Key Laboratory Breeding Base of Microbial Molecular Biology, Hunan Normal University, Changsha, 410081, China. 157125750@qq.com.

ABSTRACT

Background: Bacillus thuringiensis X022, a novel strain isolated from soil in China, produces diamond-shaped parasporal crystals. Specific mineral nutrients, such as Mg, Cu, and Mn, influence insecticidal crystal proteins (ICP) expression and the effects of these elements vary significantly. However, the molecular mechanisms of the effects caused by mineral elements have yet to be reported.

Results: The ICP are mainly composed of Cry1Ca, Cry1Ac, and Cry1Da, which have molecular weights of about 130 kDa. ICP production was most efficient when Cu(2+) was added at concentrations ranging from 10(-6) to 10(-4) mol/L at an initial pH of 8.0. Addition of Cu(2+) also evidently increased the toxicity of fermentation broth to Spodoptera exigua and Helicoverpa armigera. After analyzing changes in proteome and fermentation parameters caused by Cu(2+) addition, we propose that Cu(2+) increases PhaR expression and consequently changes the carbon flow. More carbon sources was used to produce intracellular poly-β-hydroxybutyrate (PHB). Increases in PHB as a storage material bring about increases of ICP production.

Conclusions: Bacillus thuringiensis X022 mainly expresses Cry1Ca, Cry1Ac, and Cry1Da. Cu(2+) increases the expression of Cry1Da, Cry1Ca, and also enhances the toxicity of fermentation broth to S. exigua and H. armigera.

No MeSH data available.


Related in: MedlinePlus

Phase-contrast micrograph of the cell morphology of B. thuringiensis X022 (×1000 magnification) after 46 h of cultivation in a the original medium and b the medium to which 10−6 mol/L Cu2+ had been added
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4595308&req=5

Fig6: Phase-contrast micrograph of the cell morphology of B. thuringiensis X022 (×1000 magnification) after 46 h of cultivation in a the original medium and b the medium to which 10−6 mol/L Cu2+ had been added

Mentions: Cell concentrations, glucose consumption, and pH variation were monitored during bacterial cultivation (Fig. 5). From the growth chart obtained, B. thuringiensis X022 appears to grow slowly in the lag phase at 0–4 h. Bacterial growth then enters the logarithmic phase at 4–18 h and then proceeds to the early stage of the stationary phase at 18–28 h. While no differences were observed between CK and Cu, after 28 h of cultivation, the strain declined quickly in CK but remained in the stationary phase for another 8 h in Cu. Compared with the original fermentation medium, the fermentation medium added Cu2+ is a clear plateau and from 28 h (the stability mid) the situation has been continued to decline phase. Comparing the bacterial growth curves obtained, we found that Cu2+ addition results in a prolonged stationary phase, the cell concentration in Cu is obviously higher than that in CK. We also found that Cu2+ addition causes rapid release of spores and crystals (Fig. 6). From the pH variation curves obtained, we discovered that Cu2+ brought about rapid pH rebound, prolonged pH plateau phase, and low pH in the plateau phase. No significant difference was observed between the glucose consumption of the two media.Fig. 5


Proteomic analysis of the influence of Cu(2+) on the crystal protein production of Bacillus thuringiensis X022.

Liu X, Zuo M, Wang T, Sun Y, Liu S, Hu S, He H, Yang Q, Rang J, Quan M, Xia L, Ding X - Microb. Cell Fact. (2015)

Phase-contrast micrograph of the cell morphology of B. thuringiensis X022 (×1000 magnification) after 46 h of cultivation in a the original medium and b the medium to which 10−6 mol/L Cu2+ had been added
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4595308&req=5

Fig6: Phase-contrast micrograph of the cell morphology of B. thuringiensis X022 (×1000 magnification) after 46 h of cultivation in a the original medium and b the medium to which 10−6 mol/L Cu2+ had been added
Mentions: Cell concentrations, glucose consumption, and pH variation were monitored during bacterial cultivation (Fig. 5). From the growth chart obtained, B. thuringiensis X022 appears to grow slowly in the lag phase at 0–4 h. Bacterial growth then enters the logarithmic phase at 4–18 h and then proceeds to the early stage of the stationary phase at 18–28 h. While no differences were observed between CK and Cu, after 28 h of cultivation, the strain declined quickly in CK but remained in the stationary phase for another 8 h in Cu. Compared with the original fermentation medium, the fermentation medium added Cu2+ is a clear plateau and from 28 h (the stability mid) the situation has been continued to decline phase. Comparing the bacterial growth curves obtained, we found that Cu2+ addition results in a prolonged stationary phase, the cell concentration in Cu is obviously higher than that in CK. We also found that Cu2+ addition causes rapid release of spores and crystals (Fig. 6). From the pH variation curves obtained, we discovered that Cu2+ brought about rapid pH rebound, prolonged pH plateau phase, and low pH in the plateau phase. No significant difference was observed between the glucose consumption of the two media.Fig. 5

Bottom Line: However, the molecular mechanisms of the effects caused by mineral elements have yet to be reported.Bacillus thuringiensis X022 mainly expresses Cry1Ca, Cry1Ac, and Cry1Da.Cu(2+) increases the expression of Cry1Da, Cry1Ca, and also enhances the toxicity of fermentation broth to S. exigua and H. armigera.

View Article: PubMed Central - PubMed

Affiliation: College of Life Science, Hunan Provincial Key Laboratory of Microbial Molecular Biology-State Key Laboratory Breeding Base of Microbial Molecular Biology, Hunan Normal University, Changsha, 410081, China. 157125750@qq.com.

ABSTRACT

Background: Bacillus thuringiensis X022, a novel strain isolated from soil in China, produces diamond-shaped parasporal crystals. Specific mineral nutrients, such as Mg, Cu, and Mn, influence insecticidal crystal proteins (ICP) expression and the effects of these elements vary significantly. However, the molecular mechanisms of the effects caused by mineral elements have yet to be reported.

Results: The ICP are mainly composed of Cry1Ca, Cry1Ac, and Cry1Da, which have molecular weights of about 130 kDa. ICP production was most efficient when Cu(2+) was added at concentrations ranging from 10(-6) to 10(-4) mol/L at an initial pH of 8.0. Addition of Cu(2+) also evidently increased the toxicity of fermentation broth to Spodoptera exigua and Helicoverpa armigera. After analyzing changes in proteome and fermentation parameters caused by Cu(2+) addition, we propose that Cu(2+) increases PhaR expression and consequently changes the carbon flow. More carbon sources was used to produce intracellular poly-β-hydroxybutyrate (PHB). Increases in PHB as a storage material bring about increases of ICP production.

Conclusions: Bacillus thuringiensis X022 mainly expresses Cry1Ca, Cry1Ac, and Cry1Da. Cu(2+) increases the expression of Cry1Da, Cry1Ca, and also enhances the toxicity of fermentation broth to S. exigua and H. armigera.

No MeSH data available.


Related in: MedlinePlus