Table 1

Solubilization of Bacillus thuringiensis subsp. medellin Cyt1Ab1 toxin in buffers of different pH

Buffer

pH

Obtained concentration (g/l)

Na2HPO4 50 mM, KH2PO4 50 mM

5.0

0.28

Na2HPO4 50 mM, KH2PO4 50 mM

6.0

0.30

Na2HPO4 50 mM, KH2PO4 50 mM

7.0

0.34

Tris 50 mM

8.0

0.38

Na2CO3 50 mM, NaHCO3 50 mM

9.0

0.50

Na2CO3 50 mM, NaHCO3 50 mM

10.0

0.67

Na2CO3 50 mM, NaHCO3 50 mM

10.6

1.16

Na2CO3 50 mM, NaHCO3 50 mM

11.0

1.51

NaOH 50 mM, EDTA 10 mM

12.0

2.33

 

Solubility of the Cyt1Ab1 toxin was higher at the alkaline buffers. The maximal solubilization was obtained in the buffer of pH 12.0 which produced 2.33 g/ml of solubilized toxin. This toxin is preferentially solubilized at higher pH values.

 

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