Antibacterial activity of Cry- and Cyt-proteins fromBacillus thuringiensisssp.israelensis

Abstract

Mosquitocidal endotoxins Cry4B, Cry11A, and CytA from Bacillus thuringiensis ssp. israelensis as well as the products of their limited proteolysis display antibacterial activity relative to Micrococcus luteus. The endotoxin Cry11A also induces the lysis of the micrococcus protoplasts. Potassium and sodium ions and N-acetylgalactosamine increased the antibacterial effect of Cry11A, whereas glucose and N-acetylglucosamine inhibited it. The endotoxin Cry11A displays the antibacterial effect on some other microorganisms.

Partial Restoration of Antibacterial Activity of the Protein Encoded by a Cryptic Open Reading Frame ( cyt1Ca ) from Bacillus thuringiensis subsp. israelensis by Site-Directed Mutagenesis

“…Antibacterial activity of Cyt1Aa is well reported: e.g., it is bactericidal to Micrococcus luteus (43). Expression of cyt1Aa in B. thuringiensis subsp.…”

Antibacterial activity of Cyt1Aa from Bacillus thuringiensis subsp. israelensis

“…These Cry toxins led to significant damage to Micrococcus luteus (a Gram-positive bacterium), Clostridium butyricum and C. acetobutylicum (Gram-positive anaerobic species), as well as Methanosarcina barkeri (an archaeon) (Yudina et al, 2003(Yudina et al, , 2007.…”

“…The effect of exogenous Cyt1Aa on Gram-negative bacteria has not been reported previously. Several d-endotoxins from B. thuringiensis have antibacterial effects on Gram-positive bacteria as well as on archaea, detected by zones of inhibition on agar and morphological changes in the treated bacteria (Revina et al, 2005;Yudina et al, 2003Yudina et al, , 2007. Here, we examined the effect of exogenous Cyt1Aa on both Gram-positive and Gram-negative bacteria.…”

“…israelensis d-endotoxins has been demonstrated on the Gram-positive bacterium Micrococcus luteus by the agar diffusion and MIC methods (Yudina et al, 2003). Those authors found that increasing the CytA concentration from 6.7 to 106 mg ml…”

Expression in Escherichia coli of the Native cyt1Aa from Bacillus thuringiensis subsp. israelensis

“…Cyt1Aa has low toxicity and specificity but is the most synergistic to any of the other three (9) and hence has a crucial role in suppressing resistance to Cry toxins in the targets (19). In addition, Cyt1Aa exerts, a general cytolytic effect on a variety of prokaryotic (5,20) and eukaryotic (16) cells by a detergent-like mode of action (12). This property makes it potentially useful for treating bacterial infections and even cancerous growths if specificity to tumor cells is raised by genetically fusing Cyt1Aa to targeting ligands (6).…”