Generation of antibacterial oligosaccharides derived from chitin using heterologous endochitinase synthesized in Escherichia coli.

Aims: To synthesize two heterologous endochitinases in Escherichia coli and demonstrate their potential for applied use in generating antibacterial chitin-derived oligosaccharides (OGS).

Methods And Results: Heterologous endochitinase genes, chiA Nima and chiA74, were expressed in E. coli.

Enhanced synthesis and antimicrobial activities of bacteriocins produced by Mexican strains of Bacillus thuringiensis.

Recently, we reported the synthesis of five bacteriocin-like inhibitor substances (Bt-BLIS: morricin 269, kurstacin 287, kenyacin 404, entomocin 420, and tolworthcin 524) by Mexican strains of Bacillus thuringiensis. Here we show that, collectively, these Bt-BLIS have a moderate to broad spectrum of antibacterial activity, being toxic to clinically significant against Gram-positive and Gram-negative bacteria, including common etiological agents of human diseases, such as strep throat and scarlet fever, septicemia, pneumonia, urinary tract infection, and emetic and gastrointestinal syndromes. Although synthesis of the five Bt-BLIS was independent of the presence of a target inducing bacterium, we demonstrated for the first time that a proteinaceous component(s) secreted by, or liberated by proteolytic cleavage of Bacillus cereus 183 following treatment with proteinase K, enhanced Bt-BLIS synthesis.

[Protein quality of three strains of Mexican mushrooms (Pleurotus ostreatus)].

The protein quality of fruits bodies of three Pleurotus ostreatus Mexican strains (INIREB-8, CDBB-H-896 and CDBB-H-897) was evaluated. The protein concentration (Nx4.38) ranged from 17.

[Chemical composition of three Mexican strains of mushrooms (Pleurotus ostratus)].

The chemical composition of three Mexican strains of Pleurotus ostreatus (INIREB-8, CDBB-H-896 and CDBB-H-897), were determined. The mushrooms were cultivated on wheat straw in a greenhouse (22-28 degrees C temperature and 80 +/- 5% of relative humidity). Fruits bodies of P.