Comparison of chito-oligosaccharide production from three different colloidal chitosans using the endochitonsanolytic system of Bacillus thuringiensis.

Bacillus thuringiensis is a nonhuman pathogen bacterium that is used as a fungal and insect biocontrol agent. Because of its environmental interaction, it possesses several extracellular enzymes that are able to degrade chitin and chitosan, two of the most important polymers because of their application in numerous fields. However, in recent years, it has been observed that oligosaccharides from the enzymatic degradation of chitosan have important benefits for human health.

Characterization of a novel Bacillus thuringiensis phenotype possessing multiple appendages attached to a parasporal body.

Bacillus thuringiensis is a bacterium best known for its production of crystal-like bodies comprised of one or more Cry-proteins, which can be toxic to insects, nematodes or cancer cells. Although strains of B. thuringiensis have occasionally been observed with filamentous appendages attached to their spores, appendages in association with their parasporal bodies are extremely rare.

Oil-removal enhancement in media with keratinous or chitinous wastes by hydrocarbon-degrading bacteria isolated from oil-polluted soils.

The aim of this work was to isolate oil-degrading bacteria that use chitin or keratin as carbon sources from oil contaminated soils; and additionally to study if oil removal by these bacteria is enhanced when a chitinous or a keratinous waste is added to the culture media. To isolate the above-mentioned bacteria, 12 soil samples were collected close to an oil-well. Such soils showed unsuitable nutrients content, but their counts of heterotrophic bacteria ranged within 10(5)-10(8) CFU g(-1) soil, of which 0.

Molecular cloning and purification of an endochitinase from Serratia marcescens (Nima).

An endochitinase gene from the Serratia marcescens Nima strain (chiA Nima) was cloned, sequenced, and expressed in Escherichia coli DH5alphaF', and the recombinant protein (ChiA Nima) was purified by hydrophobic interaction chromatography. chiA Nima contains an open reading frame (ORF) that encodes an endochitinase with a deduced molecular weight and an isoelectric point of 61 kDa and 6.84, respectively.

Chitinases from Serratia marcescens Nima.

Chitinolytic activity of Serratia marcescens Nima (130 U ml(-1)) was up to 43 times higher than those produced by other S. marcescens strains. This strain synthesized an endochitinase (Chi-60), an exochitinase (Chi-50) and a novel N-acetylglucosaminidase.