Chitobiose production by using a novel thermostable chitinase from Bacillus licheniformis strain JS isolated from a mushroom bed

RETRACTED: Purification and characterisation of an acidic and antifungal chitinase produced by a Streptomyces sp.

“…The major inhibitor of chitinase activity was Hg 2+ since it reacts with -SH groups found in cysteine residues in the protein chain and disrupts the tertiary structure. It strongly inhibits chitinases from different genera including Bacillus (Waghmare and Ghosh, 2010), Massilia timonae (Adrangi et al, 2010), Microbispora (Nawani et al, 2002), Rhodothermus (Hobel et al, 2005), Stenotrophomonas (Jankiewicz et al, 2012) and Streptomyces (Nagpure and Gupta, 2013;Prakash et al, 2013). The other major inhibitory metal ions which show strong inhibitory action on chitinases include Fe 2+ (Pradeep et al, 2014;Wang et al, 2010), Mn 2+ (Pradeep et al, 2014;Wang et al, 2010), Ag 2+ (Nagpure and Gupta, 2013;Liu et al, 2010), Zn 2+ (Jankiewicz et al, 2012;Prakash et al, 2013) and Co 2+ (Jiang et al, 2012;Yong et al, 2005).…”

“…Cu 2+ ions are known to catalyse the auto-oxidation of cysteines to form intra-molecular disulphide bridges or the formation of sulphenic acid. Cu 2+ was found to be a moderate to strong inhibitor of chitinases produced by different bacterial genera including Bacillus (Natsir et al, 2010;Waghmare and Ghosh, 2010), Streptomyces (Pradeep et al, 2014;Jiang et al, 2012), Micrococcus (Annamalai et al, 2010), Pseudomonas (Wang et al, 2010) and Stenotrophomonas (Jankiewicz et al, 2012). The major inhibitor of chitinase activity was Hg 2+ since it reacts with -SH groups found in cysteine residues in the protein chain and disrupts the tertiary structure.…”

“…Chitin is a high molecular weight complex polymer and is generally insoluble in aqueous media and hence its uptake as such is not possible. Hence bacteria, especially Streptomyces (Brzezinska et al, 2013;Margino et al, 2010;Nagpure and Gupta, 2013;Prakash et al, 2013;Pradeep et al, 2014) and Bacillus (Kudan and Pichyangkura, 2009;Liu et al, 2010;Natsir et al, 2010;Waghmare and Ghosh, 2010;Dai et al, 2011) species, produce extracellular chitinases for nutritional purposes, in that they are able to utilise chitin as their sole source of carbon. Application of chemical based pesticides causes long-lasting adverse effects on ecosystems and human health.…”

Purification, characterization, and molecular cloning of an extracellular chitinase from Bacillus licheniformis stain LHH100 isolated from wastewater samples in Algeria

“…4b). The high activity and stability exhibited by ChiA-65 in an acidic environment (pH 3-7) makes it suitable for biotechnological applications involving the bioconversion of chitin waste, a highly resistant and abundant biopolymer from crustacean food industry, into glucosamine and chito-oligosaccharide value-added products [26].…”

Partial biochemical characterization of a thermostable chitinase produced by Streptomyces owasiensis isolated from lichens of the Amazonian region

“…The determination of the chitinase activity was performed according to the method by Waghmare and Ghosh (2010), although with some changes. The reaction mixture was composed of 1 mL of colloidal chitin 1% (w/v), 0.5 mL of sodium phosphate buffer 25 mM, pH 7.4 and 0.5 mL of the crude enzyme extract incubated at 37°C for 30 min.…”