Pretreatment with KOH and KOH-urea enhanced hydrolysis of α-chitin by an endo-chitinase from Enterobacter cloacae subsp. cloacae

Publication date: Available online 8 February 2020Source: Carbohydrate PolymersAuthor(s): Dokku Sivaramakrishna, Bhoopal Bhuvanachandra, Mohan Krishna Mallakuntla, Subha Narayan Das, Bellamkonda Ramakrishna, Appa Rao PodileAbstractChitin is the second most abundant and renewable polysaccharide, next to cellulose. Hydrolysis of abundant and highly crystalline α-chitin, pretreated with KOH and KOH-urea aqueous solutions, by a single modular endo-chitinase from Enterobacter cloacae subsp. cloacae (EcChi1) was investigated. The hydrolysis of untreated α-chitin and colloidal chitin by EcChi1 produced N-acetylglucosamine and N, N’-diacetylchitobiose, whereas, hydrolysis of treated substrates generated N, N’, N’’-triacetylchitotriose, in addition to N-acetylglucosamine and N, N’-diacetylchitobiose. The total amount of chitooligosaccharides (COS) generated by EcChi1 from pretreated substrates was 10 to 25-fold higher compared to untreated α-chitin at 24 h (depending on the solvent type and state of substrate). EcChi1 released higher amount of DP1 and DP2 products on treated α-chitin, with a fold change of 45 and 18, respectively. Treatment of α-chitin with KOH/KOH-urea is, therefore, a promising approach for an efficient conversion of rich source of chitin to soluble COS by chitinases like EcChi1.
Source: Carbohydrate Polymers - Category: Biomedical Science Source Type: research