Pilot-scale chitin extraction from shrimp shell waste by deproteination and decalcification with bacterial enrichment cultures

Abstract

Extraction of chitin from mechanically pre-purified shrimp shells can be achieved by successive NaOH/HCl treatment, protease/HCl treatment or by environmentally friendly fermentation with proteolytic/lactic acid bacteria (LAB). For the last mentioned alternative, scale-up of shrimp shell chitin purification was investigated in 0.25 L (F1), 10 L (F2), and 300 L (F3) fermenters using an anaerobic, chitinase-deficient, proteolytic enrichment culture from ground meat for deproteination and a mixed culture of LAB from bio-yoghurt for decalcification. Protein removal in F1, F2, and F3 proceeded in parallel within 40 h at an efficiency of 89-91 %. Between 85 and 90 % of the calcit was removed from the shells by LAB in another 40 h in F1, F2, and F3. After deproteination of shrimp shells in F3, spent fermentation liquor was re-used for a next batch of 30-kg shrimp shells in F4 (300 L) which eliminated 85.5 % protein. The purity of the resulting chitin was comparable in F1, F2, F3, and F4. Viscosities of chitosan, obtained after chitin deacetylation and of chitin, prepared biologically or chemically in the laboratory, were much higher than those of commercially available chitin and chitosan.

Transcriptome analysis on the exoskeleton formation in early developmetal stages and reconstruction scenario in growth-moulting in Litopenaeus vannamei

“…For example, to produce 1 kilogram of chitosan from shrimp shells, more than 1 tonne of water is need and as well as a large amount of 40% sodium hydroxide solution. Thus, developing a natural way to degrade the waste shells will be promising and necessary 54, 55 . From our results, several chitin degradation-related genes with high expression in the moulting process could be targeted candidates.…”

Ionically Crosslinked Chitosan Hydrogels for the Controlled Release of Antimicrobial Essential Oils and Metal Ions for Wound Management Applications

“…Increasing the viscosity of chitosan from low to high effectively increases the respective molecular weight and polymeric chain length [42], which results in potentially greater inter-chain entanglement, hence affecting its viscosity and ability to release the antimicrobial agents. The antimicrobial activity of the formulations will be discussed separately based on the type of agent and chitosan viscosity.…”

Enhanced reutilization value of shrimp-shell waste via fed-batch biodegradation with higher production of reducing sugar, antioxidant, and DNA protective compounds

“…Therefore, additional substrate feeding in the fed-batch operation might contribute better cell growth and consequently lead the production of various metabolites (Abou-taleb 2015). It was also reported that change in alkalinity was caused due to breakage of peptide linkages of chitin by proteolysis (Bajaj et al 2016), and high demineralization rate was found at pH 5.86 during the batch degradation of chitin (Ghorbel-Bellaaj et al 2011). GlcNAc was reported to result from the chitin degradation optimally at pH 5.3 (Chen et al 2010).…”