title: 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.
authors.affiliation: Institute of Biology for Engineers and Biotechnology of Wastewater Treatment, Karlsruhe Institute of Technology (KIT), Am Fasanengarten, 76131, Karlsruhe, Germany. mini.bajaj@kit.edu.
authors.forename: Mini
authors.initials: M
authors.lastname: Bajaj
authors.affiliation: Institute of Biology for Engineers and Biotechnology of Wastewater Treatment, Karlsruhe Institute of Technology (KIT), Am Fasanengarten, 76131, Karlsruhe, Germany. afreiberg@paxvax.com.|PaxVax Inc, Oberriedstrasse 68, 3174, Thörishaus, Switzerland. afreiberg@paxvax.com.
authors.forename: Andrea
authors.initials: A
authors.lastname: Freiberg
authors.affiliation: Institute of Biology for Engineers and Biotechnology of Wastewater Treatment, Karlsruhe Institute of Technology (KIT), Am Fasanengarten, 76131, Karlsruhe, Germany. josef.winter@kit.edu.
authors.forename: Josef
authors.initials: J
authors.lastname: Winter
authors.affiliation: Institute of Biology for Engineers and Biotechnology of Wastewater Treatment, Karlsruhe Institute of Technology (KIT), Am Fasanengarten, 76131, Karlsruhe, Germany. youmeixu@hotmail.de.
authors.forename: Youmei
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Institute of Biology for Engineers and Biotechnology of Wastewater Treatment, Karlsruhe Institute of Technology (KIT), Am Fasanengarten, 76131, Karlsruhe, Germany. claudia.gallert@hs-emden-leer.de.|Faculty of Technology, Department of Microbiology/Biotechnology, Hochschule Emden-Leer, Constantiaplatz 4, 26732, Emden, Germany. claudia.gallert@hs-emden-leer.de.
authors.forename: Claudia
authors.initials: C
authors.lastname: Gallert
mesh_terms: D060105:Animal Shells / Q000737:chemistry*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002686:Chitin / Q000302:isolation & purification*; D033501:Crangonidae; D007778:Lactobacillus / Q000254:growth & development / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D018505:Waste Management / Q000379:methods
chemical_list: D011506:Proteins; D002686:Chitin; D002118:Calcium
keywords: Chitin extraction; Lactobacillus mixed culture; Pilot-scale fermentation; Proteolytic enrichment cultures; Shrimp shell waste