title: Optimization of chitin extraction from shrimp waste with Bacillus pumilus A1 using response surface methodology.
abstract: Chitin extraction from shrimp shells by biological treatment, using the Bacilli Bacillus pumilus A1, is a non-polluting method and offers the opportunity to preserve the exceptional qualities of chitin and its derivatives. However, the major disadvantage of the fermentative way is the low efficiency of demineralization and deproteinization. The aim of this study is to improve the yield of extraction which depends on many factors, such as the medium composition and the physical parameters. In order to look for the optimal conditions, a Plackett and Burman design was carried out to screen eight factors influencing the deproteinization and demineralization efficiencies. The four most influencing variables were then examined to achieve the optimization using a central composite design. The results obtained showed that the optimal conditions were: shrimp shell concentration of 70 g/l, glucose concentration of 50 g/l, pH of 5.0 incubated with 0.225 OD of B. pumilus A1 inoculum, at 35 °C and 150 rpm for 6 days in 500 ml flask containing 100 ml of working volume. These conditions led to 88% of demineralization and 94% of deproteinization. (13)C CP/MAS NMR spectral analysis of the chitin prepared was carried out and was found to be similar to that of the commercial α-chitin.
authors.affiliation: Laboratoire de Génie Enzymatique et de Microbiologie, Université de Sfax, Ecole Nationale d'Ingénieurs de Sfax, B.P. 1173-3038, Sfax, Tunisia. Electronic address: olfa_ghor@yahoo.fr.
authors.forename: Olfa
authors.initials: O
authors.lastname: Ghorbel-Bellaaj
authors.forename: Sawssen
authors.initials: S
authors.lastname: Hajji
authors.forename: Islem
authors.initials: I
authors.lastname: Younes
authors.forename: Moncef
authors.initials: M
authors.lastname: Chaabouni
authors.forename: Moncef
authors.initials: M
authors.lastname: Nasri
authors.forename: Kemel
authors.initials: K
authors.lastname: Jellouli
mesh_terms: D060105:Animal Shells / Q000737:chemistry*; D000818:Animals; D001407:Bacillus / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002686:Chitin / Q000737:chemistry*; D033364:Decapoda / Q000737:chemistry*; D008962:Models, Theoretical
chemical_list: D002686:Chitin
keywords: Bacillus pumilus A1; Fermentation; Response surface methodology; Shrimp waste