Shrimp shell powders (SSPs) were fermented by successive two-step fermentation of Serratia marcescens B742 and Lactobacillus plantarum ATCC 8014 to extract chitin. Taguchi experimental design with orthogonal array was employed to investigate the most contributing factors on each of the one-step fermentation first. The identified optimal fermentation conditions for extracting chitin from SSPs using S. marcescens B742 were 2% SSP, 2h of sonication time, 10% incubation level, and 4d of culture time, while that of using L. plantarum ATCC 8014 fermentation was 2% SSP, 15% glucose, 10% incubation level, and 2d of culture time. Successive two-step fermentation using identified optimal fermentation conditions resulted in chitin yield of 18.9% with the final deproteinization (DP) and demineralization (DM) rate of 94.5% and 93.0%, respectively. The obtained chitin was compared with the commercial chitin from SSP using scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FT-IR) and X-ray diffraction (XRD). Results showed that the chitin prepared by the successive two-step fermentation exhibited similar physicochemical and structural properties to those of the commercial one, while significantly less use of chemical reagents.
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