Extraction of chitin from Litopenaeus vannamei shell and its subsequent characterization: an approach of waste valorization through microbial bioprocessing

Bioprocess development as a sustainable platform for eco-friendly alkaline phosphatase production: an approach towards crab shells waste management

“…Untreated crab waste exhibited peaks at 1579 cm −1 , 1622 cm −1 , 3262 cm −1 , and 1393 cm −1 , which are consistent with chitin peaks [ 53 ]. According to spectral data, a sharp absorption peaks intensity of crab shells particle, which were taken at zero incubation time, were detected at 3262 and 2353 cm −1 , which was demonstrated to be typical of α-chitin and corresponded to NH– stretching, which is implicated in intermolecular and intramolecular hydrogen bonds [ 54 ]. As a consequence of the chitinase's activity on chitin during the fermentation process, characteristic peaks of chitin were shifted to 3255 cm −1 in the crab shell leftover samples after 32 h of incubation time.…”

“…Moreover, the O–H stretching vibration and bending hydroxyl groups in Ca(OH) 2 were shown to cause an absorption peak to appear at 3635 cm −1 [ 56 ]. The absorption spectra of crab shells leftover samples at zero incubation time demonstrate that the prominent absorption peaks at 2917, 2851, and 2877 cm –1 are allocated to asymmetric and symmetric stretching vibrations of the –CH 3 and –CH 2 groups [ 54 ]. Following 32 h of incubation time, it was clearly shown that the strength of the absorption peak decreased as well as the location of the peak was slightly shifted to 2916, 2850, and 2877 cm –1 , respectively.…”

“…Bridge oxygen stretching was ascribed to the absorption band at 1150 cm −1 . It was noticed that the deformation of C-H and C-O bonds was indicated by the bands about 1150 and 1132 cm −1 , which demonstrated the polysaccharide's β-1,4 glycosidic bond, were disappeared after the fermentation process ended [ 54 ]. However, once the incubation period ended, the absorption peak at 1028 cm −1 , which corresponds to a C-O stretching vibration in the spectra of crab shells leftover samples, was relocated to 1017 cm −1 .…”

Shrimp Waste Upcycling: Unveiling the Potential of Polysaccharides, Proteins, Carotenoids, and Fatty Acids with Emphasis on Extraction Techniques and Bioactive Properties

“…P. aeruginosa demonstrated the highest rates of deproteinization (74.76%) and demineralization (78.46%), while the lowest rate was observed for the treatment with S. marcescens [107]. Additionally, protease from Alcaligenes faecalis and lactic-acid-producing bacterial strains (Bacillus coagulans) were used for chitin extraction from L. vannamei shell wastes [108]. Another study utilized the protease-producing strain P. aeruginosa for extracting chitin from shrimp shell waste [109].…”

Optimization of fermentation conditions for protease production from Bacillus subtilis

“…When preparing chitin from crab shell, the traditional preparation process adopts a large amount of strong acid for decalcification and deproteinization [4][5] , impacting the quality of chitin and the recycle of other by-products in the crab shell, corroding production equipment corrosion, and causing serious environmental pollution [6] . Microbial fermentation to produce acids and enzymes and decalcify and deproteinize crab shell can reduce environmental pollution and recycle many valuable crab shell byproducts, such as astaxanthin and fatty acid, thus improving resource utilization [7][8] .…”