Efficient Chitin Extraction from Shrimp Exoskeletons through Single-Step Fermentation by Pseudomonas aeruginosa QF50 and Serratia sp. QCS23

Abstract

Chitin, an abundant biopolymer with potential applications in agriculture, medicine, and bioremediation, is conventionally extracted using chemical methods that have environmental disadvantages. This study investigates the extraction of chitin from Litopenaeus vannamei shrimp waste by one-step fermentation using the bacterial strains Pseudomonas aeruginosa QF50 and Serratia sp. QCS23. A total of 4 kg of shrimp waste was treated by fermentation with culture media enriched with different concentrations of glucose (1, 5, and 10%) for 7 days at 25 °C, followed by purification and characterization processes using infrared spectroscopy and X-ray diffraction. The results demonstrated an increase in the yield of crude chitin proportional to the glucose concentration, reaching a maximum of 76.81 ± 7.64% for Pseudomonas aeruginosa QF50 and 71.30 ± 1.16% for Serratia sp. QCS23. Both strains showed high efficiencies in deproteinization (80–87%) and demineralization, with significant improvements especially shown at high glucose concentrations. Structural characterization confirmed the presence of the spectral characteristics of α-chitin, with crystallinity indices of 81% and 71% for chitins obtained with Pseudomonas aeruginosa QF50 and Serratia sp. QCS23, respectively. This study concludes that single-step fermentation with Pseudomonas aeruginosa QF50 and Serratia sp. QCS23 is an effective and sustainable method for the extraction of high-quality chitin from shrimp exoskeleton waste, offering a promising alternative to traditional chemical methods.