Chitin, a cationic polymer derived from shrimp shell, has gained widespread recognition for its potential applications in medicine, environmental solutions, and agriculture. This study was aimed to investigate the biological extraction of chitin from shrimp shells using a mixed bacterial starter comprising Lactobacillus plantarum SK (5), Lactobacillus plantarum NS (9), and Pediococcus pentosaceus BP (20), with varying fermentation durations of 0, 5, 10, and 15 days. The effects of fermentation time on protein and ash content were examined, and FTIR analysis was conducted on the 15th day. Fermentation reduced protein content by 31.29%, demonstrating effective deproteinization. However, ash content increased due to challenges in separating chitin extract from bacterial biomass. FTIR analysis on day 15 identified functional groups (N-H, O-H, C-H, C=O, C-O-C) in the extracted chitin, which had a deacetylation degree of 36%. This research however underscores the protein and ash content in the chitin extract obtain still do not meet the quality standards for chitin based on SNI (Indonesia National Standard).