| Abstrak/Abstract |
The aim of this study was to screen lactic acid bacteria (LAB) from traditional Indonesian fermented fish product namely wadi and jambal with high protease activity for chitin production from Litopenaeus vannamei shrimp shells. Twenty-eight colonies were successfully isolated and further identification was carried out through biochemical tests, including catalase and Gram staining. Seven out of the twenty-eight colonies were identified as lactic acid bacteria based on their Gram-positive and catalase-negative results. These strains from wadi samples were named GWB 1.3, GWB 1.7, and GWB 2.5, while the strains from jambal samples were named GMJB 1.3, GMJB 1.6, BGJM 2.6, and BGJM 2.7. The protease activity of these strains was tested using the well diffusion method on skim milk agar to assess their deproteinize activity. The diameter of the clear zones formed after 24, 48, and 72 hours of incubation was measured. GWB 1.7 and GMJB 2.6 were showed the largest clear zone diameter with 213 mm and 225 mm respectively and were selected for the single step-fermentation of shrimp shells. The fermentation process was conducted in 6 days with different inoculum namely 0%, 5%, 10%, 15%, and 20% (v/v) as treatments. In the final days, all treatments were evaluated for proximate content including moisture, ash, and protein content. The results indicate that the 20% inoculum showed the highest deproteinization and demineralization for both bacterial strains. GWB 1.7 exhibited a deproteinization of 43.7% and demineralization of 25.2%, while GMJB 2.6 showed a deproteinization of 39% and demineralization of 16.1%. This study demonstrated that lactic acid bacteria from wadi and jambal samples could be used for producing chitin from shrimp shells which is a valuable biopolymer with various applications. |
