Biodegradation of crustacean shell waste by Halococcus salsus GUAg20; a chitinolytic and proteolytic halophilic archaeon

Seafood plays a crucial role in meeting the global food, nutrition and employment demands; however, the rapid growth of fisheries and aquaculture has posed significant environmental challenges, especially in managing seafood waste. The traditional use of chemicals for seafood waste degradation causes pollution and ecological imbalance. Therefore, our study addresses this by exploring a halophilic archaeon, Halococcus salsus, isolated from salt crystals of the Goan saltpan and identified through 16S rRNA sequencing. The halophilic archaeal isolate GUAg20, was applied in the bioprocessing of shrimp shell waste (SSW) and resulted in its degradation with a high demineralization efficiency of 93.08 % and a weight loss of 65.7 %. In the fermentation medium, the chitinolytic activity of the isolate GUAg20 was confirmed by observing an exponential release of N-acetylglucosamine (NAG) corresponding to 1.64 $\times$ 10³, 2.18 $\times$ 10³, 2.88 $\times$ 10³ and 4.35 $\times$ 10³ mg/L after 5, 10, 15 and 20 days, respectively. The degradation of SSW was further confirmed using field emission scanning electron microscopy (FE-SEM) and fourier transform infrared spectroscopy (FTIR). This study reports the first use of Halococcus salsus GUAg20, a chitinolytic, proteolytic and gelatinolytic halophilic archaeon, for marine crustacean waste biodegradation, while concurrently focusing on seafood waste management.