Valorization of
Crab Shell Waste into Bacterial Enzyme Production and Chitin Characterization
Sri Durga Devi R., Subash Anitha, Priyadarshini M. and Shobana A.
Res. J. Biotech.; Vol. 20(12); 31-39;
doi: https://doi.org/10.25303/2012rjbt031039; (2025)
Abstract
Chitin, a valuable biopolymer with significant economic and industrial applications,
is primarily found in aquatic crustaceans, particularly in crab shells, which serve
as the main commercial sources. The study involves deproteinization and demineralization
to remove proteins and minerals and extract 15.45% chitin from crab shell waste.
Chitin was characterized by determining its physicochemical properties using Fourier
transform infrared spectroscopy and Scanning electron microscope. The purified chitins
from crab shell waste were comparable to those of commercially purchased chitin.
Purified chitin further implicates in deacetylation process to convert the extracted
chitin into chitosan. Chitosaninfused media were used to isolate 31 chitinolytic
bacteria, with the highest enzyme activity at 82.45U/ml on 7X5ZA isolates. The culture
filtrate of selected bacteria degrades 2% of crab shell powder resulting in 10.5%
weight loss in the raw crab shell powder (substrate) and explores the production
of N-acetyl glucosamine (97.53U/ml), post reaction with enzyme at incubation period
of 48hrs at 47°C.
An alternative solution for the chemical process to extract chitin from the crab
shell is an enzymatic process. Crab shell powder is treated with culture filtrate
to obtain chitin which has similar chemical composition, surface morphology and
elemental content compared with both commercially purchased chitin and chemically
digested chitin of crab shell. This study suggests that crab shell waste can be
used for effective chitin extraction and discovery of chitinaseproducing bacteria
to conserve a safe environment.
