Brine shrimp (Artemia salina) belong to a group of crustaceans that feed on microalgae and require a cellulase
enzyme that can be used in ethanol production from marine algae. Protein with potential cellulase
activity was purified and the activity analyzed under different conditions. After initial identification of
cellulase activity by CMC cellulase, surface sterilization and PCR using 16s rRNA primers was conducted
to confirm that the cellulase activity was not produced from contaminating bacteria. The enzyme was
purified by ammonium sulfate fractionation, gel filtration, and ion exchange chromatography. After the
final purification, a 70-fold increase in specific enzyme activity was observed. SDS–PAGE results revealed
that the cellulase enzyme had a molecular mass of 96 kDa. Temperature, pH, and salinity values were
found to be optimal at 55 C, pH 8.0, and 600 mM NaCl, respectively. Specifically, the enzyme showed
a fivefold increase in enzyme activity in seawater compared to 600 mM NaCl in phosphate buffer. Further
analysis of the purified enzyme by molecular spectrometry showed no match to known cellulases, indicating
this enzyme could be a novel halophilic cellulase that can be used for the production of bioethanol
from marine macroalgae.