Extracellular production of a thermostable Cellvibrio endolytic β-agarase in Escherichia coli for agarose liquefaction.

ABSTRACT: Four GH16 family β-agarases (GH16A, GH16B, GH16C, and GH16D), originated from an agarolytic bacterium Cellvibrio sp. KY-GH-1, were expressed in an Escherichia coli system and their activities were compared. Only GH16B (597 amino acids, 63.8 kDa), with N-terminal 22-amino acid signal sequence, was secreted into the culture supernatant and demonstrated a robust endolytic agarose hydrolyzing activity for producing neoagarotetraose (NA4) and neoagarohexaose (NA6) as end products. The optimal temperature and pH for the enzyme activity were 50 °C and 7.0, respectively. The enzyme was stable up to 50 °C and over a pH range of 5.0-8.0. The kinetic parameters, including Km, Vmax, kcat, and kcat/Km, of GH16B β-agarases for agarose were 14.40 mg/mL, 542.0 U/mg, 576.3 s^-1, and 4.80 × 10

SUBMITTER: Lee HK 

PROVIDER: S-EPMC10163192 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature