|
KMID : 1094720080130050545
|
|
Biotechnology and Bioprocess Engineering
2008 Volume.13 No. 5 p.545 ~ p.551
|
|
|
A κ-carrageenase from a newly isolated pseudoalteromonas-like bacterium, WZUC10
|
|
Zhou Mao-Hong
Ma Jian-She
Li Jun
Ye Hai-Ren
Huang Ke-Xin
Zhao Xiao Wei
|
|
|
Abstract
|
|
|
|
A bacterial strain able to produce κ-carrageenase, designated WZUC10, was isolated from a live specimen of the red alga Plocamium telfainae collected in the East China Sea. The phylogenetic evidence and phenotypic features indicate that this strain belongs to the genus Pseudoalteromonas. WZUC10 requires NaCl for growth and κ-carrageenan to induce κ-carrageenase synthesis; galactose and lactose do not induce it. The optimal growth temperature is 23∼27°C. The secreted enzyme, which has a molecular mass of 45 kDa, breaks down κ-carrageenan into κ-neocarratetraose sulfate and larger oligosaccharides with a repeating β-D-Galp4S-(1→4)-α-D-AnGalp structure, but cannot degrade κ-neocarratetraose sulfate or κ-neocarrahexaose sulfate into κ-neocarrabiose sulfate. The enzyme retains 90% of its activity after 2 h at 40°C and is completely inactivated after 7.5 min at 70°C. The enzyme’s optimal temperature is 30°C and its optimal pH is 7.5. The enzyme-catalyzed reaction follows Michaelis-Menten kinetics, with the Michaelis constant (K m) and the turnover number (k) being 0.015 mM and 125 s?1, respectively. WZUC10 produces 50 U/mL κ-carrageenase after cultivation at 25°C for 35 h on a medium containing 80 g/L glucose, 5 g/L corn steep liquor, 3 g/L κ-carrageenan, and 15 g/L NaCl. κ-Neocarratetraose sulfate was prepared simply with precipitation by ethanol:water (5:1, v/v).
|
|
|
KEYWORD
|
|
|
κ-carrageenase, Pseudoalteromonas, sulfated oligosaccharide, κ-neocarratetraose, biodegradation, characterization
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
 
|
|