[Isolation and characterization of a marine agarase].
OBJECTIVE
This study was carried out to isolate and characterize an agarase from a marine bacterium Agarivorans albus QM38.


METHODS
SDS-PAGE grade agarase was obtained from the fermentation broth after removing the bacteria by centrifugation, ammonium sulfate precipitation, DEAE-sepharose fast flow anion exchange chromatography and Sephacryl S-100 gel filtration. Enzyme's molecular weight was determined with SDS-PAGE. The catalysates of the isolated enzyme were determined withmass spectrography.


RESULTS
Agarase A was isolated. The molecular weight of agarase A was 127.80 kDa. More characterizations of agarase A were studied and the results showed that the optimal reaction condition for agarase A was at 35 degrees C, pH 7.6, and agar concentration of 0.9% (w/v), while most of the metal ions inhibited the activity of it. The catalysates of agarase A were mainly tetrose and hexose.


CONCLUSIONS
Agarase A was purified from the medium. It could hydrolyze jellied agar and yield simple catalysates. Its molecular weight is different from all the agarases reported so far.
Xie
Hui
H
College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China. pingguo0526@yahoo.com.cn
Han
Baoqin
B
Dong
Wen
W
Yang
Yan
Y
Chang
Jing
J
Peng
Yanfei
Y
Liu
Wanshun
W
D034241:Alteromonadaceae / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004795:Enzyme Stability; D006026:Glycoside Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008970:Molecular Weight; D012623:Seawater / Q000382:microbiology*; D013379:Substrate Specificity
D001426:Bacterial Proteins; D006026:Glycoside Hydrolases; C019624:agarase