A Chitinase from Aeromonas veronii CD3 with the potential to control myxozoan disease.
BACKGROUND
The class Myxosporea encompasses about 2,400 species, most of which are parasites of fish and cause serious damage in aquaculture. Due to the concerns about food safety issues and limited knowledge of Myxozoa life cycle and fish immune system, no chemicals, antibiotics or immune modulators are available to control myxozoa infection. Therefore, little can be done once Myxozoa establishment has occurred.


RESULTS
In this paper we isolated Aeromonas veronii CD3 with significant myxospore shell valve-degrading ability from pond sediment. A 3,057-bp full-length chitinase gene was consequently cloned, and the corresponding mature, recombinant chitinase (ChiCD3) produced by Escherichia coli had substantial chitinase activity. The deduced sequence of ChiCD3 contained one catalytic domain, two chitin-binding domains, and one putative signal peptide. ChiCD3 had an optimal activity at 50°C and pH 6.0, and retained more than 50% of its optimal activity under warm water aquaculture conditions (∼30°C and pH ∼7.0). After incubation with ChiCD3, 38.0±4.8% of the myxospores had damaged shell valves, whereas myxospores incubated with commercially available chitinases remained intact.


CONCLUSIONS
This study reveals a new strategy to control myxozoan disease. ChiCD3 that has capacity to damage the shell valve of myxospores can be supplemented into fish feed and used to control Myxozoa-induced diseases specifically.
Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, People's Republic of China.
Yuchun
Y
Liu
Zhigang
Z
Zhou
Wei
W
Miao
Yuting
Y
Zhang
Yanan
Y
Cao
Suxu
S
He
Dongqing
D
Bai
Bin
B
Yao
D000333:Aeromonas / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D002688:Chitinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D003001:Cloning, Molecular; D007700:Kinetics; D008969:Molecular Sequence Data; D055764:Myxozoa / Q000033:anatomy & histology / Q000187:drug effects* / Q000302:isolation & purification / Q000378:metabolism; D010273:Parasitic Diseases, Animal / Q000188:drug therapy; D017421:Sequence Analysis; D013170:Spores / Q000187:drug effects / Q000378:metabolism; D013379:Substrate Specificity
D002688:Chitinases