Hyperexpression of two Aspergillus niger xylanase genes in Escherichia coli and characterization of the gene products
Braz. j. microbiol
;
41(3): 778-786, Oct. 2010. ilus, graf, tab
Artigo
em Inglês
| LILACS
| ID: lil-549419
ABSTRACT
The analysis of individual gene product should enable to clarify the role of a particular enzyme in a complex xylanase system of A. niger. The two genes encoding precursors of co-produced endo-1,4-¥â-D-xylanases, xynA1 and xynB, were isolated from Aspergillus niger SCTCC 400264 (SCTCC, China) by using RT-PCR technique and then successfully expressed in Escherichia coli BL21. The nucleotide sequences of the xynA1 and xynB genes revealed that they were only 52.5 percent homology to each other. Characterization of the recombinant enzymes revealed the different properties the specific activity of recombinant XYNA1 was 16.58 U/mg compared to 1201.7 U/mg for recombinant XYNB; The optimum temperature and pH of the recombinant XYNA1 were 35 ¨¬C and 3.0, respectively, whereas the corresponding values for the recombinant XYNB were 55 ¨¬C and 5.0, respectively; The recombinant XYNB showed much more thermostability than recombinant XYNA1; The recombinant XYNB showed 94 percent of maximal activity after incubating in water for 60 min at 60 ¨¬C compared to no activity for recombinant XYNA1. Various metal ions had different effects on activity between the two recombinant xylanases.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Aspergillus niger
/
Xilanos
/
Técnicas In Vitro
/
Sequência de Bases
/
Expressão Gênica
/
Reação em Cadeia da Polimerase
Idioma:
Inglês
Revista:
Braz. j. microbiol
Assunto da revista:
Microbiologia
Ano de publicação:
2010
Tipo de documento:
Artigo
/
Documento de projeto
País de afiliação:
China
Instituição/País de afiliação:
Sichuan BioShine Biotechnology Co/CN
/
Sichuan University/CN
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