An acidophilic and acid-stable beta-mannanase from phialophora sp. p13 with high mannan hydrolysis activity under simulated gastric conditions.
A beta-mannanase gene, man5AP13, was cloned from Phialophora sp. P13 and expressed in Pichia pastoris. The deduced amino acid sequence of the mature enzyme, MAN5AP13, had highest identity (53%) with the glycoside hydrolase family 5 beta-mannanase from Bispora sp. MEY-1. The purified recombinant beta-mannanase was acidophilic and acid stable, exhibiting maximal activity at pH 1.5 and retaining >60% of the initial activity over the pH range 1.5-7.0. The optimum temperature was 60 degrees C. The specific activity, K(m) and V(max) for locust bean gum substrate were 851 U/mg, 2.5 mg/mL, and 1667.7 U/min.mg, respectively. The enzyme had excellent activity and stability under simulated gastric conditions, and the released reducing sugar of locust bean gum was significantly enhanced by one-fold in simulated gastric fluid containing pepsin in contrast to that without pepsin. All these properties make MAN5AP13 a potential additive for use in the food and feed industries.
Zhao
Junqi
J
Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, P. R. China.
Shi
Pengjun
P
Luo
Huiying
H
Yang
Peilong
P
Zhao
Heng
H
Bai
Yingguo
Y
Huang
Huoqing
H
Wang
Hui
H
Yao
Bin
B
D001483:Base Sequence; D017931:DNA Primers; D004795:Enzyme Stability; D005753:Gastric Mucosa / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008351:Mannans / Q000378:metabolism*; D010676:Phialophora / Q000201:enzymology*; D013270:Stomach / Q000201:enzymology; D044902:beta-Mannosidase / Q000378:metabolism*
D017931:DNA Primers; D008351:Mannans; D044902:beta-Mannosidase