[Producing human lactoferrin by high-density fermentation recombinant Pichia pastoris].
BACKGROUND
To evaluate expression of human lactoferrin gene by high-density fermentation in recombinant Pichia pastoris on the premise of maintaining its biological activities.


METHODS
The neutrophil was isolated from human peripheral blood and its total RNA was prepared. Full-length cDNA of human lactoferrin gene was then obtained by RT-PCR, cloned into expression vector pPIC 3.5 K and transformed into Pichia pastoris strain KM71. With two-layer filter method, the transformants with high-productivity of human lactoferrin were screened out into fed-batch high-density fermentation. And later, the physical, chemical and biological activities of fermentation product were detected preliminarily.


RESULTS
The strain p3.5-k-7 with better productivity of human lactoferrin was screened out into fed-batch high-density fermentation. The fermentation lasted nearly for nine days, with A-600 of culture once above 260 and the highest productivity of human lactoferrin being 115 mg/L, 7.67 times the amount of that in shake flask cultivation.


CONCLUSIONS
The authors successfully realized high-density fermentation expression of human lactoferrin gene in recombinant Pichia pastoris.
Ying
Ge
G
Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 100052, China.
Wu
Shu-hua
SH
Wang
Jing
J
Zhao
Xiao-dong
XD
Chen
Jian-ming
JM
Zhang
Xiao-guang
XG
Hou
Yun-de
YD
D003001:Cloning, Molecular; D005285:Fermentation; D006801:Humans; D007781:Lactoferrin / Q000096:biosynthesis* / Q000235:genetics; D010843:Pichia / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis*
D011994:Recombinant Proteins; D007781:Lactoferrin