[Survival properties of ETEC surface-displayed K88ac-LT(B) on Lactobacillus casei].
K88ac-LT(B) gene derived from pQE30-K88ac-LT(B) was cloned into the expression vector pLA and then the recombinant vector was transformed into the competent cells Lactobacillus casei 525. The recombinant bacteria were grown at 37 degrees C, in MRS broth. Western blotting analysis with rabbit-anti-K88ac-LT(B) polyclonal serum indicated that the recombinant protein reacted with the specific antibodies. The results showed that the molecular weight of the recombinant protein was about 71.2 kD. The K88ac-LT(B) fusion protein on the cell surface was confirmed by immunofluorescence mciroscopy and flow cytometric analysis. In addition, the survival of recombinant Lactobacillus casei 525 was studied in imitative gastrointestinal environments such as artificial gastro fluid (pH 1.5-5.5), artificial intestinal fluid, bile(0.3-3.0 g/L). The results indicated that the recombinant strain survived well in artificial gastric fluids at pH 2.5-4.5 in 5 h. The recombinant Lactobacillus casei 525 could slowly grow in the artificial intestinal fluid for different time, and could survive in 0.3% bile.
College of Animal Science and Technology, Heilongjiang August First Land Reclamation University, Daqing 163319, China.
Chunhua
C
Wei
Jiankui
J
Liu
Xilin
X
Hou
Guihua
G
Wang
Liyun
L
Yu
D000942:Antigens, Bacterial / Q000235:genetics*; D001427:Bacterial Toxins / Q000235:genetics* / Q000378:metabolism; D054307:Enterotoxigenic Escherichia coli / Q000235:genetics* / Q000378:metabolism; D004768:Enterotoxins / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D036781:Fimbriae Proteins / Q000235:genetics*; D005750:Gastric Juice; D007780:Lacticaseibacillus casei / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D011995:Recombination, Genetic
D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C026888:K88 antigen, E coli; D011993:Recombinant Fusion Proteins; D036781:Fimbriae Proteins; C027538:heat-labile enterotoxin, E coli