title: Comparison of expression systems for the extracellular production of mannanase Man23 originated from Bacillus subtilis B23.
abstract: BACKGROUND
  Mannanase is an enzyme that can catalyze random hydrolysis of beta-1,4-mannosidic linkages in the main chain of mannans, glucomannans and galactomannans which are the key polymers in hemicellulose. It has been used in a number of different industrial applications including food, feed, pharmaceutical, pulp/paper industries, and second generation biofuel. To optimize the expression system of mannanase Man23 gene, two kinds of vectors and host bacteria were determined and compared.
  
  
  RESULTS
  Recombinants pHY-p43-man23 and pBPS-man23 were constructed and transferred into Bacillus subtilis WB600 and Brevibacillus brevis respectively. For mannanase Man23 gene, recombinant pHY-p43-man23 expressed in Brevibacillus brevis had higher production and activity. Compared to the wild-type Bacillus subtilis B23, the production of recombinant pHY-p43-man23 in B. brevis increased by 10 times and activity increased by 21.3%. pHY-p43-man23 in B. brevis had activity at the range of 20 ~ 70 °C but its optimum temperature was 50 °C and had activity from pH 4 ~ 10 but its optimum pH was around 7. This demonstrated the recombinant had improved stability as well.
  
  
  CONCLUSIONS
  Mannanase is an important industrial enzyme and combination of vector pHY-p43 and host Brevibacillus brevis is a novel expression system for a mannanase decoding gene. This work aims at exploring a better expression system of mannanase Man23 decoding gene for industrial application.
authors.affiliation: College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China. sws001@163.com.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Zhou
authors.forename: Yong
authors.initials: Y
authors.lastname: Yang
authors.forename: Xu
authors.initials: X
authors.lastname: Nie
authors.forename: Wenjiao
authors.initials: W
authors.lastname: Yang
authors.forename: Yongyao
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics; D044902:beta-Mannosidase / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics
chemical_list: D011994:Recombinant Proteins; D044902:beta-Mannosidase