title: [Superoxide dismutase, malondialdehyde and proline as new quality criteria for Schizochytrium sp. fermentation].
abstract: OBJECTIVE
  The aim of our study was to find a novel method to evaluate the strain quality of Schizochytrium sp. HX-308.
  
  
  METHODS
  An acclimatized strain and an original strain were cultivated under normal condition. Meanwhile, the same acclimatized strain was cultured under two different conditions, the optimum condition and the harsh condition. We detected the activity of superoxide dismutase and the contents of malondialdehyde and proline by WST-1 method, thiobarbituric acid test and colorimetry, respectively. The relationship between the three criteria and the fermentation performance of Schizochytrium sp. HX-308 was studied.
  
  
  RESULTS
  The acclimatized strain cultured under the optimal fermentation condition had the lowest superoxide dismutase activity (0.025 U/g protein), malondialdehyde (26.20 mmol/g x Fw) and proline contents (0.098 mg/g x Fw). In contrast, the superoxide dismutase activity of the original strain cultured in the harsh conditions was 5 times higher than that of the acclimatized strain, the malondialdehyde and proline contents were both 2 times as high as the acclimatized strain.
  
  
  CONCLUSIONS
  The three criteria were correlated negatively with the fermentation performance. Thus, they could be used to evaluate quality and fermentation performance of Schizochytrium sp.
authors.affiliation: College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, China. lizhang.0402@163.com
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Lujing
authors.initials: L
authors.lastname: Ren
authors.forename: Yuanwei
authors.initials: Y
authors.lastname: Hu
authors.forename: Liang
authors.initials: L
authors.lastname: Qu
authors.forename: He
authors.initials: H
authors.lastname: Huang
mesh_terms: D005285:Fermentation; D008315:Malondialdehyde / Q000378:metabolism*; D058086:Microalgae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D011392:Proline / Q000378:metabolism*; D058009:Stramenopiles / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism*
chemical_list: D008315:Malondialdehyde; D011392:Proline; D013482:Superoxide Dismutase