title: Fermentation characteristics of Mortierella alpina in response to different nitrogen sources.
abstract: The fermentation characteristics of Mortierella alpina were investigated in response to various nitrogen sources. Influences on nitrogen source and glucose uptake rate, mycelial morphology of M. alpina, and pH of medium in relation to different nitrogen sources were discussed. Effects of different nitrogen sources on cell growth, fatty acid composition, arachidonic acid (ARA), and total lipid concentration were also evaluated. It revealed that the maximum nitrogen source uptake ratio was obtained when corn steep liquor was used as nitrogen source. When yeast extract was used as the sole nitrogen source, glucose was completely exhausted at the end of fermentation. The maximum dry cell weight obtained from medium with yeast extract as nitrogen source had the highest total lipid concentration. Sodium nitrate was the favorable nitrogen source for ARA accumulation, and the highest ARA percentage in total fatty acids was obtained, 35.9%. Urea was identified as the favorable nitrogen source for ARA production, the highest ARA concentration obtained from urea was 5.8 g/l. Compared with inorganic nitrogen sources, organic nitrogen compounds are favorable for both cell growth and total lipids accumulation.
authors.affiliation: College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, No. 5 Xinmofan Road, Nanjing 210009, People's Republic of China.
authors.forename: Jinmiao
authors.initials: J
authors.lastname: Lu
authors.forename: Chao
authors.initials: C
authors.lastname: Peng
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Ji
authors.forename: Jiangying
authors.initials: J
authors.lastname: You
authors.forename: Leilei
authors.initials: L
authors.lastname: Cong
authors.forename: Pingkai
authors.initials: P
authors.lastname: Ouyang
authors.forename: He
authors.initials: H
authors.lastname: Huang
mesh_terms: D016718:Arachidonic Acid / Q000096:biosynthesis; D001709:Biotechnology / Q000379:methods*; D002244:Carbon / Q000378:metabolism; D003470:Culture Media; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D020094:Mortierella / Q000737:chemistry / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D025282:Mycelium / Q000737:chemistry / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D012988:Soil Microbiology; D013696:Temperature; D014508:Urea / Q000378:metabolism; D003313:Zea mays / Q000378:metabolism
chemical_list: D003470:Culture Media; D009566:Nitrates; D016718:Arachidonic Acid; D002244:Carbon; C031618:sodium nitrate; D014508:Urea; D005947:Glucose; D009584:Nitrogen