title: Optimization of cultural conditions for conversion of glycerol to ethanol by Enterobacter aerogenes S012.
abstract: The aim of this research is to optimize the cultural conditions for the conversion of glycerol to ethanol by Enterobacter aerogenes S012. Taguchi method was used to screen the cultural conditions based on their signal to noise ratio (SN). Temperature (°C), agitation speed (rpm) and time (h) were found to have the highest influence on both glycerol utilization and ethanol production by the organism while pH had the lowest. Full factorial design, statistical analysis, and regression model equation were used to optimize the selected cultural parameters for maximum ethanol production. The result showed that fermentation at 38°C and 200 rpm for 48 h would be ideal for the bacteria to produce maximum amount of ethanol from glycerol. At these optimum conditions, ethanol production, yield and productivity were 25.4 g/l, 0.53 g/l/h, and 1.12 mol/mol-glycerol, repectively. Ethanol production increased to 26.5 g/l while yield and productivity decreased to 1.04 mol/mol-glycerol and 0.37 g/l/h, respectively, after 72 h. Analysis of the fermentation products was performed using HPLC, while anaerobic condition was created by purging the fermentation vessel with nitrogen gas.
authors: Energy and Environmental Systems, Sockwell Hall North Carolina A&T State University, 1601 East Market Street, Greensboro, NC, 27411, USA. nwannaray@yahoo.com.
authors: Raymond E S
authors: RE
authors: Nwachukwu
authors: Abolghasem
authors: A
authors: Shahbazi
authors: Lijun
authors: L
authors: Wang
authors: Mulumebet
authors: M
authors: Worku
authors: Salam
authors: S
authors: Ibrahim
authors: Keith
authors: K
authors: Schimmel
references: Biotechnol Bioeng. 2006 Aug 5;94(5):821-9
references: 16715533
references: Appl Microbiol Biotechnol. 2012 Mar;93(5):1865-75
references: 22322872
references: Curr Opin Biotechnol. 2007 Jun;18(3):213-9
references: 17532205
references: Biosci Biotechnol Biochem. 2007 Dec;71(12):3048-54
references: 18071247
references: J Biosci Bioeng. 2005 Sep;100(3):260-5
references: 16243274
references: Metab Eng. 2008 Sep;10(5):234-45
references: 18632294
references: Biotechnol Bioeng. 2009 May 1;103(1):148-61
references: 19189409
references: Appl Environ Microbiol. 2008 Feb;74(4):1124-35
references: 18156341
references: Bioresour Technol. 2011 Feb;102(4):3918-22
references: 21186120
references: Appl Microbiol Biotechnol. 2011 Feb;89(4):1255-64
references: 21212944
references: Recent Pat Biotechnol. 2008;2(3):173-80
references: 19075864
references: AMB Express. 2012 Mar 29;2:20
references: 22455837
references: Bioresour Technol. 2012 Feb;106:154-60
references: 22206915
references: Appl Microbiol Biotechnol. 2007 Jan;73(5):1017-24
references: 16960737
references: Appl Microbiol Biotechnol. 2003 Dec;63(2):143-6
references: 12908084