title: Enhancement of ethanol production from potato-processing wastewater by engineering Escherichia coli using Vitreoscilla haemoglobin.
abstract: Ethanologenic Escherichia coli strain FBR5 was transformed with the Vitreoscilla haemoglobin (VHb) gene (vgb) in two constructs (resulting in strains TS3 and TS4). Strains FBR5, TS3 and TS4 were grown at two scales in LB medium supplemented with potato-processing wastewater hydrolysate. Aeration was varied by changes in the medium volume to flask volume ratio. Parameters measured included culture pH, cell growth, VHb levels and ethanol production. VHb expression in strains TS3 and TS4 was consistently correlated with increases in ethanol production (5-18%) under conditions of low aeration, but rarely did this occur with normal aeration. The increase in ethanol yields under low aeration conditions was the result of enhancement of ethanol produced per unit of biomass rather than enhancement of growth. 'VHb technology' may be a useful adjunct in the production of biofuels from food-processing wastewater.
  
  
  CONCLUSIONS
  Genetic engineering using Vitreoscilla haemoglobin (VHb) has been shown previously to increase ethanol production by Escherichia coli from fermentation of the sugars in corn fibre hydrolysate. The study reported here demonstrates a similar VHb enhancement of ethanol production by fermentation of the glucose from potato waste water hydrolysate and thus extends the list of sugar containing waste products from which ethanol production may be enhanced by this strategy.
authors.affiliation: Department of Molecular Biology and Genetics, Gebze Institute of Technology, Gebze-Kocaeli, Turkey.
authors.forename: K
authors.initials: K
authors.lastname: Abanoz
authors.affiliation: Biology Division, Department of Biological and Chemical Sciences, Illinois Institute of Technology, Chicago, IL, USA.
authors.forename: B C
authors.initials: BC
authors.lastname: Stark
authors.affiliation: Department of Molecular Biology and Genetics, Gebze Institute of Technology, Gebze-Kocaeli, Turkey.
authors.forename: M Y
authors.initials: MY
authors.lastname: Akbas
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000502:physiology*; D005818:Genetic Engineering; D005947:Glucose / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D011198:Solanum tuberosum / Q000737:chemistry*; D054793:Truncated Hemoglobins / Q000235:genetics*; D020589:Vitreoscilla / Q000235:genetics; D062065:Wastewater / Q000737:chemistry; D003313:Zea mays / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D000431:Ethanol; D005947:Glucose; D054793:Truncated Hemoglobins; D062065:Wastewater; C082613:hemoglobin protein, Vitreoscilla