title: Growth, ethanol production, and inulinase activity on various inulin substrates by mutant Kluyveromyces marxianus strains NRRL Y-50798 and NRRL Y-50799.
abstract: Economically important plants contain large amounts of inulin. Disposal of waste resulting from their processing presents environmental issues. Finding microorganisms capable of converting inulin waste to biofuel and valuable co-products at the processing site would have significant economic and environmental impact. We evaluated the ability of two mutant strains of Kluyveromyces marxianus (Km7 and Km8) to utilize inulin for ethanol production. In glucose medium, both strains consumed all glucose and produced 0.40 g ethanol/g glucose at 24 h. In inulin medium, Km7 exhibited maximum colony forming units (CFU)/mL and produced 0.35 g ethanol/g inulin at 24 h, while Km8 showed maximum CFU/mL and produced 0.02 g ethanol/g inulin at 96 h. At 24 h in inulin + glucose medium, Km7 produced 0.40 g ethanol/g (inulin + glucose) and Km8 produced 0.20 g ethanol/g (inulin + glucose) with maximum CFU/mL for Km8 at 72 h, 40 % of that for Km7 at 36 h. Extracellular inulinase activity at 6 h for both Km7 and Km8 was 3.7 International Units (IU)/mL.
authors.affiliation: Department of Chemistry, Illinois State University, Normal, IL, 61790-4160, USA.
authors.forename: Luz Ángela
authors.initials: LÁ
authors.lastname: Galindo-Leva
authors.affiliation: United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA. stephen.hughes@ars.usda.gov.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Hughes
authors.affiliation: National Coffee Research Centre (Cenicafe) National Federation of Coffee Growers of Colombia (FNC), Cenicafé Planalto Km 4 vía Antigua Chinchiná, Manizales, Caldas, Colombia.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: López-Núñez
authors.affiliation: Department of Chemistry, Illinois State University, Normal, IL, 61790-4160, USA.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Jarodsky
authors.affiliation: Department of Chemistry, Illinois State University, Normal, IL, 61790-4160, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Erickson
authors.affiliation: United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA.
authors.forename: Mitchell R
authors.initials: MR
authors.lastname: Lindquist
authors.affiliation: United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA.
authors.forename: Elby J
authors.initials: EJ
authors.lastname: Cox
authors.affiliation: United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA.
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Bischoff
authors.affiliation: United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Hoecker
authors.affiliation: United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA.
authors.forename: Siqing
authors.initials: S
authors.lastname: Liu
authors.affiliation: United States Department of Agriculture (USDA) Agricultural Research Service (ARS) National Center for Agricultural Utilization Research (NCAUR) Renewable Product Technology Research Unit, 1815, North University Street, Peoria, IL, 61604, USA.
authors.forename: Nasib
authors.initials: N
authors.lastname: Qureshi
authors.affiliation: Department of Chemistry, Illinois State University, Normal, IL, 61790-4160, USA.
authors.forename: Marjorie A
authors.initials: MA
authors.lastname: Jones
mesh_terms: D056804:Biofuels; D003069:Coffee / Q000737:chemistry; D003470:Culture Media / Q000737:chemistry; D000431:Ethanol / Q000378:metabolism*; D005947:Glucose / Q000737:chemistry; D006026:Glycoside Hydrolases / Q000378:metabolism*; D007444:Inulin / Q000737:chemistry*; D007716:Kluyveromyces / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D009154:Mutation
chemical_list: D056804:Biofuels; D003069:Coffee; D003470:Culture Media; D000431:Ethanol; D007444:Inulin; D006026:Glycoside Hydrolases; C023086:inulinase; D005947:Glucose
keywords: Biorefinery platform; Coffee waste fermentation; Inulin; Inulinase; Kluyveromyces marxianus