title: Interactions between oil substrates and glucose on pure cultures of ruminal lipase-producing bacteria.
abstract: The hydrolysis of free fatty acids from lipids is a prerequisite for biohydrogenation, a process that effectively saturates free fatty acids. Anaerovibrio lipolyticus 5s and Butyrivibrio fibrisolvens have long been thought to be the major contributors to ruminal lipolysis; however, Propionibacterium avidum and acnes recently have been identified as contributing lipase activity in the rumen. In order to further characterize the lipase activity of these bacterial populations, each was grown with three different lipid substrates, olive oil, corn oil, and flaxseed oil (3 %). Because different finishing rations contain varying levels of glycogen (a source of free glucose) this study also documented the effects of glucose on lipolysis. P. avidum and A. lipolyticus 5s demonstrated the most rapid rates (P < 0.05) of lipolysis for cultures grown with olive oil and flaxseed oil, respectively. A. lipolyticus, B. fibrisolvens, and P. avidum more effectively hydrolyzed flaxseed oil than olive oil or corn oil, especially in the presence of 0.02 % glucose. Conversely, P. acnes hydrolyzed corn oil more readily than olive oil or flaxseed oil and glucose had no effect on lipolytic rate. Thus, these bacterial species demonstrated different specificities for oil substrates and different sensitivities to glucose.
authors.affiliation: United States Department of Agriculture/Agricultural Research Service, Southern Plains, College Station 77845, USA.
authors.forename: H D
authors.initials: HD
authors.lastname: Edwards
authors.forename: R C
authors.initials: RC
authors.lastname: Anderson
authors.forename: T M
authors.initials: TM
authors.lastname: Taylor
authors.forename: R K
authors.initials: RK
authors.lastname: Miller
authors.forename: M D
authors.initials: MD
authors.lastname: Hardin
authors.forename: D J
authors.initials: DJ
authors.lastname: Nisbet
authors.forename: N A
authors.initials: NA
authors.lastname: Krueger
authors.forename: S B
authors.initials: SB
authors.lastname: Smith
mesh_terms: D000818:Animals; D045856:Butyrivibrio / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D002417:Cattle; D003314:Corn Oil / Q000378:metabolism; D003470:Culture Media; D005947:Glucose / Q000378:metabolism* / Q000494:pharmacology; D008043:Linseed Oil / Q000378:metabolism; D008049:Lipase / Q000378:metabolism*; D008066:Lipolysis / Q000187:drug effects; D000069463:Olive Oil; D010938:Plant Oils / Q000378:metabolism*; D011424:Propionibacterium / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D012417:Rumen / Q000187:drug effects / Q000382:microbiology*; D013379:Substrate Specificity; D045854:Veillonellaceae / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development
chemical_list: D003470:Culture Media; D000069463:Olive Oil; D010938:Plant Oils; D008043:Linseed Oil; D003314:Corn Oil; D008049:Lipase; D005947:Glucose