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Title: Metabolism of fatty acids by Syntrophomonas wolfei. Progress report, March 15, 1983-December 15, 1984

Abstract

The main objective in this research is to obtain basic information on the metabolism and physiology of the H/sub 2/-producing acetogenic bacteria. Syntrophomonas wolfei degrades butyrate, caproate and caprylate to acetate and H/sub 2/, valerate and heptanoate to acetate, propionate and H/sub 2/, and isoheptanoate to acetate, isovalerate and H/sub 2/. Since the degradation of these compounds with H/sub 2/ production is energetically favorable only when the partial pressure of H/sub 2/ is maintained at a very low level, S. wolfei can only be grown in coculture with H/sub 2/-using bacteria. The first objectives of this research were to determine if S. wolfei could be grown alone if the partial pressure of H/sub 2/ was maintained at a low level by sparging the culture with anaerobic gas.

Authors:
Publication Date:
Research Org.:
Oklahoma Univ., Norman (USA)
OSTI Identifier:
5022654
Report Number(s):
DOE/ER/13053-1
ON: DE84008351
DOE Contract Number:
AS05-83ER13053
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; 08 HYDROGEN; BACTERIA; GROWTH; MONOCARBOXYLIC ACIDS; METABOLISM; ANAEROBIC CONDITIONS; SYMBIOSIS; CARBOXYLIC ACIDS; MICROORGANISMS; ORGANIC ACIDS; ORGANIC COMPOUNDS; 550700* - Microbiology; 080106 - Hydrogen- Production- Biosynthesis & Photochemical Processes

Citation Formats

McInerney, M.J.. Metabolism of fatty acids by Syntrophomonas wolfei. Progress report, March 15, 1983-December 15, 1984. United States: N. p., 1984. Web.
McInerney, M.J.. Metabolism of fatty acids by Syntrophomonas wolfei. Progress report, March 15, 1983-December 15, 1984. United States.
McInerney, M.J.. 1984. "Metabolism of fatty acids by Syntrophomonas wolfei. Progress report, March 15, 1983-December 15, 1984". United States. doi:.
@article{osti_5022654,
title = {Metabolism of fatty acids by Syntrophomonas wolfei. Progress report, March 15, 1983-December 15, 1984},
author = {McInerney, M.J.},
abstractNote = {The main objective in this research is to obtain basic information on the metabolism and physiology of the H/sub 2/-producing acetogenic bacteria. Syntrophomonas wolfei degrades butyrate, caproate and caprylate to acetate and H/sub 2/, valerate and heptanoate to acetate, propionate and H/sub 2/, and isoheptanoate to acetate, isovalerate and H/sub 2/. Since the degradation of these compounds with H/sub 2/ production is energetically favorable only when the partial pressure of H/sub 2/ is maintained at a very low level, S. wolfei can only be grown in coculture with H/sub 2/-using bacteria. The first objectives of this research were to determine if S. wolfei could be grown alone if the partial pressure of H/sub 2/ was maintained at a low level by sparging the culture with anaerobic gas.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 1984,
month = 1
}

Technical Report:
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  • Progress is reported in the following research areas: (1) metabolic studies of Syntrophomonas wolfei; (2) evidence for a carrier-mediated system for the electrogenic excretion of acetate in Desulfovibrio desulfurecans; and (3) development of a method to positively select for nitrous oxide producing bacteria. (ACR)
  • The degradation of fatty acids is often the rate-limiting step in the complete anaerobic degradation of organic matter to CO/sub 2/ and CH/sub 4/. Syntrophomonas wolfei anaerobically degrades even-numbered fatty acids to acetate and H/sub 2/, odd-numbered fatty acids to acetate, propionate and H/sub 2/, and isoheptanoate to acetate, isovalerate and H/sub 2/ only when grown in co-culture with H/sub 2/-using bacteria such as methanogens. Methods to mass culture the S. wolfei - Methanospirillum hungatei co-culture have been developed and about 1 to 1.5 g (wet weight) of cells is obtained from a 10-liter culture in 4 to 6 weeks.more » S. wolfei cells were selective lyzed by lysozyme and the unlyzed cells of M. hungatei were removed by centrifugation. Methods have been developed to study the biochemistry of this important group of bacteria. Cell-free-extracts of S. wolfei have very high specific activities of the following beta-oxidation enzymes: acyl-coenzyme A(CoA) dehydrogenase, enoyl-CoA hydratase, L-3-hydroxy-acyl-CoA dehydrogenase and thiolase. The specific activity of these enzymes in S. wolfei is 5 to 168-fold higher than the specific activity of the respective enzyme in Escherichia coli extracts assayed under identical conditions. We have recently obtained preliminary evidence that the hydrogenase of S. wolfei is membrane-bound.« less
  • We developed methods to physically separate cells of the anaerobic, fatty acid degrade, Syntrophomonas wolfei, from cells of the hydrogen user by Percoll gradient centrifugation and to selectively lyse S. wolfei cells using lysozyme. These methods allowed the study of the physiology of S. wolfei without significant contamination. Fatty acids were degraded by the B-oxidation pathway using a coenzyme A (CoA) transferase activity to activate the fatty acid and substrate- level phosphorylation reactions to synthesize. The substrate specificity of the CoA transferase activity in the pure culture of S. wolfei differed from that found in the coculture suggesting that themore » ability to use crotonate resulted from an alteration of this enzyme. S. wolfei grown alone degraded crotonate in a manner similar to that of other crotonate-fermenting anaerobes, but the molar growth yields of S. wolfei were 2 to 3 times higher than those organisms. This suggests that the reduction of crotonyl-CoA to butyryl-CoA is energy yielding. S. wolfei contained a c-type cytochrome which may be involved in this reaction. S. wolfei synthesized large amounts of the storage polymer, poly-B-hydroxybutyrate.« less
  • This work addresses the metabolism of fatty acids and the energetics of growth of the anaerobic, syntrophic, fatty acid-degrading bacterium, Syntrophomonas wolfei. S. wolfei degrades C/sub 4/ to C/sub 8/ straight chain fatty acids to acetate and H/sub 2/ or acetate, propionate and H/sub 2/; isoheptanoate is degraded to isovalerate, acetate, and H/sub 2/. S. wolfei can not use any common bacterial energy source that will allow it to grow in pure culture. A significant breakthrough in the cultivation of S. wolfei was achieved. Long term (3 months) incubation of S. wolfei cocultures in medium with crotonate selects for amore » population of S. wolfei cells that can use this compound. These cultures contain large numbers of S. wolfei cells and very few cells of the methanogen. Pure cultures of S. wolfei do not use butyrate. However, when pure cultures of S. wolfei are incubated in the presence of H/sub 2/-using bacteria, butyrate is degraded to acetate and H/sub 2/. These data show that the cells present in the pure cultures are in fact S. wolfei. Growth of S. wolfei with crotonate is faster and much higher cell densities are obtained. Thus, large amounts of cell material will be available for biochemical studies. 3 refs.« less
  • We have studied the growth and metabolism of Syntrophomonas wolfei in pure culture with crotonate as the energy source. S. wolfei grows in crotonate mineral salts medium without rumen fluid with cobalamin, thymine, lipoic acid and biotin added. However, after four to six transfers in this medium, growth ceases, indicating that another vitamin is required. The chemically defined medium allows large batches of S. wolfei to be grown for enzyme purification. All the enzymes involved in the oxidation of crotonyl-CoA to acetate have been detected. The pure culture of S. wolfei or coculture of S. wolfei grown with crotonate containmore » high activities of a crotonate: acetyl-CoA CoA-transferase activity. This activity is not detected in cocultures grown with butyrate. Thus, we believe that the reason why S. wolfei can now grow with crotonate is that an alteration or mutation occurred which allows the organism to activate this crotonate. S. wolfei also makes small amounts of H/sub 2/ when grown in pure culture with crotonate. A methyl viologen-dependent hydrogenase activity was found. We have also demonstrated the production of H/sub 2/ from 3-hydroxybutyryl-CoA in cell-free extracts of S. wolfei by coupling H/sub 2/ production to CH/sub 4/ production with the addition of Methanobacterium bryantii and directly using a hydrogen electrode. These results clearly show that S. wolfei makes H/sub 2/. S. wolfei does not contain formate dehydrogenase or CO dehydrogenase activities.« less