Syntrophic saturated fatty acid-oxidizing bacteria and their phylogeny: An extremely thermophilic, methanogenic bacterium and its plasmid
Zhao, Hongxue
This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.
Permalink
https://hdl.handle.net/2142/19250
Description
Title
Syntrophic saturated fatty acid-oxidizing bacteria and their phylogeny: An extremely thermophilic, methanogenic bacterium and its plasmid
Author(s)
Zhao, Hongxue
Issue Date
1991
Doctoral Committee Chair(s)
Bryant, Marvin P.
Department of Study
Microbiology
Discipline
Microbiology
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Biology, Microbiology
Language
eng
Abstract
Enriched from rural anaerobic digester sludge, anaerobic, sporing and nonsporing, curved and straight rod-shaped bacteria were isolated as cocultures with H$\sb2$- and formate-utilizing Methanospirillum hungatei or Desulfovibrio strain G-11. They oxidized four carbon to eight carbon saturated fatty acids, including isobutyrate and 2-methylbutyrate, with H$\sb2$ or formate as the electron sink product. The cocultures were adapted to grow on unsaturated acid crotonate, and pure subcultures of the syntrophs were then isolated. The crotonate-grown pure cultures alone did not grow on butyrate in either the presence or absence of some common electron acceptors. However, when they were reconstituted with M. hungatei, growth on butyrate again occurred. The pure isolates were subjected to 16S rRNA sequence analysis. Several previously documented mesophilic fatty acid-$\beta$-oxidizing syntrophs were also subjected to this comparative sequence analysis after adaptation to grow on crotonate and further purification. The sequence analyses revealed that our new sporeforming and nonsporing isolates and other syntrophs we sequenced, with either Gram-negative or Gram-positive cell wall ultrastructure, all belonged to the phylogenetically Gram-positive phylum of eubacteria. However, they were not closely related to any of the clusters of the Gram-positive phylum with which they were compared but they were all closely related to each other, forming a new cluster in the phylum. We recommended that this cluster be placed in the new family SYTROPHOMONADACEAE.
An extremely thermophilic methanogenic bacterium, strain AG86, was isolated from a deep sea hydrothermal vent mud sample. On the bases of its morphology, physiology, nutrition, DNA base composition and 16S rRNA partial sequence, the new isolate was the second strain of the species Methanococcus jannaschii. One plasmid was isolated from strain AG86 and two plasmids were isolated from the type strain of M. jannaschii. The three plasmids were different in DNA sequences. Membrane-bound ATPases of strain AG86 and other 4 strains of Methanococcus were studied in comparison to P-type and F-type ATPases at the levels of DNA homology, protein homology, inhibitor sensitivity, ion requirement and ion transport.
Use this login method if you
don't
have an
@illinois.edu
email address.
(Oops, I do have one)
IDEALS migrated to a new platform on June 23, 2022. If you created
your account prior to this date, you will have to reset your password
using the forgot-password link below.
