Chlorochromatium aggregatum - molecular basis of a bacterial symbiosis [Elektronische Ressource] / vorgelegt von Kajetan Vogl

Kajetan Vogl

Sujets

• Biologie

Informations

• Publié par: ludwig-maximilians-universitat_munchen
• Publié le: 01 janvier 2007
• Nombre de lectures: 17
• Langue: English
• Poids de l'ouvrage: 7 Mo

Extrait

"Chlorochromatium aggregatum" – molecular basis of
a bacterial symbiosis




Dissertation
der Fakultät für Biologie
der Ludwig-Maximilians-Universität München


vorgelegt von





Kajetan Vogl
aus München



München
im Dezember 2007










































1. Gutachter: Prof. Dr. Jörg Overmann, LMU München
2. Gutachter: Prof. Dr. Anton Hartma




Tag des Promotionskolloquiums: 18.02.2008
Publications originating from this thesis



Chapter 2:
Vogl K, Glaeser J, Pfannes KR, Wanner G, Overmann J (2006) Chlorobium chlorochromatii sp.
nov., a symbiotic green sulfur bacterium isolated from the phototrophic consortium
“Chlorochromatium aggregatum”. Arch Microbiol 185:363-372

Chapter 3:
Vogl K, Dreßen M, Wenter R, Schlickenrieder M, Overmann J (2007) Identification and analysis
of four candidate symbiosis genes from "Chlorochromatium aggregatum", a highly developed
bacterial symbiosis. Submitted

Chapter 4:
Wanner G, Vogl K, Overmann J (2007) Ultrastructural characterization of the prokaryotic
symbiosis in "Chlorochromatium aggregatum". manuscript

Chapter 5:
Kanzler BEM, Pfannes KR, Vogl K, Overmann J (2005) Molecular characterization of the
nonphotosynthetic partner bacterium in the consortium “Chlorochromatium aggregatum”. Appl
Environ Microbiol 71:7434-7441

Chapter 6:
Pfannes KR, Vogl K, Overmann J (2007) Heterotrophic symbionts of phototrophic consortia:
members of a novel diverse cluster of Betaproteobacteria characterized by a tandem rrn operon
structure. Environ Microbiol 9:2782-94

Contributions of the Co-authors



Chapter2:
Dr. Jens Glaeser generated an enrichment culture containing the epibiont of “Chlorochromatium
aggregatum” and a heterotrophic bacterium. He also performed the DGGE.
Kristina Pfannes determined the salinity optimum and the cell surface hydrophobicity of the
epibiont. She did the KOH-string test and the gram-staining and extracted the pigments of the
epibiont.
Prof. Dr. Gerhard Wanner carried out the electron microscopy.

Chapter 3:
Martina Müller and Martina Schlickenrieder made the disaggregation studies of
“Chlorochromatium aggregatum”.
Roland Wenter performed the long range RT-PCR of Cag_1919.

Chapter 4:
Kajetan Vogl cultivated the phototrophic consortia and Chlorobium chlorochromatii. He
discussed the results and wrote the manuscript together with Prof. Dr. Wanner.

Chapter 5:
Kajetan Vogl developed the experimental strategy to get the 16S rRNA sequence of the central
bacterium together with Prof. Dr. Overmann. He established the design of specific probe and
FISH with helper oligonucleotides with Cont-995 and instructed the diploma student Birgit
Kanzler in these methods.

Chapter 6:
Kajetan Vogl developed the new cultivation approach of phototrophic consortia.




I hereby confirm the above statements









Kajetan Vogl Prof. Dr. Jörg Overmann Table of contents
Table of contents

Page
Chapter 1 Introduction 1
Chapter 2 Chlorobium chlorochromatii sp. nov., a symbiotic green sulfur 19
bacterium isolated from the phototrophic consortium
"Chlorochromatium aggregatum"
Abstract 20
Introduction 21Material and Methods 22Results and Discussion 28
References 38
Chapter 3 Identification and analysis of three candidate symbiosis genes 41
from "Chlorochromatium aggregatum", a highly developed
bacterial symbiosis
Summary 42
Introduction 43Results 44Discussion 57
Experimental Procedures 62References 69
Ultrastructural elements of the prokaryotic symbiosis in Chapter 4 75
"Chlorochromatium aggregatum"
Abstract 76
Introduction 77Material and Methods 78Results 80
Discussion 89References 95
Table of contents
Chapter 5 Molecular characterization of the non-photosynthetic partner 99
bacterium in the consortium “Chlorochromatium aggregatum”
Abstract 100
Introduction 101Material and Methods 102Results and Discussion 109
References 118
Chapter 6 Heterotrophic symbionts of phototrophic consortia: members of a 123
novel diverse cluster of Betaproteobacteria characterized by a
tandemrrn operon structure
Summary 124
Introduction 125Results and Discussion 127Experimental Procedures 141
References 146
Chapter 7 Discussion 153

Chapter 8 Summary 169

Ι. Danksagung

ΙΙ. Lebenslauf
Introduction Chapter 1
Introduction

Symbiotic relationships
Living together of two different species of organisms independent on the outcome of the
interaction was defined as symbiosis by de Bary (1879). Symbiosis can therefore be seen as a
long-term interaction between organisms that ranges from mutualistic to pathogenic associations.
Mostly the term “symbiosis” is used for interactions where at least one organism benefits from
the other. Two kinds of cooperation can be distinguished: commensalism and mutualism. In a
commensal relationship one individuum benefits but not the other. In mutual interaction both
partners benefits with a range from only marginal support to absolute mutual dependence.

Symbiosis of bacteria with eukaryotes
Many symbioses involve prokaryotes which are associated with eukaryotes. For symbiosis
between microbes and animals, several model systems have been developed and full genome
sequences of symbionts are available. Examples are the genomes of Buchnera sp.,
Wigglesworthia sp., Sodalis glossinidius, Vibrio fischeri and Photorhabdus luminescens (Moran
2006). Buchnera aphidocola is a symbiont of aphids and provides them with essential amino
acids. African tsetse flies harbor Wigglesworthia sp., Sodalis glossinidius. Sodalis glossinidius
has three type III secretion systems and Wigglesworthia supplies the flies with vitamins and
cofactors. Vibrio fisheri lives in specialized light organs of Euprymna scolopes. The light
produced by Vibrio fisheri uses Euprymna scolopes for counterlighting to reduce its visibility to
predators (Dale and Moran 2006; Moran 2006). Photorhabdus luminescens shows a mutual and
virulent behavior during his life–cycle. Photorhabdus colonizes the intestinal tract of young
nematodes with infect insect hosts. The bacteria are released into the blood of the insects.
Photorhabdus then kills the insects and converts the insect body into food source for nematodes
and reinfects young nematodes. Genes for the production of bioactive compounds were found in
the genome of Photorhabdus luminescens (Moran 2006; Goodrich-Blair and Clarke 2007).
Among the symbioses between bacteria and plant, the root nodule symbiosis of rhizobia and
legumes is well understood. The bacterial symbionts fix molecular dinitrogen and provide
reduced nitrogen for plant growth. The plant provides photosynthates in form of dicarboxylic
acid, particularly malate and succinate (Lodwig and Poole 2003) and a microaerobic niche for
the oxygen-sensitive nitrogenase. Both partners can be manipulated genetically and genome
1Chapter 1 Introduction
sequence information is available. Genome sequences of the symbiotic nitrogen fixing bacteria
Bradyrhizobium japonicum, Mesorhizobium loti, Rhizobium leguminosarum bv. viciae and
Sinorhizobium meliloti are accessible via the webpage of DOE Joint genome institute
(http://www.jgi.doe.gov/) and for Medicago truncatula TIGR Medicago truncatula Genome
Project provides access to sequence information.

Bacteria-bacteria interaction
In contrast to interactions between prokaryotes and eukaryotes, interspecies interactions between
prokaryotic cells have been studied mainly with respect to syntrophic cooperations (Schink
2002). Syntrophic cooperations comprise anaerobic degradation of amino acids and sugars where
energetical restrictions do not necessarily force the partner organisms into strict
interdependencies because one of both can run the fermentation process on its own.
Methanogenic degradation of electron-rich substrates like fatty acids, alcohols and aromatics
where hydrogen acts predominantly as electron carrier between oxidative and reductive
metabolic processes are further examples for syntrophic cooperations. Due to energy limitation,
with only fractions of an ATP unit synthesized per substrate molecule metabolized, the
cooperation is intensified by close proximity of the partner cells (Schink 1997; Schink 2002). A
stable syntrophic association