Day 2 :
Keynote Forum
Kathrin I Mohr
Helmholtz Centre for Infection Research, Germany
Keynote: Myxobacteria in moors: An astonishing diversity in an unusual habitat
Biography:
Kathrin I Mohr studied Biology at the TU Braunschweig. While doing Post doctorate, she investigated the biodiversity of algae and cyanobacteria in calcifying biofilms and in soil crusts from Namibia and South Africa at the University of Göttingen. Since 2009 she works as a Scientist at the Helmholtz Centre forInfectionResearch,Department Microbial Drugs, Braunschweig. Her main focus is set on the isolation of myxobacteria and their screen and enhancement of production of new and known secondary metabolites. She is the author and co-author of about 30 papers in reputed journals.
Abstract:
Many bacteria are able to generate resistances against antibiotics leading to an uncontrolled spreading of pathogenic strains.However, an efficient treatment of numerous diseases is missing due to the lack of specific drugs. Despite intensive world-wide efforts using alternative strategies based on synthetic chemistry, the exploitation of biologically active natural products as candidates for anti infective drugs is still the most promising approach. The majority of the medically important antibiotic drugs are derived from secondary metabolites, which are produced by bacteria and fungi. In addition to the wellstudied, highly productive actinobacteria, myxobacteria are a further rich source for new antibiotics. To date more than 100
new metabolites and more than 500 derivatives were described from these soil dwelling, predatory microorganisms. In the past it turns out that in particular new families, genera andspeciesofmyxobacteria are reliable sources for new bioactive compounds. Promising sources for the isolation of new myxobacteria are uncommon habitats like moors (peat bogs and fen), characterized by low pH values. Moors have been neglected with regard to the isolation of myxobacteria in the past. In our study, the diversity of myxobacteria in peat bogs and fen samples from the Harz-region, Germany, was evaluated by enhanced standard cultivation methods as well as by cultivation independent 16S rDNA clone bank analyses. Therefore a total of 278
clone sequences, sequences of 24 cultures isolated from moor within this study as well as sequences from the next relatives (NCBI) were added to a phylogenetic tree which in addition contains all myxobacterial type strains. The phylogenetic analysis revealed that the cultivated strains exclusively belong to the genus Corallococcus and that the majority of clone sequences represents unknown myxobacteria which could not be acquired by cultivation so far. In addition, most of our clone bank sequences are exclusively related to other, also uncultivated myxobacteria, which to a large extant came from studies about acidic soils, too. These results are in accordance with our preliminary comparative study about the diversity of myxobacteria in Kiritimati Island and German compost which also revealed significant discrepancies between the diversity of cultivable
myxobacteria and those exclusively detectable with cultivation-independent methods. Both studies have shown that there is a strong need to develop new and innovative isolation techniques to reach the numerous groups of myxobacteria which resist cultivation approaches. Especially uncommon habitats like moors, but also classical habitats like compost consist of numerous unknown myxobacterial species, genera and even families which in turn harbor a great potential of urgently needed, new antibiotics.
Keynote Forum
Kathrin I Mohr
Helmholtz Centre for Infection Research, Germany
Keynote: Myxobacteria in moors: An astonishing diversity in an unusual habitat
Time : 10:00-10:45
Biography:
Kathrin I Mohr studied Biology at the TU Braunschweig. While doing Post doctorate, she investigated the biodiversity of algae and cyanobacteria in calcifying biofilms and in soil crusts from Namibia and South Africa at the University of Göttingen. Since 2009 she works as a Scientist at the Helmholtz Centre forInfectionResearch,Department Microbial Drugs, Braunschweig. Her main focus is set on the isolation of myxobacteria and their screen and enhancement of production of
new and known secondary metabolites. She is the author and co-author of about 30 papers in reputed journals.
Abstract:
Many bacteria are able to generate resistances against antibiotics leading to an uncontrolled spreading of pathogenic strains.However, an efficient treatment of numerous diseases is missing due to the lack of specific drugs. Despite intensive world-wide efforts using alternative strategies based on synthetic chemistry, the exploitation of biologically active natural products as candidates for anti infective drugs is still the most promising approach. The majority of the medically important antibiotic drugs are derived from secondary metabolites, which are produced by bacteria and fungi. In addition to the wellstudied, highly productive actinobacteria, myxobacteria are a further rich source for new antibiotics. To date more than 100
new metabolites and more than 500 derivatives were described from these soil dwelling, predatory microorganisms. In the past it turns out that in particular new families, genera andspeciesofmyxobacteria are reliable sources for new bioactive compounds. Promising sources for the isolation of new myxobacteria are uncommon habitats like moors (peat bogs and fen), characterized by low pH values. Moors have been neglected with regard to the isolation of myxobacteria in the past. In our study, the diversity of myxobacteria in peat bogs and fen samples from the Harz-region, Germany, was evaluated by enhanced standard cultivation methods as well as by cultivation independent 16S rDNA clone bank analyses. Therefore a total of 278
clone sequences, sequences of 24 cultures isolated from moor within this study as well as sequences from the next relatives (NCBI) were added to a phylogenetic tree which in addition contains all myxobacterial type strains. The phylogenetic analysis revealed that the cultivated strains exclusively belong to the genus Corallococcus and that the majority of clone sequences represents unknown myxobacteria which could not be acquired by cultivation so far. In addition, most of our clone bank sequences are exclusively related to other, also uncultivated myxobacteria, which to a large extant came from studies about acidic soils, too. These results are in accordance with our preliminary comparative study about the diversity of myxobacteria in Kiritimati Island and German compost which also revealed significant discrepancies between the diversity of cultivable
myxobacteria and those exclusively detectable with cultivation-independent methods. Both studies have shown that there is a strong need to develop new and innovative isolation techniques to reach the numerous groups of myxobacteria which resist cultivation approaches. Especially uncommon habitats like moors, but also classical habitats like compost consist of numerous unknown myxobacterial species, genera and even families which in turn harbor a great potential of urgently needed, new
antibiotics.
Keynote Forum
Jonathan Gerbore
Biovitis, France
Keynote: Microorganisms to protect plants: Beneficial effects of the oomycete Pythium oligandrum on grapevines
Time : 10:45-11:30
Biography:
Jonathan Gerbore has received his PhD at the University of Pau et des Pays de l’Adour, France in 2013 in the field of Biotechnology and Agronomy. He is the Head of Research and Development at Biovitis company and works in collaboration with the research unit SAVE at the National Research French Institute (INRA).
Abstract:
Development of alternative methods to chemical pesticides to control plant diseases increased considerably in recent years.Among them, the use of beneficial microorganisms for plant protection and/or plant growth stimulation is promising,in particular under recent advances in trancriptomics and genome sequencing that give new insights in the potential of microorganisms and new product development opportunities. Here, we report the development of a biocontrol product based on the oomycete, Pythium oligandrum, to protect grape P. oligandrum ine against Esca, a major grapevine trunk disease that causes substantial losses in vineyards worldwide. No efficient chemical products are registered against this disease. In order to control Esca, P. oligandrum strains have been isolated from the rhizosphere of grapevines cultivated in the winegrowing region of Bordeaux (France). A multiyear greenhouse assay showed that P. oligandrum colonized grapevine rhizosphere over months, stimulated plant defense and can protect grapevine against Esca (disease reduction ranged from 40 to 60%). Trancriptomic analysis (Microarrays and RNAseq) showed that Induced Systemic Resistance (ISR) was activated in plants treated with P.oligandrum when challenged with pathogen. A priming effect was also pointed out. Currently, a method to manage Esca disease with this plant beneficial microorganism is developed.