Bioprospecting plant metagenomes for novel enzymes and bioactive volatiles

(c) Christina A. Müller

Funding & Project no.: FFG-ACIB, 24.080

PI: Gabriele Berg; Project leader: Christina A. Müller; Coworker: Melanie M. Obermeier

Duration: 2015-2019

Abstract: In these ACIB strategic project we have two main objectives: The first part of the project covers the functional analysis of recently discovered metagenomic enzymes for biocatalytic processes (“enzyme research”). We established a screening platform for the moss metagenome and screeningstrategies that led to identification of novel enzymes (esterases, decarboxylases, phosphatases) with potential application in biocatalysis. Based on the growing demand for enzymes acting on polymeric compounds, we want to place emphasis especially on the degradation of polyethylene terephthalate or similar biodegradable synthetic polymers. In ongoing research we have detected several esterases acting on polymers (polyesterases). The identified polyesterases have to be characterized in detail to evaluate their industrial applicability.

(c) Christina A. Müller

The second part of the project will focus on the discovery of novel bioactive volatile compounds from microbial origin in plant-associated metagenomes (“natural product research”). We will apply a new in vitro screening system to assess the availability of microbial volatile organic compounds (VOCs) in selected metagenomic databases and libraries available at our institute. This will include the exploitation of the microbiomes from moss and lichens for the discovery of novel gene sequences and pathways involved in the production of volatile secondary metabolites.

Publications: Müller CA, Oberauner-Wappis L, Peyman A, Amos GCA, Wellington EMH, Berg G. 2015. Appl Environ Microbiol 81:5064–5072; Müller CA, Obermeier MM, Berg G. 2016. J Biotechnol. 235:171–180; Müller CA, Perz V, Provasnek C, Quartinello F, Guebitz GM, Berg G. Appl Environ Microbiol. (accepted)


Enzyme mining in 1-alkene producing microorganisms

Funding: Field of Expertise Human- and Biotechnology, TU Graz

Project leader: Dr. Christina A. Mülle, Coworker: Andrea Friedrich

Duration: July-Dec. 2016

Abstract: The economic importance of terminal alkenes is undeniable, especially of propene which is the second most abounded and used compound in chemical industry. Therefore, the discovery of novel biocatalytic routes for production of alkenes will impact many scientific areas in the field of biology and biotechnology as well as chemistry, pharmacology and polymer science. The proposed project aims to: 1) identify and characterize novel and natural redox mediators for 1‑alkene producing monooxygenases, 2) promote the discovery of new microbial sources for fatty acid decarboxylating monooxygenases, 3) unravel the diversity of 1-alkene-forming monooxygenases in strain collections and metagenomic sources, 4) decipher the natural function of such enzymes in the investigated environments, and 5) advance the application of P450 monooxygenases and suitable redox-mediator proteins for production of terminal alkenes in whole cell biocatalysts.

Partners:  Institute of Biotechnology and Biochemical Engineering, TU Graz (Dr. Alexander Dennig/ Univ.-Prof. Bernd Nidetzky)


Biological importance and industrial potential of diazine derivatives

Cellular structures providing increased resistance towards the volatile diazine IBDM in E. coli (c) P. Mülner

Funding organisation & Project no.: FFG-ACIB, 24.043

Project leader: Gabriele Berg

Coworkers: Tomislav Cernava, Pascal Mülner, Peter Kusstatscher, Matthias Schöck

Duration: 2015-2017

Abstract: Naturally found diazines produced by plant associated bacteria (e.g. Paenibacillus sp.) have been described for their antimicrobial activity (Berg group). Some of the found natural derivatives produced by plant associated bacteria show unique chemical structures and are so far not understood regarding their mode-of-action on the molecular level. Diazines are discussed as metabolites which play an important role in the signal transduction pathway of organisms. In addition, the knowledge for their broad antimicrobial action requires more information on the biological targets in organisms which is of high importance for their safe application.

Partner: Roombiotic GmbH (


Baclight LIVE/DEAD staining of a control (A-C) and diazine-treated hatchery eggs (D-F). Living (green) and dead (red) microorganisms. (c) T. Cernava