1. aInstitute of Microbiology and Biotechnology, University of Latvia, Riga, Latvia
2. Faculty of Biology, University of Latvia, Riga, Latvia
3. Faculty of Geography and Earth Sciences, University of Latvia, Riga, Latvia
4. Organic Plant Production and Agroecosystems Research in the Tropics and Subtropics, University of Kassel, Witzenhausen, Germany