【丛枝菌根真菌与土壤细菌群落和氮循环过程】Erin E. Nuccio¹ Angela Hodge² Jennifer Pett-Ridge³ Donald J. Herman¹ Peter K. Weber³ Mary K. Firestone^1*. An arbuscular mycorrhizal fungus significantly modifies the soil bacterial community and nitrogen cycling during litter decomposition. Environmental MicrobiologyVolume 15Issue 6 pages 1870–1881 June 2013

Abstract

Arbuscular mycorrhizal fungi (AMF) perform an important ecosystem service by improving plant nutrient capture from soil yet little is known about how AMF influence soil microbial communities during nutrient uptake. We tested whether an AMF modifies the soil microbial community and nitrogen cycling during litter decomposition. A two-chamber microcosm system was employed to create a root-free soil environment to control AMF access to ¹³C- and ¹⁵N-labelled root litter. Using a 16S rRNA gene microarray we documented that approximately 10% of the bacterial community responded to the AMF Glomus hoi. Taxa from the Firmicutes responded positively to AMF while taxa from the Actinobacteria and Comamonadaceae responded negatively to AMF. Phylogenetic analyses indicate that AMF may influence bacterial community assembly processes. Using nanometre-scale secondary ion mass spectrometry (NanoSIMS) we visualized the location of AMF-transported ¹³C and ¹⁵N in plant roots. Bulk isotope ratio mass spectrometry revealed that the AMF exported 4.9% of the litter ¹⁵N to the host plant (Plantago lanceolata L.) and litter-derived ¹⁵N was preferentially exported relative to litter-derived ¹³C. Our results suggest that the AMF primarily took up N in the inorganic form and N export is one mechanism by which AMF could modify the soil microbial community and decomposition processes.

【微生物多样性】Migun Shakya¹² Christopher Quince⁴ James H. Campbell¹ Zamin K. Yang¹ Christopher W. Schadt¹²³ Mircea Podar^123*. Comparative metagenomic and rRNA microbial diversity characterization using archaeal and bacterial synthetic communities. Environmental MicrobiologyVolume 15Issue 6 pages 1882–1899 June 2013

Abstract

Next-generation sequencing has dramatically changed the landscape of microbial ecology large-scale and in-depth diversity studies being now widely accessible. However determining the accuracy of taxonomic and quantitative inferences and comparing results obtained with different approaches are complicated by incongruence of experimental and computational data types and also by lack of knowledge of the true ecological d