Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens

Journal Article · Sat Sep 01 00:00:00 EDT 2012 · The ISME Journal

DOI:https://doi.org/10.1038/ismej.2012.10· OSTI ID:1049011

Aylward, Frank O; Burnum, Kristin E; Scott, Jarrod J; Suen, Garret; Tringe, Susannah G; Adams, Sandra M; Barry, Kerrie W; Nicora, Carrie D; Piehowski, Paul D; Purvine, Samuel O; Starrett, Gabriel J; Goodwin, Lynne A; Smith, Richard D; Lipton, Mary S; Currie, Cameron R

Herbivores gain access to nutrients stored in plant biomass largely by harnessing the metabolic activities of microbes. Leaf-cutter ants of the genus Atta are a hallmark example; these dominant Neotropical herbivores cultivate symbiotic fungus gardens on massive quantities of fresh plant forage. As the external digestive system of the ants, fungus gardens facilitate the production and sustenance of millions of workers in mature Atta colonies. Here we use metagenomic, and metaproteomic techniques to characterize the bacterial diversity and overall physiological potential of fungus gardens from two species of Atta. Our analysis of over 1.2 Gbp of community metagenomic sequence and three 16S pyrotag libraries reveals that, in addition to harboring the dominant fungal crop, these ecosystems contain abundant populations of Enterobacteriaceae, including the genera Enterobacter, Pantoea, Klebsiella, Citrobacter, and Escherichia. We show that these bacterial communities possess genes commonly associated with lignocellulose degradation, and likely participate in the processing of plant biomass. Additionally, we demonstrate that bacteria in these environments encode a diverse suite of biosynthetic pathways, and that they may enrich the nitrogen-poor forage of the ants with B-vitamins, amino acids, and proteins. These results are consistent with the hypothesis that fungus gardens are highly-specialized fungus-bacteria communities that efficiently convert plant material into usable energy for their ant hosts. Together with recent investigations into the microbial symbionts of vertebrates, our work underscores the importance of microbial communities to the ecology and evolution of herbivorous metazoans.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1049011
• Report Number(s): PNNL-SA-82393; 29591; KP1601050; TRN: US201217%%282
• Journal Information: The ISME Journal, Vol. 6, Issue 9
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
AMINO ACIDS
ANTS
BACTERIA
BIOMASS
COMMUNITIES
DIGESTIVE SYSTEM
ECOLOGY
ECOSYSTEMS
FORAGE
GENES
HYPOTHESIS
KLEBSIELLA
NUTRIENTS
POPULATIONS
PROCESSING
PRODUCTION
PROTEINS
VERTEBRATES
Leaf-cutter ants
Symbiosis
Leucoagaricus gongylophorus
Microbial Consortia
Atta
Environmental Molecular Sciences Laboratory