Dynamics of bacterial communities in relation to soil aggregate formation during the decomposition of 13C-labelled rice straw

• Published in: Applied soil ecology : a section of Agriculture, ecosystems & environment ecosystems & environment, 2012-02, Vol.53, p.1-9
• Main Authors: Blaud, A., Lerch, T.Z., Chevallier, T., Nunan, N., Chenu, C., Brauman, A.
• Format: Article
• Language: English
• Subjects: 13C-labelling; Actinobacteria; Agronomy. Soil science and plant productions; Bacteria; bacterial communities; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; community structure; FAME-SIP; fatty acid esters; Fundamental and applied biological sciences. Psychology; habitats; Microscale biogeography; Mineralisation; mineralization; organic matter; Oryza sativa; Physical properties; Physics, chemistry, biochemistry and biology of agricultural and forest soils; rice straw; soil; Soil aggregation; Soil bacterial communities structure; soil ecology; soil formation; soil microorganisms; soil sampling; Soil science; stable isotopes; Structure, texture, density, mechanical behavior. Heat and gas exchanges
• ISSN: 0929-1393; 1873-0272
• DOI: 10.1016/j.apsoil.2011.11.005

► Rapid formation of soil macroaggregates. ► Rapid change in soil bacterial community structure. ► Close relationship between bacterial community structure and their new habitats. ► Straw degraders’ community change followed that of the whole bacterial community. The addition of fresh organic matter is known to modify both microbial community structure and soil aggregation. The objective of this study was to understand the relationship between the dynamics of the soil microbial community structure in relation to that of their habitats during the decomposition of straw. Soil samples, ground (2000μm) occurred within 2 days in amended and unamended samples but did so to a greater extent in the amended samples. The CStraw was mainly located in fractions >200μm, where degraders were the most abundant. The 13C-FAME profiles followed the same trends as total FAME profiles through time and within soil fractions, suggesting common dynamics between straw degraders and total bacterial communities: Gram-negative were more important in fraction >200μm and during the early stages of the incubation while Gram-positive and actinobacteria dominated in fine fractions and at the end of the incubation. Bacterial community structure changed rapidly (within 2 days) in conjunction with the formation of new microbial habitats, suggesting that the relationship between the two is very close.