Cycling and composition of organic matter in terrestrial and marine ecosystems

Baldock, J. A.; Masiello, Caroline A.; Gélinas, Yves; Hedges, John I.

doi:10.1016/j.marchem.2004.06.016

Cited by 351 publications

(314 citation statements)

References 117 publications

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“…Chemical shift regions were defined relative to the methyl resonance of hexamethylbenzene at 17.36 ppm as follows: alkyl-C (0e45 ppm), N-alkyl/methoxyl-C (45e60 ppm), O-alkyl-C (60e95 ppm), di-O-alkyl C (95e110 ppm), aryl-C (110e145 ppm), O-aryl C (145e165 ppm), amide/carboxyl C (165e190 ppm) and ketone-C (190e215). Integration areas within these chemical shift regions were inputted into a five component molecular mixing model to determine proportional quantities of carbohydrate, protein, lignin, lipid, and carbonyl C (Baldock et al, 2004).…”

Section: Nmrmentioning

confidence: 99%

Microbial community structure mediates response of soil C decomposition to litter addition and warming

Creamer

Menezes

Krull

et al. 2015

Soil Biology and Biochemistry

198

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Section: Nmrmentioning

confidence: 99%

Microbial community structure mediates response of soil C decomposition to litter addition and warming

Creamer

Menezes

Krull

et al. 2015

Soil Biology and Biochemistry

198

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“…Tendo em vista que os grupos alifáticos de C são consideradas uma das estruturas mais recalcitrantes da matéria orgânica do solo (Baldock et al, 1997), torna-se possível, a partir desse atributo, inferir o grau de humificação da MOS (Dick et al, 2003). De fato, cada tipo de molécula em resíduos decompostos apresenta um grau característico de recalcitrância bioquímica, que é definida pela força de ligações inter e intramoleculares, pelo grau de polimerização, pela regularidade das unidades estruturais nos polímeros e pelo teor de grupos funcionais aromáticos e alifáticos na fração orgânica analisada (Baldock et al, 1997;Gleixner et al, 2001;Baldock et al, 2004). Segundo Zech et al (1997), em solos tropicais, a dominância na matéria orgânica do solo de constituintes aromáticos é o fator responsável pela maior estabilidade no ambiente das frações orgânicas.…”

Section: Os Espectros De Infravermelho Para Os áCidosunclassified

Infravermelho na caracterização de ácidos húmicos de latossolo sob efeito de uso contínuo de lodo de esgoto

Dias

Silva²,

Soares³

et al. 2009

Rev. Bras. Ciênc. Solo

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RESUMOObjetivou-se caracterizar, por meio de espectroscopia no infravermelho com transformada de Fourier (IVTF), possíveis mudanças na natureza química de ácidos húmicos (AHs) extraídos de amostras de Latossolo (0-10 cm) do Campo Experimental da Embrapa Meio Ambiente, em Jaguariúna (SP). Os dados foram obtidos após seis cultivos de milho e a aplicação de doses variáveis de lodo de esgoto de Barueri (LB) (base seca), conforme os tratamentos avaliados: LB0, LB1, LB2, LB4 e LB8, sendo 0, 1, 2, 4 e 8 vezes a necessidade de N para o milho. Como referência, foi amostrada uma área sob mata. Foram obtidos espectros de ácidos húmicos e do lodo de esgoto utilizado no experimento, e calculados os índices de hidrofobicidade (IH) e de condensação (IC) nas amostras de ácidos húmicos. Foram notadas pequenas alterações na natureza química de AHs de áreas tratadas com lodo de esgoto, em relação à testemunha. Os AHs apresentam grupos aromáticos, -OH fenólicos, -COOH, estruturas alifáticas, carboidratos e impurezas minerais. O uso contínuo de elevadas doses de LB reduziu a concentração de C-alifático e o grau de condensação dos ácidos húmicos, o que sinaliza que há frações orgânicas

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“…However, sediment organic matter (OM) is a complex and heterogeneous mixture of high-and low-molecular-weight organic carbon compounds derived from multiple sources (for example, marine or terrestrial) at different states of degradation. Generally, land-derived OM are thought to be more recalcitrant to degradation than plankton-derived OM (Hedges et al, 1997;Baldock et al, 2004), but in environments with a mixture of both kinds, different microbial groups can allow refractory OM to be metabolized through mutualistic relationships (Bianchi, 2011). Such relationships are, however, poorly understood as microbial communities are rarely investigated in the same context as OM source or OM quality, defined here as composition and lability.…”

Section: Introductionmentioning

confidence: 99%

River organic matter shapes microbial communities in the sediment of the Rhône prodelta

et al. 2014

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Microbial-driven organic matter (OM) degradation is a cornerstone of benthic community functioning, but little is known about the relation between OM and community composition. Here we use Rhô ne prodelta sediments to test the hypothesis that OM quality and source are fundamental structuring factors for bacterial communities in benthic environments. Sampling was performed on four occasions corresponding to contrasting river-flow regimes, and bacterial communities from seven different depths were analyzed by pyrosequencing of 16S rRNA gene amplicons. The sediment matrix was characterized using over 20 environmental variables including bulk parameters (for example, total nitrogen, carbon, OM, porosity and particle size), as well as parameters describing the OM quality and source (for example, pigments, total lipids and amino acids and d 13 C), and molecular-level biomarkers like fatty acids. Our results show that the variance of the microbial community was best explained by d 13 C values, indicative of the OM source, and the proportion of saturated or polyunsaturated fatty acids, describing OM lability. These parameters were traced back to seasonal differences in the river flow, delivering OM of different quality and origin, and were directly associated with several frequent bacterial operational taxonomic units. However, the contextual parameters, which explained at most 17% of the variance, were not always the key for understanding the community assembly. Co-occurrence and phylogenetic diversity analysis indicated that bacteria-bacteria interactions were also significant. In conclusion, the drivers structuring the microbial community changed with time but remain closely linked with the river OM input.

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Cycling and composition of organic matter in terrestrial and marine ecosystems

Cited by 351 publications

References 117 publications

Microbial community structure mediates response of soil C decomposition to litter addition and warming

Microbial community structure mediates response of soil C decomposition to litter addition and warming

Infravermelho na caracterização de ácidos húmicos de latossolo sob efeito de uso contínuo de lodo de esgoto

River organic matter shapes microbial communities in the sediment of the Rhône prodelta

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