Nuclear magnetic resonance (1.40 T) and mid infrared (FTIR-ATR) associated with chemometrics as analytical methods for the analysis of methyl ester yield obtained by esterification reaction

In this work, we compared 1.40 T nuclear magnetic resonance (NMR) to 7.05 T (60 and 300 MHz for proton, respectively), and mid-infrared with attenuated total reflectance (FTIR-ATR), associated with chemometrics methods, for the quantification of the reaction yield during esterification of fatty acids with methanol. The results showed that the integrated intensities of the ester C=O stretching region, relative to the total C=O stretching region, is useful to quantify the fatty acid methyl ester (FAME) concentration. Comparing the results obtained by the different final models: NMR (1.40 T and 7.05 T), FTIR-ATR using multivariate partial last squares regression (PLS) with orthogonal signal correction (OSC), and univariate ordinary least squares (OLS), the NMR of 1.40 T (60 MHz for proton) showed more advantages when compared to a high field spectrometer, due to the non-use of cryogenic and solvents and less laborious work for obtaining results

Defining functional diversity for lignocellulose degradation in a microbial community using multi-omics studies

Abstract\ud \ud Background\ud Lignocellulose is one of the most abundant forms of fixed carbon in the biosphere. Current industrial approaches to the degradation of lignocellulose employ enzyme mixtures, usually from a single fungal species, which are only effective in hydrolyzing polysaccharides following biomass pre-treatments. While the enzymatic mechanisms of lignocellulose degradation have been characterized in detail in individual microbial species, the microbial communities that efficiently breakdown plant materials in nature are species rich and secrete a myriad of enzymes to perform “community-level” metabolism of lignocellulose. Single-species approaches are, therefore, likely to miss important aspects of lignocellulose degradation that will be central to optimizing commercial processes.\ud \ud \ud Results\ud Here, we investigated the microbial degradation of wheat straw in liquid cultures that had been inoculated with wheat straw compost. Samples taken at selected time points were subjected to multi-omics analysis with the aim of identifying new microbial mechanisms for lignocellulose degradation that could be applied in industrial pre-treatment of feedstocks. Phylogenetic composition of the community, based on sequenced bacterial and eukaryotic ribosomal genes, showed a gradual decrease in complexity and diversity over time due to microbial enrichment. Taxonomic affiliation of bacterial species showed dominance of Bacteroidetes and Proteobacteria and high relative abundance of genera Asticcacaulis, Leadbetterella and Truepera. The eukaryotic members of the community were enriched in peritrich ciliates from genus Telotrochidium that thrived in the liquid cultures compared to fungal species that were present in low abundance. A targeted metasecretome approach combined with metatranscriptomics analysis, identified 1127 proteins and showed the presence of numerous carbohydrate-active enzymes extracted from the biomass-bound fractions and from the culture supernatant. This revealed a wide array of hydrolytic cellulases, hemicellulases and carbohydrate-binding modules involved in lignocellulose degradation. The expression of these activities correlated to the changes in the biomass composition observed by FTIR and ssNMR measurements.\ud \ud \ud Conclusions\ud A combination of mass spectrometry-based proteomics coupled with metatranscriptomics has enabled the identification of a large number of lignocellulose degrading enzymes that can now be further explored for the development of improved enzyme cocktails for the treatment of plant-based feedstocks. In addition to the expected carbohydrate-active enzymes, our studies reveal a large number of unknown proteins, some of which may play a crucial role in community-based lignocellulose degradation.This work was funded by Biotechnology and Biological Sciences Research\ud Council (BBSRC) Grants BB/1018492/1, BB/K020358/1 and BB/P027717/1, the\ud BBSRC Network in Biotechnology and Bioenergy BIOCATNET and São Paulo\ud Research Foundation (FAPESP) Grant 10/52362-5. ERdA thanks EMBRAPA\ud Instrumentation São Carlos and Dr. Luiz Alberto Colnago for providing the\ud NMR facility and CNPq Grant 312852/2014-2. The authors would like to thank\ud Deborah Rathbone and Susan Heywood from the Biorenewables Develop‑\ud ment Centre for technical assistance in rRNA amplicon sequencing

Biochar: pyrogenic carbon for agricultural use: a critical review.

O biocarvão (biomassa carbonizada para uso agrícola) tem sido usado como condicionador do solo em todo o mundo, e essa tecnologia é de especial interesse para o Brasil, uma vez que tanto a ?inspiração?, que veio das Terras Pretas de Índios da Amazônia, como o fato de o Brasil ser o maior produtor mundial de carvão vegetal, com a geração de importante quantidade de resíduos na forma de finos de carvão e diversas biomassas residuais, principalmente da agroindústria, como bagaço de cana, resíduos das indústrias de madeira, papel e celulose, biocombustíveis, lodo de esgoto etc. Na última década, diversos estudos com biocarvão têm sido realizados e atualmente uma vasta literatura e excelentes revisões estão disponíveis. Objetivou-se aqui não fazer uma revisão bibliográfica exaustiva, mas sim uma revisão crítica para apontar alguns destaques na pesquisa sobre biochar. Para isso, foram selecionados alguns temaschave considerados críticos e relevantes e fez-se um ?condensado? da literatura pertinente, mais para orientar as pesquisas e tendências do que um mero olhar para o passad

Pulse sequence induced variability combined with multivariate analysis as a potential tool for 13C solid-state NMR signals separation, quantification, and classification

Multivariate Curve Resolution (MCR) is a multivariate analysis procedure commonly used to analyze spectroscopic data providing the number of components coexisting in a chemical system, the pure spectra of the components as well as their concentration profiles. Usually, this procedure relies on the existence of distinct systematic variability among spectra of the different samples, which is provided by different sources of variation associated to differences in samples origin, composition, physical chemical treatment, etc. In solid-state NMR, MCR has been also used as a post-processing method for spectral denoising or editing based on a given NMR property. In this type of use, the variability is induced by the incrementation of a given parameter in the pulse-sequence, which encodes the separation property in the acquired spectra. In this article we further explore the idea of using a specific pulse sequence to induce a controlled variability in the 13C solid-state NMR spectra and then apply MCR to separate the pure spectra of the components according to the properties associated to the induced variability. We build upon a previous study of sugarcane bagasse where a series of 13C solid-state NMR spectra acquired with the Torchia-T1 CPMAS pulse sequence, with varying relaxation periods, was combined with different sample treatments, to estimate individual 13C solid-state NMR spectra of different molecular components (cellulose, xylan and lignin). Using the same pulse sequence, we show other application examples to demonstrate the potentiality, parameter optimization and/or establish the limitations of the procedure. As a first proof of principle, we apply the approach to commercial semicrystalline medium density polyethylene (MDPE) and polyether ether ketone (PEEK) providing the estimation of the individual 13C ssNMR spectra of the polymer chains in the amorphous (short T1) and crystalline (long T1) domains. The analysis also provided the relative intensities of each estimated pure spectra, which are related to the characteristic T1 decays of the amorphous and crystalline domain fractions. We also apply the analysis to isotactic poly (1-butene) (iPB-I) as an example in which the induced T1 variability occurs due to the mobility difference between the polymer backbone and side-chains. A jack-knifing procedure and a student t text allow us to stablish the minimum number of spectra and the range of relaxation periods that need to be used to achieve a precise estimation of the individual pure spectra and their relative intensities. A detail discussion about possible drawbacks, applications to more complex systems, and potential extensions to other type of induced variability are also presented

Effect of residual vanadyl ions on the spectroscopic analysis of humic acids: a multivariate approach

6 pages, 3 figures, 2 tables, 29 references.In a study of the vanadyl (VO2þ )-humic acids system, the residual vanadyl ion suppressed fluorescence and specific electron paramagnetic resonance (EPR) and NMR signals. In the case of NMR, the proton rotating frame relaxation times (T1q H) indicate that this suppression is due to an inefficient H-C cross polarization, which is a consequence of a shortening of T1q H. Principal components analysis (PCA) facilitated the isolation of the effect of the VO2þ ion and indicated that the organic free radical signal was due to at least two paramagnetic centres and that the VO2þ ion preferentially suppressed the species whose electronic density is delocalized over O atoms (greater g-factor). Additionally, the newly obtained variables (principal components – PC) indicated that, as the result of the more intense tillage a relative increase occurred in the accumulation of: (i) recalcitrant structures; (ii) lignin and long-chain alkyl structures; and (iii) organic free radicals with smaller g-factors.The authors are grateful to the Fundacxa˜o de Amparo a` Pesquisa do Estado de Sa˜o Paulo (FAPESP) and to the Irish Research Council for Science, Engineering and Technology (IRCSET) for post-doctoral support.Peer reviewe

Compositional Changes in the Hydrophobic acids fraction of Drainage Water from Different Land Management Practices

peer-reviewedDissolved organic matter (DOM) can play a key role in many environmental processes, including carbon cycling, nutrient transport and the fates of contaminants and of agrochemicals. Hydrophobic acids (Ho), the major components of the DOM, were recovered from the drainage waters from well-drained (WDS) and poorly-drained (PDS) Irish grassland soils in lysimeters, amended with N fertiliser (F) and with bovine urine (U) and were studied using 1D and 2D solution-state Nuclear Magnetic Resonance (NMR) spectroscopy. The Diffusion Edited (DE) 1H NMR spectra indicated that the Ho consisted largely of larger molecules, or of molecules that formed rigid aggregates, and the 1D and the 2D (Heteronuclear Multiple Quantum Coherence – HMQC, the Total Correlation Spectroscopy – TOCSY, and the Nuclear Overhauser Effect – NOESY) spectra indicated that the samples were composed of lignin residues, carbohydrates, protein/peptides, and aliphatic components derived from plant waxes/cuticular materials and from microbial lipids. The F amendments increased the concentrations of Ho in the waters by 1.5 and 2.5 times those in the controls in the cases of WDS and PDS, respectively. The lignin-derived components were increased by 50% and 300% in the cases of the Ho from the WDS and PDS, respectively. Applications of F + U decreased the losses of Ho, (compared to the F amendments alone) and very significantly decreased those of the lignin-derived materials, indicating that enhanced microbial activity from U gave rise to enhanced metabolism of the Ho components, and especially of lignin. In contrast the less biodegradable aliphatic components containing cuticular materials increased as the result of applications of F + U. This study helps our understanding of how management practices influence the movement of C between terrestrial and aquatic environments.Teagasc, Ireland Walsh Fellowship scheme; Environmental Protection Agency, Ireland; International Humic Substance Society for a Training Bursary award to CMB for a research period in the laboratory of AJS; AJS thanks NSERC (Discovery and Strategic Programs) and an Early Researcher Award (Ontario Government) for providing support

Humic acid composition and soil fertility of soils near an ancient charcoal kiln: are they similar to Terra Preta de Índios soils?

6 páginas.-- 5 figuras.-- 1 tabla.-- 31 referenciasPurpose: Charcoal production during the nineteenth century transformed landscapes in the Brazilian Atlantic Forests in Rio de Janeiro city. These paleo-territories were studied to improve our understanding of how this activity altered soil properties. By comparing their humic acids (HA) with those extracted from a Terra Preta de Índios (TPI) site, we showed that the aging of charcoal in soils alone is sufficient to generate recalcitrant organic material with high cation exchange capacity (CEC). Materials and methods: The soils were sampled: at the center of the area affected by the ancient charcoal kiln (center of the kiln—CK), at the dump site (D—local deposition of charcoal residues not used for marketing, downstream of the ancient charcoal kiln), and from the surrounding soil, upstream of the kiln, as a control (natural soil—NS). Elemental analysis and fertility characterization of the soil samples were performed. Solid-state 13C nuclear magnetic resonance (NMR) spectra were obtained from their humic acids (HA). These spectra were compared against HA data on TPI. Results and discussion: As shown by solid-state 13C NMR spectroscopy, the soil organic matter (SOM) fraction which is high in charged functional groups (the so-called humic acids—HA) was extracted from areas rich in ancient charcoal and dominated by recalcitrant carboxylated aromatic structures (aged charcoal). This peculiar SOM explains the observed high cation exchange capacity (CEC). It yields a fertile soil with a high resistance against degradation by potential intensive use. Comparable results are described in the literature for SOM of TPI. Conclusions: The high structural similarity between the HA from the soils under the paleo-charcoal kilns and from TPI supports the hypothesis that just the natural weathering and biochemical reworking of charcoal in soils, together with ash input, is sufficient to generate fertile and resilient soils with peculiar SOM and properties commonly associated with the high fertility and C sequestration potential of TPIThis study was financially supported by the Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq)Peer reviewe