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1.
Front Plant Sci ; 14: 1281733, 2023.
Article in English | MEDLINE | ID: mdl-38298607

ABSTRACT

Feijoa (Acca sellowiana (O. Berg.) Burret), also known as pineapple guava, is a member of the Myrtaceae family and is well known for its fruit. Chemical profiling of the different tissues of the feijoa plant has shown that they generate an array of useful bioactive compounds which have health benefits such as significant antioxidant activities. In this study, an in vitro culture system has been developed, which could be explored to extract high-value bioactive compounds from feijoa. Feijoa tissue culture was initiated by the induction of callus from floral buds. Sections of floral buds were plated on MS medium supplemented with 2,4-D and BAP at 2.0mg/L and 0.2mg/L concentrations, respectively. Cell suspension cultures of feijoa were established using a liquid MS medium with different concentrations of 2,4-D and BAP and cultured on a rotary shaker. The growth of the cell suspension was evaluated with different parameters such as different carbohydrate sources, concentration of MS media, and inoculum density. When the cell suspensions were treated with different concentrations of MeJA at different time points, phytochemicals UPLC - QTOF MS analysis identified extractables of interest. The main compounds identified were secondary metabolites (flavonoids and flavonoid-glucosides) and plant hormones. These compounds are of interest for their potential use in therapeutics or skin and personal care products. This report investigates essential methodology parameters for establishing cell suspension cultures from feijoa floral buds, which could be used to generate in vitro biomass to produce high-value bioactive compounds. This is the first study reporting the identification of arctigenin from feijoa, a high-value compound whose pharmaceutical properties, including anti-tumour, anti-inflammatory and anti-colitis effects, have been widely reported. The ability of feijoa cell cultures to produce such high-value bioactive compounds is extremely promising for its use in pharmaceuticals, cosmeceuticals and nutraceuticals applications.

2.
STAR Protoc ; 2(1): 100227, 2021 03 19.
Article in English | MEDLINE | ID: mdl-33786457

ABSTRACT

This protocol describes the application of breath testing and ex vivo fermentations to study the association between breath methane and the composition and functionality of the gut microbiome. The protocol provides a useful systems biology approach for studying the gut microbiome in humans, which combines standardized methods in human breath testing and fecal sampling. The model described is accessible and easy to repeat, but its relative simplicity means that it can deviate from human physiological conditions.


Subject(s)
Feces/microbiology , Gastrointestinal Microbiome , Breath Tests , Humans
3.
Rapid Commun Mass Spectrom ; 35(9): e9051, 2021 May 15.
Article in English | MEDLINE | ID: mdl-33474806

ABSTRACT

RATIONALE: A combination of stable carbon (δ13 C) and hydrogen (δ2 H) isotope ratios and carbon content (% C) was evaluated as a rapid, low-cost analytical approach to authenticate bioplastics, complementing existing radiocarbon (14 C) and Fourier transform infrared (FTIR) analytical methods. METHODS: Petroleum- and bio-based precursor materials and in-market plastics were analysed and their δ13 C, δ2 H and % C values were used to establish isotope criteria to evaluate plastic claims, and the source and biocontent of the samples. 14 C was used to confirm the findings of the isotope approach and FTIR analysis was used to vertify the plastic type of the in-market plastics. RESULTS: Distinctive carbon and hydrogen stable isotope ratios were found for authentic bio-based and petroleum-based precursor plastics, and it was possible to classify in-market plastics according to their source materials (petroleum, C3, C4, and mixed sources). An estimation of C4 biocontent was possible from a C4-petroleum isotope mixing model using δ13 C which was well correlated (R2 = 0.98) to 14 C. It was not possible to establish a C3-petroleum isotope mixing model due to δ13 C isotopic overlap with petroleum plastics; however, the addition of δ2 H and % C was useful to evaluate if petroleum-bioplastic mixes contained C3 bioplastics, and PLS-DA modelling reliably clustered each plastic type. CONCLUSIONS: A combined dual stable isotope and carbon content approach was found to rapidly and accurately identify C3 and C4 bio-based products from their petroleum counterparts, and identify instances of petroleum and bio-based mixes frequently found in mislabelled bioplastics. Out of 37 in-market products labelled as bioplastic, 19 were found to contain varying amounts of petroleum-based plastic and did not meet their bio-based claims.


Subject(s)
Carbon Isotopes/analysis , Deuterium/analysis , Phytochemicals/analysis , Plastics/analysis , Spectroscopy, Fourier Transform Infrared/methods , Carbon Radioisotopes/analysis , Petroleum/analysis
4.
Methods Mol Biol ; 2149: 203-223, 2020.
Article in English | MEDLINE | ID: mdl-32617937

ABSTRACT

A knowledge of the mobilities of the polysaccharides or parts of polysaccharides in a cell-wall preparation provides information about possible molecular interactions among the polysaccharides in the cell wall and the relative locations of polysaccharides within the cell wall. A number of solid-state 13C NMR techniques have been developed that can be used to investigate different types of polysaccharide mobilities: rigid, semirigid, mobile, and highly mobile. In this chapter techniques are described for obtaining spectra from primary cell-wall preparations using CP/MAS, proton-rotating frame, proton spin-spin, spin-echo relaxation spectra and single-pulse excitation. We also describe how proton spin relaxation editing can be used to obtain subspectra for cell-wall polysaccharides of different mobilities, and how 2D and 3D solid-state NMR experiments have recently been applied to plant cell walls.


Subject(s)
Carbon-13 Magnetic Resonance Spectroscopy , Cell Wall/chemistry , Plant Cells/chemistry , Diffusion , Polysaccharides/chemistry , Protons , Spin Labels
5.
Plant Physiol ; 178(3): 1142-1153, 2018 11.
Article in English | MEDLINE | ID: mdl-30217826

ABSTRACT

The porosity of wood cell walls is of interest for both understanding xylem functionality and from a wood materials perspective. The movement of water in xylem generally occurs through the macroporous networks formed in softwood by bordered pits and in hardwood by the intervessel pits and open conduits created by vessels and perforation plates. In some situations, such as cavitated xylem, water can only move through the micropores that occur in lignified tracheid and fiber cell walls; however, these micropore networks are poorly understood. Here, we used molecular microscopy analysis of radiata pine (Pinus radiata) and red beech (Nothofagus fusca) to determine the distribution of micropores in the secondary walls and middle lamellae of tracheids and fibers in relation to cell wall composition. Using two different types of probe, we identified a greater porosity of secondary cell walls and a reduced porosity of the middle lamella. Areas of reduced porosity were observed in the outer regions of the secondary cell wall of both tracheids and fibers that appear unrelated to lignification or the distribution of cellulose, mannan, and xylan. Hardwood fiber cell walls were less lignified than those of softwood tracheids and showed greater accessibility to porosity probes. Vessel cell walls were comparable to those of fibers in terms of both porosity and lignification. Lignification is probably the primary determinant of cell wall porosity in xylem. The highly lignified middle lamella, and lumen surface, act as a barrier to probe movement and, therefore, water movement in both softwood and hardwood.


Subject(s)
Pinus/cytology , Water/metabolism , Wood/cytology , Cell Wall/metabolism , Fluorescence Resonance Energy Transfer , Lignin/metabolism , Microscopy , Pinus/metabolism , Porosity , Wood/metabolism , Xylem/cytology , Xylem/metabolism
6.
Biotechnol Bioeng ; 113(3): 540-9, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26369903

ABSTRACT

Pretreating lignocellulosic biomass with certain ionic liquids results in structural and chemical changes that make the biomass more digestible by enzymes. In this study, pine wood was pretreated with 1-ethyl-3-methylimidazolium chloride/acetate ([C2 mim]Cl and [C2 mim][OAc]) at different temperatures to investigate the relative importance of substrate features, such as accessible surface area, cellulose crystallinity, and lignin content, on enzymatic digestibility. The ionic liquid pretreatments resulted in glucan conversions ranging from 23% to 84% on saccharification of the substrates, with [C2 mim][OAc] being more effective than [C2 mim]Cl. The pretreatments resulted in no delignification of the wood, some loss of cellulose crystallinity under certain conditions, and varying levels of increased surface area. Enzymatic digestibility closely correlated with accessible surface area and porosity measurements obtained using Simons' staining and thermoporosimetry techniques. Increased accessible surface area was identified as the principal structural feature responsible for the improved enzymatic digestibility.


Subject(s)
Hydrolases/metabolism , Imidazoles/metabolism , Ionic Liquids/metabolism , Lignin/metabolism , Wood/drug effects , Pinus , Temperature
7.
Materials (Basel) ; 9(8)2016 Jul 26.
Article in English | MEDLINE | ID: mdl-28773739

ABSTRACT

Plant cell walls form an organic complex composite material that fulfils various functions. The hierarchical structure of this material is generated from the integration of its elementary components. This review provides an overview of wood as a composite material followed by its deconstruction into fibres that can then be incorporated into biobased composites. Firstly, the fibres are defined, and their various origins are discussed. Then, the organisation of cell walls and their components are described. The emphasis is on the molecular interactions of the cellulose microfibrils, lignin and hemicelluloses in planta. Hemicelluloses of diverse species and cell walls are described. Details of their organisation in the primary cell wall are provided, as understanding of the role of hemicellulose has recently evolved and is likely to affect our perception and future study of their secondary cell wall homologs. The importance of the presence of water on wood mechanical properties is also discussed. These sections provide the basis for understanding the molecular arrangements and interactions of the components and how they influence changes in fibre properties once isolated. A range of pulping processes can be used to individualise wood fibres, but these can cause damage to the fibres. Therefore, issues relating to fibre production are discussed along with the dispersion of wood fibres during extrusion. The final section explores various ways to improve fibres obtained from wood.

8.
Plant Physiol ; 163(4): 1558-67, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24154621

ABSTRACT

A synchrotron wide-angle x-ray scattering study of mung bean (Vigna radiata) primary cell walls was combined with published solid-state nuclear magnetic resonance data to test models for packing of (1→4)-ß-glucan chains in cellulose microfibrils. Computer-simulated peak shapes, calculated for 36-chain microfibrils with perfect order or uncorrelated disorder, were sharper than those in the experimental diffractogram. Introducing correlated disorder into the models broaden the simulated peaks but only when the disorder was increased to unrealistic magnitudes. Computer-simulated diffractograms, calculated for 24- and 18-chain models, showed good fits to experimental data. Particularly good fits to both x-ray and nuclear magnetic resonance data were obtained for collections of 18-chain models with mixed cross-sectional shapes and occasional twinning. Synthesis of 18-chain microfibrils is consistent with a model for cellulose-synthesizing complexes in which three cellulose synthase polypeptides form a particle and six particles form a rosette.


Subject(s)
Cell Wall/chemistry , Cellulose/chemistry , Fabaceae/cytology , Magnetic Resonance Spectroscopy , Microfibrils/chemistry , Scattering, Radiation , X-Ray Diffraction , Models, Molecular
9.
Environ Technol ; 14(11): 1015-1026, 1993 Nov.
Article in English | MEDLINE | ID: mdl-29016273

ABSTRACT

Adsorption of 10-100 ppb lead and thallium by borosilicate glass and polypropylene surfaces was studied. No thallium was adsorbed by either substrate at pH 7.0. About 50-60% of the lead was adsorbed by borosilicate glass at pH 5.5 and pH 7.0, with statistically indistinguishable conditional equilibrium constants (KD* values) of 1.47±0.40 mL cm-2 and 1.80±0.11 mL cm-2, respectively. Polypropylene adsorbed significantly more lead than borosilicate glass at pH 7.0 (80.9%, KD* =5.33±0.45 mL cm-2), and substantially less at pH 5.5 (16.7%, KD* = 0.27±0.03 mL cm-2), indicating a fundamental change in the nature of the polypropylene surface. All adsorption data fitted Freundlich plots. Preliminary experiments indicate that at pH 5.5, a fraction of the lead sequestered by the borosilicate glass may be bound irreversibly by migrating into the glass matrix. The results suggest that tectosilicates and silicate glasses may represent important adsorbents of some heavy metals in soils, despite showing very low intrinsic cation exchange capacities.

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