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Six-week-old root samples were evaluated using high resolution (maximum resolution [MaxRes]) thermogravimetric analyses (TGA) of the cell wall compositions of Gram-positive (Bacillus mucilaginosus, Bacillus amyloliquefaciens, and Bacillus subtilis) and Gram-negative (Burkholderia sp., Rahnella aquatilis strain H 2.6, and R. aquatilis strain RC 2.5) root colonizing plant growth promoting rhizobacteria (PGPR) commercial inoculant strains (biostimulants) applied to pot grown wheat plants. TGA discriminated the strains within the two types of rhizobacterial cohorts and thus provided a rapid non-molecular means for the detection of PGPR inoculant biostimulants within hours of root sampling. The latter was due to the greater degree of definition of TGA fingerprints of individual thermal weight loss events occurring over a degradation range, and heightened the corresponding peak temperature divergences within strains of either type of bacteria themselves for their unequivocal identification. Confirmation of biostimulant rhizobacteria identity in concomitant root samples was achieved through either cultural methods or direct tissue PCR molecular protocols within 5 days and 2 days of sampling, respectively. The results suggested that MaxRes TGA could serve as a rapid, inexpensive stand-alone tool or as combinatorial utility alongside pyrolysis gas chromatography mass spectra, and Fourier transform infrared analytics for the early detection of PGPR biostimulants in precision farming.

The aim of this study was to investigate the application of Fourier Transform Infrared (FTIR) spectroscopy to provide calibration equations for assessing faecal composition, intake and digestibility in sheep. Four grass-based feed types and corresponding faecal samples were collected from two separate sheep digestibility experiments. The feed (n = 41) and faecal samples (n = 132) were analysed for chemical composition, digestibility, were scanned using FTIR spectroscopy and intakes were recorded. Data were analysed using principle component analysis and partial least squares (PLS) regression techniques for calibration equation development. Calibration accuracy and performance were assessed by calculating regression coefficient of cross validation (R2cv) and the ratio of performance to deviation (RPD value) respectively. Results indicated that the composition of feed and faecal samples along with associated digestibilities and intakes were significantly different for a number of parameters studied. Some of the PLS regression equations generated were comparable to those reported in the published literature, and based on calibration statistics and performance those developed for faecal ash and neutral detergent fibre were good and could be used for quantification (R2cv = 0.9–0.8, RPD = 3.0–2.5); those for acid detergent fibre, lignin, feed ash intake and dry matter digestibility (DMD) were adequate for qualitative analysis and screening (R2cv = 0.8–0.7, RPD = 2.3–2.0); and the calibration equations for dry matter, nitrogen, dry matter intake, gross energy, gross energy intake and gross energy digestibility were poor and unsuitable for prediction (R2cv ≤ 0.7, RPD ≤ 1.8). Further development of calibration equations and in particular the prediction of DMD, could be of benefit to animal scientists and the livestock industry.

The measurement of lignin content in ruminant diet and faecal samples is important for 2 digestibility studies, but it is typically time consuming and costly. The work reported 3 involved correlation of traditional wet chemistry data with that from three rapid instrumental 4 techniques, Fourier Transform Infrared spectroscopy (FTIR), Conventional 5 Thermogravimteric Analysis (TGA) and High Resolution TGA (MaxRes TGA) to predict 6 lignin content of diets and faeces from digestibility trials. Calibration and performance data 7 indicated that the FTIR model was acceptable for screening whilst the Conventional and 8 MaxRes TGA predictions were of high accuracy for quantitative analysis. Cross validation 9 and model performance data revealed that MaxRes TGA provided the best performing 10 predictive model. This work showed that MaxRes TGA can accurately predict lignin content 11 in ruminant diet and faecal samples with distinct advantages over traditional wet chemistry, 12 namely the requirement for small sample size, ease of sample preparation, speed of analysis 13 and high sample throughput at considerably lower cost.

Background: There is growing interest in the bio-refining of foliage grasses to yield a range of industrial raw products. The aim of this research was to evaluate if aqueous extracts from grasses have the potential to act as crop bio-stimulants by assessing their defence elicitor activity.Results: Field-grown foliage (500 g fresh weight) from the Lolium perenne varieties Tyrella, Dromara, Abermagic, and Spelga were homogenised in water (2 l) and the run-off liquid filtered through Whatman No. 1 filter paper before freezing. Thawed filtrate was centrifuged at 21,000 rpm for 15 min, to give pellet and supernatant fractions, which were assayed separately for defence elicitor activity by adding them to cell suspension cultures of Phaseolus vulgaris in the early exponential phase of growth (7–10 days into a 14 days culture passage). Elicitor activity was evaluated 24 h after treatment by assessing the extent of necrosis (browning) in the P. vulgaris cells. Supernatant and pellet fractions of all four L. perenne varieties were found to have potent cell defence elicitor activity, although there were relatively small but significant differences between the varieties. In a second series of extractions, homogenisation of tissues in water was compared with screw-pressed juice using the varieties, Malone, Seagoe, and Copeland. Varietal differences in elicitor activity of these extracts were removed if they were first equalised for protein content prior to eliciting the bean cells, although the screw-pressed juice was marginally more active as an elicitor than the homogenised extract. Autoclaving the extracts in attempts to solubilise/release additional elicitor compounds neither increased nor decreased the elicitor activities of the supernatant or pellet fractions. Elicitor activity of the extract was partially reduced by treating with a cation exchange resin, almost entirely removed by adsorption onto activated carbon and completely abolished by ashing at 650 °C.Conclusion: The L. perenne defence elicitor(s) is therefore organic rather than inorganic, heat-stable, cationic at neutral pH, and readily soluble in water at room temperature.

Optimised routes have been established to obtain high aspect ratio cellulose microfibrils derived from plant feedstocks, involving a combination of a chemical and mechanical treatment using a high pressure microfluidizer. By this means, nano-cellulose was produced using different pretreatment protocols. The nanofibres produced were characterised for its particle size distribution measurement (laser diffraction and zeta potential analysis) and fourier transform infrared for its structural analysis. Results obtained and subsequent trends observed in chemical, mechanical and chemo-mechanical treated nanofibres were compared and contrasted. The chemomechanical treatment (TEMPO-oxidation and high pressure microfluidisation) yielded higher aspect ratio nanofibrils than nanofibrils made by solely chemical or mechanical treatment.

Recycled compost leachate (RCL or euphemistically named "goody water") can be a potent source of foul odor on mushroom substrate production sites and contributes to composting smells. A complex mixture of sulfur compounds, fatty acids, and nitrogen containing compounds is responsible for odor production. Fifty samples, collected from 14 compost production sites in Ireland and the U.K. over a 2 year period, were analyzed for chemical properties and by thermogravimetry-mass spectrometry (TG-MS) for compositional differences. Results indicated that aerated samples had lower values of electrical conductivity, redox potential, and dry matter content than nonaerated samples and that the higher thermal stability of aerated samples measured by TGA could be attributed to greater mineralization of the substrate due to aerobic processes. The lower temperatures noted for peak evolution of methane, water, and carbon dioxide from TG-MS analysis suggested that a more energetic process had occurred in aerated RCL storage facilities, producing greater decomposition of macromolecules that volatilized at lower temperatures. Chemical composition, thermal stability of the freeze-dried leachate, pyrolysis profiles, and relative amounts of pyrolysis products were all markers of as to how effective control measures could influence RCL quality.

This study has demonstrated biorefining steps for ryegrass and silage at a pilot scale to extrude fibre cake for the production of nanofibrillated cellulose (NFC), a potentially green biomaterial for replacing conventional fillers in the manufacture of polymer composites. Further treatments of processed ryegrass fibres with mechanical shearing, microfluidising, hydrochloric acid (HCl)/sulphuric acid and a four stage {ethylenediaminetetra-acetic acid, sodium hydroxide, sodium hypochlorite and HCl} hydrolysis yielded 43.8, 36.1, 25.6 and 39.8 kg t−1 DM of NFCs respectively. The NFCs were characterised using microscopy, X-ray diffraction, dynamic light scattering, spectroscopy and thermogravimetry. The NFC had diameters from 3.0–9.1 nm and length 308 nm–4.6 μm. NFC-polyvinyl alcohol composites containing NFC (5 wt%) exhibited enhanced Young's modulus and thermal stability by factors of 2.5 and 2 respectively compared with control. The mass, energy, water and chemical balances of the four process steps were assessed to evaluate technical feasibility and also to provide baseline production data for scaling up. The microfluidised product has been identified as the best NFC product, but production cost needs to be reduced.

Background: The objective of this study was to develop instrumental protocols for evaluating physicochemical characteristics of plant biostimulant/biofertiliser formulations. Six formulations (Rygex, Algavyt, Ryzoset, Manek, Ecoryg and Algavyt Zn/Mn) containing algal/plant extracts, humic and amino acids, lipids and inorganic components were assessed for particle size distribution and zeta potential (ZP) by dynamic light scattering (DLS) and gross compositional differences by thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS).Results: The six commercial formulations were assessed by mung bean root and wheat leaf senescence bioassays to determine auxin- and cytokinin-like activities. Among them, Rygex, Manek and Ecoryg showed significant auxin-like activities compared to the other formulations. Only Manek showed very low cytokinin-like activity. In combination, the four instrumental techniques highlighted gross differences in the particle sizes, ZP and compositions of the products, and provided key results on the physicochemical characteristics of the formulations including potential stability of the products.Conclusion: The three techniques (TGA, FTIR and Py-GC/MS) require no sample preparation beyond drying of the materials. The activities of the plant growth hormones have been compared to show advantages of the growth hormone bioassay methods for selecting better formulations. Graphical abstract Examples of macro-algae and plant species used in the processing of plant biostimulants.