The Contribution of G-Layer Glucose in Salix Clones for Biofuels; Comparative Enzymatic and HPLC Analysis of Stem Cross-Sections

Author(s):  
Jie Gao ◽  
Mohamed Jebrane ◽  
Nasko Terziev ◽  
Geoffrey Daniel

Abstract Background Interest on the use of short-rotation willow as a lignocellulose resource for liquid transport fuels has increased greatly over the last ten years. Investigations have shown the advantages and potential of using Salix spp. for such fuels but have also emphasized the wide variations existing in the compositional structure between different species and genotypes in addition to their effects on overall yield. The present work studied the importance of tension wood (TW) as a readily available source of glucose in two-year-old stems of four Salix clones (Tora, Björn, Jorr, Loden). Studies involved application of a novel approach whereby TW-glucose and residual sugars and lignin were quantified using stem cross-sections with results correlated with HPLC analyses of milled wood. Compositional analyses were made for four points along stems and glucose derived from enzyme saccharification of TW gelatinous (G) layers (G-glucose), structural cell wall glucose (CW-glucose) remaining after saccharification and total glucose (T-glucose) determined both theoretically and from HPLC analyses. Comparisons were also made between presence of other characteristic sugars as well as acid-soluble and -insoluble lignin. Results Initial studies showed good agreement between using stem serial sections and milled powder for determining total sugar and lignin. Therefore, sections were used throughout the work. HPLC determination of T-glucose in Salix clones varied between 47.1–52.8%, showing a trend for higher T-glucose with increasing height (Björn, Tora and Jorr). Using histochemical/microscopy and image analysis, Tora (24.2%) and Björn (28.2%) showed greater volumes of % TW than Jorr (15.5%) and Loden (14.0%). Total G-glucose with enzyme saccharification of TW G-layers varied between 3.7–14.7% increasing as the total TW volume increased. CW-glucose measured after enzyme saccharification showed mean values of 41.9–49.1%. Total lignin between and within clones showed small differences with mean variations of 22.4–22.8% before, and 22.4–24.3% after enzyme saccharification. Calculated theoretical and quantified values for CW-glucose at different heights for clones were similar with strong correlation: T-glucose = G-glucose + CW-glucose. Pearson´s correlation displayed a strong and positive correlation between T-glucose and G-glucose, % TW and stem height, and between G-glucose with % TW and stem height. Conclusions The use of stem cross-sections to estimate TW together with enzyme saccharification represents a viable approach for determining freely available G-glucose from TW allowing comparisons between Salix clones. Using stem sections provides for discrete morphological/compositional tissue comparisons between clones with results consistent with traditional wet chemical analysis approaches where entire stems are milled and analyzed. The four clones showed variable TW and presence of total % G-glucose in the order Björn > Tora > Jorr > Loden. Calculated in terms of 1 m3, Salix stems Tora and Björn would contain ca. 0.24 and 0.28 m3 of tension wood representing a significant amount of freely available glucose.

Author(s):  
K. W. Robinson

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.


2014 ◽  
Vol 31 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Braca Kundalić ◽  
Slađana Ugrenović ◽  
Ivan Jovanović ◽  
Natalija Stefanović ◽  
Vladimir Petrović ◽  
...  

Summary The aim of our study was to analyze the changes of connective tissue sheaths of epi-, peri- and endoneurium of sural nerve during aging. The study was conducted on sural nerve samples of 10 cases aged 9-80 years. The specimens were embedded in paraffin using standard procedures, after which 5-μm-thick cross-sections of nerve trunks were made and stained using Masson’s trichrome staining. After morphological analysis of fascicular structure and connective sheaths of the nerve, morphometric analysis was conducted using the software for digital image analysis “ImageJ”. Each investigated case was analyzed for total neural, epineurial and fascicular cross-section area, mean values of perineurial index, volume density of myelinated axons and of endoneurial content. To test the difference in mean values for statistical significance we used the Student’s T-test for small independent sample. The number of fascicles was 5-13, while the majority of the nerves had less than 10 fascicles. Fascicular structure, which included the number of fascicles and epifascicular/fascicular area ratio, did not show significant changes during aging. Perineurial thickness /fascicle size ratio statistically significantly increased in the older investigated group (p<0.05). Myelinated fibres were of smaller diameter, with more irregular form and markedly less frequent in older cases. Quantitative analysis showed statistically significant decrease in volume density of myelinated fibres in the older group. As results of applied investigation methods we found thickening of perineurial sheath of sural nerve during aging, as well as endoneurial fibrosis. Future investigations of age-related changes should focus on analysis of the components of extracellular matrix within perineurium and endoneurium.


2010 ◽  
Vol 3 (6) ◽  
pp. 1629-1646 ◽  
Author(s):  
H. K. Roscoe ◽  
M. Van Roozendael ◽  
C. Fayt ◽  
A. du Piesanie ◽  
N. Abuhassan ◽  
...  

Abstract. In June 2009, 22 spectrometers from 14 institutes measured tropospheric and stratospheric NO2 from the ground for more than 11 days during the Cabauw Intercomparison Campaign of Nitrogen Dioxide measuring Instruments (CINDI), at Cabauw, NL (51.97° N, 4.93° E). All visible instruments used a common wavelength range and set of cross sections for the spectral analysis. Most of the instruments were of the multi-axis design with analysis by differential spectroscopy software (MAX-DOAS), whose non-zenith slant columns were compared by examining slopes of their least-squares straight line fits to mean values of a selection of instruments, after taking 30-min averages. Zenith slant columns near twilight were compared by fits to interpolated values of a reference instrument, then normalised by the mean of the slopes of the best instruments. For visible MAX-DOAS instruments, the means of the fitted slopes for NO2 and O4 of all except one instrument were within 10% of unity at almost all non-zenith elevations, and most were within 5%. Values for UV MAX-DOAS instruments were almost as good, being 12% and 7%, respectively. For visible instruments at zenith near twilight, the means of the fitted slopes of all instruments were within 5% of unity. This level of agreement is as good as that of previous intercomparisons, despite the site not being ideal for zenith twilight measurements. It bodes well for the future of measurements of tropospheric NO2, as previous intercomparisons were only for zenith instruments focussing on stratospheric NO2, with their longer heritage.


2018 ◽  
Vol 8 (1) ◽  
pp. 117-123
Author(s):  
Vera V. VAKHNINA ◽  
Aleksey A. KUVSHINOV ◽  
Vladimir N. KUZNETSOV ◽  
Vladimir A. SHAPOVALOV

A technique for modeling the magnetic fi elds of power transformers in the environment of the software product FEMM 4.2 is developed taking into account the design scheme and real geometric dimensions of the magnetic system and tank, quasi-permanent current components in high-voltage windings, and the experimental magnetization characteristics of electrical and structural steel. Modeling of magnetic fi elds of magnetic systems of rod and armored rod structures is carried out on the example of serial power transformers TRDN- 63000/115 / 6.3 / 6.3 and TDTs-400000/242/20. The dependences of the mean values of induction in the central cross sections of the rods and side yokes on the quasi-constant currents are determined. It is shown that the saturation of the magnetic system of the rod structure begins with the outer rods at a multiplicity of quasi-constant current equal to 2.2 relative to the nominal phase current of the high-voltage winding. The saturation of the magnetic system of the armored rod structure begins with the lateral yokes at a multiplicity of the quasi-constant current equal to 2.63 with respect to the idle current rating.


1977 ◽  
Vol 11 (4) ◽  
pp. 291-303 ◽  
Author(s):  
R. A. Parham ◽  
K. W. Robinson ◽  
J. G. Isebrands

2012 ◽  
Vol 24 (1) ◽  
pp. 140
Author(s):  
A. M. Duszewska ◽  
A. Compa ◽  
M. Zelechowska ◽  
A. Piliszek ◽  
A. Rynkowska ◽  
...  

The oviduct provides the environment necessary for the gamete transport, completion of spermatozoa capacitation, oocyte fertilization and the early development of embryos. In cattle, all of these processes take place between Day 0 to 4 of the ovarian cycle (Day 0 is the day of ovulation). In previous studies, temporal changes in the bovine oviduct morphology were evaluated by dividing the ovarian cycle into luteal and follicular phases. In order to understand the relation between the bovine oviduct morphology and processes occurring there, the ovarian cycle has been further divided into four phases: I (Day 0–4), II (Day 5–10), III (Day 11–17) and IV (Day 18–20), with the day of ovulation considered Day 0 (1980 J. Dairy Sci. 63, 155–160). The aim of the study was to evaluate the oviduct morphology of the infundibulum, ampulla and isthmus in 4 phases of the ovarian cycle. Research material comprised cattle oviducts (classified into 1 of the 4 phases of the cycle based on ovarian morphology), dissected into infundibulum, ampulla and isthmus and subsequently sectioned and processed for histological preparations (hematoxylin and eosin, H&E, staining). Diameters of transverse cross-sections of oviduct and its lumen and thickness of tunicas: mucosa, muscularis and serosa were evaluated in relation to the region of oviduct and the phase of ovarian cycle. Values are given in μm. Statistical analysis was carried out by 1-way analysis of variance and comparisons of mean values were made with the Tukey honestly significant difference test (Statgraphics Plus 5); P < 0.05 was considered to reflect the presence of statistical significance. The comparison of the diameters of transverse cross-sections (A) of oviduct and its lumen (B) shows significant statistical differences between ampulla and isthmus within the phases: A-I (4507.26 vs 2524.47), II (4510.53 vs 2540.67), III (4503.28 vs 2534.07), IV (4500.73 vs 2533.90); B-I (4191.10 vs 1950.88), II (4173.63 vs 1986.33), III (4198.53 vs 1966.88) and IV (4192.50 vs 1959.33). There are no differences among 4 phases of the ovarian cycle. The thickness of tunicas muscularis and serosa of infundibulum (I: 26.81 vs 196.85; II: 27.03 vs 201.80; III: 26.22 vs 199.45; IV: 23.97 vs 198.01), ampulla (I: 91.51 vs 214.50; II: 90.72 vs 212.55; III: 88.61 vs 213.30; IV: 89.65 vs 206.28) and isthmus (I: 202.29 vs 216.52; II: 199.24 vs 207.74; III: 200.90 vs 212.38; IV: 200.38 vs 210.86) show only statistically significant differences within the phases, whereas the tunica mucosa shows only statistically significant differences between phases and the term of the height of epithelium at the base of mucosal folds (I: 26.49; II: 25.20; III: 24.14; IV: 29.96) and their apical parts (I: 28.09; II: 26.01; III: 25.45; IV: 30.96). In conclusion, differences in oviduct morphology are mainly region specific, whereas the epithelium morphologically infundibulum, ampulla and isthmus show variation in the 4 phases of the ovarian cycle. Supported by Grant MNiSW N311236137.


1985 ◽  
Vol 63 (6) ◽  
pp. 995-1007 ◽  
Author(s):  
S. G. Aiken ◽  
S. J. Darbyshire ◽  
L. P. Lefkovitch

Diverse anatomical patterns observed in 18 narrow-leaved Festuca taxa are illustrated by composite block diagrams formed from a synthesis of at least 10 leaf cross sections from five plants chosen across the geographical range of each taxon; the terms used are described; and cross sections are illustrated using semithin leaf sections and block diagrams. Measurements on seven variables and notes on sclerenchyma patterns from the cross sections are presented in anatomical descriptions for 18 taxa (16 species and 2 infraspecies). Results of analyses of variance and deviance show that five of the seven variables have significant differences in mean values that coincide with the taxonomy. However, the range of values observed for each taxon was found to overlap with that of others so much that measuring these variables for an unknown plant would not always give a reliable identification to species, although it would reduce the possibilities.


Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Robyn E. Goacher ◽  
Yaseen Mottiar ◽  
Shawn D. Mansfield

AbstractEsterified phenolics occur as γ-linked lignin acylations in many plant taxa but little is known about the distribution or function of such groups. In the family Salicaceae, p-hydroxybenzoate groups are present in the lignin of poplars (Populus spp.) and willows (Salix spp.). In this study, the distribution of cell wall-bound p-hydroxybenzoate was examined in different tissue and cell types of poplar and willow trees. This analysis showed that p-hydroxybenzoate groups were most prevalent in juvenile stems, and were elevated in tension wood and following nitrogen fertilisation. Closer examination of stem cross-sections using time-of-flight secondary-ion mass spectrometry (ToF-SIMS) directly showed that p-hydroxybenzoate groups occur predominantly in the cell walls of fibres and are largely absent from vessel elements. These results point to a role for ester-linked groups in modifying the syringyl-rich lignin of fibres, perhaps to strengthen the cell walls of these structural elements or to increase lignification rates.


2012 ◽  
Vol 13 (1) ◽  
pp. 223-238 ◽  
Author(s):  
Sergey Y. Matrosov

Abstract The potential of CloudSat W-band radar for observing wintertime storms affecting the West Coast of North America is evaluated. Storms having high hydrological impact often result from landfalls of “atmospheric rivers” (“ARs”), which are the narrow elongated regions of water vapor transport from the tropics. CloudSat measurements are used for retrievals of rain rate R and cloud ice water path (IWP) along the satellite ground track over ocean and land. These retrievals present quasi-instantaneous vertical cross sections of precipitating systems with high-resolution information about hydrometeors. This information is valuable in coastal areas with complex terrain where observations with existing instrumentation, including ground-based radars, are limited. CloudSat reflectivity enhancements [i.e., bright band (BB)] present a way to estimate freezing levels, indicating transitions between rainfall and snowfall. CloudSat estimates of these levels were validated using data from radiosonde soundings and compared to model and microwave sounder data. Comparisons of CloudSat retrievals of rain rates with estimates from ground-based radars in the areas where measurements from these radars were available indicated an agreement within retrieval uncertainties, which were around 50%. The utility of CloudSat was illustrated for case studies of pronounced AR events at landfall and over ocean. Initial analysis of CloudSat crossings of ARs during the 2006/07 season were used for rainfall regime prevalence assessment. It indicated that stratiform rain, which often had BB features, warm rain, and mixed rain were observed with about 26%, 24%, and 50% frequency. Stratiform regions generally had higher rain rates. Significant correlation (~0.72) between mean values of IWP and rain rate was observed for stratiform rainfall.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jie Gao ◽  
Mohamed Jebrane ◽  
Nasko Terziev ◽  
Geoffrey Daniel

Abstract Background Salix (willow) species represent an important source of bioenergy and offer great potential for producing biofuels. Salix spp. like many hardwoods, produce tension wood (TW) characterized by special fibres (G-fibres) that produce a cellulose-rich lignin-free gelatinous (G) layer on the inner fibre cell wall. Presence of increased amounts of TW and G-fibres represents an increased source of cellulose. In the present study, the presence of TW in whole stems of different Salix varieties was characterized (i.e., physical measurements, histochemistry, image analysis, and microscopy) as a possible marker for the availability of freely available cellulose and potential for releasing d-glucose. Stem cross sections from different Salix varieties (Tora, Björn) were characterized for TW, and subjected to cellulase hydrolysis with the free d-glucose produced determined using a glucose oxidase/peroxidase (GOPOD) assay. Effect of cellulase on the cross sections and progressive hydrolysis of the G-layer was followed using light microscopy after staining and scanning electron microscopy (SEM). Results Tension wood fibres with G-layers were developed multilaterally in all stems studied. Salix TW from varieties Tora and Björn showed fibre G-layers were non-lignified with variable thickness. Results showed: (i) Differences in total % TW at different stem heights; (ii) that using a 3-day incubation period at 50 °C, the G-layers could be hydrolyzed with no apparent ultrastructural effects on lignified secondary cell wall layers and middle lamellae of other cell elements; and (iii) that by correlating the amount of d-glucose produced from cross sections at different stem heights together with total % TW and density, an estimate of the total free d-glucose in stems can be derived and compared between varieties. These values were used together with a literature value (45%) for estimating the contribution played by G-layer cellulose to the total cellulose content. Conclusions The stem section-enzyme method developed provides a viable approach to compare different Salix varieties ability to produce TW and thus freely available d-glucose for fermentation and biofuel production. The use of Salix stem cross sections rather than comminuted biomass allows direct correlation between tissue- and cell types with d-glucose release. Results allowed correlation between % TW in cross sections and entire Salix stems with d-glucose production from digested G-layers. Results further emphasize the importance of TW and G-fibre cellulose as an important marker for enhanced d-glucose release in Salix varieties.


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