scholarly journals Inflorescence Development and Floral Organogenesis in Taraxacum kok-saghyz

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1258
Author(s):  
Carolina Schuchovski ◽  
Tea Meulia ◽  
Bruno Francisco Sant’Anna-Santos ◽  
Jonathan Fresnedo-Ramírez
Keyword(s):  
Natural Rubber ◽  
Carbon Sources ◽  
Corolla Tube ◽  
Industrial Applications ◽  
Inflorescence Meristem ◽  
Rubber Content ◽  
Inflorescence Development ◽  
Flower Primordia ◽  
Floral Organogenesis ◽  
Floral Micromorphology

Rubber dandelion (Taraxacum kok-saghyz Rodin; TK) has received attention for its natural rubber content as a strategic biomaterial, and a promising, sustainable, and renewable alternative to synthetic rubber from fossil carbon sources. Extensive research on the domestication and rubber content of TK has demonstrated TK’s potential in industrial applications as a relevant natural rubber and latex-producing alternative crop. However, many aspects of its biology have been neglected in published studies. For example, floral development is still poorly characterized. TK inflorescences were studied by scanning electron microscopy. Nine stages of early inflorescence development are proposed, and floral micromorphology is detailed. Individual flower primordia development starts at the periphery and proceeds centripetally in the newly-formed inflorescence meristem. Floral organogenesis begins in the outermost flowers of the capitulum, with corolla ring and androecium formation. Following, pappus primordium—forming a ring around the base of the corolla tube—and gynoecium are observed. The transition from vegetative to inflorescence meristem was observed 21 days after germination. This description of inflorescence and flower development in TK sheds light on the complex process of flowering, pollination, and reproduction. This study will be useful for genetics, breeding, systematics, and development of agronomical practices for this new rubber-producing crop.

scholarly journals Prospection of Fungal Lignocellulolytic Enzymes Produced from Jatoba (Hymenaea courbaril) and Tamarind (Tamarindus indica) Seeds: Scaling for Bioreactor and Saccharification Profile of Sugarcane Bagasse

2021 ◽  
Vol 9 (3) ◽  
pp. 533
Author(s):  
Alex Graça Contato ◽  
Tássio Brito de Oliveira ◽  
Guilherme Mauro Aranha ◽  
Emanuelle Neiverth de Freitas ◽  
Ana Claudia Vici ◽  
...  
Keyword(s):  
Carbon Sources ◽  
Temporal Analysis ◽  
Industrial Applications ◽  
Lignocellulolytic Enzymes ◽  
Tamarindus Indica ◽  
Acetyl Xylan Esterase ◽  
Trametes Hirsuta ◽  
Hymenaea Courbaril ◽  
The Media ◽  
Main Components

The lignocellulosic biomass comprises three main components: cellulose, hemicellulose, and lignin. Degradation and conversion of these three components are attractive to biotechnology. This study aimed to prospect fungal lignocellulolytic enzymes with potential industrial applications, produced through a temporal analysis using Hymenaea courbaril and Tamarindus indica seeds as carbon sources. α-L-arabinofuranosidase, acetyl xylan esterase, endo-1,5-α-L-arabinanase, β-D-galactosidase, β-D-glucosidase, β-glucanase, β-D-xylosidase, cellobiohydrolase, endoglucanase, lichenase, mannanase, polygalacturonase, endo-1,4-β-xylanase, and xyloglucanase activities were determined. The enzymes were produced for eight filamentous fungi: Aspergillus fumigatus, Trametes hirsuta, Lasiodiplodia sp., two strains of Trichoderma longibrachiatum, Neocosmospora perseae, Fusarium sp. and Thermothelomyces thermophilus. The best producers concerning enzymatic activity were T. thermophilus and T. longibrachiatum. The optimal conditions for enzyme production were the media supplemented with tamarind seeds, under agitation, for 72 h. This analysis was essential to demonstrate that cultivation conditions, static and under agitation, exert strong influences on the production of several enzymes produced by different fungi. The kind of sugarcane, pretreatment used, microorganisms, and carbon sources proved limiting sugar profile factors.

scholarly journals Fast Determination of the Rubber Content in Taraxacum Kok-Saghyz Fresh Biomass Using Portable Near Infrared Spectroscopy and Pyrolysis-Gas Chromatography

2021 ◽  
Author(s):  
Ying Chen ◽  
Dong Yiyang ◽  
Xiang Ma ◽  
Jiaru Li ◽  
Minmin Guo ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Infrared Spectroscopy ◽  
Natural Rubber ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Low Cost ◽  
Rubber Content ◽  
Pyrolysis Gas ◽  
Pyrolysis Gas Chromatography

Abstract Background: Taraxacum kok-saghyz (TKS), a plant native to the Tianshan valley on the border between China and Kazakhstan and inherently rich in natural rubber, inulin and other bioactive ingredients, is an important industrial crop. TKS rubber is a good substitute for natural rubber. TKS's breeding work necessitates the need to screen high-yielding varieties, hence rapid determination of rubber content is essential for the screening. Conventional analytical methods cannot meet actual needs in terms of real-time testing and economic cost. Near-infrared spectroscopy analysis technology, which has developed rapidly in the field of industrial process analysis in recent years, is a green detection technology with obvious merits of fast measurement speed, low cost and no sample loss. This research aims to develop a portable non-destructive near-infrared spectroscopic detection scheme to evaluate the content of natural rubber in TKS fresh roots. Pyrolysis gas chromatography (PyGC), was chosen as the reference method for the development of NIR prediction model. Results: 208 TKS fresh root samples were collected from the Inner Mongolia Autonomous Region of China. Near-infrared spectra were acquired for all samples. Randomly two-thirds of them were selected as the calibration set, the remaining one-third as the verification set, and the partial least squares method was successfully used to establish a good NIR prediction model at 1080-1800nm with a performance to deviation ratio (RPD) of 5.54 and coefficient of determination (R2) of 0.95. Conclusions: This study showed that portable near-infrared spectroscopy could be used with ease for large-scale screening of TKS plants in farmland, and could greatly facilitate TKS germplasm preservation, high-yield cultivation, environment-friendly, high-efficiency and low-cost rubber extraction, and comprehensive advancement of the dandelion rubber industry thereof.

scholarly journals Screening and directed evolution of transporters to improve xylodextrin utilization in the yeast Saccharomyces cerevisiae

2017 ◽  
Author(s):  
Chenlu Zhang ◽  
Ligia Acosta-Sampson ◽  
Vivian Yaci Yu ◽  
Jamie H. D. Cate
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Directed Evolution ◽  
Plant Biomass ◽  
Carbon Sources ◽  
Industrial Applications ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cellulosic Biofuel ◽  
Economic Production ◽  
Report Analysis ◽  
Selection Medium

AbstractThe economic production of cellulosic biofuel requires efficient and full utilization of all abundant carbohydrates naturally released from plant biomass by enzyme cocktails. Recently, we reconstituted the Neurospora crassa xylodextrin transport and consumption system in Saccharomyces cerevisiae, enabling growth of yeast on xylodextrins aerobically. However, the consumption rate of xylodextrin requires improvement for industrial applications, including consumption in anaerobic conditions. As a first step in this improvement, we report analysis of orthologues of the N. crassa transporters CDT-1 and CDT-2. Transporter ST16 from Trichoderma virens enables faster aerobic growth of S. cerevisiae on xylodextrins compared to CDT-2. ST16 is a xylodextrin-specific transporter, and the xylobiose transport activity of ST16 is not inhibited by cellobiose. Other transporters identified in the screen also enable growth on xylodextrins including xylotriose. Taken together, these results indicate that multiple transporters might prove useful to improve xylodextrin utilization in S. cerevisiae. Efforts to use directed evolution to improve ST16 from a chromosomally-integrated copy were not successful, due to background growth of yeast on other carbon sources present in the selection medium. Future experiments will require increasing the baseline growth rate of the yeast population on xylodextrins, to ensure that the selective pressure exerted on xylodextrin transport can lead to isolation of improved xylodextrin transporters.

REINFORCEMENT OF NATURAL RUBBER BY SILICA/SILANE IN DEPENDENCE OF DIFFERENT AMINE TYPES

2017 ◽  
Vol 90 (4) ◽  
pp. 651-666 ◽  
Author(s):  
C. Hayichelaeh ◽  
L. A. E. M. Reuvekamp ◽  
W. K. Dierkes ◽  
A. Blume ◽  
J. W. M. Noordermeer ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Natural Rubber ◽  
Health And Safety ◽  
Aliphatic Amines ◽  
Shielding Effect ◽  
Processing Temperature ◽  
Rubber Content ◽  
Payne Effect ◽  
Rubber Compounds ◽  
Bound Rubber

ABSTRACT Diphenyl guanidine (DPG) is the most commonly used secondary accelerator in silica-reinforced rubber compounds because of its additional positive effect on the silanization reaction and deactivation of free silanol groups that are left over after the silanization. However, because of health and safety concerns about the use of DPG, which decomposes to give highly toxic aniline during high processing temperature, safe alternatives are required. This work investigates the effect of various types of aliphatic amines having alkyl or cyclic structures and similar pKa (i.e., hexylamine [HEX], decylamine [DEC], octadecylamine [OCT], cyclohexylamine [CYC], dicyclohexylamine [DIC], and quinuclidine [QUI]) on the properties of silica-reinforced natural rubber (NR) compounds by taking the ones with DPG and without amine as references. When compared with the compound without amine, the use of all amine types reduces filler–filler interaction (i.e., the Payne effect) and enhances filler–rubber interaction, as indicated by bound rubber content and decreased heat capacity increment. The amines with alkyl chains can reduce the Payne effect and enhance cure rate to a greater extent compared with the amines with cyclic rings as a result of better accessibility toward the silica surface and a shielding effect because of less steric hindrance. The longer carbon tails on linear aliphatic amines ranging from HEX, DEC, to OCT lead to a lower Payne effect, lower heat capacity increment, higher bound rubber content, and higher modulus as well as tensile strength. Overall, the use of OCT provides silica-reinforced NR compounds with properties closest to the reference one with DPG and can act as a potential alternative for DPG.

Evaluation of Natural Rubber from Clones of Hevea Brasiliensis

2002 ◽  
Vol 75 (1) ◽  
pp. 171-177 ◽  
Author(s):  
Mariselma Ferreira ◽  
Rogério M. B. Moreno ◽  
Paulo S. Gonçalves ◽  
Luiz H. C. Mattoso
Keyword(s):  
Natural Rubber ◽  
Linear Correlation ◽  
Hevea Brasiliensis ◽  
Cold Season ◽  
The State ◽  
Rubber Content ◽  
Good Linear ◽  
Mooney Viscosity ◽  
In The Beginning ◽  
Good Linear Correlation

Abstract The latex and natural rubber from rubber trees [Hevea brasiliensis (Willd. exAdr. de Juss.) Muell. Arg.] from clones (RRIM 600, IAN 873, GT 1 and PB 252) recommended to the state of São Paulo, Brazil, were studied in three different tapping systems. The parameters studied were dry rubber content (DRC), percentages of ash and of nitrogen, Wallace Plasticity (P0) and Mooney Viscosity (VR). The rubber properties vary considerably as a function of clone type, tapping method and season of the year. DRC tends to decrease in the beginning of the dry, cold season (May and June), whereas both nitrogen % and ash % increase in the same period. A good linear correlation was obtained for P0 and VR. The highest P0 and VR were obtained for RRIM 600.

Ozonolytic Degradation of Interpolymers of Natural Rubber with Methyl Methacrylate and Styrene

1958 ◽  
Vol 31 (1) ◽  
pp. 82-85
Author(s):  
D. Barnard
Keyword(s):  
Molecular Weight ◽  
Carbon Black ◽  
Natural Rubber ◽  
Accurate Determination ◽  
Synthetic Polymers ◽  
Polymer Chains ◽  
Low Molecular Weight ◽  
Rubber Content ◽  
Tert Butyl Hydroperoxide

Abstract The preparation of graft and block interpolymers of natural rubber and synthetic polymers has made it desirable that the number and size of polymer chains attached to rubber be readily determinate. The degradation of unsaturated polymers with tert-butyl hydroperoxide in the presence of osmium tet oxide has been used for the determination of free polystyrene in SBR and carbon black in several elastomers, and has recently been applied to the present problem. The accurate determination of the rubber content of interpolymers by quantitative ozonolysis essentially according to the method of Boer and Kooyman suggested that this might be made the basis of isolation of the attached polymer, the rubber being degraded into fragments of low molecular weight, from which the polymer could be separated by conventional techniques. The method should be applicable to any interpolymer, or mixture, of a polyunsaturated and a saturated polymer and is illustrated with reference to interpolymers of natural rubber (NR)-polymethyl methacrylate (PMM) and NR-polystyrene (PS).

Effect of Methyl Methacrylate Content in Carbon Black Filled Natural Rubber Compounds

2012 ◽  
Vol 501 ◽  
pp. 3-7
Author(s):  
Abu Bakar Rohani ◽  
Mustafa Kamal Mazlina ◽  
Fauzi Mohd Som
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Methyl Methacrylate ◽  
Proton Nuclear Magnetic Resonance ◽  
Performance Parameters ◽  
Rubber Content ◽  
Elongation At Break ◽  
Compression Set ◽  
Rubber Compounds ◽  
Emulsion Polymerisation

Natural rubber-grafted-poly(methyl methacrylate) containing 30 and 50 percent of methyl methacrylate (MMA) monomer per 100 parts by weight of the dry rubber content denoted as NR-g-PMMA 30 and NR-g-PMMA 50, respectively were prepared via emulsion polymerisation technique. The occurrences of graft copolymerisation of PMMA onto NR were confirmed by proton Nuclear Magnetic Resonance (1H NMR) and Fourier Transform Infrared (FTIR) following purifications. The reinforcement of rubber by fillers is of great practical and technical importance. Thus, these fillers are added to rubber formulations to optimize the properties to meet a given application or set of performance parameters. In this study, the effect of carbon black in NR-g-PMMA 30 and NR-g-PMMA 50 rubber compounds were evaluated. Our results demonstrated that tensile strength, elongation at break and compression set reduced, while the hardness and solvent resistance increased in the presence of carbon black filler in comparison to the unfilled compound.

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