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1.
Molecules ; 29(11)2024 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-38893494

RESUMEN

Syzgium cumini (L.) Skeels powder (S. cumini powder), also known as Jamun, is well-known for its various medical and health benefits. It is especially recognized for its antidiabetic and antioxidant properties. Thus, S. cumini powder is used in various industries, such as the food and cosmetic industries. In this work, the fruit of S. cumini was utilized; its seeds were extracted, dried, and ground into powder. The ground powders were subjected to various techniques such as physicochemical tests, Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), particle size analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and antioxidant analysis. From the physicochemical tests, it was revealed that the jamun seed filler contained cellulose (43.28%), hemicellulose (19.88%), lignin (23.28%), pectin (12.58%), and wax (0.98%). The FTIR analysis supported these results. For instance, a peak at 2889 cm-1 was observed and associated with CH stretching, typically found in methyl and methylene groups, characteristic of cellulose and hemicellulose structures. The XRD results demonstrated that the crystallinity index of the jamun seed filler was 42.63%. The particle analysis indicated that the mean (average) particle size was 25.34 µm. This observation was ensured with SEM results. The EDX spectrum results showed the elemental composition of the fillers. Regarding thermal degradation, the jamun seed filler had the ability to withstand temperatures of up to 316.5 °C. Furthermore, endothermic and exothermic peaks were observed at 305 °C and 400 °C, respectively. Furthermore, the antioxidant property of the powder displayed a peak scavenging activity of 91.4%. This comprehensive study not only underscores the viability of S. cumini powder as a sustainable and effective particulate filler in polymer composites but also demonstrates its potential to enhance the mechanical properties of composites, thereby offering significant implications for the development of eco-friendly materials in various industrial applications.

2.
Environ Res ; 233: 116415, 2023 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-37343749

RESUMEN

The production of reinforced composite materials can generally benefit greatly from the use of natural cellulosic woody fibers as good sustainable resources. Natural plants like hemp, cotton, and bamboo are great options for knitters and crocheters looking to make eco-friendly goods. The current study examines the properties of natural fiber obtained from the stem of the Acacia pennata (AP) plant, as well as its basic physico-chemical, structural, thermal, and mechanical characteristics. The key goal of this work was to investigate how alkali treatment affected the AP fibers' morphology, chemical composition, tensile capabilities, morphological changes, structural changes, and thermal degradation (APFs). The SEM image and pXRD analyses support the improved surface roughness of the fiber, and that was seen after the alkaline treatment. From XRD analysis, the fiber crystallinity index (54.65%) was improved and it was connected to their SEM pictograms in comparison to untreated APF. Alkali-treated AP fibers include a higher percentage of chemical components including cellulose (51.38%) and ash (5.13%). Alkali-treated AP fibers have a lower amount of hemi-cellulose (30.30%), lignin (20.96%), pectin (8.77%), wax (0.12%), and moisture (13.44%) than untreated APF. Their low density and high cellulosic content will improve their ability to fiber matrices. The thermal behavior of AP fiber at various temperatures was demonstrated by TG-DTA analysis, and tensile strength was also investigated.


Asunto(s)
Acacia , Álcalis/química , Celulosa/química , Lignina/química , Resistencia a la Tracción
3.
Int J Mol Sci ; 24(18)2023 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-37762703

RESUMEN

Biodegradable bacterial nanocellulose (BNC) is a highly in-demand but expensive polymer, and the reduction of its production cost is an important task. The present study aimed to biosynthesize BNC on biologically high-quality hydrolyzate media prepared from miscanthus and oat hulls, and to explore the properties of the resultant BNC depending on the microbial producer used. In this study, three microbial producers were utilized for the biosynthesis of BNC: individual strains Komagataeibacter xylinus B-12429 and Komagataeibacter xylinus B-12431, and symbiotic Medusomyces gisevii Sa-12. The use of symbiotic Medusomyces gisevii Sa-12 was found to have technological benefits: nutrient media require no mineral salts or growth factors, and pasteurization is sufficient for the nutrient medium instead of sterilization. The yield of BNCs produced by the symbiotic culture turned out to be 44-65% higher than that for the individual strains. The physicochemical properties of BNC, such as nanofibril width, degree of polymerization, elastic modulus, Iα allomorph content and crystallinity index, are most notably dependent on the microbial producer type rather than the nutrient medium composition. This is the first study in which we investigated the biosynthesis of BNC on hydrolyzate media prepared from miscanthus and oat hulls under the same conditions but using different microbial producers, and showed that it is advisable to use the symbiotic culture. The choice of a microbial producer is grounded on the yield, production process simplification and properties. The BNC production from technical raw materials would cover considerable demands of BNC for technical purposes without competing with food resources.

4.
Environ Dev Sustain ; 24(8): 9963-9984, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34629941

RESUMEN

In order to increase resilience of planters against climate change and bring additional economic benefits, agro-wastes can be exploited for extracting nanocellulose to produce eco-friendly composites. This paper focused on extracting nanocellulose from sugarcane bagasse and coir (cocos nucifera) using chemical methods including mercerisation, bleaching and acid hydrolysis. Taguchi Design of Experiment showed that the optimum alkaline treatment conditions of bagasse were at 2 wt% NaOH at 90 °C for 16 h. The morphological changes occurring along each treatment stage were observed using Fourier-Transform Infrared spectroscopy and Scanning Electron Microscopy. The differences in the nanoparticles extracted from the two biomass were studied through the determination of crystallinity indexes and particle size. Cellulose nanocrystals (CNCs) from coir exhibited a total crystallinity index (TCI) of 1.03 and an average particle size of 137.3 nm while CNCs extracted from sugarcane bagasse under similar treatment conditions had a TCI of 0.85 and an average particle size of around 48 µm. Dynamic Light Scattering findings showed risks of agglomeration after freeze drying. Bio-nanocomposite films with polyvinyl alcohol (PVA) as matrix were manufactured by the solvent casting process. The highest tensile strength (38.2 MPa) was obtained for CNCs extracted from coir at a CNC/PVA loading of 0.5 wt%, representing a 96.9% increase in the tensile strength as compared to the unreinforced PVA matrix. This study showed that sugarcane bagasse and coir are suitable sources of nanocellulose and can be used to prepare bio-composites with considerably high tensile strengths.

5.
Prep Biochem Biotechnol ; 51(8): 811-820, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33347361

RESUMEN

In the present study, the cellulose from sugarcane tops (SCT) was separated and characterized for its purity. Approximately, 85% (w/w) of total cellulose present in raw SCT was recovered by using alkaline method. The monosaccharide analysis of SCT cellulose by HPLC showed 91% D-glucose, 7.5% D-xylose and 1.5% D-arabinose residues. Surface morphology study of dried cellulosic fibers by FESEM exhibited the fibrous structure. The FTIR analysis of separated cellulose displayed the peaks corresponding to the peaks obtained from commercial cellulose, confirming its purity. The crystallinity index (CrI) of separated cellulose increased to 49% after delignification and xylan extraction from 36% of raw SCT. The typical TGA curve of separated SCT cellulose showed decomposition and mass reduction at 327 °C resulting in single decomposition peak in TGA analysis, confirming its purity. CHNS analysis supported the purity of separated cellulose by confirming absence of nitrogen and sulfur. The separated cellulose was hydrolyzed by recombinant endo-ß-1,4-glucanase (CtCel8A), cellobiohydrolase (CtCBH5A) from Clostridium themocellum and ß-1,4-glucosidase (HtBgl) from Hungateiclostridium thermocellum at pH 5.8, 50 °C for 24 h, resulting in the production of 188 mg/g of total reducing sugar (TRS). The separated cellulose from SCT can be utilized as an alternative substrate for commercialization and for bioethanol production.


Asunto(s)
Proteínas Bacterianas/química , Celulasa/química , Celulosa 1,4-beta-Celobiosidasa/química , Celulosa/química , Saccharum/química , Proteínas Bacterianas/genética , Celulasa/genética , Celulosa 1,4-beta-Celobiosidasa/genética , Clostridium thermocellum/enzimología , Clostridium thermocellum/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética
6.
Int J Mol Sci ; 21(15)2020 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-32727025

RESUMEN

The plant cell wall is a complex structure consisting of a polysaccharide network. The rearrangements of the cell wall during the various physiological reactions of plants, however, are still not fully characterized. Profound changes in cell wall organization are detected by microscopy in the phloem fibers of flax (Linum usitatissimum) during the restoration of the vertical position of the inclined stems. To characterize the underlying biochemical and structural changes in the major cell wall polysaccharides, we compared the fiber cell walls of non-inclined and gravistimulated plants by focusing mainly on differences in non-cellulosic polysaccharides and the fine cellulose structure. Biochemical analysis revealed a slight increase in the content of pectins in the fiber cell walls of gravistimulated plants as well as an increase in accessibility for labeling non-cellulosic polysaccharides. The presence of galactosylated xyloglucan in the gelatinous cell wall layer of flax fibers was demonstrated, and its labeling was more pronounced in the gravistimulated plants. Using solid state NMR, an increase in the crystallinity of the cellulose in gravistimulated plants, along with a decrease in cellulose mobility, was demonstrated. Thus, gravistimulation may affect the rearrangement of the cell wall, which can enable restoration in a vertical position of the plant stem.


Asunto(s)
Pared Celular/metabolismo , Celulosa/metabolismo , Lino/crecimiento & desarrollo , Regulación de la Expresión Génica de las Plantas , Gravitropismo , Floema/crecimiento & desarrollo
7.
Anal Bioanal Chem ; 408(29): 8403-8414, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27695986

RESUMEN

This work deals with the modifications resulting from the dissolution of four commercial cellulosic samples, with different crystallinity rates and degrees of polymerization (DPs), in four solvent systems, known and used to dissolve cellulose. The dissolution conditions were optimized for the 16 various systems and followed by turbidity measurements. After regeneration, the samples were analyzed by thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray diffractometry (XRD) to study their modification. Viscosimetry measurements were used to evaluate the potential decrease of the DP after dissolution. The observed structural modifications established that, for low DP, all the solvent systems were efficient in dissolving the cellulose without altering the DP, except BMIM [Cl], which provoked a decrease of up to 40 % and a decrease of around 20 % of the degradation temperature (onset temperature, T o). For high molecular weight (MW) celluloses, DMSO/TBAF was the only system to allow a complete dissolution without any molar mass loss and degradation temperature modification.

8.
Int J Biol Macromol ; 276(Pt 2): 134029, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39084993

RESUMEN

New cellulose (CL) fibers are derived from Chamaerops humilis (Ch) rachis. They play an essential role in various industries to produce environmentally friendly products as an alternative to enhancing and strengthening lightweight composites, such as dashboards automotive. Distinctive properties of Ch fibers (ChFs) were determined by extracting fibers from dwarf palm plant branches using anaerobic analysis. This search comprehensively studies morphological, physical, mechanical, and thermal characteristics and water absorption testing. The fiber diameter was 241.23 ± 34.77 µm, while the obtained linear density and density were 13.71 ± 0.57 Tex and 0.801 ± 0.05 g/cm3, respectively. The moisture content was 8.5 %, and the moisture regain was 9.29 %. Scanning electron microscopy images showed the fibers and smooth and rough surfaces. The thermogravimetric analysis demonstrated the maximum degradation of 352 °C, thermal stability of 243 °C, and the kinetic activation energy reached (79.78 kJ/mol). X-ray diffraction proves the availability of CL, with a crystallinity index = 68.38 % and crystal size = 2.92 nm. Fourier transform infrared succeeded in detecting functional groups and chemical compounds of fibers. The fibers exhibited a tensile stress of 110.85 ± 77.08 MPa, an elongation at a break rate of 2.29 ± 1.27 %, and Young's modulus of 6.05 ± 3.9 GPa. The maximum likelihood method (2P-Weibull distribution) was employed to examine the distribution of mechanical properties of fibers. According to the results above, new ChFs are an excellent reinforcement for elaborating fiber-reinforced biocomposites.


Asunto(s)
Celulosa , Textiles , Celulosa/química , Termogravimetría , Resistencia a la Tracción , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X , Temperatura , Agua/química
9.
Heliyon ; 10(10): e31117, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38778970

RESUMEN

Fibers extracted from Lasia spinosa (L.) thwaites (LS) were characterized to investigate their potential use as biodegradable textile materials. Mechanical and alkali extraction methods were followed to extract LS rhizome fibers. The morphological, physical, chemical, mechanical, and thermal properties of the mechanically extracted rhizome fibers from the commonly available LS species of Lamina-dissected type [LDT] and Sagittate type [SG] were investigated. No previous studies have been done to characterize the LS rhizome fibers. Examination of rhizome fiber morphology using scanning electron microscopy (SEM) revealed that fibers within the dispersed vascular bundles of the rhizome possess a natural crimp.The FTIR result confirmed that the fibers are rich in cellulose. X-RD results confirm a 43 % and 58 % crystallinity index of LDT and SG fibers, respectively, indicating higher amorphous regions and lower crystal phases. Moisture regain of 12.5 % and 14.5 %, single fiber tensile strength of 213.92 MPa and 216.97 MPa, elongation at break of 16.65 % and 17.67 %, and Young's modulus of 1.32 GPa and 1.26 GPa were observed for LDT and SG fibers respectively. Thermogravimetric analysis confirmed thermal stability up to 230 °C for both fiber types confirming their ability to withstand textile processing.

10.
Int J Biol Macromol ; 269(Pt 1): 131818, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38670191

RESUMEN

In this present work, characterize the chemical, physical, thermal and Morphological behaviour of raw and alkali-treated (NaOH 5 %,10 % & 15 %) new natural cellulose Habara plant stem fiber (HF). From the chemical analysis, the 10 % alkali-treated HF obtained cellulose (67.9 %), hemicellulose (12.7 %), lignin (11.8 %) wax (0.18 %), moisture (2.44 %) and Ash (1.21 %). Fourier Transform Infrared Spectroscopy Analysis, alkali treatment effectively eliminates hemicellulose and lignin from the surfaces of natural fiber, as seen changes in the FTIR peaks at 1730, 1480, and 1140 cm-1.The X-ray analysis results indicate that, there is crystalline cellulose present, with a crystallinity level of 43.87 %, and that the other components are amorphous. In addition, the thermal stability of lignocellulosic fiber up to 230 °C was observed, and the degradation steps of each major component could be identified. The 10 % alkali-treated HF provides tensile strength of 790.9 MPa, with an elongation at break of about 3.41 %. The Scanning Electron Microscope analysis showcased the morphological changes on the fiber fractured surface, diameter variation, and impurities, etc. The Atomic Force Microscopy was used to determine the surface roughness characteristics of the HF, which confirmed the possible reinforcement in the structure of the polymer matrix composite structure.


Asunto(s)
Celulosa , Tallos de la Planta , Celulosa/química , Tallos de la Planta/química , Lignina/química , Resistencia a la Tracción , Espectroscopía Infrarroja por Transformada de Fourier , Polímeros/química , Polisacáridos/química , Temperatura
11.
Int J Biol Macromol ; 266(Pt 2): 131163, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38547950

RESUMEN

Novel kinds of starch spectra were generated from a lesser-known plant, making this investigation unique. The recent trend of starch characterization shows the establishment of novel bioresources from nonconventional unexplored databases. The present endeavor was made to obtain the starch fingerprint of Ampelopteris prolifera (rhizome) belonging to seedless vascular plants. For comparison, a commercial local cultivar of potato (Kufri Jyoti) was taken. The starch particle of A. prolifera shows much uniqueness depicting its novelty viz., crystallinity index of 60.04 %, powder diffractogram at (2θ scale)17.57° to 39.78°; this diffractogram pattern is reported from this study as newer one i.e. R type(whereas potato starch is CB type); characteristic peak at 2θ = 20.07° suggests starch-lipid complex formation and V type crystallinity (i.e. RS 5 type); FTIR spectra showing the presence of more short chain branching; high gelatinization temperature(84.62 ±â€¯0.10), particle size and zeta value of A. prolifera is 4.00 ±â€¯0.81 µm and - 18.91 ±â€¯3.58 mV respectively. Bragg's peak from the single crystal X-ray diffraction has been generated for the first time of A. prolifera. Extraction of the starch particle was performed in chilled water. Therefore, the present study suggests wide-spectrum commercial utility and cost-effective production.


Asunto(s)
Solanum tuberosum , Almidón , Solanum tuberosum/química , Almidón/química , Difracción de Rayos X , Espectroscopía Infrarroja por Transformada de Fourier
12.
Environ Sci Pollut Res Int ; 30(33): 79706-79723, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37336854

RESUMEN

In the recent past, an increasing interest is mostly observed in using microwave and ultrasonic irradiation to aid the biological conversion of waste materials into value-added products. This study is focused on various individual impacts of microwaves and ultrasonic waves for the treatment of biomass before the synthesis of value-added products. Following, a comprehensive review of the mechanisms governing microwaves and ultrasonication as the treatment methods, their effects on biomass disruption, solubilization of organic matter, modification of the crystalline structure, enzymatic hydrolysis and production of reducing sugars was performed. However, based on the lab-scale experiments evaluated, microwaves and ultrasonication were studied to be economically and energetically ineffective despite their beneficial effects on the waste biomass. This article reviews some of the difficulties associated with using microwaves and ultrasonic irradiation for the efficient processing of waste biomasses and identified some potential directions for future study.


Asunto(s)
Lignina , Microondas , Lignina/química , Biomasa , Hidrólisis , Residuos
13.
Bioresour Technol ; 346: 126617, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34954358

RESUMEN

The chemical compositions of lignin, hemicellulose and cellulose are so far unascertained to various lignocellulose in respect to effect of cellulose enzymatic hydrolysis. The novel and environment-friendly gluconic acid (GA) pretreatment technology showed impressive results on the enzymatic hydrolysis of cellulose in various agricultural straws. However, only few of the main reasons or critical issues pertaining to this reaction are known. Therefore, the novel GA pretreatment was carried out to remove hemicellulose from the three representative waste straws under different conditions. Next, for the enzymatic hydrolysis of the residual cellulose fraction in the pretreated straws, some mathematical correlations have been investigated between enzyme accessibility, hemicellulose removal rate, and cellulose crystallinity index. Both linear and nonlinear models were compared using five-parameter logic curve, four-parameter logic curve, and Deming regression. Hemicellulose removal was logically ascribed to be the trigger for cellulose saccharification efficiency during GA pretreatment of these waste straws.


Asunto(s)
Celulosa , Lignina , Agricultura , Gluconatos , Hidrólisis
14.
Polymers (Basel) ; 14(23)2022 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-36501592

RESUMEN

Cellulose crystallinity can be described according to the crystal size and the crystallinity index (CI). In this research, using Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) methods, we studied the crystallinity of three different types of cellulose: banana rachis (BR), commercial cellulose (CS), and bacterial cellulose (BC). For each type of cellulose, we analyzed three different crystallization grades. These variations were obtained using three milling conditions: 6.5 h, 10 min, and unmilled (films). We developed a code in MATLAB software to perform deconvolution of the XRD data to estimate CI and full width at half-maximum (FWHM). For deconvolution, crystalline peaks were represented with Voigt functions, and a Fourier series fitted to the amorphous profile was used as the amorphous contribution, which allowed the contribution of the amorphous profile to be more effectively modeled. Comparisons based on the FTIR spectra and XRD results showed there were no compositional differences between the amorphous samples. However, changes associated with crystallinity were observed when the milling time was 10 min. The obtained CI (%) values show agreement with values reported in the literature and confirm the effectiveness of the method used in this work in predicting the crystallization aspects of cellulose samples.

15.
Polymers (Basel) ; 14(10)2022 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-35631813

RESUMEN

Recently, environmental and ecological concerns have become a major issue owing to the shortage of resources, high cost, and so forth. In my research, I present an innovative, environmentally friendly, and economical way to prepare nanocellulose from grass wastes with a sodium hypochlorite (NaClO) solution of different concentrations (1−6% mol) at different times 10−80 min, washed with distilled water, and treated with ultrasonic waves. The optimum yield of the isolated cellulose was 95%, 90%, and 87% NaClO at 25 °C for 20 min and with NaOH and H2SO4 at 25 °C with 5% M, respectively. The obtained samples were characterized by dynamic light scattering (DLS), Fourier-transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD). The effect of test temperature and reaction times on the crystallinity index (IC) of GNFC with different treated mediums was carried out and investigated. The IC was analyzed using the diffraction pattern and computed according to the Segal empirical method (method A), and the sum of the area under the crystalline adjusted peaks (method B) and their values proved that the effect of temperature is prominent. In both methods, GNFC/H2SO4 had the highest value followed by GNFC/NaOH, GNFC/NaClO and real sample nano fiber cellulose (RSNFC). The infrared spectral features showed no distinct changes of the four cellulose specimens at different conditions. The particle size distribution data proved that low acid concentration hydrolysis was not sufficient to obtain nano-sized cellulose particles. The Zeta potential was higher in accordance with (GNFC/H2SO4 > GNFC/NaOH > GNFC/NaClO), indicating the acid higher effect.

16.
Data Brief ; 39: 107571, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34825035

RESUMEN

In the present work, rock samples were collected from Paleolithic archaeological site of Attirampakkam, Tamil Nadu, India to assess the mineralogical composition using Fourier transform infrared-spectroscopic (FT-IR) technique and X-Ray Diffraction Spectrometry (XRD). The quartz, kaolinite, montmorillonite, calcite, orthoclase, microcline and illite minerals are identified in rock samples and crystallinity index of quartz (SiO2) is estimated for all the samples by comparing the ratio of intensity of the characteristic peak at 778 and 695 cm-1 using FT-IR spectrum. In rock samples, calculated crystallinity index of quartz is greater than the 1 from FT-IR spectrum and it shows that the distribution is disordered in nature. Additionally, some more minerals such as hematite and rutile are identified in rock samples by X-ray diffraction technique. This extensive study shows that archeological rock samples are wide variation in mineral composition.

17.
Carbohydr Polym ; 253: 117203, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33278974

RESUMEN

Acetes shrimp is an unexploited tiny shrimp mainly landed as bycatch which is a good source for the recovery of protein and chitin. In the present study, the residual shell obtained after the hydrolysis of Acetes was used for the extraction of chitin by combining enzymatic and chemical treatments. Enzymatic hydrolysis with Alcalase was performed at different rates. Results showed that the protein removal efficiency increases with the increase in DH and the maximum deproteinzation was achieved at 30 % DH (93.68 %). The FTIR spectra showed two sharp bands for chemically prepared chitin and 30 % DH chitin at 1627-1629 and 1664-1665 cm-1 indicating that its alpha amorphous structure. The degree of N-acetylation was found to be higher in enzymatically prepared chitin in all different hydrolytic treatment rather than chemically prepared. The surface morphologies of chitin revealed the porous and nanofibrous structures for 30 % DH chitin and chemically prepared chitin.


Asunto(s)
Exoesqueleto/química , Quitina/química , Quitina/aislamiento & purificación , Decápodos/química , Acetilación , Animales , Proteínas de Peces/química , Hidrólisis , Nanofibras/química , Péptido Hidrolasas/química , Porosidad , Mariscos , Espectroscopía Infrarroja por Transformada de Fourier
18.
Data Brief ; 38: 107421, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34632017

RESUMEN

The oxygen (δ18Ocarbonate), strontium (87Sr/86Sr), and previously unpublished carbon (δ13Ccarbonate) isotope data presented herein from the Imperial Roman site of Velia (ca. 1st to 2nd c. CE) were obtained from the dental enamel of human permanent second molars (M2). In total, the permanent M2s of 20 individuals (10 male and 10 female) were sampled at the Museo delle Civiltà in Rome (formerly the Museo Nazionale Preistorico Etnografico "L. Pigorini") and were subsequently processed and analysed at McMaster University. A subsample of teeth (n=5) was initially subjected to Fourier transform infrared spectroscopy (FTIR) analysis to assess for diagenetic alteration through calculation of crystallinity index (CI) values. Subsequently, tooth enamel was analysed for δ13Ccarbonate and δ18Ocarbonate (VPDB) using a VG OPTIMA Isocarb isotope ratio mass spectrometer (IRMS) at McMaster Research for Stable Isotopologues (MRSI), and 87Sr/86Sr was measured by dynamic multi-collection using a thermal ionization mass spectrometer (TIMS) in the School of Geography and Earth Sciences. The dental enamel isotope data presented represent the first δ18O, δ13Ccarbonate, and 87Sr/86Sr values analysed from Imperial Roman Campania to date, providing data of use for comparative analyses of δ18O, δ13C, and 87Sr/86Sr values within the region and for assisting in documenting human mobility in archaeological contexts. Full interpretation of the δ18O and 87Sr/86Sr data presented here is provided in "Imperial Roman mobility and migration at Velia (1st to 2nd c. CE) in southern Italy" [1].

19.
Biotechnol Rep (Amst) ; 28: e00554, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33209590

RESUMEN

The use of chitosan to harvest microalgae is a strategic step that seeks to reach an economically competitive price to recover lipids, proteins, and pigments. The aim of the present work was to design low-molecular-weight chitosan from shrimp shells and its physicochemical characterization, to be used for the harvesting of wild microalgae consortia. The chitosan was obtained by chemical deacetylation of shrimp shells, and physicochemical characterization was made using the instrumental methods DSC, TGA, X-ray, FTIR, and SEM. The harvesting of wild microalgae consortia was performed by the jar test method. The obtained chitosan had a low molecular weight (169 KDa), a deacetylation degree of 83 %, a decomposition temperature (TD) of 280 °C, and a crystallinity of 38.2 %. The microalgae genera found in the consortium were Scenedesmus sp., Chlorella sp., Schroderia sp., and Chlamydomonas sp. The microalgae removal efficiency of the chitosan was 99.2 % with 20 mg L-1.

20.
Int J Biol Macromol ; 154: 538-544, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32194122

RESUMEN

Effective management and the valorization of agro-industrial lignocellulosic feedstocks can only be realized if a versatile cellulase cocktail is developed that can release glucose at affordable cost irrespective of biomass type. In the present study the flexibility of using cellulase cocktail obtained from mutant UV-8 of Talaromyces verruculosus IIPC 324 in depolymerizing multiple agro-industrial lignocellulosic feedstocks was explored. Five different dilute acid pretreated biomasses were evaluated and cellulase loading was done at 25 mg protein/g cellulose content. After 72 h of hydrolysis at 55 °C and pH 4.5, corn cob and rice straw emerged as the easiest and toughest substrates with saccharification yield of 83.9 ± 1.17 and 35.5 ± 1.16% respectively from their cellulose fraction. Addition of PEG 6000 could retain >65% of all mono-component enzymes present in cellulase cocktail. Structural elucidation of biomasses gave an insight about key features responsible for variable recalcitrance in the different agro-industrial feedstock. Cellulose hydrolysis showed a significant negative correlation in the order of Cr I > S/G ratio > ash content. The chemical composition of lignin had a major impact on enzyme-lignin interactions. Higher H lignin content and lower S/G ratio promoted enzyme desorption, thereby increasing the likelihood of their recycling and reuse.


Asunto(s)
Celulasa/genética , Celulasa/metabolismo , Lignina/química , Lignina/metabolismo , Mutación , Polimerizacion , Talaromyces/enzimología , Agricultura , Hidrólisis , Industrias
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