Статті в журналах: "Guar gum enzymatic degradation"

1

Chen, Feng, Xu Guang Wang, and Ren Shu Yang. "Preparation of Low Molecular Weight Guar Gum for Fracturing by Enzymatic Degradation." Advanced Materials Research 971-973 (June 2014): 127–30. http://dx.doi.org/10.4028/www.scientific.net/amr.971-973.127.

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Guar gum was subjected to degradation in high concentration aqueous solution by enzymatic treating to obtain high concentration low molecular weight guar gum for fracturing. The study indicates that the high concentration guar gum aqueous solution can be degraded effectively by enzymatic treating. The enzymatic treating conditions were investigated and the optical enzymatic treating pH, temperature and enzyme add amount are respectively 6, 50°C and 0.1g/L, and various of low molecular weight guar gum with different molecular weight can be obtained by controlling the enzymatic treating time.

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Maslennikova, Elena V., and Vasilii V. Ermakov. "Using biochemical agents to intensify the treatment of highly concentrated drilling wastewater." Vestnik MGSU, no. 9 (September 2020): 1274–84. http://dx.doi.org/10.22227/1997-0935.2020.9.1274-1284.

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Introduction. The co-authors have developed a new approach to the treatment of highly concentrated drilling wastewater (DWW). The approach is based on the enzymic degradation of polysaccharides that drilling wastewater contains. The research objective is to perform an experimental evaluation of the ability of this biochemical agent to intensify the process of removal of solid impurities from highly concentrated polysaccharide-containing DWW. Materials and methods. The research was performed using standardized test solutions of polysaccharides (carboxymethyl cellulose (CMC), xanthane gum, guar gum), highly concentrated DWW-containing polysaccharides. The reliability of results is ensured by certified methods of analysis, included into the Federal Register of Measurement Procedures and performed by an accredited laboratory, as well as multiple series of experiments. Results. The ability of the biochemical agents (brewing waste (BW) and an enzymatic agent (EP)) to intensify the process of removal of solid impurities from highly concentrated DWW-containing polysaccharides is identified experimentally. The efficiency of biochemical agents used in the process of treatment is determined. The biological degradation of CMC and guar gum solutions is faster than the natural biological degradation that involves BW. Depolymerization time is detected for CMC and guar gum solutions that contain EP. Conclusions. The co-authors have developed a cheaper and more environmentally friendly alternative to existing solutions. It represents a biological method of solid impurities removal from highly concentrated BWW-containing polysaccharides. The use of brewing waste products (BW) as a source of microorganisms, that trigger the polysaccharide hydrolysis, is theoretically substantiated and experimentally proven as a method of treatment of highly concentrated BWW-containing polysaccharides. The expediency of using biochemical agents (BW and EP in isolation) to accelerate the settling rate of solid components of highly concentrated BWW is proven experimentally.

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Gastone, Francesca, Tiziana Tosco, and Rajandrea Sethi. "Green stabilization of microscale iron particles using guar gum: Bulk rheology, sedimentation rate and enzymatic degradation." Journal of Colloid and Interface Science 421 (May 2014): 33–43. http://dx.doi.org/10.1016/j.jcis.2014.01.021.

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Feng, Guoping, Amanda Hew, Ramesh Manoharan, and Siva Subramanian. "Impact of Mannanase-Producing Bacillus spp. on the Accuracy of the 3M Petrifilm Aerobic Count Method." Journal of Food Protection 80, no. 7 (June 2, 2017): 1117–22. http://dx.doi.org/10.4315/0362-028x.jfp-16-473.

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ABSTRACTConsistent deviations of the 3M Petrifilm aerobic counts (AC) from the standard pour plate aerobic plate count (APC) were observed with dehydrated onion and garlic products. A large study was designed to determine the relationship of these two methods and the root cause for the deviations. A total of 3,800 dehydrated onion and garlic samples were analyzed by both the Petrifilm AC and the standard pour plate APC method. Large spreader-like liquefied areas were observed on numerous Petrifilm plates. These liquefied areas made enumeration inaccurate. “Liquefier” microorganisms from Petrifilm plates were isolated and identified to species level by 16S rRNA and gyrB gene sequencing. Enzyme diffusion assay was performed to determine potential enzymatic degradation of guar gum, the gelling agent used in Petrifilm plates. The results indicated that the correlation between Petrifilm AC and standard APC is relatively low. Paired t test results suggested that the Petrifilm AC method produced significantly different results compared with standard APC. The discrepancies were attributable at least partly to a liquefier organism that hydrolyzed guar gum, leading to liquefaction. Liquefaction of Petrifilm plates seems to have two effects on accuracy: (i) liquefied areas may allow motile organisms to move and multiply in the liquefied area during the incubation period, yielding more than one colony from one cell and, as a result, leading to overestimation of the microbial load and (ii) the blurred areas obscure other colonies, leading to potential underestimation. The liquefier organism was identified as Bacillus amyloliquefaciens, a potent mannanase producer and heat-resistant spore former. Enzyme diffusion assay confirmed that mannanase contained in the cell-free supernatant of B. amyloliquefaciens can hydrolyze the 1,4-β-mannopyranosyl bond, the backbone of guar gum. This is the first report of the role of B. amyloliquefaciens in the liquefaction of Petrifilm plates and its negative impact on accuracy.

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Ansari, Zoha, and Sangeet Goomer. "Natural Gums and Carbohydrate-Based Polymers: Potential Encapsulants." Indo Global Journal of Pharmaceutical Sciences 12 (2022): 01–20. http://dx.doi.org/10.35652/igjps.2022.12001.

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Plants possess a wide range of bioactive compounds with established health benefits which are highly susceptible to degradation. The environmental dynamics such as high temperature, light, oxygen limits the shelf life and bioavailability of these compounds in food and drug formulations. Encapsulation serves as an effective way of preserving these sensitive compounds by enclosing them within a coating/wall material and hence improves their bioavailability and functional properties.Scope and Approach: The wall materials used for encapsulation also known as encapsulants act as physical barriers between core compound and external stimuli. There are different edible protein, lipid and carbohydrate based encapsulants used for coating of bioactive compounds. However, this review gives a detailed insight on composition, functional properties, and applications of carbohydrate based polymers in food, and pharmaceutical industries while emphasizing on the advantages and limitations of these polymers in encapsulation process. So, we explored recent expansion in the area of natural polysaccharides and their derivatives as carriers for the targeted and sustained delivery of active compounds. Key Findings and Conclusions:Polysaccharides, natural gums (Carrageenan, Alginate, Gum arabic, Guar gum, Gellan gum, Xanthan gum) and their derivatives are biodegradable polymers being used as sustained release carriers. They are more advantageous over lipid based and protein based carriers by virtue of their unique features such as thermo stability and versatility of interacting with a range of hydrophilic and hydrophobic compounds. Tailor-made carriers made by structural modifications of the polysaccharides using physical, chemical and enzymatic reactions result in improved functional properties and hence widen their area of applications.©2022iGlobal Research and PublishingFoundation. All rights reserved.Cite this article as:Ansari, Z.; Goomer, S.Natural gums and carbohydrate-based polymers: Potential encapsulants. Indo Global J. Pharm. Sci., 2022; 12:1-20. DOI:http://doi.org/10.35652/IGJPS.2022.12001.

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Bradley, T. D., A. Ball, S. E. Harding, and J. R. Mitchell. "Thermal degradation of guar gum." Carbohydrate Polymers 10, no. 3 (January 1989): 205–14. http://dx.doi.org/10.1016/0144-8617(89)90012-x.

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Hussain, Majid, Saeed Akhtar, Nazia Khalid, Muhammad Azam, Muhammad Waheed Iqbal, Tariq Ismail, Imran Mahmood Khan, et al. "Hydrolysis, Microstructural Profiling and Utilization of Cyamopsis tetragonoloba in Yoghurt." Fermentation 9, no. 1 (January 4, 2023): 45. http://dx.doi.org/10.3390/fermentation9010045.

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The present study investigates the hydrolysis, microstructural profiling and utilization of guar gum (Cyamopsis tetragonoloba) as a prebiotic in a yoghurt. Guar galactomannans (GG) was purified and partially depolymerized using an acid, alkali and enzyme to improve its characteristics and increase its utilization. The prebiotic potential of hydrolyzed guar gum was determined using Basel and supplemented media. Crude guar galactomannans (CGG), purified guar galactomannans (PGG), base hydrolyzed guar galactomannans (BHGG), acid hydrolyzed guar galactomannans (AHGG) and enzymatic hydrolyzed guar galactomannans (EHGG) were analyzed using scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Yoghurt was prepared with a starter culture and incorporating guar gum, its hydrolyzed forms (0.1, 0.5 and 1%) and Bifidobacterium bifidum. The results showed that PHGG significantly improved the viability of B. bifidum. SEM revealed a significant change in the surface morphology of guar gum after acidic and enzymatic hydrolysis. Enzymatic hydrolysis developed a well-defined framework within guar gum molecules. The XRD pattern of CGG, PGG and AHGG presented an amorphous structure and showed low overall crystallinity while EHGG and BHGG resulted in slightly increased crystallinity regions. FTIR spectral analysis suggested that, after hydrolysis, there was no major transformation of functional groups. The addition of the probiotic and prebiotic significantly improved the physiochemical properties of the developed yoghurt. The firmness, cohesiveness, adhesiveness and syneresis were increased while consistency and viscosity were decreased during storage. In sum, a partial hydrolysis of guar gum could be achieved using inexpensive methods with commercial significance.

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Oprea, Stefan, and Veronica Oprea. "Biodegradation of crosslinked polyurethane acrylates/guar gum composites under natural soil burial conditions." e-Polymers 16, no. 4 (July 1, 2016): 277–86. http://dx.doi.org/10.1515/epoly-2016-0038.

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AbstractThis study investigated the effect of the guar gum content on the degradation behavior of the polyester and polyether polyurethane acrylate composites under outdoor soil-burial exposure. Polyurethane acrylates-guar gum composites were characterized before and after soil degradation by Fourier transform infrared spectroscopy (FTIR), mechanical measurements and scanning electron microscopy (SEM). The results showed that the addition of guar gum produces significant improvement in the degradation rate of these composites. The guar gum filler’s susceptibility to humidity and to soil microorganisms resulted in significant chemical and morphological changes in the entire structure of the composite. Guar gum incorporation into the matrix of the crosslinked polyurethane acrylates leads to a significant decrease in the mechanical properties of the composite films after soil burial exposure.

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9

Reddy, T. Thimma, and Shekharam Tammishetti. "Free radical degradation of guar gum." Polymer Degradation and Stability 86, no. 3 (December 2004): 455–59. http://dx.doi.org/10.1016/j.polymdegradstab.2004.05.017.

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Tomlin, J., N. W. Read, C. A. Edwards, and B. I. Duerden. "The degradation of guar gum by a faecal incubation system." British Journal of Nutrition 55, no. 3 (May 1986): 481–86. http://dx.doi.org/10.1079/bjn19860055.

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1. Homogenized and diluted faeces (50 g/l) from one human source were incubated with the complex plant polysaccharide, guar gum, to investigate the degradation of viscous polysaccharides by intestinal bacteria.2. Incubation of the faecal homogenate with guar gum produced a rapid decrease in viscosity and in pH, accompanied by the release of hydrogen.3. No changes in viscosity or pH were observed and there was no production of H2gas when guar gum was incubated with autoclaved faecal homogenate (20 min, 1.03 × 105Pa).4. A bacteria-free filtrate of faeces was prepared by centrifuging the faecal homogenate (2400 g for 100 min) followed by filtration through a Seitz filter and then a millipore filter (size 0.45 μm). Incubating this with guar gum produced a slow decrease in viscosity, but no significant change in pH and no generation of H2.5. Our results show that guar gum can be fermented by human colonic bacteria and suggest the possibility of predigestion by extracellular free enzymes.

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11

Cheng, Yu, and Robert K. Prud'homme. "Enzymatic Degradation of Guar and Substituted Guar Galactomannans." Biomacromolecules 1, no. 4 (December 2000): 782–88. http://dx.doi.org/10.1021/bm005616v.

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12

Kozhevnikova, E. Yu, A. V. Shnyreva, A. V. Barkov, Yu A. Topolyuk, I. N. Grishina, L. A. Magadova, and D. V. Voronin. "Biodegradation of Guar Gum in Hydraulic Fracturing Fluid under the Action of Enzyme Preparations of Basidiomycetes." Biotekhnologiya 37, no. 4 (2021): 96–105. http://dx.doi.org/10.21519/0234-2758-2021-37-4-96-105.

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Guar gum is a polymer that is widely used as a gelling agent for technological liquids in the petroleum industry. In this paper, we have studied the potential for the environmentally friendly biodegradation of guar gum by enzymes of basidiomycetes for efficient disposal of oil industry wastes. For the first time, we compared the enzymatic activity towards guar gum of seven basidiomycete strains, namely Trametes hirsuta MT-24.24, Lactarius necator, Trametes hirsuta MT-17.24, Schizophyllum commune MT-33.01, Fomes fomentarius MT-4.05, Fomitopsis pinicola MT-5.21, and Trametes versicolor It-1. This comparison showed that the preparation based on Fomitopsis pinicola MT-5.21 fungal mycelium at a concentration of 0.05% provides the most efficient decomposition of a frac fluid containing guar gum. By varying the enzyme concentration in this fluid it is possible to control the decrease in its viscosity over time. The developed enzyme preparation is an efficient and environmentally friendly guar gum biodegradant and can be used to process waste fracturing fluids based on polysaccharides in order to reuse water resources. Key words: biodegradants, basidiomycetes, guar gum, enzymatic hydrolysis, enzyme destructors, fracturing fluids. Funding - The work was financially supported by the National University of Oil and Gas "Gubkin University" (Internal grant no. 120720 "Development of New Biotechnological Methods and Materials for Environmental Protection and Biomedicine").

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HARTEMINK, Ralf, Siemen E. SCHOUSTRA, and Frans M. ROMBOUTS. "Degradation of Guar Gum by Intestinal Bacteria." Bioscience and Microflora 18, no. 1 (1999): 17–25. http://dx.doi.org/10.12938/bifidus1996.18.17.

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Elias, Edwin J., Singhal Anil, Showkat Ahmad, and Anwar Daud. "Colon Targeted Curcumin Delivery Using Guar Gum." Natural Product Communications 5, no. 6 (June 2010): 1934578X1000500. http://dx.doi.org/10.1177/1934578x1000500621.

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Curcumin is used in the treatment of colon cancer, but its very poor absorption in the upper part of the GIT is a major concern. As a site for drug delivery, the colon offers a near neutral pH, reduced digestive enzymatic activity, a long transit time and an increased responsiveness to absorption enhancers. The aim of the present study was to identify a suitable polymer (guar gum) based matrix tablet for curcumin with sufficient mechanical strength and promising in vitro mouth-to-colon release profile. Three formulations of curcumin were prepared using varying concentrations of guar gum containing 50 mg curcumin by the wet granulation method. Tablets were subjected to evaluation by studying parameter like hardness, friability, drug content uniformity, and in-vitro drug release. In vitro drug release was evaluated using simulated stomach, intestinal and colonic fluids. The susceptibility of guar gum to colonic bacteria was also assessed by a drug release study with rat caecal contents. The 40% guar gum containing formulation (F-1) showed better drug release (91.1%) after 24 hours in the presence of rat caecal contents in comparison with the 50% guar gum containing formulation (F-2) (82.1%). Curcumin could, thus, be positively delivered to the colon for effective colon cancer treatment using guar gum.

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Prajapat, Amrutlal L., Preeti B. Subhedar, and Parag R. Gogate. "Ultrasound assisted enzymatic depolymerization of aqueous guar gum solution." Ultrasonics Sonochemistry 29 (March 2016): 84–92. http://dx.doi.org/10.1016/j.ultsonch.2015.09.009.

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Tang, Ying, Huan Liu, Ling Zhou, Haomiao Ren, Hong Li, Jie Zhang, Gang Chen, and Chengtun Qu. "Enhanced Fenton-like oxidation of hydroxypropyl guar gum catalyzed by EDTA-metal complexes in a wide pH range." Water Science and Technology 79, no. 9 (May 1, 2019): 1667–74. http://dx.doi.org/10.2166/wst.2019.169.

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Abstract A series of EDTA-metal complexes was prepared for the Fenton oxidation catalysts and Fe(II)L exhibits high catalytic performance for degradation of hydroxypropyl guar gum in a wide pH range 7.0–13.0. The viscosity of hydroxypropyl guar gum can be reduced with the 10.0% H2O2 and 5.0% Fe(II)L. The viscosity average molecular weight of hydroxypropyl guar gum was decreased from almost 2 million to 3,199. Most important of all, the chemical oxygen demand (COD) value can be decreased to 104 mg/L from 8,080 mg/L with enough H2O2, and Fe(II)L also shows great catalytic ability in the degradation of various polymers by H2O2. The proposed mechanism of the activation of H2O2 by the complex was studied.

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Wang, Jin, Bingbing Bai, Yan Wei, Qingchen Wang, Qiang Deng, Tingting Kong, Chengtun Qu, and Ying Tang. "Catalytic Oxidation of Polymers Remained in Oilfield by Transition Metal-Ethylenediamine Complex." Journal of Biobased Materials and Bioenergy 16, no. 5 (October 1, 2022): 765–69. http://dx.doi.org/10.1166/jbmb.2022.2233.

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This work is intended to seek for an efficient Fe-based Fenton reagent for clean oxidation of waste fracturing fluid containing hydroxypropyl guar gum (HGG) and other polymers in wide pH range. A series of complex was prepared with transition metal and ethylenediamine (L) by the coordination. The catalytic performance of the complexes were evaluated in the degradation of HGG, and the reaction conditions were optimized. The kinetics of HGG degradation was evaluated by means of the chemical oxygen demand (COD) and the viscosity. The results show that Fe(II)L exhibits high catalytic performance for the degradation of hydroxypropyl guar gum in a wide pH range of 7.0–11.0, the COD removal can reach to 86.4%. Under the optimum experimental conditions, the relative viscosity of hydroxypropyl guar gum solution can be reduced effectively to 7.99 from 247 with 10.0% H2O2 in presence of 5.0% Fe(II)L. Besides, under the optimized condition, three typical polymers used in oilfield can be degradated effectively.

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Wang, Shunwu, Ziwang Li, and Qinglong Yu. "Kinetic degradation of guar gum in oilfield wastewater by photo-Fenton process." Water Science and Technology 75, no. 1 (October 7, 2016): 11–19. http://dx.doi.org/10.2166/wst.2016.470.

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Guar gum is considered as a main component of oilfield wastewater. This work is intended to optimize the experimental conditions (H2O2 dosage, Fe2+ dosage, initial concentration of organics, initial pH and temperature) for the maximum oxidative degradation of guar gum by Fenton's reagent. The kinetics of guar gum removal were evaluated by means of the chemical oxygen demand (COD) and the absorbance measurements. The batch experiment results showed that the optimum conditions were: H2O2 dosage, 10,000 mg/L; Fe2+dosage, 2,000 mg/L; initial concentration of organics, 413 mg/L; pH, 3 and temperature, 35 °C, under which the COD removal could reach 61.07% and fairly good stability could be obtained. Under the optimum experimental conditions, using UV irradiation to treat the wastewater, the photo-Fenton systems can successfully eliminate COD from guar gum solution. The COD removal always obeyed a pseudo-first-order kinetics and the degradation rate (kapp) was increased by 25.7% in the photo-Fenton process compared to the Fenton process. The photo-Fenton system needed less time and consequently less quantity of H2O2 to obtain the same results as the Fenton process. The photo-Fenton process needs a dose of H2O2 20.46% lower than that used in the Fenton process to remove 79.54% of COD. The cost of the photo/Fenton process amounted to RMB9.43/m3, which was lower than that of the classic Fenton process alone (RMB10.58/m3) and the overall water quality of the final effluent could meet the class Ι national wastewater discharge standard for the petrochemical industry of China.

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19

Patel, Shailesh P., Ranjan G. Patel, and Vithal S. Patel. "Kinetic study of thermal degradation of guar gum esters." Thermochimica Acta 128 (June 1988): 141–48. http://dx.doi.org/10.1016/0040-6031(88)85360-7.

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Hong, C. H., K. Zhang, H. J. Choi, and S. M. Yoon. "Mechanical degradation of polysaccharide guar gum under turbulent flow." Journal of Industrial and Engineering Chemistry 16, no. 2 (March 2010): 178–80. http://dx.doi.org/10.1016/j.jiec.2009.09.073.

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Mudgil, Deepak, Sheweta Barak, and B. S. Khatkar. "Optimization of enzymatic hydrolysis of guar gum using response surface methodology." Journal of Food Science and Technology 51, no. 8 (March 20, 2012): 1600–1605. http://dx.doi.org/10.1007/s13197-012-0678-z.

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Cahalan, Mark, David Moskal, Cimon Song, and Jianhan Wu. "Optimization of reverse osmosis flowback water treatment using halotolerant microbes naturally enriched in fractured shales." University of Ottawa Science Undergraduate Research Journal 1 (August 23, 2018): 60. http://dx.doi.org/10.18192/osurj.v1i1.3720.

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Flowback water recovered after hydraulic fracturing operations poses a serious environmental concern due to the sheer quantity produced and its toxic chemical composition. Traditional methods of wastewater treatment cannot be used for flowback water treatment due to its high concentration of non-biodegradable dissolved solids. Consequently, alternative technology has been developed to address this problem. Reverse osmosis (RO) treatment is one such example. However, guar gum gelling agents found in flowback water impede membrane permeability and water flux rate of RO, consequently decreasing the efficiency and practicality of this desirable, environment-friendly technology. Previously, a biological solution using activated sludge to degrade guar gum prior to RO treatment was attempted with limited success due to the inhibitory effects of hypersalinity (characterized by high total dissolved solids content) on microbial activity. To solve this problem, several recently discovered strains of bacteria and archaea found to be naturally enriched in fractured shales may be utilized through genetic modification to degrade guar gum under hypersaline conditions. These microbes are naturally halotolerant and thrive under hypersaline conditions, making them prime targets for genetic modification targeting various chemical additives in flowback water. Here, we provide a proof of concept model using these microbes to selectively target guar gum degradation to improve the efficiency of RO treatment.

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Mudgil, Deepak, Sheweta Barak, and B. S. Khatkar. "Effect of enzymatic depolymerization on physicochemical and rheological properties of guar gum." Carbohydrate Polymers 90, no. 1 (September 2012): 224–28. http://dx.doi.org/10.1016/j.carbpol.2012.04.070.

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Tomlin, J., and N. W. Read. "The relation between bacterial degradation of viscous polysaccharides and stool output in human beings." British Journal of Nutrition 60, no. 3 (November 1988): 467–75. http://dx.doi.org/10.1079/bjn19880119.

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1. The relation between bacterial degradation of three viscous polysaccharides (guar gum, ispaghula and xanthan gum) by colonic bacteria in vitro and their effects on colonic function were investigated by comparing the results of anaerobic in vitro incubations with fresh faeces from seven healthy volunteers (measuring viscosity, pH and gas production) with the effects of feeding all three polysaccharides to the same volunteers for 1 week each (14–15 g/d) on faecal mass and whole-gut transit time.2. Guar gum was rapidly fermented in vitro by faecal bacteria from all volunteers with concomitant loss of viscosity, reduction in pH and generation of gases. Ispaghula maintained its viscosity during incubation, but the pH fell significantly. The results of xanthan gum incubations showed considerable individual variation.3. Only ispaghula significantly increased faecal mass, whilst none of the gums significantly affected stool frequency or transit time. Statistical analysis of the pooled results showed that although transit time and faecal output were inversely related, feeding viscous polysaccharides could influence these indices independently. Stool frequency was significantly correlated with the transit time, but not the faecal output.4. Transit time was reduced by gum feeding to a significantly greater extent in those subjects whose faecal bacteria reduced or removed the viscosity of that gum, than in those subjects where the viscosity was maintained. In contrast, there was a smaller increase in faecal mass when the viscosity of the appropriate cultures was removed than when it was maintained or reduced. Increases in stool frequency were significantly associated with hydrogen production from in vitro cultures.

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Vashist, Ghosal, Vashist, Kaushik, Gupta, Nair, and Ahmad. "Impact of Nanoclay on the pH-Responsiveness and Biodegradable Behavior of Biopolymer-Based Nanocomposite Hydrogels." Gels 5, no. 4 (October 16, 2019): 44. http://dx.doi.org/10.3390/gels5040044.

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This research work deployed free radical polymerization for the development of pH-responsive hybrid nanocomposite hydrogels (NCHs) with the formation of improved interpenetrating networks (IPN). The crosslinked biopolymeric system was composed of (chitosan (CH)/guar gum (GG)/polyol) and a nanofiller (Cloisite 30B). The study was aimed to investigate the role of Cloisite 30B as a nanofiller and linseed oil-derived polyol to induce stable interpenetrating networks in chitosan‒guar gum-based hydrogels. FT-IR analysis confirmed the formation of crosslinked networks with the formation of hydrogen bonds in the synthesized NCHs. Thermogravimetric analysis and differential scanning calorimetry revealed high thermal stability of the NCHs. The hydrolytic and soil burial degradation tests confirmed the biodegradability of the synthesized NCHs. An extraordinarily high swelling capacity in a buffer solution of pH 4.0 and 7.4 demonstrated their pH-responsive behavior. It has been demonstrated that even the minimal addition of polyol to the guar gum-based hydrogels has influenced the stability and characteristic features such as high swelling capacity owing to the formation of interpenetrating networks and the biodegradability of the hydrogels.

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Hindrichsen, I. K., H. R. Wettstein, A. Machmüller, C. R. Soliva, K. E. Bach Knudsen, J. Madsen, and M. Kreuzer. "Effects of feed carbohydrates with contrasting properties on rumen fermentation and methane release in vitro." Canadian Journal of Animal Science 84, no. 2 (June 1, 2004): 265–76. http://dx.doi.org/10.4141/a03-095.

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The RUSITEC system was used to test eight diets where the supplements differed in their main carbohydrate source. The forage-to-supplement ratio was 1:1. The eight feeds characterizing the supplements by specific carbohydrates were oat hulls (modeling lignified fiber), soybean hulls (non-lignified fiber), apple pulp (pectin), sugar beet pulp (hemicelluloses and pectin), guar gum (galactomannan), Jerusalem artichoke tubers (fructan), molasses (sucrose), and wheat (starch). Supplements were iso-energetic and iso-nitrogenous. The dietary carbohydrate fractions were analyzed in detail with a combination of enzymatic and chemical methods. The methane release (mmol g-1 degraded organic matter) increased in the order of diets characterized by oat hulls (0.92), guar gum (0.99), wheat (1.04), soybean hulls (1.13), apple pulp (1.15), Jerusalem artichoke (1.21), sugar beet pulp (1.24), and molasses (1.37). According to multiple regression analysis, diets with high sugar content enhanced methane release while methane was low with high dietary lignin content. Regressions also showed that different fibrous carbohydrates had only a minor effect on methane release, probably due to lignification of the fiber. The present results suggest that equations for the estimation of methane emission of ruminants should consider dietary carbohydrate composition and lignin content. Key words: Methane, carbohydrates, lignin, Jerusalem artichoke, guar gum, ruminant

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Musa, Tagwa A., Ahmed F. Ibrahim, Hisham A. Nasr-El-Din, and Anas M. Hassan. "New insights into guar gum as environmentally friendly polymer for enhanced oil recovery in high-salinity and high-temperature sandstone reservoirs." Journal of Petroleum Exploration and Production Technology 11, no. 4 (February 1, 2021): 1905–13. http://dx.doi.org/10.1007/s13202-020-01080-3.

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AbstractChemical enhanced oil recovery (EOR) processes are usually used as additives for hydrocarbon production due to its simplicity and relatively reasonable additional production costs. Polymer flooding uses polymer solutions to increase oil recovery by decreasing the water/oil mobility ratio by increasing the viscosity of the displacing water. The commonly used synthetic water-soluble polymer in EOR application is partially hydrolyzed polyacrylamide (HPAM). However, synthetic polymers in general are not attractive because of high cost, environmental concerns, limitation in high temperature, and high-salinity environment. Guar gum is an environmentally friendly natural water-soluble polymer available in large quantities in many countries and widely used in various applications in the oil and gas industry especially in drilling fluids and hydraulic fracturing operations; however, very limited studies investigated on guar as a polymer for EOR and no any study investigated on its uses in high-temperature and high -salinity reservoirs. The objective of this study is to confirm the use of guar gum as a natural polymer for EOR applications in sandstone reservoirs and investigate its applicability for high-temperature and high-salinity reservoirs. The study experimentally investigated rheological characteristics of a natural polymer obtained from guar gum with consideration of high temperature (up to 210 °F) and high salinity (up to 20% NaCl) and tested the guar solution as EOR polymer. The results of this study show that the guar solution can be used as an environmentally friendly polymer to enhance oil recovery. Based on the results, it can be concluded that guar gum shows shear-thinning behavior and strongly susceptible to microbial degradation but also shows a very good properties stability in high temperature and salinity, where in low shear rate case, about 100 cp viscosity can be achieved at 210 °F for polymer prepared in deionized water. Guar polymer shows good viscosity in the presence of 20% NaCl where the viscosity is acceptable for temperature less than 190 °F. Also, the flooding experiment shows that the recovery factor can be increased by 16%.

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Nyman, Margareta, Nils-Georg Asp, John Cummings, and Hugh Wiggins. "Fermentation of dietary fibre in the intestinal tract: comparison between man and rat." British Journal of Nutrition 55, no. 3 (May 1986): 487–96. http://dx.doi.org/10.1079/bjn19860056.

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1. The breakdown and faecal bulking capacity of dietary fibre preparations from wheat bran, apple, cabbage, carrot, and guar gum were compared in man and rat.2. The degradation of the fibre showed good correlation between man and rat (r 0.99, regression coefficient 0.86). Wheat bran was the least well-digested, 66 and 59% of the neutral sugars being excreted in faeces of man and rat respectively. The breakdown of the fibre in apple, cabbage, carrot and guar gum was more complete and 4–29% of the neutral sugars were recovered in faeces.3. The main dietary fibre constituents in each preparation were degraded to a similar extent in man and rat. The main dietary fibre constituents of apple, carrot, cabbage and guar gum were almost completely degraded. Of the xylose in wheat bran 45% (man) and 48% (rat) were recovered in faeces. However, the percentage excretion of glucose and arabinose from bran was higher in man.4. A faecal glucan other than cellulose was identified in human faeces after guar gum, and has been provisionally identified as starch. No such glucan occurred in rat faeces.5. A good correlation between the faecal bulking capacity in man and rat was seen (r 0.97, regression coefficient 0.56). Wheat bran had the best bulking capacity, while that of apple, cabbage, carrot and guar gum was less pronounced. Faecal bulking was inversely related to the amount of fibre which was water-soluble in each preparation.6. It is concluded that this rat experimental model is useful for the prediction of fermentative breakdown and bulking capacity of dietary fibre in man. However, more comparative studies are needed to evaluate animal experiments regarding other physiological effects of dietary fibre.

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Sugita, Purwantiningsih, Bambang Srijanto, Budi Arifin, and Ellin Vina Setyowati. "STABILITY OF KETOPROFEN COATED BY CHITOSAN-GUAR GUM GEL." Indonesian Journal of Chemistry 9, no. 3 (June 24, 2010): 391–97. http://dx.doi.org/10.22146/ijc.21504.

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The coating stability of ketoprofen by chitosan-guar gum gel has been studied. Into 228.6 mL of 1.75% (w/v) chitosan solution in 1% (v/v) acetic acid, 38.1 mL of guar gum (gg) solution was added with concentration variation of 0.35, 0.55, and 0.75% (w/v) for ketoprofen microcapsules, and stirred with magnetic stirrer until homogenous. Afterwards, 7.62 mL of glutaraldehyde (glu) was added slowly under stirring, with concentrations varied: 3, 3.5, and 4% (v/v). All mixtures were shaked for 20 min for homogenization. Into each microcapsule mixture for ketoprofen, a solution of 2 g of ketoprofen in 250 mL of 96% ethanol was added. Every mixture was then added with 5 mL of 2% Tween-80 and stirred with magnetic stirrer for an hour at room temperature. Conversion of suspension into fine powders/granules (microcapsules) was done by using spray dryer. Every microcapsule formula was packed into capsules, as much as 100 g per capsule. The capsules were contained in 100-mL dark bottles and the bottles were kept in climatic chamber at (40 ± 2) °C and RH (75 ± 5) % for 3 months. The microcapsule stabilities were tested chemically and physically. The result showed that formulation of ketoprofen preparation composed of 1.75% (w/v) chitosan, 0.35% (w/v) gg, and 3.50% (v/v) glu, was relatively the best, with ketoprofen percentage left in microcapsule after 3 months, degradation rate constant, and shelf life of 80.33%, 0.0351 % week-1, and 18.92 months, respectively. Reaction kinetic model for this formula followed Prout-Tompkins equation and the degradation of ketoprofen was seem to follow autocatalytic reaction mechanism controlled by the formation and growth of reaction core. Keywords: Ketoprofen, chitosan-guar gum gel

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30

Okamura, Takuro, Masahide Hamaguchi, Jun Mori, Mihoko Yamaguchi, Katsura Mizushima, Aya Abe, Makoto Ozeki, Ryoichi Sasano, Yuji Naito, and Michiaki Fukui. "Partially Hydrolyzed Guar Gum Suppresses the Development of Sarcopenic Obesity." Nutrients 14, no. 6 (March 9, 2022): 1157. http://dx.doi.org/10.3390/nu14061157.

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Partially hydrolyzed guar gum (PHGG) is a soluble dietary fiber derived through controlled enzymatic hydrolysis of guar gum, a highly viscous galactomannan derived from the seeds of Cyamopsis tetragonoloba. Here, we examined the therapeutic potential of dietary supplementation with PHGG against sarcopenic obesity using Db/Db mice. Db/Db mice fed a normal diet alone or a fiber-free diet, or supplemented with a diet containing PHGG (5%), were examined. PHGG increased grip strength and the weight of skeletal muscles. PHGG increased the short-chain fatty acids (SCFAs) concentration in feces and sera. Concerning innate immunity, PHGG decreased the ratio of inflammatory cells, while increasing the ratio of anti-inflammatory cells in the small intestine. The present study demonstrated the preventive effect of PHGG on sarcopenic obesity. Changes in nutrient absorption might be involved through the promotion of an anti-inflammatory shift of innate immunity in the intestine accompanied by an increase in SCFA production by PHGG.

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31

Deshmukh, Payal, Nikita Upadhyaya, Sunita Patidar, and Rajat Pawar. "Probiotic-Assisted Colon-Specific Delivery of Anti-Inflammatory Drug – 5 ASA." International Journal of Pharmaceutical Sciences and Medicine 7, no. 10 (October 30, 2022): 119–35. http://dx.doi.org/10.47760/ijpsm.2022.v07i10.007.

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Background: Mesalamine, one derivative of 5-aminosalicylic acid (5-ASA), has been recommended as the first-line medicine to induce and maintain remission in patients with mild-to-moderately active ulcerative colitis on account of its efficacy and safety. Objective: To evaluate the efficacy and safety of mesalamine in conjunction with probiotics for ulcerative colitis an ideal colon targeting system aims to deliver a therapeutic agent, selectively and effectively, to the colon. This system should ideally retain the drug release in the upper GI tract (stomach and small intestine); while trigger the drug release in the colon. Several approaches have been used to fabricate formulations to achieve a colon specific delivery of mesalamine such as; time dependent, enzymatic/microbial responsive approaches. This overview outlines the recent advances in mesalamine-colon delivery approaches for the potential treatment of ulcerative colitis and Crohn’ disease. Method: The matrix tablets of guar gum were prepared by wet granulation method Lactose, guar gum, talc and magnesium stearate were sifted separately through sieve number 60 to obtain particles of uniform size. Weighed quantity of Mesalamine was sifted through sieve number 100. Result: Matrix tablets containing Mesalamine were prepared by wet granulation method using guar gum as the colon targeting polymer and varying concentrations of probiotics Sporlac and Vivaflora to assist in colon targeting.

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32

Gupta, Sumit, Chaturbhuj K. Saurabh, Prasad S. Variyar, and Arun Sharma. "Comparative analysis of dietary fiber activities of enzymatic and gamma depolymerized guar gum." Food Hydrocolloids 48 (June 2015): 149–54. http://dx.doi.org/10.1016/j.foodhyd.2015.02.013.

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33

Skalickova, Sylvie, Tereza Aulichova, Eva Venusova, Jiri Skladanka, and Pavel Horky. "Development of pH-Responsive Biopolymeric Nanocapsule for Antibacterial Essential Oils." International Journal of Molecular Sciences 21, no. 5 (March 5, 2020): 1799. http://dx.doi.org/10.3390/ijms21051799.

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It is generally believed that antibacterial essential oils have the potential to become one of the alternatives in preventing diarrheal diseases of monogastric animals. The disadvantage is their low efficiency per oral due to easy degradation during digestion in the stomach. This study compares the efficacy of chitosan, alginate-chitosan, guar gum-chitosan, xanthan gum-chitosan and pectin-chitosan nanocapsules to the synthesis of pH-responsive biopolymeric nanocapsule for Thymus vulgaris, Rosmarinus officinalis and Syzygium aromaticum essential oils. Using spectrophotometric approach and gas chromatography, release kinetics were determined in pH 3, 5.6 and 7.4. The growth rates of S. aureus and E. coli, as well as minimal inhibition concentration of essential oils were studied. The average encapsulation efficiency was 60%, and the loading efficiency was 70%. The size of the nanocapsules ranged from 100 nm to 500 nm. Results showed that chitosan-guar gum and chitosan-pectin nanocapsules released 30% of essential oils (EOs) at pH 3 and 80% at pH 7.4 during 3 h. Similar release kinetics were confirmed for thymol, eugenol and α-pinene. Minimal inhibition concentrations of Thymus vulgaris and Syzygium aromaticum essential oils ranged from 0.025 to 0.5%. Findings of this study suggest that the suitable pH-responsive nanocapsule for release, low toxicity and antibacterial activity is based on chitosan-guar gum structure.

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Motta, Marcus Vinícius Lisboa, Eustáquio Vinícius Ribeiro de Castro, Emanuel José Bassani Muri, Bruno Venturini Loureiro, Michell Luiz Costalonga, and Paulo Roberto Filgueiras. "Thermal and spectroscopic analyses of guar gum degradation submitted to turbulent flow." International Journal of Biological Macromolecules 131 (June 2019): 43–49. http://dx.doi.org/10.1016/j.ijbiomac.2019.03.037.

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35

Ni, Weijun, Yubo Lian, Yan Wei, Bo Zheng, Man Liu, Le Qu, and Ling Zhou. "Fenton-like oxidation of Hydroxypropyl guar gum catalysed by Cu(II) complex at high pH." E3S Web of Conferences 329 (2021): 01005. http://dx.doi.org/10.1051/e3sconf/202132901005.

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Large amounts of wastewater containing hydroxypropyl guar gum (HPGG), polyacrylamide (PAM) and carboxymethyl cellulose (CMC) are produced in the process of fracturing. In the work, a Fentonlike system in the presence of H2O2 was employed to degrade wastewater. The effects of oxidant concentration, catalyst dosage, the temperature and pH on the degradation efficiency of the polymer were studied in detail. Results showed that the prepared complex (Cu(II)L) exhibited a great catalytic effects in the range of pH 7-12. It was also found that under the conditions of 45℃ and pH=10, when the amount of H2O2 was 5.0% (mass ratio to hydroxypropyl guar gum) and the amount of Cu (II)L complex was 10%, HPGG had a great reduction rate, and its viscosity value can be reduced from 18 to 6.47.

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36

Eiroboyi, Itohan, and S. S. Ikiensikimama. "Thermal Stability of Bio-Polymers and their Blends." Nigerian Journal of Technological Development 19, no. 1 (June 5, 2022): 9–15. http://dx.doi.org/10.4314/njtd.v19i1.2.

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Studies from research have shown that one of the major problems associated with the use of polymers during polymer flooding is polymer degradation. Polymers lose their viscosity as well as their efficiency in the presence of high temperatures. Hence, the need for polymers that are environmentally friendly and can withstand high reservoir temperatures. Therefore, this study was necessary to address this challenge. Three commercial bio-polymers currently being used in the oil and gas industry were used in this study, they are Xanthan gum, Guar gum, and the Imported Locust bean gum (LBG). Also used in this study were, Gum Arabic and Nigerian Locust bean gum (LBG). The thermal stabilities of these polymers were investigated at different temperatures to determine their thermal resistances at high temperatures. Polymer blending was applied to study the impact of blending on the thermal stabilities of the different polymer blends formulated. Rheological analysis was carried out before and after subjecting the polymers and polymer blends using temperatures from 50oC to 150oC. The results showed that Guar gum, Imported LBG, and Nigerian LBG displayed improved resistances from 75oC to 90oC compared to Xanthan gum, which was thermally stable up to 70oC. Furthermore, the blends showed higher stable temperatures compared to that of polymers alone and also compared to the thermal stability of Xanthan gum. This study showed that the blends would perform better at high-temperature reservoir conditions.

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37

Godge, GR, and SN Hiremath. "Development and evaluation of colon targeted drug delivery system by using natural Polysaccharides/Polymers." Dhaka University Journal of Pharmaceutical Sciences 13, no. 1 (February 3, 2015): 105–13. http://dx.doi.org/10.3329/dujps.v13i1.21874.

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Colon is being extensively investigated as a drug delivery site. This study contains comparison of the usual enteric coating polymers viz. xanthan gum, guar gum, chitosan and ethyl cellulose, as carriers for colon specific drug delivery. Lactose based metoprolol succinate tablets were prepared. These were coated with one of the coating polymers to a varying coat thickness. Tablets were prepared using polysaccharides or synthetic polymer as binders. These included xanthan gum, guar gum, chitosan and ethyl cellulose. Metoprolol Succinate was used as a model drug. The prepared tablets were enteric coated with kollicoat MAE 100 DP to give protection in the stomach. The coated tablets were tested in-vitro for their suitability as colon specific drug delivery systems. The drug release studies were carried out in simulated stomach environment (pH 1.2) for 2 h followed by small intestinal environment at pH 6.8. The dissolution data obtained from tablets demonstrates that the dissolution rate of the tablet is dependent upon the type and concentration of polysaccharide/polymer used as binder. The results demonstrate that enteric coated tablets containing 3% chitosan as a binder, showed only 12.5% drug release in the first 5 h, which is the usual upper gastrointestinal transit time, whereas, tablets prepared using guar gum as binder, were unable to protect drug release under similar conditions. Preparations with xanthan gum as a binder formed time-dependent release formulations. When used in a concentration of 5.92% in the tablets, 28% drug release was observed in the usual upper gastrointestinal tract conditions. It was also found that enteric coated preparation formulated with 8.88% of kollicoat MAE 100 DP as binder could be used to carry water insoluble drug molecules. The above study shows that chitosan could be successfully used as a binder, for colon targeting of water insoluble drugs in preference to guar gum when used in the same concentration. Additionally, formulations developed with chitosan and kollicoat MAE 100 DP would be highly site specific since drug release would be at a retarded rate till microbial degradation or polymer solubilization takes place in the colon. DOI: http://dx.doi.org/10.3329/dujps.v13i1.21874 Dhaka Univ. J. Pharm. Sci. 13(1): 105-113, 2014 (June)

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38

Velimirovic, Milica, Hong Chen, Queenie Simons, and Leen Bastiaens. "Reactivity recovery of guar gum coupled mZVI by means of enzymatic breakdown and rinsing." Journal of Contaminant Hydrology 142-143 (November 2012): 1–10. http://dx.doi.org/10.1016/j.jconhyd.2012.09.003.

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39

Tayal, Akash, Vandita B. Pai, and Saad A. Khan. "Rheology and Microstructural Changes during Enzymatic Degradation of a Guar−Borax Hydrogel." Macromolecules 32, no. 17 (August 1999): 5567–74. http://dx.doi.org/10.1021/ma990167g.

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40

Zhang, Zhenchao. "Combined treatment of hydroxypropyl guar gum in oilfield fracturing wastewater by coagulation and the UV/H2O2/ferrioxalate complexes process." Water Science and Technology 77, no. 3 (November 1, 2017): 565–75. http://dx.doi.org/10.2166/wst.2017.552.

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Abstract Hydroxypropyl guar gum is considered to be a main component of oilfield fracturing wastewater (OFW). This work is intended to optimize the experimental conditions for the maximum oxidative degradation of hydroxypropyl guar gum by the coagulation and UV/H2O2/ferrioxalate complexes process. Optimal reaction conditions were proposed based on the chemical oxygen demand (COD) removal efficiency and UV_vis spectra analysis. The overall removal efficiency of COD reached 83.8% for a dilution ratio of raw wastewater of 1:2, pH of 4 and FeCl3 loading of 1,000 mg/L in the coagulation process; the dosage of H2O2 (30%,v/v) was 0.6% (v/v) and added in three steps, the n(H2O2)/n(Fe2+) was 2:1, n(Fe2+)/n(C2O42−) was 3:1 and pH was 4 in the UV/H2O2/ferrioxalate complexes process; pH was adjusted to 8.5–9 by NaOH and then cationic polyacrylamide (CPAM) of 2 mg/L was added in the neutralization and flocculation process. The decrease in COD during the coagulation process reduced the required H2O2 dosage and improved efficiency in the subsequent UV/H2O2/ferrioxalate complexes process. Furthermore, COD removal efficiency significantly increased by more than 13.4% with the introduction of oxalate compared with UV/Fenton. The UV_vis spectra analysis results indicated that the coagulation and UV/H2O2/ferrioxalate complexes process could efficiently remove the hydroxypropyl guar gum dissolved in OFW. An optimal combination of these parameters produced treated wastewater that met the GB8978-1996 Integrated Wastewater Discharge Standard level III emission standard.

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Motta, Marcus Vinícius Lisboa, Eustáquio Vinícius Ribeiro de Castro, Emanuel José Bassani Muri, Michell Luiz Costalonga, Bruno Venturini Loureiro, and Paulo Roberto Filgueiras. "Study of the mechanical degradation mechanism of guar gum in turbulent flow by FTIR." International Journal of Biological Macromolecules 121 (January 2019): 23–28. http://dx.doi.org/10.1016/j.ijbiomac.2018.09.214.

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42

Anjum, Farhana, Saima Gul, Mohammad Iqbal Khan, and Murad Ali Khan. "Efficient synthesis of palladium nanoparticles using guar gum as stabilizer and their applications as catalyst in reduction reactions and degradation of azo dyes." Green Processing and Synthesis 9, no. 1 (December 24, 2019): 63–76. http://dx.doi.org/10.1515/gps-2020-0008.

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AbstractPalladium is very expensive metal and has numerous applications especially as a versatile hydrogenation and dehydrogenation catalyst for chemical reactions. The main hurdle in its wide use is the high materials cost. In the present study a cost effective palladium nano catalyst was prepared using the green method of synthesis with guar gum as capping and reducing agent. The formations of palladium nanoparticles were confirmed by UV-spectrophotometer while for morphology and nature, SEM and XRD were performed that confirmed the crystalline nature of PdNPs and proved the roughly spherical shape of nanoparticles. FT-IR analysis showed different functional groups of reducing agent and proved that guar gum have the ability to stabilized as well as to reduce the Pd (II) to Pd (0). Specific signal for the palladium is present in EDX spectra that further confirmed the formation of PdNPs. The catalytic efficiency was studied using the hydrogenation of 4-nitrophenol. Rate constant of prepared nano-catalyst was 0.1436/min, its efficiency, TON, TOF, in above mention reaction is 90.83, 27.78, and 185.2/hrs, respectively. Data obtained proved synthesized PdNPs to be efficient heterogeneous catalyst for the reduction of 4-NP and for the degradation of azo dyes.

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43

Hammill, Terry B., and Ronald L. Crawford. "Bacterial microencapsulation with three algal polysaccharides." Canadian Journal of Microbiology 43, no. 11 (November 1, 1997): 1091–95. http://dx.doi.org/10.1139/m97-156.

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Methods for encapsulating pollutant-degrading bacteria into microbeads of carrageenan type I, carrageenan type II, and guar gum are described. Cell suspensions in solutions of encapsulating agents were passed through a low-pressure nozzle into an aqueous medium. The resultant aerosols polymerized to form microbeads that ranged in diameter from 2–70 μm. Pentachlorophenol degradation experiments with an encapsulated Sphingomonas sp. showed degradation rates similar to those seen using free cells. These results describe three additional matrices for the microencapsulation of bacteria that have potential for use in bioremediation processes.Key words: Sphingomonas, pentachlorophenol, immobilization, encapsulation, bioremediation.

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44

Sharma, Gaurav, Rishu Katwal, and Gaurav Sharma. "Fabrication, Characterization and Cytotoxicity of Guar Gum/Copper Oxide Nanocomposite: Efficient Removal of Organic Pollutant." Materials Science Forum 842 (February 2016): 88–102. http://dx.doi.org/10.4028/www.scientific.net/msf.842.88.

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Gaur gum/copper oxide (GG/CuO) nanocomposite was synthesized using sol-gel method. GG/CuO nanocomposite was characterized by techniques such as ultraviolet-visible (UV-visible) spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermo gravimetric analysis (TGA/DTA), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). TEM analysis revealed the size of the GG/CuO nanocomposite particles in the range of 20-50 nm. GG/CuO nanocomposite was used for degradation of malachite green dye under different conditions.The degradation of MG dye was recorded 89% under irradiationtime of 180 min. The antimicrobial activity of GG/CuO was also ascertained against S. aureus. The GG/CuO nanocomposite was non-toxic for the CHO-K1 cells, oral cancer cells KB and rat glioma C6 cells.

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45

Clinckspoor, Karl Jan, Vitor Hugo de Sousa Ferreira, and Rosangela Barros Zanoni Lopes Moreno. "Bulk rheology characterization of biopolymer solutions and discussions of their potential for enhanced oil recovery applications." CT&F - Ciencia, Tecnología y Futuro 11, no. 1 (June 30, 2021): 123–35. http://dx.doi.org/10.29047/01225383.367.

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Enhanced oil recovery (EOR) techniques are essential to improve oil production, and polymer flooding has become one of the promising technologies for the Brazilian Pre-Salt scenario. Biopolymers offer a range of advantages considering the Pre-Salt conditions compared to synthetic polymers, such as resistance to high salinity, high temperature, and mechanical degradation. In that sense, bulk rheology is the first step in a workflow for performance analysis. This paper presents a rheological analysis of four biopolymers (Schizophyllan, Scleroglucan, Guar Gum, and Xanthan Gum) in concentrations from 10 to 2,300 ppm, generally suitable for EOR applications, in temperature levels of 25, 40, 50, 60 and 70°C and two brines of 30,100 ppm and 69,100 ppm total dissolved solids, which aim to model seawater and the mixture between injected seawater and reservoir water typical in Pre-Salt conditions. The pseudoplastic behavior, the overlap concentration, and the activation energy were determined for each polymer solution. The structural differences in the polymers resulted in different rheological behaviors. Schizophyllan is the most promising, as its viscosifying power is higher than synthetic polymers comparable to Xanthan Gum. Its resistance at high temperatures is higher than that of synthetic polymers. Scleroglucan behaved similarly to Xanthan Gum, with the added advantage of being nonionic. Guar Gum had the lowest viscosities, highest overlap concentrations, and most pronounced viscosity decay among the tested polymers. To the author’s knowledge, rheological studies of the biopolymers presented here, considering the viscosities and the overlap concentration and activation energy, in the Pre-salt conditions, are not available in the literature and this will benefit future works that depend on this information

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46

Kumar, Anoop, Shweta Kumari, Parmanand, and Sunil K. Sharma. "Constructing the nanomixture of guar gum and Fe3O4 for photocatalytic degradation of dyes and heavy metal." Journal of Materials Science: Materials in Electronics 33, no. 5 (January 15, 2022): 2643–53. http://dx.doi.org/10.1007/s10854-021-07472-3.

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47

Pathania, Deepak, Rishu Katwal, Gaurav Sharma, Mu Naushad, Mohammad Rizwan Khan, and Ala’a H. Al-Muhtaseb. "Novel guar gum/Al2O3 nanocomposite as an effective photocatalyst for the degradation of malachite green dye." International Journal of Biological Macromolecules 87 (June 2016): 366–74. http://dx.doi.org/10.1016/j.ijbiomac.2016.02.073.

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48

Prajapat, Amrutlal L., and Parag R. Gogate. "Intensification of degradation of guar gum: Comparison of approaches based on ozone, ultraviolet and ultrasonic irradiations." Chemical Engineering and Processing: Process Intensification 98 (December 2015): 165–73. http://dx.doi.org/10.1016/j.cep.2015.09.018.

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49

Wang, Fuhua, Zezhuang Sun, Xian Shi, Luyi Wang, Weidong Zhang, and Zhihao Zhang. "Mechanism analysis of hydroxypropyl guar gum degradation in fracture flowback fluid by homogeneous sono-Fenton process." Ultrasonics Sonochemistry 93 (February 2023): 106298. http://dx.doi.org/10.1016/j.ultsonch.2023.106298.

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50

Martín-Orúe, Susana M., Anthony G. O'Donnell, Joaquin Ariño, Trudy Netherwood, Harry J. Gilbert, and John C. Mathers. "Degradation of transgenic DNA from genetically modified soya and maize in human intestinal simulations." British Journal of Nutrition 87, no. 6 (June 2002): 533–42. http://dx.doi.org/10.1079/bjn2002573.

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The inclusion of genetically modified (GM) foods in the human diet has caused considerable debate. There is concern that the transfer of plant-derived transgenes to the resident intestinal microflora could have safety implications. For these gene transfer events to occur, the nucleic acid would need to survive passage through the gastrointestinal tract. The aim of the present study was to evaluate the rate at which transgenes, contained within GM soya and maize, are degraded in gastric and small bowel simulations. The data showed that 80 % of the transgene in naked GM soya DNA was degraded in the gastric simulations, while no degradation of the transgenes contained within GM soya and maize were observed in these acidic conditions. In the small intestinal simulations, transgenes in naked soya DNA were degraded at a similar rate to the material in the soya protein. After incubation for 30 min, the transgenes remaining in soya protein and naked DNA were 52 (SEM 13·1) % AND 34 (sem 17·5) %, respectively, and at the completion of the experiment (3 h) these values were 5 % and 3 %, respectively. In contrast to the soya transgene, the maize nucleic acid was hydrolysed in the small intestinal simulations in a biphasic process in which approximately 85 % was rapidly degraded, while the rest of the DNA was cleaved at a rate similar to that in the soya material. Guar gum and tannic acid, molecules that are known to inhibit digestive enzymes, did not influence the rate of transgene degradation in soya protein. In contrast guar gum reduced the rate of transgene degradation in naked soya DNA in the initial stages, but the polysaccharide did not influence the amount of nucleic acid remaining at the end of the experiment. Tannic acid reduced the rate of DNA degradation throughout the small bowel simulations, with 21 (sem 5·4) % and 2 (sem 1·8) % of the naked soya DNA remaining in the presence and absence of the phenolic acid, respectively. These data indicate that some transgenes in GM foods may survive passage through the small intestine.

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