Microbial polysaccharides,due to their unique physicochemical properties,have been shown to effec-tively enhance the stability of foam fracturing fluids.However,the combined application of microbial polysaccharides an...Microbial polysaccharides,due to their unique physicochemical properties,have been shown to effec-tively enhance the stability of foam fracturing fluids.However,the combined application of microbial polysaccharides and surfactants under high-temperature and high-salinity conditions remain poorly understood.In this study,we innovatively investigate this problem with a particular focus on foam stabilization mechanisms.By employing the Waring blender method,the optimal surfactant-microbial polysaccharide blends are identified,and the foam stability,rheological properties,and decay behavior in different systems under varying conditions are systematically analyzed for the first time.The results reveal that microbial polysaccharides significantly enhance foam stability by improving the viscoelasticity of the liquid films,particularly under high-salinity and high-temperature conditions,leading to notable improvements in both foam stability and sand-carrying capacity.Additionally,scanning electron microscopy(SEM)is used to observe the microstructure of the foam liquid films,demonstrating that the network structure formed by the foam stabilizer within the liquid film effectively inhibits foam coarsening.The Lauryl betaine and Diutan gum blend exhibits outstanding foam stability,superior sand-carrying capacity,and minimal core damage,making(LAB+MPS04)it ideal for applications in enhanced production and reservoir stimulation of unconventional reservoirs.展开更多
The objective of this study was to investigate the sulfonation of （1→6）-β-D-glucan （lasiodiplodan） as a potentiating mechanism for biological functionalities. Lasiodiplodan was sulfonated by the chlorosulfonic a...The objective of this study was to investigate the sulfonation of （1→6）-β-D-glucan （lasiodiplodan） as a potentiating mechanism for biological functionalities. Lasiodiplodan was sulfonated by the chlorosulfonic acid-pyridine method. The modified exopolysaccharide was characterized by FT-IR and 13C NMR spectroscopy, X-ray diffraction and SEM. Antioxidant activity was assessed by the methods of H2O2 and OH radical removal and reducing power. Antimicrobial potential was evaluated by the broth-microdilution method. Sulfonation resulted in a derivative with DS of 0.24. FT-IR analysis indicated the introduction of sulfonyl groups in the macromolecule structure through specific bands in the regions of 1,240 cm-1 and 810 cm-1. 13C NMR analysis suggested that sulfonation occurred at carbon 2 of the glucose residue. Sulfonation led to morphological changes in the structure of the biopolymer resulting in a heterogeneous structure with the presence of fibrils. Derivatization promoted an increase in the antioxidant ability of the macromolecule, with a high OH removal potential （74.32%）. Bacteriostatic activity against E. coli （Escherichia coli） and S. enterica （Salmonella enterica） typhimurium and fungicidal activity against C. albicans （Candida albicans） and C. tropicalis （Candida tropicalis） were found in the sulfonated sample. Sulfonation potentiated the antioxidant and antimicrobial activities of the biomacromolecule, suggesting that it is a potentiating mechanism of biological functions.展开更多
Lignocellulose—a major component of biomass available on earth is a renewable and abundantly available with great potential for bioconversion to value-added bio-products. The review aims at physio-chemical features o...Lignocellulose—a major component of biomass available on earth is a renewable and abundantly available with great potential for bioconversion to value-added bio-products. The review aims at physio-chemical features of lignocellulosic biomass and composition of different lignocellulosic materials. This work is an overview about the conversion of lignocellulosic biomass into bio-energy products such as bio-ethanol, 1-butanol, bio-methane, bio-hydrogen, organic acids including citric acid, succinic acid and lactic acid, microbial polysaccharides, single cell protein and xylitol. The biotechnological aspect of bio-transformation of lignocelluloses research and its future prospects are also discussed.展开更多
Apple pomace,a by-product of the apple juice processing industry,is significant agro-based waste in the Union Territory of Jammu&Kashmir,India.A considerable amount of apple is processed for juice production,resul...Apple pomace,a by-product of the apple juice processing industry,is significant agro-based waste in the Union Territory of Jammu&Kashmir,India.A considerable amount of apple is processed for juice production,resulting in a surplus of apple pomace,which is generally underutilized.This study utilized apple pomace as a substrate matrix for producing pullulan by applying Aureobasidium pullulans MTCC 1991.Solid-state fermentation was done at a lab scale in Erlenmeyer flasks to produce this exopolysaccharide.The suitable conditions for solid-state fermentation of apple pomace were:a solid-liquid ratio of 1:4,inoculum volume of 3 mL,pH 6 and incubation time of 14 days.A yield of 42 mg/g dw was obtained in the control sample without adding any other nutrients or chemicals.The addition of yeast extract at a concentration of 1%(w/w)and sucrose(5%w/w)significantly(p<0.05)increased the yield to 62 mg/g dw and 75 mg/g dw,respectively.The purified pullulan had similar characteristics to that of standard pullulan,as confirmed by ATR-FTIR,H NMR and TLC techniques.Pullulan production from apple pomace can be a better way to utilize this by-product from the apple juice industry.It will be a cost-effective technique for pullulan production as an inexpensive substrate and an environmentally friendly approach are also used.展开更多
基金supported by the Key Technology Research on Increasing Recovery Rate in Tight Sandstone Gas Reservoirs,a Major Scientific and Technological Special Project of China National Petroleum Corporation(Project No.2023ZZ25).
文摘Microbial polysaccharides,due to their unique physicochemical properties,have been shown to effec-tively enhance the stability of foam fracturing fluids.However,the combined application of microbial polysaccharides and surfactants under high-temperature and high-salinity conditions remain poorly understood.In this study,we innovatively investigate this problem with a particular focus on foam stabilization mechanisms.By employing the Waring blender method,the optimal surfactant-microbial polysaccharide blends are identified,and the foam stability,rheological properties,and decay behavior in different systems under varying conditions are systematically analyzed for the first time.The results reveal that microbial polysaccharides significantly enhance foam stability by improving the viscoelasticity of the liquid films,particularly under high-salinity and high-temperature conditions,leading to notable improvements in both foam stability and sand-carrying capacity.Additionally,scanning electron microscopy(SEM)is used to observe the microstructure of the foam liquid films,demonstrating that the network structure formed by the foam stabilizer within the liquid film effectively inhibits foam coarsening.The Lauryl betaine and Diutan gum blend exhibits outstanding foam stability,superior sand-carrying capacity,and minimal core damage,making(LAB+MPS04)it ideal for applications in enhanced production and reservoir stimulation of unconventional reservoirs.
文摘The objective of this study was to investigate the sulfonation of （1→6）-β-D-glucan （lasiodiplodan） as a potentiating mechanism for biological functionalities. Lasiodiplodan was sulfonated by the chlorosulfonic acid-pyridine method. The modified exopolysaccharide was characterized by FT-IR and 13C NMR spectroscopy, X-ray diffraction and SEM. Antioxidant activity was assessed by the methods of H2O2 and OH radical removal and reducing power. Antimicrobial potential was evaluated by the broth-microdilution method. Sulfonation resulted in a derivative with DS of 0.24. FT-IR analysis indicated the introduction of sulfonyl groups in the macromolecule structure through specific bands in the regions of 1,240 cm-1 and 810 cm-1. 13C NMR analysis suggested that sulfonation occurred at carbon 2 of the glucose residue. Sulfonation led to morphological changes in the structure of the biopolymer resulting in a heterogeneous structure with the presence of fibrils. Derivatization promoted an increase in the antioxidant ability of the macromolecule, with a high OH removal potential （74.32%）. Bacteriostatic activity against E. coli （Escherichia coli） and S. enterica （Salmonella enterica） typhimurium and fungicidal activity against C. albicans （Candida albicans） and C. tropicalis （Candida tropicalis） were found in the sulfonated sample. Sulfonation potentiated the antioxidant and antimicrobial activities of the biomacromolecule, suggesting that it is a potentiating mechanism of biological functions.
文摘Lignocellulose—a major component of biomass available on earth is a renewable and abundantly available with great potential for bioconversion to value-added bio-products. The review aims at physio-chemical features of lignocellulosic biomass and composition of different lignocellulosic materials. This work is an overview about the conversion of lignocellulosic biomass into bio-energy products such as bio-ethanol, 1-butanol, bio-methane, bio-hydrogen, organic acids including citric acid, succinic acid and lactic acid, microbial polysaccharides, single cell protein and xylitol. The biotechnological aspect of bio-transformation of lignocelluloses research and its future prospects are also discussed.
文摘Apple pomace,a by-product of the apple juice processing industry,is significant agro-based waste in the Union Territory of Jammu&Kashmir,India.A considerable amount of apple is processed for juice production,resulting in a surplus of apple pomace,which is generally underutilized.This study utilized apple pomace as a substrate matrix for producing pullulan by applying Aureobasidium pullulans MTCC 1991.Solid-state fermentation was done at a lab scale in Erlenmeyer flasks to produce this exopolysaccharide.The suitable conditions for solid-state fermentation of apple pomace were:a solid-liquid ratio of 1:4,inoculum volume of 3 mL,pH 6 and incubation time of 14 days.A yield of 42 mg/g dw was obtained in the control sample without adding any other nutrients or chemicals.The addition of yeast extract at a concentration of 1%(w/w)and sucrose(5%w/w)significantly(p<0.05)increased the yield to 62 mg/g dw and 75 mg/g dw,respectively.The purified pullulan had similar characteristics to that of standard pullulan,as confirmed by ATR-FTIR,H NMR and TLC techniques.Pullulan production from apple pomace can be a better way to utilize this by-product from the apple juice industry.It will be a cost-effective technique for pullulan production as an inexpensive substrate and an environmentally friendly approach are also used.
