Tetracycline(TC)residues from anthropogenic activities undesirably present in nature as an emerging sustainability challenge and thereby require innovations in remediation technologies.Herein,as inspired by the microc...Tetracycline(TC)residues from anthropogenic activities undesirably present in nature as an emerging sustainability challenge and thereby require innovations in remediation technologies.Herein,as inspired by the microcompartment structure in living organisms,we adopt a synthetic biology approach to engineer the FerTiG,a modular enzyme assembly,to robustly scavenge TC residues with improved performance.The FerTiG consists of three functional modules,namely,a TC degradation module(Tet(X4)),a cofactor recycling module glucose dehydrogenase(GDH),and a protection module(ferritin),to organize diverse catalytic processes simultaneously as a biological circuit.The incorporation of GDH suitably fuels the FerTiG-dependent TC degradation by regenerating expensive nicotinamide adenine dinucleotide phosphate(NADPH)cofactor with glucose.The ferritin shields the catalytic core of FerTiG to resiliently decompose TC under unfavorable conditions.Due to collaboration among functional modules,FerTiG strongly catalyzes the residual TC removal from multiple environmental matrices.The degradation pathways and environmental/biological safety of FerTiG are then elaborated,indicating the promising readiness for the application of FerTiG.In summary,this work presents a synthetic biology-based strategy to spontaneously impose residual antibiotic biodegradation for better sustainability management.The FerTiG is engineered as a proof-of-principle for TC removal;however,this'microcompartment-mimick ing'concept is of great interest in mitigating other sustainability challenges where modular catalytic machinery is applied.展开更多
The cytological characteristics of major green-tide-forming green algae Ulva prolifera collected from Yellow Sea were studied th<span style="white-space:normal;"><span style="font-family:;"...The cytological characteristics of major green-tide-forming green algae Ulva prolifera collected from Yellow Sea were studied th<span style="white-space:normal;"><span style="font-family:;" "="">r<span style="white-space:normal;"><span style="font-family:;" "="">ough cutting segments, long time low temperature or dark treatments. After <span style="white-space:normal;"><span style="font-family:;" "="">being <span style="white-space:normal;"><span style="font-family:;" "="">dried in the shade and preserved at -<span style="white-space:normal;"><span style="font-family:;" "="">20<span style="white-space:nowrap;">°<span style="white-space:normal;"><span style="font-family:;" "="">C for 30 days, the U. prolifera was cultured at 4<span style="white-space:nowrap;">°C in sterilized seawater under 40 μmol photons m<sup>-2</sup>·s<sup>-1</sup> light intensity for 120 days, results indicated that the plastid of U. prolifera continuously shrank with the extension of treatment, and most cells turned white and died, only a small amount of cells still contained a few of visible inclusions at the 120d of treatment. Then those samples were transferred to 20<span style="white-space:nowrap;">°C and 40 μmol photons m<sup>-2</sup>·s<sup>-1</sup> condition for recovery cultivation, after about 10 days, some recovery cells were observed in the thallus, and those cells developed to young thallus gradually and released germ cells almost in the same time. After about 60 days of recovery cultivation, the newly-grown green thallus broke through the original dead thallus, and the germ cells also grew to new individual thallus. Before dark treatment, the U. prolifera cells were filled with plastid, contained visible starch grain and discernible cell outlines, while after 120 days of dark treatment, the plastid shrank and degraded together with the disappearance of cell inclusions, and the cell outlines also blurred, then those samples were transferred to optimal culture conditions at 20<span style="white-space:nowrap;">°C in 40 μmol photons m<sup>-2</sup>·s<sup>-1</sup> light intensity, and 15 days later, newly-grown cells appeared on the almost dead thallus, these cells divided continuously and grew to young thallus, and those newly-grown thallus also generated active germ cells, which developed to new thallus that cytologically identical to the original thallus. Observation of chopped tissue of U. prolifera cultivated at 20<span style="white-space:nowrap;">°C, 40<span style="white-space:normal;"><span style="font-family:;" "=""> <span style="white-space:normal;"><span style="font-family:;" "="">μmol m<span style="white-space:normal;"><sup><span style="font-family:;" "="">-</sup><span style="white-space:normal;"><sup><span style="font-family:;" "="">2</sup><span style="white-space:normal;"><span style="font-family:;" "="">·s<span style="white-space:normal;"><sup><span style="font-family:;" "="">-</sup><span style="white-space:normal;"><sup><span style="font-family:;" "="">1</sup><span style="white-space:normal;"><span style="font-family:;" "=""> showed that the morphological upper part cells turned to germ cells first, those germ cells including gametophyte and sporophyte, which released later and grew to new individual thallus. These findings provided cytological evidences for how U. prolifera live through stress conditions such as low temperature, darkness, and also useful for understanding the mechanism of the occurrence of green tide.展开更多
The Upper Permian Changxing dolomite reservoirs serves as one of the most important gas and oil reservoirs in the NE Sichuan Basin. Determining the dolomitizing fluid＇s pathway is regarded as the key to solve the ＂d...The Upper Permian Changxing dolomite reservoirs serves as one of the most important gas and oil reservoirs in the NE Sichuan Basin. Determining the dolomitizing fluid＇s pathway is regarded as the key to solve the ＂dolomite problem＂ and further petroleum exploration. Outcrop samples from Upper Permian Changhsingian Panlongdong Section were studied using oxygen isotopic analysis, cathodoluminescence（CL） and major element analysis, in an attempt to determine the migration path way and properties of the dolomitizing fluid. Of the Changxing dolomite, the δ18O values ranged from-3.494‰ to-5.481‰, which decreased from the top layer to the bottom in the section; the MgO contents varied from 9.24% to 21.43%, CaO contents from 28.65% to 39.87%, the CaO/MgO ratio from 1.40 to 4.31 and the Mn O contents from 0.004% to 0.009 8%. The Mg O contents showed a downwardly decreasing trend in the section, while the Ca O/Mg O showed an opposite rule. All of the dolomites looked dull or dark when they were exposed to the electron beam of the cathodoluminescence device. None of the fine-to medium grained dolomite showed a banded structure. Given that dolomitizing fluid＇s salinity decreased during the dolomitization process in its pathway, we concluded that the dolomitizing fluid migrated downwardly in Changxing Formation after excluding the possibility of deep burial or meteoric-marine mixing-water influences. As the dolomitizing fluid＇s pathway has always been difficult to be determined in highly dolomitized Formation, this study showed an important application of oxygen isotope values in resolving this problem.展开更多
基金supported by the National Natural Science Foundation of China(32121004 and 32102720)the Guangzhou Science and Technology Plan Project(2024A04J6509)+3 种基金the National Key Research and Development Program of China(2023YFD1800100)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2019BT02N054)the Double First-Class Discipline Promotion Project(2023B10564003)the 111 Project(D20008)。
文摘Tetracycline(TC)residues from anthropogenic activities undesirably present in nature as an emerging sustainability challenge and thereby require innovations in remediation technologies.Herein,as inspired by the microcompartment structure in living organisms,we adopt a synthetic biology approach to engineer the FerTiG,a modular enzyme assembly,to robustly scavenge TC residues with improved performance.The FerTiG consists of three functional modules,namely,a TC degradation module(Tet(X4)),a cofactor recycling module glucose dehydrogenase(GDH),and a protection module(ferritin),to organize diverse catalytic processes simultaneously as a biological circuit.The incorporation of GDH suitably fuels the FerTiG-dependent TC degradation by regenerating expensive nicotinamide adenine dinucleotide phosphate(NADPH)cofactor with glucose.The ferritin shields the catalytic core of FerTiG to resiliently decompose TC under unfavorable conditions.Due to collaboration among functional modules,FerTiG strongly catalyzes the residual TC removal from multiple environmental matrices.The degradation pathways and environmental/biological safety of FerTiG are then elaborated,indicating the promising readiness for the application of FerTiG.In summary,this work presents a synthetic biology-based strategy to spontaneously impose residual antibiotic biodegradation for better sustainability management.The FerTiG is engineered as a proof-of-principle for TC removal;however,this'microcompartment-mimick ing'concept is of great interest in mitigating other sustainability challenges where modular catalytic machinery is applied.
文摘The cytological characteristics of major green-tide-forming green algae Ulva prolifera collected from Yellow Sea were studied th<span style="white-space:normal;"><span style="font-family:;" "="">r<span style="white-space:normal;"><span style="font-family:;" "="">ough cutting segments, long time low temperature or dark treatments. After <span style="white-space:normal;"><span style="font-family:;" "="">being <span style="white-space:normal;"><span style="font-family:;" "="">dried in the shade and preserved at -<span style="white-space:normal;"><span style="font-family:;" "="">20<span style="white-space:nowrap;">°<span style="white-space:normal;"><span style="font-family:;" "="">C for 30 days, the U. prolifera was cultured at 4<span style="white-space:nowrap;">°C in sterilized seawater under 40 μmol photons m<sup>-2</sup>·s<sup>-1</sup> light intensity for 120 days, results indicated that the plastid of U. prolifera continuously shrank with the extension of treatment, and most cells turned white and died, only a small amount of cells still contained a few of visible inclusions at the 120d of treatment. Then those samples were transferred to 20<span style="white-space:nowrap;">°C and 40 μmol photons m<sup>-2</sup>·s<sup>-1</sup> condition for recovery cultivation, after about 10 days, some recovery cells were observed in the thallus, and those cells developed to young thallus gradually and released germ cells almost in the same time. After about 60 days of recovery cultivation, the newly-grown green thallus broke through the original dead thallus, and the germ cells also grew to new individual thallus. Before dark treatment, the U. prolifera cells were filled with plastid, contained visible starch grain and discernible cell outlines, while after 120 days of dark treatment, the plastid shrank and degraded together with the disappearance of cell inclusions, and the cell outlines also blurred, then those samples were transferred to optimal culture conditions at 20<span style="white-space:nowrap;">°C in 40 μmol photons m<sup>-2</sup>·s<sup>-1</sup> light intensity, and 15 days later, newly-grown cells appeared on the almost dead thallus, these cells divided continuously and grew to young thallus, and those newly-grown thallus also generated active germ cells, which developed to new thallus that cytologically identical to the original thallus. Observation of chopped tissue of U. prolifera cultivated at 20<span style="white-space:nowrap;">°C, 40<span style="white-space:normal;"><span style="font-family:;" "=""> <span style="white-space:normal;"><span style="font-family:;" "="">μmol m<span style="white-space:normal;"><sup><span style="font-family:;" "="">-</sup><span style="white-space:normal;"><sup><span style="font-family:;" "="">2</sup><span style="white-space:normal;"><span style="font-family:;" "="">·s<span style="white-space:normal;"><sup><span style="font-family:;" "="">-</sup><span style="white-space:normal;"><sup><span style="font-family:;" "="">1</sup><span style="white-space:normal;"><span style="font-family:;" "=""> showed that the morphological upper part cells turned to germ cells first, those germ cells including gametophyte and sporophyte, which released later and grew to new individual thallus. These findings provided cytological evidences for how U. prolifera live through stress conditions such as low temperature, darkness, and also useful for understanding the mechanism of the occurrence of green tide.
基金supported by the National Natural Science Foundation of China (Nos.40472015, 40802001, and 41372121)the State Key Laboratory of Oil/Gas Reservoir Geology and Exploitation at CDUT (PL200801)
文摘The Upper Permian Changxing dolomite reservoirs serves as one of the most important gas and oil reservoirs in the NE Sichuan Basin. Determining the dolomitizing fluid＇s pathway is regarded as the key to solve the ＂dolomite problem＂ and further petroleum exploration. Outcrop samples from Upper Permian Changhsingian Panlongdong Section were studied using oxygen isotopic analysis, cathodoluminescence（CL） and major element analysis, in an attempt to determine the migration path way and properties of the dolomitizing fluid. Of the Changxing dolomite, the δ18O values ranged from-3.494‰ to-5.481‰, which decreased from the top layer to the bottom in the section; the MgO contents varied from 9.24% to 21.43%, CaO contents from 28.65% to 39.87%, the CaO/MgO ratio from 1.40 to 4.31 and the Mn O contents from 0.004% to 0.009 8%. The Mg O contents showed a downwardly decreasing trend in the section, while the Ca O/Mg O showed an opposite rule. All of the dolomites looked dull or dark when they were exposed to the electron beam of the cathodoluminescence device. None of the fine-to medium grained dolomite showed a banded structure. Given that dolomitizing fluid＇s salinity decreased during the dolomitization process in its pathway, we concluded that the dolomitizing fluid migrated downwardly in Changxing Formation after excluding the possibility of deep burial or meteoric-marine mixing-water influences. As the dolomitizing fluid＇s pathway has always been difficult to be determined in highly dolomitized Formation, this study showed an important application of oxygen isotope values in resolving this problem.
