Botryococcus braunii is widely studied due to its high hydrocarbon content. In this study, B . braunii Abt02 was subjected to several analyses, including cytological observation, hydrocarbon composition analysis by ga...Botryococcus braunii is widely studied due to its high hydrocarbon content. In this study, B . braunii Abt02 was subjected to several analyses, including cytological observation, hydrocarbon composition analysis by gas chromatography mass spectrometry (GC-MS), phylogenetic identification using known races (A, B and L) of B . braunii strains based on their 18S rDNA sequences, and qPCR-based investigation of transcript accumulation levels of hydrocarbon biosynthesis-related enzymes (DXS, MCS, DLS, SQS) during diff erent growth phases (lag phase, log phase, early stationary growth phase, late stationary growth phase) under nitrogen-replete and nitrogen-depleted growth conditions, respectively. Based on cytological observation and on the 18S rDNA phylogenetic analysis, strain Abt02 was assigned to race B. Analysis of the strain’s chemical composition showed that the B . braunii Abt02 contained high levels of hydrocarbons, which accounted for 43.75% of the cell’s dry weight. Of these hydrocarbons, squalene and its derivatives accounted for up to 87.54%. In addition, all four enzymes investigated were expressed at higher levels during the log growth phase under nitrogen depleted conditions than under nitrogen replete conditions.展开更多
In this study, we report a two-dimensional (2D) hexagonal disk obtained by carbonization of Botryococcus braunii (B. braunii) residues. Carbonization at 700℃followed by naturally cooling down to room temperature unde...In this study, we report a two-dimensional (2D) hexagonal disk obtained by carbonization of Botryococcus braunii (B. braunii) residues. Carbonization at 700℃followed by naturally cooling down to room temperature under a non-inert gas flow atmosphere affords to yield this unique structure. The 2D hexagonal disks consist of more than 52% carbon and more than 25% oxygen. Slight amount of Fe, silicon and magnesium would be the trigger of the formation of hexagonal structure. Treatment of biomass residue is a challenge in the near future accompanied by the achievement of new energy technology in the industrial level. This research points out that efficient use of discharged biomass residue could create a new avenue for material science. The morphology of obtained crystals carbonized in different conditions, especially with the existence of argon flow, was also investigated.展开更多
The high-quality laminated source rock organic matter(OM)originated from planktonic algae,and its sedimentation was affected by global climate change significantly in the upper Xiaganchaigou Formation of the western Q...The high-quality laminated source rock organic matter(OM)originated from planktonic algae,and its sedimentation was affected by global climate change significantly in the upper Xiaganchaigou Formation of the western Qaidam Basin.However,coupling research on the paleoenvironment change and OM enrichment during the sedimentation period of the source rock is still lacking.This study from the aspects of sedimentary petrology,geochemistry and paleontology palynology,the paleoenvironment of source rock is restored and the OM enrichment model is established in the study area.Firstly,kerogen maceral identification indicates that the kerogen maceral is mainly composed of Botryococcus,accompanied with amorphous organic matter and plant debris.Secondly,arid climate and relatively active tectonic were observed during the deposition of the source rock.The water column was received felsic source from the continental island arc tectonic background,and has the environmental characteristics of relatively saline,shallow depth,medium low productivity,fast sedimentation rate and anoxic reduction and so on.Lastly,the first-order controlling factors for the OM enrichment are anoxic water conditions and suitable sedimentation rate,and the secondary controlling factor is paleoproductivity.Through the coupling study of paleoclimate,paleoenvironment and OM enrichment,the paleoclimate high frequency alternating evolution was the root cause of sedimentary environment change and OM enrichment of the laminated shale in the Upper Xiaganchaigou Formation.The study on the OM enrichment mechanism of algae in Qaidam provides a good model for understanding the coupling relationship between the algae bloom in the saline lake basins and the environments,and provides important theoretical basis for predicting shale oil“sweet spot”and production well sites arrangement for the continental saline lacustrine basins.展开更多
Botryococcus braunii is a colonial green microalga which can produce extracellular hydrocarbons at a high rate,it is considered as one of the most promising feedstocks for sustainable biofuel production.However,B.brau...Botryococcus braunii is a colonial green microalga which can produce extracellular hydrocarbons at a high rate,it is considered as one of the most promising feedstocks for sustainable biofuel production.However,B.braunii is generally recognized difficulties for cultivating and has limited amount of substantive scale-up and productivity assessments with conventional aqua-suspended cultivation systems(open pond and varieties of closed photobioreactors).This paper introduces a novel cultivation system based on biofilm technology,which is called“attached cultivation”.To investigate the potential of attached cultivation method,attached cultivation of B.braunii SAG 807-1 was compared with aqueous-suspension cultivation(flat plate reactors).The growth,hydrocarbon accumulation and metabolites were studied under identical conditions(e.g.temperature,light intensity,CO2 concentration).The main research results obtained are as follows:compared with conventional aqueous-suspension cultivation,the biomass productivity of B.braunii under biofilm attached cultivation was 4.78 g/(m^(2)·d),which was higher than of 4.43 g/(m^(2)·d)by aqueous-suspension,and hydrocarbon productivity of the two cultivation methods were 2.52 g/(m^(2)·d)and 2.37 g/(m^(2)·d),respectively.The contents of carbohydrate and protein were also similar.This attached cultivation method showed a new model of commercialization for the microalgae-derived biofuels.展开更多
随着传统化石燃料短缺和环境污染日趋严重,微藻因其繁殖快、含油量高、固碳效率高及易于与现代工业技术集成等优势成为近年来生物能源研究的热点。与其它微藻相比,布朗葡萄藻更多的是合成与传统化石原料更相近的烃类。因此,通过生物炼...随着传统化石燃料短缺和环境污染日趋严重,微藻因其繁殖快、含油量高、固碳效率高及易于与现代工业技术集成等优势成为近年来生物能源研究的热点。与其它微藻相比,布朗葡萄藻更多的是合成与传统化石原料更相近的烃类。因此,通过生物炼制制备的生物燃料与传统汽柴油更接近,更易于实现燃料替代。文章以布朗葡萄藻Botryococcus braunii SAG 807-1为主要研究对象,尝试了含钴废水进行葡萄藻贴壁培养的可行性。结果表明,含钴废水可用于葡萄藻Bbraunii SAG 807-1贴壁培养,并可以促进烃类的合成。展开更多
The molecular composition and biomarker distribution of various occurrences of organic matter in argillaceous source rocks developed in fresh and saline lacustrine environments were revealed by successive treatments o...The molecular composition and biomarker distribution of various occurrences of organic matter in argillaceous source rocks developed in fresh and saline lacustrine environments were revealed by successive treatments of solvent extraction followed by acid hydrolysis using gas chromatography–mass spectrometry. The free fraction obtained by solvent extraction provided abundant geochemical information concerning the sedimentary environment, thermal maturity and biogenic origin, and obvious differences existed between fresh and saline lacustrine source rock samples. Our research results indicate that the carbonate-mineral-bound(CM-bound) fraction released by successive acid hydrolysis could also serve as a significant biogenic indicator, as the bicyclic sesquiterpenoids, indicative of Botryococcus braunii origin, were specifically detected in quite high abundance in the acid-soluble fraction. In addition, the light end hydrocarbons were much better preserved in the acid-soluble fraction, and elemental sulfur was only detected in the CM-bound fraction, suggesting a relatively confined environment for the CM-bound fraction, which thus could preserve additional geochemical information compared to that of the free fraction. The CM-bound fraction also exhibited discernable differences between fresh and saline lacustrine samples. Therefore, it can be concluded that comprehensive analysis of free and CM-bound fractions in the argillaceous source rocks can provide a more authentic and objective interpretation of geologic conditions.展开更多
An earlier study of GC-MS analysis on bitumen samples from the Agbabu area in Western Niger Delta showed the significant presence of gammacerane and no Oleanane and is suggested to be generated from the Lower Cretaceo...An earlier study of GC-MS analysis on bitumen samples from the Agbabu area in Western Niger Delta showed the significant presence of gammacerane and no Oleanane and is suggested to be generated from the Lower Cretaceous (Neocomian) source rock, however, twelve core samples were obtained from the geological survey of Nigeria for both optical geochemical and biomarker analysis, two of the samples from Isan-9 well indicated the presence of Botryococcus braunii a freshwater alga which is characteristic of a lacustrine lake type environment. The extracts from the same core showed m/z = 191 chromatogram with the significant presence of gammacerane which is diagnostic for stratified water columns and characterizes a typical lake environment. However, the m/z = 191 chromatogram also shows the presence of Oleanane which is diagnostic for vascular plant materials, this doesn’t corroborate with that of the Ise-2 well. The Isan-9 well source rock is suggested to have occurred due to the evolving structural geology of the continental shelf after the onset of the rifting, whereby the dominant lake-type environment in the Early Cretaceous was accompanied by a sediment fill of continental runoffs containing vascular plant materials. This implies that an ancient lacustrine lake system was gradually modified as a result of sedimentary infill. And that the bitumen is sourced from the lower Cretaceous Neocomian source rocks.展开更多
A green colonial microalgae Botryococcus braunii was hydrothermally processed under subcritical water conditions without the addition of catalysts,obtaining an oil yield as high as 68%.The higher heating value of liqu...A green colonial microalgae Botryococcus braunii was hydrothermally processed under subcritical water conditions without the addition of catalysts,obtaining an oil yield as high as 68%.The higher heating value of liquefaction products is close to that of petroleum crude oil.The oil fraction from Botryococcus braunii liquefaction was specified for the first time,and the liquefaction mechanism was proposed.Due to the high lipid content of Botryococcus braunii,the liquefaction product distribution is quite distinct from other microalgae.The produced biocrudes contain9%oxygen,with oleic acid as the main source.Amides derived from oleic acid and proteins are the major nitrogenates in the biocrudes.The biocrude was processed using catalytic cracking and hydrotreating.Catalytic cracking mostly produces aromatics,while the majority of hydrotreating products are straight and branched hydrocarbons.The oxygen content in the catalytic cracking products was very low.The presence of amides in the hydrotreating feed changes the reaction pathway from hydrodecarboxylation to hydrodeoxygenation as a result of the competitive adsorption of amides on the active sites for hydrodecarboxylation.Both processes show satisfactory denitrogenation performance.Catalytic cracking displays superior ability than hydrotreating with regards to the removal of oxygen.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.31372517,31672641,31401116)the Fundamental Research Funds for the Central Universities(Nos.201762016,201562018)+2 种基金the MOA Modern Agricultural Talents Support Project,the ScientificTechnological Innovation Project Financially Supported by Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02)the National Infrastructure of Fishery Germplasm Resources(No.2018DKA30470)
文摘Botryococcus braunii is widely studied due to its high hydrocarbon content. In this study, B . braunii Abt02 was subjected to several analyses, including cytological observation, hydrocarbon composition analysis by gas chromatography mass spectrometry (GC-MS), phylogenetic identification using known races (A, B and L) of B . braunii strains based on their 18S rDNA sequences, and qPCR-based investigation of transcript accumulation levels of hydrocarbon biosynthesis-related enzymes (DXS, MCS, DLS, SQS) during diff erent growth phases (lag phase, log phase, early stationary growth phase, late stationary growth phase) under nitrogen-replete and nitrogen-depleted growth conditions, respectively. Based on cytological observation and on the 18S rDNA phylogenetic analysis, strain Abt02 was assigned to race B. Analysis of the strain’s chemical composition showed that the B . braunii Abt02 contained high levels of hydrocarbons, which accounted for 43.75% of the cell’s dry weight. Of these hydrocarbons, squalene and its derivatives accounted for up to 87.54%. In addition, all four enzymes investigated were expressed at higher levels during the log growth phase under nitrogen depleted conditions than under nitrogen replete conditions.
文摘In this study, we report a two-dimensional (2D) hexagonal disk obtained by carbonization of Botryococcus braunii (B. braunii) residues. Carbonization at 700℃followed by naturally cooling down to room temperature under a non-inert gas flow atmosphere affords to yield this unique structure. The 2D hexagonal disks consist of more than 52% carbon and more than 25% oxygen. Slight amount of Fe, silicon and magnesium would be the trigger of the formation of hexagonal structure. Treatment of biomass residue is a challenge in the near future accompanied by the achievement of new energy technology in the industrial level. This research points out that efficient use of discharged biomass residue could create a new avenue for material science. The morphology of obtained crystals carbonized in different conditions, especially with the existence of argon flow, was also investigated.
基金supported by the Joint Funds of the National Natural Science Foundation of China(No.2024DJ8702)the Science and Technology Research Project of the China National Petroleum Corporation(No.2024DJ87)+1 种基金the National Natural Science Foundation of China(No.42272029)the“Light of West China”Program of the Chinese Academy of Sciences(No.xbzglzb2022025)。
文摘The high-quality laminated source rock organic matter(OM)originated from planktonic algae,and its sedimentation was affected by global climate change significantly in the upper Xiaganchaigou Formation of the western Qaidam Basin.However,coupling research on the paleoenvironment change and OM enrichment during the sedimentation period of the source rock is still lacking.This study from the aspects of sedimentary petrology,geochemistry and paleontology palynology,the paleoenvironment of source rock is restored and the OM enrichment model is established in the study area.Firstly,kerogen maceral identification indicates that the kerogen maceral is mainly composed of Botryococcus,accompanied with amorphous organic matter and plant debris.Secondly,arid climate and relatively active tectonic were observed during the deposition of the source rock.The water column was received felsic source from the continental island arc tectonic background,and has the environmental characteristics of relatively saline,shallow depth,medium low productivity,fast sedimentation rate and anoxic reduction and so on.Lastly,the first-order controlling factors for the OM enrichment are anoxic water conditions and suitable sedimentation rate,and the secondary controlling factor is paleoproductivity.Through the coupling study of paleoclimate,paleoenvironment and OM enrichment,the paleoclimate high frequency alternating evolution was the root cause of sedimentary environment change and OM enrichment of the laminated shale in the Upper Xiaganchaigou Formation.The study on the OM enrichment mechanism of algae in Qaidam provides a good model for understanding the coupling relationship between the algae bloom in the saline lake basins and the environments,and provides important theoretical basis for predicting shale oil“sweet spot”and production well sites arrangement for the continental saline lacustrine basins.
基金the National Natural Science Foundation of China(31560724)China Postdoctoral Science Foundation(2016M600616).
文摘Botryococcus braunii is a colonial green microalga which can produce extracellular hydrocarbons at a high rate,it is considered as one of the most promising feedstocks for sustainable biofuel production.However,B.braunii is generally recognized difficulties for cultivating and has limited amount of substantive scale-up and productivity assessments with conventional aqua-suspended cultivation systems(open pond and varieties of closed photobioreactors).This paper introduces a novel cultivation system based on biofilm technology,which is called“attached cultivation”.To investigate the potential of attached cultivation method,attached cultivation of B.braunii SAG 807-1 was compared with aqueous-suspension cultivation(flat plate reactors).The growth,hydrocarbon accumulation and metabolites were studied under identical conditions(e.g.temperature,light intensity,CO2 concentration).The main research results obtained are as follows:compared with conventional aqueous-suspension cultivation,the biomass productivity of B.braunii under biofilm attached cultivation was 4.78 g/(m^(2)·d),which was higher than of 4.43 g/(m^(2)·d)by aqueous-suspension,and hydrocarbon productivity of the two cultivation methods were 2.52 g/(m^(2)·d)and 2.37 g/(m^(2)·d),respectively.The contents of carbohydrate and protein were also similar.This attached cultivation method showed a new model of commercialization for the microalgae-derived biofuels.
文摘随着传统化石燃料短缺和环境污染日趋严重,微藻因其繁殖快、含油量高、固碳效率高及易于与现代工业技术集成等优势成为近年来生物能源研究的热点。与其它微藻相比,布朗葡萄藻更多的是合成与传统化石原料更相近的烃类。因此,通过生物炼制制备的生物燃料与传统汽柴油更接近,更易于实现燃料替代。文章以布朗葡萄藻Botryococcus braunii SAG 807-1为主要研究对象,尝试了含钴废水进行葡萄藻贴壁培养的可行性。结果表明,含钴废水可用于葡萄藻Bbraunii SAG 807-1贴壁培养,并可以促进烃类的合成。
基金funded by NSFC (National Science Foundation of China) No. 41372130
文摘The molecular composition and biomarker distribution of various occurrences of organic matter in argillaceous source rocks developed in fresh and saline lacustrine environments were revealed by successive treatments of solvent extraction followed by acid hydrolysis using gas chromatography–mass spectrometry. The free fraction obtained by solvent extraction provided abundant geochemical information concerning the sedimentary environment, thermal maturity and biogenic origin, and obvious differences existed between fresh and saline lacustrine source rock samples. Our research results indicate that the carbonate-mineral-bound(CM-bound) fraction released by successive acid hydrolysis could also serve as a significant biogenic indicator, as the bicyclic sesquiterpenoids, indicative of Botryococcus braunii origin, were specifically detected in quite high abundance in the acid-soluble fraction. In addition, the light end hydrocarbons were much better preserved in the acid-soluble fraction, and elemental sulfur was only detected in the CM-bound fraction, suggesting a relatively confined environment for the CM-bound fraction, which thus could preserve additional geochemical information compared to that of the free fraction. The CM-bound fraction also exhibited discernable differences between fresh and saline lacustrine samples. Therefore, it can be concluded that comprehensive analysis of free and CM-bound fractions in the argillaceous source rocks can provide a more authentic and objective interpretation of geologic conditions.
文摘An earlier study of GC-MS analysis on bitumen samples from the Agbabu area in Western Niger Delta showed the significant presence of gammacerane and no Oleanane and is suggested to be generated from the Lower Cretaceous (Neocomian) source rock, however, twelve core samples were obtained from the geological survey of Nigeria for both optical geochemical and biomarker analysis, two of the samples from Isan-9 well indicated the presence of Botryococcus braunii a freshwater alga which is characteristic of a lacustrine lake type environment. The extracts from the same core showed m/z = 191 chromatogram with the significant presence of gammacerane which is diagnostic for stratified water columns and characterizes a typical lake environment. However, the m/z = 191 chromatogram also shows the presence of Oleanane which is diagnostic for vascular plant materials, this doesn’t corroborate with that of the Ise-2 well. The Isan-9 well source rock is suggested to have occurred due to the evolving structural geology of the continental shelf after the onset of the rifting, whereby the dominant lake-type environment in the Early Cretaceous was accompanied by a sediment fill of continental runoffs containing vascular plant materials. This implies that an ancient lacustrine lake system was gradually modified as a result of sedimentary infill. And that the bitumen is sourced from the lower Cretaceous Neocomian source rocks.
文摘A green colonial microalgae Botryococcus braunii was hydrothermally processed under subcritical water conditions without the addition of catalysts,obtaining an oil yield as high as 68%.The higher heating value of liquefaction products is close to that of petroleum crude oil.The oil fraction from Botryococcus braunii liquefaction was specified for the first time,and the liquefaction mechanism was proposed.Due to the high lipid content of Botryococcus braunii,the liquefaction product distribution is quite distinct from other microalgae.The produced biocrudes contain9%oxygen,with oleic acid as the main source.Amides derived from oleic acid and proteins are the major nitrogenates in the biocrudes.The biocrude was processed using catalytic cracking and hydrotreating.Catalytic cracking mostly produces aromatics,while the majority of hydrotreating products are straight and branched hydrocarbons.The oxygen content in the catalytic cracking products was very low.The presence of amides in the hydrotreating feed changes the reaction pathway from hydrodecarboxylation to hydrodeoxygenation as a result of the competitive adsorption of amides on the active sites for hydrodecarboxylation.Both processes show satisfactory denitrogenation performance.Catalytic cracking displays superior ability than hydrotreating with regards to the removal of oxygen.
