As one of the soil microorganisms, bacillus pasteurii exhibits good urease-produ-cing ability. A novel method is used to prepare BaCO3 crystals by the induction of bacillus pasteurii. The crystals have been characteri...As one of the soil microorganisms, bacillus pasteurii exhibits good urease-produ-cing ability. A novel method is used to prepare BaCO3 crystals by the induction of bacillus pasteurii. The crystals have been characterized by XRD, SEM and FT-IR. X-ray diffraction analysis quantified that the BaCO3 crystals obtained belong to the orthorhombic crystal system. Examination by scanning electron microscopy identified that the BaCO3 crystals have different morphologies under different preparation conditions. FT-IR indicated that surfactant EDTA had great effect on the morphology of BaCO3 crystals. Different morphology crystals had uniform distribution and integral shape. The forming mechanism and influence of EDTA on the morphology of BaCO3 crystals have been discussed.展开更多
Sporosarcina pasteurii(S.pasteurii)is widely used in microbial-induced carbonate precipitation(MICP)due to its high urease activity.In this paper,the effects of nutrients on the metabolic mechanism and mineralization ...Sporosarcina pasteurii(S.pasteurii)is widely used in microbial-induced carbonate precipitation(MICP)due to its high urease activity.In this paper,the effects of nutrients on the metabolic mechanism and mineralization ability of S.pasteurii were studied by comparing the bacteria's growth,gene expression,and mineralized sand column under different nitrogen sources.The results showed that urea and soy peptone replacing the inorganic and organic nitrogen sources in ammonium sulfate-yeast extract(NH4-YE)medium can increase the urease activity of S.pasteurii by 11.43%and 17.10%,respectively.In the composite nitrogen source medium composed of urea and soy peptone,the urease activity of S.pasteurii increased by 25.30%.The transcriptome sequencing results showed that the modified medium of urea and soy peptone could promote the basic life activity and metabolism of S.pasteurii and is beneficial to urease expression.Among them,the gene difference between the modified urea medium and the primary medium was more obvious,and the urea medium could promote the ATP synthase related to urease expression and urea hydrolysis.The unconfined compressive strength(UCS)of sand columns reinforced with S.pasteurii cultured in Urea-YE,NH4-Soy peptone and Urea-Soy peptone increased by 27.6%,36%and 58.1%respectively.The permeability decreased by 14.8%,20.1%and 81.3%respectively compared with that of sand columns reinforced with S.pasteurii cultured in NH4-YE.The higher the urease activity of cultured bacteria,the more calcium carbonate produced after mineralization reaction.In addition,the urease activity of bacteria has an influence on the morphology of calcite crystals.This study can facilitate our understanding of optimizing the culture medium of S.pasteurii and the artificial regulation of urease activity in the process of MICP.展开更多
This research was carried out to evaluate the relationship between the incorporation of calcite precipitation bacteria,sporosarcina pasteurii using calcium lactate as nutrient source and the properties of calcined cla...This research was carried out to evaluate the relationship between the incorporation of calcite precipitation bacteria,sporosarcina pasteurii using calcium lactate as nutrient source and the properties of calcined clay and limestone powder blended self-compacting concrete.Ten mixes were designed and designated S0 to S9 with S0 the control(without bacteria and nutrient)and S1 to S9 at varying bacteria and calcium lactate concentrations and the effect of the bacteria cell density and calcium lactate concentration on the compressive strength,sorptivity and tensile strength with age were evaluated using experimental program and statistical packages(ANOVA and post hoc tests).The result of both the experimental program and statistical evaluation shows that the incorporation of sporosarcina pasteurii and calcium lactate as nutrients had a positive impact on the properties of the ternary blended self-compacting concrete.展开更多
Microplastics(MPs)are present throughout the environment,and due to their nature,they are extremely difficult to decompose.Reportedly,microorganisms play an important role in degrading and decomposing MPs.Bacillus pas...Microplastics(MPs)are present throughout the environment,and due to their nature,they are extremely difficult to decompose.Reportedly,microorganisms play an important role in degrading and decomposing MPs.Bacillus pasteurii can degrade various complex organic matter,including MPs,which are a class of polymeric organic compounds.This study investigated the degradation effect of B.pasteurii on polypropylene MPs(PP-MPs)in soil.B.pasteurii was extracted from gold mine tailings.Herein,three experimental groups were establishedda blank control treatment group,a group with bacteria without Ca2t added(T2 group),and a group with bacteria supplemented with Ca2t(T3 group)dfor a 30-day indoor simulation of MP degradation in MP-treated soil.The results showed that the total mass change rate of the PP-MPs in the T2 group was 20.95%,and grooves and holes appeared on the PP-MP surfaces.The total mass change rate of the PP-MPs in the T3 group was 23.22%,and abundant fissures and pits appeared on the PP-MP surfaces.Additionally,new dominant phyla,such as Bacteroidetes and Firmicutes,appeared after bacterial addition.The relative abundance of several common soil genera,such as Bacillus,Brevundimonas,Flavobacterium,and Arthrobacter,and genera capable of breaking down complex compounds increased after B.pasteurii addition.The soil microbial community diversity improved,with the distribution of each species being relatively uniform.These findings indicated that the B.pasteurii strain can be used to degrade PP-MPs.Additionally,the addition of Ca2t generated microbially induced calcium carbonate precipitation,which further improved the degradation of MPs.This study provides theoretical support for studying the degradation mechanism of PP-MPs.展开更多
To master the culture optimization and regulation mechanism of Sporosarcina Pasteurii,this study explored the adaptability of MICP technology for restoring root splitting fissures of plants,and used single factor comp...To master the culture optimization and regulation mechanism of Sporosarcina Pasteurii,this study explored the adaptability of MICP technology for restoring root splitting fissures of plants,and used single factor comparative experimental method to study the characteristics of growth curves and urease activity of Pasteurii in different conditions in earthen sites of Jinyang Ancient City.The conclusions are as follows.The technology of MICP was an ideal method for restoring root splitting fissures of plants,which could meet the requirements of restoring earthen sites by sealing surface fissures,inhibiting root growth of plants and preserving the physical morphology of damaged plant roots and stems.It was recommended to use the medium of M1,with an initial pH of 7.25,a culture temperature of 30℃,inoculation age range of 12-13h,and inoculation amount of 3%.The suggestion was to select Pasteurii as restoration solution when the urease activity was at peak period.The conclusions can provide suitable breeding conditions for Pasteurii,providing an important reference for MICP technology to restore root splitting fissures of plants for earthen sites.展开更多
Hydroxylapatite(HAp),owing to its excellent biocompatibility,is a promising carrier for lanthanide ions to encourage antibacterial activity.However,hydroxylapatite powder would still require modification to ensure the...Hydroxylapatite(HAp),owing to its excellent biocompatibility,is a promising carrier for lanthanide ions to encourage antibacterial activity.However,hydroxylapatite powder would still require modification to ensure the optimal integration of antibacterial characteristics.In this study,Sm-doped nano-hydroxylapatite(SmHAp)was synthesized by spontaneous mineralization of amorphous SmHAp precursors,which ensures a homogeneous distribution of Sm^(3+)within bulk SmHAp.Powder X-ray diffraction and its Pawley fitting results for SmHAp indicate the lattice substitution of Ca^(2+)with Sm^(3+),resulting in the lattice distortion in SmHAp compared to pure HAp.Meanwhile,polymer-encapsulated Sm-doped nano-hydroxylapatite composite(p_SmHAp)was synthesized by a dual-step polymerization involving UV curing of an outer crust and heat treatment for bulk reaction completion.Irgacure 2959 and a toluene solution of AIBN were used as catalysts for the radical polymerization process.The antibacterial property of p_SmHAp was evaluated by observing the growth of Sporosarcina pasteurii(ATCC 11859)both in the solid and the liquid medium,correlating with the Sm fraction and SmHAp's crystallinity in p_SmHAp.These bacteriostatic rings'diameters exceed 20 mm,demonstrating that p_SmHAp with a SmHAP/p_SmHAp mass ratio of 0.1 and Sm/(Ca+Sm)molar ratio of 0.05-0.1 effectively releases Sm^(3+),serving as a strong antibacterial agent.展开更多
文摘As one of the soil microorganisms, bacillus pasteurii exhibits good urease-produ-cing ability. A novel method is used to prepare BaCO3 crystals by the induction of bacillus pasteurii. The crystals have been characterized by XRD, SEM and FT-IR. X-ray diffraction analysis quantified that the BaCO3 crystals obtained belong to the orthorhombic crystal system. Examination by scanning electron microscopy identified that the BaCO3 crystals have different morphologies under different preparation conditions. FT-IR indicated that surfactant EDTA had great effect on the morphology of BaCO3 crystals. Different morphology crystals had uniform distribution and integral shape. The forming mechanism and influence of EDTA on the morphology of BaCO3 crystals have been discussed.
基金support of National Natural Science Foundation of China(Grant Nos.52178334 and 52374171)Guiding Project of Science and Technology Department of Fujian Province(Grant No.2024Y0014).
文摘Sporosarcina pasteurii(S.pasteurii)is widely used in microbial-induced carbonate precipitation(MICP)due to its high urease activity.In this paper,the effects of nutrients on the metabolic mechanism and mineralization ability of S.pasteurii were studied by comparing the bacteria's growth,gene expression,and mineralized sand column under different nitrogen sources.The results showed that urea and soy peptone replacing the inorganic and organic nitrogen sources in ammonium sulfate-yeast extract(NH4-YE)medium can increase the urease activity of S.pasteurii by 11.43%and 17.10%,respectively.In the composite nitrogen source medium composed of urea and soy peptone,the urease activity of S.pasteurii increased by 25.30%.The transcriptome sequencing results showed that the modified medium of urea and soy peptone could promote the basic life activity and metabolism of S.pasteurii and is beneficial to urease expression.Among them,the gene difference between the modified urea medium and the primary medium was more obvious,and the urea medium could promote the ATP synthase related to urease expression and urea hydrolysis.The unconfined compressive strength(UCS)of sand columns reinforced with S.pasteurii cultured in Urea-YE,NH4-Soy peptone and Urea-Soy peptone increased by 27.6%,36%and 58.1%respectively.The permeability decreased by 14.8%,20.1%and 81.3%respectively compared with that of sand columns reinforced with S.pasteurii cultured in NH4-YE.The higher the urease activity of cultured bacteria,the more calcium carbonate produced after mineralization reaction.In addition,the urease activity of bacteria has an influence on the morphology of calcite crystals.This study can facilitate our understanding of optimizing the culture medium of S.pasteurii and the artificial regulation of urease activity in the process of MICP.
文摘This research was carried out to evaluate the relationship between the incorporation of calcite precipitation bacteria,sporosarcina pasteurii using calcium lactate as nutrient source and the properties of calcined clay and limestone powder blended self-compacting concrete.Ten mixes were designed and designated S0 to S9 with S0 the control(without bacteria and nutrient)and S1 to S9 at varying bacteria and calcium lactate concentrations and the effect of the bacteria cell density and calcium lactate concentration on the compressive strength,sorptivity and tensile strength with age were evaluated using experimental program and statistical packages(ANOVA and post hoc tests).The result of both the experimental program and statistical evaluation shows that the incorporation of sporosarcina pasteurii and calcium lactate as nutrients had a positive impact on the properties of the ternary blended self-compacting concrete.
基金supported by the Natural Science Foundation of Inner Mongolia(2023MS05016)the Science and Technology Plan Project of Inner Mongolia Autonomous Region(2023YFHH0041,2023KJHZ0026)+1 种基金the Fundamental Research Pro-jects of Universities directly under the Inner Mongolia Autonomous Region(2022038)the China Scholarship Fund.
文摘Microplastics(MPs)are present throughout the environment,and due to their nature,they are extremely difficult to decompose.Reportedly,microorganisms play an important role in degrading and decomposing MPs.Bacillus pasteurii can degrade various complex organic matter,including MPs,which are a class of polymeric organic compounds.This study investigated the degradation effect of B.pasteurii on polypropylene MPs(PP-MPs)in soil.B.pasteurii was extracted from gold mine tailings.Herein,three experimental groups were establishedda blank control treatment group,a group with bacteria without Ca2t added(T2 group),and a group with bacteria supplemented with Ca2t(T3 group)dfor a 30-day indoor simulation of MP degradation in MP-treated soil.The results showed that the total mass change rate of the PP-MPs in the T2 group was 20.95%,and grooves and holes appeared on the PP-MP surfaces.The total mass change rate of the PP-MPs in the T3 group was 23.22%,and abundant fissures and pits appeared on the PP-MP surfaces.Additionally,new dominant phyla,such as Bacteroidetes and Firmicutes,appeared after bacterial addition.The relative abundance of several common soil genera,such as Bacillus,Brevundimonas,Flavobacterium,and Arthrobacter,and genera capable of breaking down complex compounds increased after B.pasteurii addition.The soil microbial community diversity improved,with the distribution of each species being relatively uniform.These findings indicated that the B.pasteurii strain can be used to degrade PP-MPs.Additionally,the addition of Ca2t generated microbially induced calcium carbonate precipitation,which further improved the degradation of MPs.This study provides theoretical support for studying the degradation mechanism of PP-MPs.
基金supported by[Shanxi Provincial Basic Research Program of China and Shanxi Provincial Cultural Relics Technology Program of China]under Grant[202303021212060 and 2023KT15].
文摘To master the culture optimization and regulation mechanism of Sporosarcina Pasteurii,this study explored the adaptability of MICP technology for restoring root splitting fissures of plants,and used single factor comparative experimental method to study the characteristics of growth curves and urease activity of Pasteurii in different conditions in earthen sites of Jinyang Ancient City.The conclusions are as follows.The technology of MICP was an ideal method for restoring root splitting fissures of plants,which could meet the requirements of restoring earthen sites by sealing surface fissures,inhibiting root growth of plants and preserving the physical morphology of damaged plant roots and stems.It was recommended to use the medium of M1,with an initial pH of 7.25,a culture temperature of 30℃,inoculation age range of 12-13h,and inoculation amount of 3%.The suggestion was to select Pasteurii as restoration solution when the urease activity was at peak period.The conclusions can provide suitable breeding conditions for Pasteurii,providing an important reference for MICP technology to restore root splitting fissures of plants for earthen sites.
基金Project supported by the Fundamental and Applied Fundamental Research Major Program of Guangdong Province,China(2019B030302013)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA0430205)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(2021A1515011531)the Science and Technology Planning Project of Guangdong Province,China(2023B1212060044,2023B1212060048)the Market Readiness Assistance Grant of Singapore(04INS000458C15000E01)。
文摘Hydroxylapatite(HAp),owing to its excellent biocompatibility,is a promising carrier for lanthanide ions to encourage antibacterial activity.However,hydroxylapatite powder would still require modification to ensure the optimal integration of antibacterial characteristics.In this study,Sm-doped nano-hydroxylapatite(SmHAp)was synthesized by spontaneous mineralization of amorphous SmHAp precursors,which ensures a homogeneous distribution of Sm^(3+)within bulk SmHAp.Powder X-ray diffraction and its Pawley fitting results for SmHAp indicate the lattice substitution of Ca^(2+)with Sm^(3+),resulting in the lattice distortion in SmHAp compared to pure HAp.Meanwhile,polymer-encapsulated Sm-doped nano-hydroxylapatite composite(p_SmHAp)was synthesized by a dual-step polymerization involving UV curing of an outer crust and heat treatment for bulk reaction completion.Irgacure 2959 and a toluene solution of AIBN were used as catalysts for the radical polymerization process.The antibacterial property of p_SmHAp was evaluated by observing the growth of Sporosarcina pasteurii(ATCC 11859)both in the solid and the liquid medium,correlating with the Sm fraction and SmHAp's crystallinity in p_SmHAp.These bacteriostatic rings'diameters exceed 20 mm,demonstrating that p_SmHAp with a SmHAP/p_SmHAp mass ratio of 0.1 and Sm/(Ca+Sm)molar ratio of 0.05-0.1 effectively releases Sm^(3+),serving as a strong antibacterial agent.
