Calcareous sand is widely present in coastal areas around the world and is usually considered as a weak and unstable material due to its high compressibility and low strength.Microbial-induced calcium carbonate precip...Calcareous sand is widely present in coastal areas around the world and is usually considered as a weak and unstable material due to its high compressibility and low strength.Microbial-induced calcium carbonate precipitation(MICP)is a promising technique for soil improvement.However,the commonly adopted bio-augmented MICP approach is in general less compatible with the natural soil environment.Thus,this study focuses on the bio-stimulated MICP approach,which is likely to enhance the dominance of ureolytic bacteria for longer period and thus is deemed more efficient.The main objective of this paper is to investigate the compressibility of calcareous sand treated by bio-stimulated MICP approach.In the current study,a series of one-dimension compression tests was conducted on bio-cemented sand pre-pared via bio-stimulation with different initial relative densities(D r).Based on the obtained compression curves and particle size distribution(PSD)curves,the parameters including cementation content,the coefficient of compressibility(a v),PSD,relative breakage(B r),and relative agglomeration(A r)were discussed.The results showed that a v decreased with the increasing cementation content.The bio-cemented sand prepared with higher initial D r had smaller(approximately 20%e70%)a v values than that with lower initial D r.The specimen with higher initial D r and higher cementation content resulted in smaller B r but larger A r.Finally,a conceptual framework featuring multiple contact and damage modes was proposed.展开更多
Background Natural and synthetic plant growth regulators are essential for plant health,likewise these regulators also play a role in increasing organic production productivity and improving quality and yield stabilit...Background Natural and synthetic plant growth regulators are essential for plant health,likewise these regulators also play a role in increasing organic production productivity and improving quality and yield stability.In the present study,we have evaluated the effects of foliar applied plant growth regulators,i.e.,moringa leaf extract(MLE)and mepiquat chloride(MC)alone and in combination MC and MLE on the conventional cotton cultivar(CIM 573)and transgenic one(CIM 598).The growth regulators were applied at the start of bloom,45 and 90 days after blooming.Results The application of MC and MLE at 90 days after blooming significantly improved the relative growth rate,net assimilation rate,the number of bolls per plant,and seed cotton yield.Likewise,the combined application of MLE and MC at 90 days after blooming significantly boosted the nitrogen uptake in locules,as well as the phosphorus and potassium uptake in the leaves of both cotton cultivars.The application of MLE alone has considerably improved the nitrogen uptake in leaves,and phosphorus and potassium contents in locules of Bt and conventional cotton cultivars.Similarly,Bt cotton treated with MLE at 90 days after blooming produced significantly higher ginning out turn and oil contents.Treatment in combination(MLE+MC)at 90 days after blooming produced considerably higher micronaire value,fiber strength,and staple length in conventional cultivar.Conclusion The natural growth enhancer,MLE is a rich source of minerals and zeatin,improving the nutrient absorption and quality of cotton fiber in both conventional and Bt cotton cultivars.展开更多
There is a great interest in developing cost-efficient nutrients to stimulate microorganisms in indigenous microbial enhanced oil recovery（IMEOR） processes.In the present study,the potential of rice bran as a carbon...There is a great interest in developing cost-efficient nutrients to stimulate microorganisms in indigenous microbial enhanced oil recovery（IMEOR） processes.In the present study,the potential of rice bran as a carbon source for promoting IMEOR was investigated on a laboratory scale.The co-applications of rice bran,K2HPO4 and urea under optimized bio-stimulation conditions significantly increased the production of gases,acids and emulsifiers.The structure and diversity of microbial community greatly changed during the IMEOR process,in which Clostridium sp.,Acidobacteria sp.,Bacillus sp.,and Pseudomonas sp.were dominant.Pressurization,acidification and emulsification due to microbial activities and interactions markedly improved the IMEOR processes.This study indicated that rice bran is a potential carbon source for IMEOR.展开更多
Microorganisms have been essential in the natural world for millions of years,contributing significantly to environmental interaction.It has been disoverd that some bacteria are potential in geotechnical and environme...Microorganisms have been essential in the natural world for millions of years,contributing significantly to environmental interaction.It has been disoverd that some bacteria are potential in geotechnical and environmental engineering due to their outstanding ability of biomineralization.Therefore,how to train bacteria as special and professional“workers”for biomineralization is increasingly a key topic in related research fields.This article briefly introduces the methods that are commonly utilized to improve the environmental adaptability and mineralization efficiency of bacteria,including microbial domestication,microbial mutation breeding,microbial targeted screening,and bio-stimulation,which make great implications to advance the field of biomineralization.展开更多
The competitive global fruit market mandates production of apples with high quality attributes, particularly fruit color. Harpin Protein (Messenger<sup>®</sup>) is shown to trigger resistance to bl...The competitive global fruit market mandates production of apples with high quality attributes, particularly fruit color. Harpin Protein (Messenger<sup>®</sup>) is shown to trigger resistance to blue mold in apples, but limited information can be found on the effect of this compound on fruit quality. In this study, the impact of Harpin protein on quality attributes of four apple cultivars was studied. “Red Spur Delicious” apple fruit from trees receiving Harpin protein had significantly (about 23%) better color, earlier ethylene evolution, and higher respiration than those from untreated control trees, while their firmness was not adversely affected. Application of Harpin protein on “Red Chief Delicious” apple improved fruit color and increased fruit size in two locations, and advanced starch degradation pattern in one orchard but reduced fruit firmness in one location. Harpin protein tended (but not significantly) to improve fruit color in “Jonathan” and “Early Spur Rome” but reduced fruit size in “Jonathan” apples. Messenger<sup>®</sup> increased fruit percentage dry weight and Fe but decreased fruit Ca, Mg, K, and Zn. Improving apple fruit color by Harpin protein could have major impacts on apple industry and warrants further study.展开更多
Polyamines(PAs)are nitrogenous and polycationic compounds containing more than two amine residues.Numerous investigations have demonstrated that cellular PA homeostasis plays a key role in various developmental and ph...Polyamines(PAs)are nitrogenous and polycationic compounds containing more than two amine residues.Numerous investigations have demonstrated that cellular PA homeostasis plays a key role in various developmental and physiological processes.The PA balance,which may be affected by many environmental factors,is finely maintained by the pathways of PA biosynthesis and degradation(catabolism).In this review,the advances in PA transport and distribution and their roles in plants were summarized and discussed.In addition,the interplay between PAs and phytohormones,NO,and H_(2)O_(2)were detailed during plant growth,senescence,fruit repining,as well as response to biotic and abiotic stresses.Moreover,it was elucidated how environmental signals such as light,temperature,and humidity modulate PA accumulation during plant development.Notably,PA has been shown to exert a potential role in shaping the domestication of rice.The present review comprehensively summarizes these latest advances,high-lighting the importance of PAs as endogenous signaling molecules in plants,and as well proposes future perspectives on PA research.展开更多
Nutritional bio-stimulant(NBS)technology is an attractive method to improve the efficiency of biological treatment of wastewater by stimulating the microbial growth and increasing species diversity.In this study,a com...Nutritional bio-stimulant(NBS)technology is an attractive method to improve the efficiency of biological treatment of wastewater by stimulating the microbial growth and increasing species diversity.In this study,a commercial NBS,which consisted of organic acids,absorbable nitrogen and phosphorus and trace elements,was applied as a nutrient supplement to replace conventional chemical fertilizer(CCF)in aerobic biological treatment of a traditional Chinese medicine(TCM)wastewater.A mill trials was carried out in a commercial scale TCM wastewater treatment system for 41 days.The process performance and active sludge characteristics were continuously monitored when the CCF was replaced with NBS gradually in the system.It was found that the chemical oxygen demand(COD)of the effluent decreased from 118 to 89 mg·L^(-1),well below the 100 mg·L^(-1)wastewater discharge limit,when the CCF was replaced with NBS completely.More importantly,the ammonia concentration of the effluent stayed constantly low in the NBS stage of the trial,indicating that the added NBS was completely utilized by the microorganisms.In contrast,the effluent ammonia concentration was gradually increasing and exceeded the limit in the CCF stage of the trial,indicating that the CCF was not fully utilized by the microbes.The improved perfromance of the aerobic wastewater treatment system was attributed to the fact that the NBS nutrients were more bio-available than the CCF to the microorganisms.展开更多
基金This study was financially supported by the Natural Science Foundation of China(Grant No.42007246)the Fundamental Research Funds for the Central Universities(Grant No.2242022k30055)Indo-U.S.Science and Technology Forum(Grant No.IUSSTF/AUG/JC/047/2018).
文摘Calcareous sand is widely present in coastal areas around the world and is usually considered as a weak and unstable material due to its high compressibility and low strength.Microbial-induced calcium carbonate precipitation(MICP)is a promising technique for soil improvement.However,the commonly adopted bio-augmented MICP approach is in general less compatible with the natural soil environment.Thus,this study focuses on the bio-stimulated MICP approach,which is likely to enhance the dominance of ureolytic bacteria for longer period and thus is deemed more efficient.The main objective of this paper is to investigate the compressibility of calcareous sand treated by bio-stimulated MICP approach.In the current study,a series of one-dimension compression tests was conducted on bio-cemented sand pre-pared via bio-stimulation with different initial relative densities(D r).Based on the obtained compression curves and particle size distribution(PSD)curves,the parameters including cementation content,the coefficient of compressibility(a v),PSD,relative breakage(B r),and relative agglomeration(A r)were discussed.The results showed that a v decreased with the increasing cementation content.The bio-cemented sand prepared with higher initial D r had smaller(approximately 20%e70%)a v values than that with lower initial D r.The specimen with higher initial D r and higher cementation content resulted in smaller B r but larger A r.Finally,a conceptual framework featuring multiple contact and damage modes was proposed.
文摘Background Natural and synthetic plant growth regulators are essential for plant health,likewise these regulators also play a role in increasing organic production productivity and improving quality and yield stability.In the present study,we have evaluated the effects of foliar applied plant growth regulators,i.e.,moringa leaf extract(MLE)and mepiquat chloride(MC)alone and in combination MC and MLE on the conventional cotton cultivar(CIM 573)and transgenic one(CIM 598).The growth regulators were applied at the start of bloom,45 and 90 days after blooming.Results The application of MC and MLE at 90 days after blooming significantly improved the relative growth rate,net assimilation rate,the number of bolls per plant,and seed cotton yield.Likewise,the combined application of MLE and MC at 90 days after blooming significantly boosted the nitrogen uptake in locules,as well as the phosphorus and potassium uptake in the leaves of both cotton cultivars.The application of MLE alone has considerably improved the nitrogen uptake in leaves,and phosphorus and potassium contents in locules of Bt and conventional cotton cultivars.Similarly,Bt cotton treated with MLE at 90 days after blooming produced significantly higher ginning out turn and oil contents.Treatment in combination(MLE+MC)at 90 days after blooming produced considerably higher micronaire value,fiber strength,and staple length in conventional cultivar.Conclusion The natural growth enhancer,MLE is a rich source of minerals and zeatin,improving the nutrient absorption and quality of cotton fiber in both conventional and Bt cotton cultivars.
基金supported in part by the National Natural Science Foundation of China (Nos. 51209216 and 21306229)the Korean RDA Grant (No. PJ009472)
文摘There is a great interest in developing cost-efficient nutrients to stimulate microorganisms in indigenous microbial enhanced oil recovery（IMEOR） processes.In the present study,the potential of rice bran as a carbon source for promoting IMEOR was investigated on a laboratory scale.The co-applications of rice bran,K2HPO4 and urea under optimized bio-stimulation conditions significantly increased the production of gases,acids and emulsifiers.The structure and diversity of microbial community greatly changed during the IMEOR process,in which Clostridium sp.,Acidobacteria sp.,Bacillus sp.,and Pseudomonas sp.were dominant.Pressurization,acidification and emulsification due to microbial activities and interactions markedly improved the IMEOR processes.This study indicated that rice bran is a potential carbon source for IMEOR.
基金support from the National Natural Science Foundation of China(Grant No.52078085)Chongqing Planning and Natural Resources Bureau(No.KJ-2021048).
文摘Microorganisms have been essential in the natural world for millions of years,contributing significantly to environmental interaction.It has been disoverd that some bacteria are potential in geotechnical and environmental engineering due to their outstanding ability of biomineralization.Therefore,how to train bacteria as special and professional“workers”for biomineralization is increasingly a key topic in related research fields.This article briefly introduces the methods that are commonly utilized to improve the environmental adaptability and mineralization efficiency of bacteria,including microbial domestication,microbial mutation breeding,microbial targeted screening,and bio-stimulation,which make great implications to advance the field of biomineralization.
文摘The competitive global fruit market mandates production of apples with high quality attributes, particularly fruit color. Harpin Protein (Messenger<sup>®</sup>) is shown to trigger resistance to blue mold in apples, but limited information can be found on the effect of this compound on fruit quality. In this study, the impact of Harpin protein on quality attributes of four apple cultivars was studied. “Red Spur Delicious” apple fruit from trees receiving Harpin protein had significantly (about 23%) better color, earlier ethylene evolution, and higher respiration than those from untreated control trees, while their firmness was not adversely affected. Application of Harpin protein on “Red Chief Delicious” apple improved fruit color and increased fruit size in two locations, and advanced starch degradation pattern in one orchard but reduced fruit firmness in one location. Harpin protein tended (but not significantly) to improve fruit color in “Jonathan” and “Early Spur Rome” but reduced fruit size in “Jonathan” apples. Messenger<sup>®</sup> increased fruit percentage dry weight and Fe but decreased fruit Ca, Mg, K, and Zn. Improving apple fruit color by Harpin protein could have major impacts on apple industry and warrants further study.
基金supported by the National Key Research and Development Program of China(2022YFD1200503)grants from the Open Competition Program of Top Ten Critical Priorities of Agricultural Science and Technology Innovation for the 14th Five-Year Plan of Guangdong Province(2022SDZG05)+1 种基金the National Natural Science Foundation of China(91535101,32272644,32330095)the Natural Science Foundation of Guangdong Province(2023A1515010439)。
文摘Polyamines(PAs)are nitrogenous and polycationic compounds containing more than two amine residues.Numerous investigations have demonstrated that cellular PA homeostasis plays a key role in various developmental and physiological processes.The PA balance,which may be affected by many environmental factors,is finely maintained by the pathways of PA biosynthesis and degradation(catabolism).In this review,the advances in PA transport and distribution and their roles in plants were summarized and discussed.In addition,the interplay between PAs and phytohormones,NO,and H_(2)O_(2)were detailed during plant growth,senescence,fruit repining,as well as response to biotic and abiotic stresses.Moreover,it was elucidated how environmental signals such as light,temperature,and humidity modulate PA accumulation during plant development.Notably,PA has been shown to exert a potential role in shaping the domestication of rice.The present review comprehensively summarizes these latest advances,high-lighting the importance of PAs as endogenous signaling molecules in plants,and as well proposes future perspectives on PA research.
基金the support from State Key Laboratory of Pulp and Paper Engineering,South China University of Technology,(201604).
文摘Nutritional bio-stimulant(NBS)technology is an attractive method to improve the efficiency of biological treatment of wastewater by stimulating the microbial growth and increasing species diversity.In this study,a commercial NBS,which consisted of organic acids,absorbable nitrogen and phosphorus and trace elements,was applied as a nutrient supplement to replace conventional chemical fertilizer(CCF)in aerobic biological treatment of a traditional Chinese medicine(TCM)wastewater.A mill trials was carried out in a commercial scale TCM wastewater treatment system for 41 days.The process performance and active sludge characteristics were continuously monitored when the CCF was replaced with NBS gradually in the system.It was found that the chemical oxygen demand(COD)of the effluent decreased from 118 to 89 mg·L^(-1),well below the 100 mg·L^(-1)wastewater discharge limit,when the CCF was replaced with NBS completely.More importantly,the ammonia concentration of the effluent stayed constantly low in the NBS stage of the trial,indicating that the added NBS was completely utilized by the microorganisms.In contrast,the effluent ammonia concentration was gradually increasing and exceeded the limit in the CCF stage of the trial,indicating that the CCF was not fully utilized by the microbes.The improved perfromance of the aerobic wastewater treatment system was attributed to the fact that the NBS nutrients were more bio-available than the CCF to the microorganisms.
