One new sorbicillin derivative, 2-deoxy-sohirnone C(1), one new diketopiperazine alkaloid, 5 S-hydroxynorvalineS-Ile(2), and two naturally occurring diketopiperazines, 3 S-hydroxylcyclo(S-Pro-S-Phe)(3) and cyclo(S-Phe...One new sorbicillin derivative, 2-deoxy-sohirnone C(1), one new diketopiperazine alkaloid, 5 S-hydroxynorvalineS-Ile(2), and two naturally occurring diketopiperazines, 3 S-hydroxylcyclo(S-Pro-S-Phe)(3) and cyclo(S-Phe-S-Gln)(4), together with three known compounds were isolated from the Chinese mangrove endophytic fungus Penicillium sp. GD6. Their structures were determined on the basis of extensive spectroscopic analyses and by comparison with literature data. The absolute configuration of 3-hydroxyl moiety in 3 was determined by Mosher's method, while the absolute stereochemistry of 2 and 4 was established by comparison with the CD spectra of natural and synthesized diketopiperazines. Compound 1 showed moderate antibacterial activity against Methicillin-resistant Staphylococcus aureus with a MIC value of 80 μg·m L^(-1).展开更多
As a material with good biocompatibility,hydroxyapatite(HAP)can have optical properties after doping with various rare earth ions.As a biocompatible fluorescent material,doped HAP could have broad applications in biol...As a material with good biocompatibility,hydroxyapatite(HAP)can have optical properties after doping with various rare earth ions.As a biocompatible fluorescent material,doped HAP could have broad applications in biological probes,drug delivery,optoelectronic materials,fluorescence anti-counterfeiting,and other aspects.In this paper,we put forward the preparation of HAP doped with terbium(Ⅲ)ions(Tb^(3+))by hydrothermal co-precipitation.By controlling the Tb^(3+)doping content in reaction and the reaction time,the changes in HAP's structure,morphology,and luminescence properties under different conditions were studied.When the doping amount of Tb^(3+)reached an optimal value,the dipole-quadrupole would occur and the concentration would be quenched.The control experiment showed that the optimal Tb3+content was 7.5×10^(-5)mol,which showed the best fluorescence performance.HAP,a non-luminous material,was rarely used in the field of fluorescent anti-counterfeiting and photoelectric devices.We proposed to prepare a luminescent aramid/polyphenylene sulfide(ACFs/PPS)fiber paper and a new light-emitting diode(LED)using the Tb-doped HAP phosphor.The composite sample exhibited an excellent stability and fluorescence performance,which also demonstrated a possibility of HAP applications in anticounterfeiting and photoelectric.The introduction of Tb3+dopant HAP was done to give HAP optical properties and broaden the application range of HAP.展开更多
In order to develop novel LpxC inhibitors with good activities and metabolic stability, two series of compounds with hydrophilic terminus have been synthesized and their in vitro antibacterial activities against Esche...In order to develop novel LpxC inhibitors with good activities and metabolic stability, two series of compounds with hydrophilic terminus have been synthesized and their in vitro antibacterial activities against Escherichial coil and Pseudomonas aemginosa were evaluated. Especially, compounds 22b and c exhibited comparable antibacterial activities to CHIR-090 and better metabolic stability than CHIR-090 and LPC-011 in liver microsomes (rat and mouse), which indicated the terminal methylsulfone may be a preferred structure in the design of LpxC inhibitors and worthy of further investigations.展开更多
Evaluation of the effectiveness of refuge strategies involved in cotton boll- worm Bt resistance management would be aided by technologies that allow monitoring and quantification of key factors that affect the proces...Evaluation of the effectiveness of refuge strategies involved in cotton boll- worm Bt resistance management would be aided by technologies that allow monitoring and quantification of key factors that affect the process under field conditions. We hy- pothesized that characterization of stable carbon and nitrogen isotopes in adult bollworm, Helicoverpa armigera (Htibner) (Lepidoptera: Noctuidae) moths may aid in determining the larval host that they developed upon. We found moths reared from larvae fed on peanut, soybean or cotton, respectively, could be differentiated using isotopic analyses that also corresponded to their respective larval host origins. These techniques were then used to classify feral second-generation bollworm moths caught in Bt cotton (Gossypium hirsu- rum) fields into different populations based on their isotopic signatures. In 2006-2007 feral moths captured in Bt cotton fields predominantly correlated with the peanut (Arachis hypogea) having served as their larval host, indicating this is the most important refuge crop for Bt-susceptible bollworm individuals (providing 58%-64% individuals) during independent moth peaks for the second generation in North China. The remaining feral moths correlated with soybean (Glycine max) (0-10%); other C3 plant (20%-22%) and non-C3 plant (12%-14%) host types also provided some Bt-sensitive moths. Field obser- vations showed that peanut constitutes the primary refuge crop contributing to sustaining Bt-susceptible moths dispersing into cotton in North China. These results suggest that peanut may be a more effective refuge to sustain Bt-susceptible bollworm individuals and reduce the risk of development of a Bt-resistant biotype.展开更多
The corrosion behaviors of CNS-I and modified CNS-II were evaluated by exposing to superciritical water (SCW) at 550℃ and 25 MPa with a dissolved oxygen concentration of 200× 10 ^-9 for up to 1 000 h. Detailed...The corrosion behaviors of CNS-I and modified CNS-II were evaluated by exposing to superciritical water (SCW) at 550℃ and 25 MPa with a dissolved oxygen concentration of 200× 10 ^-9 for up to 1 000 h. Detailed corrosion results of these two alloys were provided, including the growth rate of the oxide scales, microstructure of the oxide scales, distribution of phases and alloying elements. The mass gains of CNS-I and modified CNS-II were 609.73 mg/dm2 and 459.42 mg/dm2 , respectively, after exposing to SCW for 1 000 h. A duplex oxide scale with an outer porous magnetite layer and an inner relatively dense magnetite/spinel-mixed layer was identified on CNS-I and modified CNS-II after the test. The oxide scales were rather porous at the beginning of the test but the porosity decreased with increase of the exposure duration. It was found that Fe was enriched in the outer oxide layer, Cr was enriched in the inner oxide layer and O existed at a very high concnetration in the whole oxide scale. Other alloying elements such as Mo, W, Mn were depleted from the outer oxide layer and showed slightly enrichment in the inner oxide layer. The distributution of Ni was different from other elements, it was enriched in the interface bewteen the base metal and the oxide scale and depleted in the outer and inner oxide layers.展开更多
Aphis glycines (Hemiptera: Aphididae) is considered as a cosmopolitan pest of cultivated soybean, major difficulties in its control measures may be due to its higher genetic diversity; however, the knowledge about ...Aphis glycines (Hemiptera: Aphididae) is considered as a cosmopolitan pest of cultivated soybean, major difficulties in its control measures may be due to its higher genetic diversity; however, the knowledge about population genetic diversity of this species is limited. This study aimed to represent the genetic differentiation among different geographic populations of soybean aphid in Northeast China. In order to investigate and assess the genetic diversity, genetic differentiation, molecular variance, population structure, ecological importance and evolutionary history of A. glycines, we sequenced a fragment of one protein-coding gene, the cytochrome c oxidase I/of mitochondrial DNA gene. The results showed that four haplotypes were defined among CO 11 gene of 180 sequences of soybean aphid in Northeast China including H1 shared by all the populations. Lower haplotype diversity (Hd=0.3590± 0.0420) and nucleotide diversity (Pi=0.0012±0.0002) were observed and high gene flow was detected in every two populations, while most of the variation (80.81%) arose from variability within A. glycines from individuals. Low genetic differentiation and high gene flow (Nm=2.106) indicated a high migration rate between the populations, which might reveal that gene flow in different geographic populations did not affect by geographical distance. The phylogenetic tree and the haplotype network ofA. glycines were obtained based on sequences of CO Ⅱ gene, there were no significant genealogical branches or clusters recognized in NJ tree, and no clear distribution, delineation of haplotypes were demonstrated in the haplotype network according to geographical location. This study rejected the vicariance hypothesis: geographic isolation could be a barrier and it restricted A. glycines gene flow among 10 populations.展开更多
This paper investigated effects of four ecological variables on the damage levels of elm leaf beetle (different effects of minimum and maximum values, relations between each two variables were also explored) and dis...This paper investigated effects of four ecological variables on the damage levels of elm leaf beetle (different effects of minimum and maximum values, relations between each two variables were also explored) and discussed current management measures. The results showed that among these factors, interval between elm trees significantly affected damage level by this leaf beetle species, and perimeter of elm trunk could change this effect. On the other side, while middle values for each index were deleted, effects comparison between minimum and maximum parts showed that good root soil as overwintering was related with more damage; more severe damages on elm tree would result in more control measures used; on elm tree with bigger mink, more damages were observed; and if other elm tree was closer, more damages would occur. Secondly, good root soil was related with more measures used; good root soil was correlated with smaller perimeter; good root soil was associated with bigger interval. Thirdly, more measures were correlated with bigger perimeter; more measures were also correlated with good root soil. Fourthly, bigger perimeter was correlated with worse root soil. Current dominant control measures included chemical pesticide application preventing adult insects from descending or climbing up along trunk before and after overwintering. These results suggested that we should focus on elm leaf beetle management on all the elm trees instead of only on bigger elm trees at proper period simultaneously because occurrence on these elm trees were related intensively although this adult elm leaf beetle species could not fly and had limited movement ability.展开更多
Mineral apatite compounds have attracted significant interest due to their chemical stability and adjustable hexagonal structure,which makes them suitable as new photovoltaic functional materials.The band gap of natur...Mineral apatite compounds have attracted significant interest due to their chemical stability and adjustable hexagonal structure,which makes them suitable as new photovoltaic functional materials.The band gap of natural apatite is ~5.45 eV,and such a large value limits their applications in the field of catalysis and energy devices.In this research,we designed a method to narrow the band gap via the tetrahedral substitution effect in apatite-based compounds.The density functional theory(DFT) and experimental investigation of the electronic and optical properties revealed that the continuous incorporation of [MO_(4)]^(4-) tetrahedrons(M=Si,Ge,Sn,and Mn) into the crystal lattice can significantly reduce the band gap.In particular,this phenomenon was observed when the[MnO_(4)]^(4-) tetrahedron replaces the [PO_(4)]^(4-) tetrahedron because of the formation of a Mn 3 d-derived conduction band minimum(CBM) and interacts with other elements,leading to band broadening and obvious reduction of the band gap.This approach allowed us to propose a novel scheme in the band gap engineering of apatite-based compounds toward an entire spectral range modification.展开更多
Environmental safety issues involved in transgenic plants have become the concern of researchers, practitioners and policy makers in recent years. Potential differences between Bt maize(ND1324 and ND2353 expressing t...Environmental safety issues involved in transgenic plants have become the concern of researchers, practitioners and policy makers in recent years. Potential differences between Bt maize(ND1324 and ND2353 expressing the insecticidal Cry1Ab protein) and near-isogenic non-Bt varieties(ND1392 and ND223) in their influence on the composite microbial system of MC1 during the fermentation process were studied during 2011-2012. Cry1Ab protein in Bt maize residues didn't affect characteristics of lignocellulose degradation by MC1, pH of fermentation broth decreasing at initial stage and increasing at later stage of degradation. The quality of various volatile products in fermentation broth showed that no signifi cant difference of residues fermentation existed between Bt maize and non-Bt maize. During the fermentation MC1 efficiently degraded maize residues by 83%-88%, and cellulose, hemicelluloses and lignin content decreased by 70%-72%, 72%-75% and 30%-37%, respectively. Besides that, no consistent difference was found between Bt and non-Bt maize residues lignocellulose degradation by MC1 during the fermentation process. MC1 degraded 88%-89% Cry1Ab protein in Bt maize residues, and in the fermentation broth of MC1 and bacteria of MC1 Cry1Ab protein was not detected. DGGE profi le analyses revealed that the microbial community drastically changed during 1-3 days and became stable until the 9th day. Though the dominant strains at different fermentation stages had signifi cantly changed, no difference on the dominant strains was observed between Bt and non-Bt maize at different stages. Our study indicated that Cry1Ab protein did not infl uence the growth characteristic of MC1.展开更多
基金the financial supports from the Natural Science Foundation of Hunan Province, China (Nos. 2020JJ4114, 2016JJ3151)the National Natural Science Foundation of China (No. 51601229)+2 种基金the Young Elite Scientist Sponsorship Program by CAST, China (No. 2015QNRC001)the Hunan Province Innovation Platform and Talent Plan Project, China (No. 2015RS4001)the Open-end Fund for the Valuable and Precision Instruments of Central South University, China (No. CSUZC201815)。
基金financially supported by the Natural Science Foundation of Hunan Province,China(Nos.2020JJ4114,2016JJ3151)the National Natural Science Foundation of China(No.51601229)+2 种基金the Young Elite Scientist Sponsorship Program by CAST,China(No.2015QNRC001)the Hunan Province Innovation Platform and Talent Plan,China(No.2015RS4001)the Open-End Fund for the Valuable and Precision Instruments of Central South University,China(No.CSUZC201815)。
基金supported by the Natural Science Foundation of China(No.81520108028)SCTSM Projects(Nos.14431901100 and 15431901000)the SKLDR/SIMM Project(No.SIMM1501ZZ-03)
文摘One new sorbicillin derivative, 2-deoxy-sohirnone C(1), one new diketopiperazine alkaloid, 5 S-hydroxynorvalineS-Ile(2), and two naturally occurring diketopiperazines, 3 S-hydroxylcyclo(S-Pro-S-Phe)(3) and cyclo(S-Phe-S-Gln)(4), together with three known compounds were isolated from the Chinese mangrove endophytic fungus Penicillium sp. GD6. Their structures were determined on the basis of extensive spectroscopic analyses and by comparison with literature data. The absolute configuration of 3-hydroxyl moiety in 3 was determined by Mosher's method, while the absolute stereochemistry of 2 and 4 was established by comparison with the CD spectra of natural and synthesized diketopiperazines. Compound 1 showed moderate antibacterial activity against Methicillin-resistant Staphylococcus aureus with a MIC value of 80 μg·m L^(-1).
基金financially supported by the National Natural Science Foundation of China(Nos.52274273 and 51872269)the Key Laboratory of Testing and Tracing of Rare Earth Products for State Market Regulation(Jiangxi University of Science and Technology)(No.TTREP2022YB04)+4 种基金the Science and Technology Research Project of Hubei Provincial Department of Education(No.B2021091)Key Laboratory for New Textile Materials and Applications of Hubei Province(Wuhan Textile University)(No.FZXCL202107)the Open Project Program of High-Tech Organic Fibers Key Laboratory of Sichuan ProvinceChina and National Project Cultivation Plan of Wuhan Textile Universityaided by the graduate innovation fund project of Wuhan Textile University。
文摘As a material with good biocompatibility,hydroxyapatite(HAP)can have optical properties after doping with various rare earth ions.As a biocompatible fluorescent material,doped HAP could have broad applications in biological probes,drug delivery,optoelectronic materials,fluorescence anti-counterfeiting,and other aspects.In this paper,we put forward the preparation of HAP doped with terbium(Ⅲ)ions(Tb^(3+))by hydrothermal co-precipitation.By controlling the Tb^(3+)doping content in reaction and the reaction time,the changes in HAP's structure,morphology,and luminescence properties under different conditions were studied.When the doping amount of Tb^(3+)reached an optimal value,the dipole-quadrupole would occur and the concentration would be quenched.The control experiment showed that the optimal Tb3+content was 7.5×10^(-5)mol,which showed the best fluorescence performance.HAP,a non-luminous material,was rarely used in the field of fluorescent anti-counterfeiting and photoelectric devices.We proposed to prepare a luminescent aramid/polyphenylene sulfide(ACFs/PPS)fiber paper and a new light-emitting diode(LED)using the Tb-doped HAP phosphor.The composite sample exhibited an excellent stability and fluorescence performance,which also demonstrated a possibility of HAP applications in anticounterfeiting and photoelectric.The introduction of Tb3+dopant HAP was done to give HAP optical properties and broaden the application range of HAP.
基金National Science and Technology Major Project for the support of this researchsupported by Key New Drug Creation and Manufacturing Program,China (No.2014ZX09507009-016)
文摘In order to develop novel LpxC inhibitors with good activities and metabolic stability, two series of compounds with hydrophilic terminus have been synthesized and their in vitro antibacterial activities against Escherichial coil and Pseudomonas aemginosa were evaluated. Especially, compounds 22b and c exhibited comparable antibacterial activities to CHIR-090 and better metabolic stability than CHIR-090 and LPC-011 in liver microsomes (rat and mouse), which indicated the terminal methylsulfone may be a preferred structure in the design of LpxC inhibitors and worthy of further investigations.
文摘Evaluation of the effectiveness of refuge strategies involved in cotton boll- worm Bt resistance management would be aided by technologies that allow monitoring and quantification of key factors that affect the process under field conditions. We hy- pothesized that characterization of stable carbon and nitrogen isotopes in adult bollworm, Helicoverpa armigera (Htibner) (Lepidoptera: Noctuidae) moths may aid in determining the larval host that they developed upon. We found moths reared from larvae fed on peanut, soybean or cotton, respectively, could be differentiated using isotopic analyses that also corresponded to their respective larval host origins. These techniques were then used to classify feral second-generation bollworm moths caught in Bt cotton (Gossypium hirsu- rum) fields into different populations based on their isotopic signatures. In 2006-2007 feral moths captured in Bt cotton fields predominantly correlated with the peanut (Arachis hypogea) having served as their larval host, indicating this is the most important refuge crop for Bt-susceptible bollworm individuals (providing 58%-64% individuals) during independent moth peaks for the second generation in North China. The remaining feral moths correlated with soybean (Glycine max) (0-10%); other C3 plant (20%-22%) and non-C3 plant (12%-14%) host types also provided some Bt-sensitive moths. Field obser- vations showed that peanut constitutes the primary refuge crop contributing to sustaining Bt-susceptible moths dispersing into cotton in North China. These results suggest that peanut may be a more effective refuge to sustain Bt-susceptible bollworm individuals and reduce the risk of development of a Bt-resistant biotype.
基金Item Sponsored by National Basic Research Program of China(2007CB209800)
文摘The corrosion behaviors of CNS-I and modified CNS-II were evaluated by exposing to superciritical water (SCW) at 550℃ and 25 MPa with a dissolved oxygen concentration of 200× 10 ^-9 for up to 1 000 h. Detailed corrosion results of these two alloys were provided, including the growth rate of the oxide scales, microstructure of the oxide scales, distribution of phases and alloying elements. The mass gains of CNS-I and modified CNS-II were 609.73 mg/dm2 and 459.42 mg/dm2 , respectively, after exposing to SCW for 1 000 h. A duplex oxide scale with an outer porous magnetite layer and an inner relatively dense magnetite/spinel-mixed layer was identified on CNS-I and modified CNS-II after the test. The oxide scales were rather porous at the beginning of the test but the porosity decreased with increase of the exposure duration. It was found that Fe was enriched in the outer oxide layer, Cr was enriched in the inner oxide layer and O existed at a very high concnetration in the whole oxide scale. Other alloying elements such as Mo, W, Mn were depleted from the outer oxide layer and showed slightly enrichment in the inner oxide layer. The distributution of Ni was different from other elements, it was enriched in the interface bewteen the base metal and the oxide scale and depleted in the outer and inner oxide layers.
基金Supported by the Special funds for Construction of Modern Agricultural Technology System(CARS-04)Public Welfare Industry(Agriculture)Special Fund(201103002)
文摘Aphis glycines (Hemiptera: Aphididae) is considered as a cosmopolitan pest of cultivated soybean, major difficulties in its control measures may be due to its higher genetic diversity; however, the knowledge about population genetic diversity of this species is limited. This study aimed to represent the genetic differentiation among different geographic populations of soybean aphid in Northeast China. In order to investigate and assess the genetic diversity, genetic differentiation, molecular variance, population structure, ecological importance and evolutionary history of A. glycines, we sequenced a fragment of one protein-coding gene, the cytochrome c oxidase I/of mitochondrial DNA gene. The results showed that four haplotypes were defined among CO 11 gene of 180 sequences of soybean aphid in Northeast China including H1 shared by all the populations. Lower haplotype diversity (Hd=0.3590± 0.0420) and nucleotide diversity (Pi=0.0012±0.0002) were observed and high gene flow was detected in every two populations, while most of the variation (80.81%) arose from variability within A. glycines from individuals. Low genetic differentiation and high gene flow (Nm=2.106) indicated a high migration rate between the populations, which might reveal that gene flow in different geographic populations did not affect by geographical distance. The phylogenetic tree and the haplotype network ofA. glycines were obtained based on sequences of CO Ⅱ gene, there were no significant genealogical branches or clusters recognized in NJ tree, and no clear distribution, delineation of haplotypes were demonstrated in the haplotype network according to geographical location. This study rejected the vicariance hypothesis: geographic isolation could be a barrier and it restricted A. glycines gene flow among 10 populations.
基金Supported by SIPT of Northeast Agricultural University(201410224069)the National Natural Science Foundation of China(31100304)"Academic Backbone" Project of Northeast Agricultural University(15XG01)
文摘This paper investigated effects of four ecological variables on the damage levels of elm leaf beetle (different effects of minimum and maximum values, relations between each two variables were also explored) and discussed current management measures. The results showed that among these factors, interval between elm trees significantly affected damage level by this leaf beetle species, and perimeter of elm trunk could change this effect. On the other side, while middle values for each index were deleted, effects comparison between minimum and maximum parts showed that good root soil as overwintering was related with more damage; more severe damages on elm tree would result in more control measures used; on elm tree with bigger mink, more damages were observed; and if other elm tree was closer, more damages would occur. Secondly, good root soil was related with more measures used; good root soil was correlated with smaller perimeter; good root soil was associated with bigger interval. Thirdly, more measures were correlated with bigger perimeter; more measures were also correlated with good root soil. Fourthly, bigger perimeter was correlated with worse root soil. Current dominant control measures included chemical pesticide application preventing adult insects from descending or climbing up along trunk before and after overwintering. These results suggested that we should focus on elm leaf beetle management on all the elm trees instead of only on bigger elm trees at proper period simultaneously because occurrence on these elm trees were related intensively although this adult elm leaf beetle species could not fly and had limited movement ability.
基金financially supported by the National Natural Science Foundations of China (Nos. 41831288 and51672257)the Fundamental Research Funds for the Central Universities (Nos. 2652018305 and 2652017335)+3 种基金Guangdong Innovation Research Team for Higher Education (No. 2017KCXTD030)the High-Level Talents Project of Dongguan University of Technology (No. KCYKYQD2017017)Engineering Research Center of None-food Biomass Efficient Pyrolysis and Utilization Technology of Guangdong Higher Education Institutes (No. 2016GCZX009)Russian Science Foundation (No. 19-77-10013)。
文摘Mineral apatite compounds have attracted significant interest due to their chemical stability and adjustable hexagonal structure,which makes them suitable as new photovoltaic functional materials.The band gap of natural apatite is ~5.45 eV,and such a large value limits their applications in the field of catalysis and energy devices.In this research,we designed a method to narrow the band gap via the tetrahedral substitution effect in apatite-based compounds.The density functional theory(DFT) and experimental investigation of the electronic and optical properties revealed that the continuous incorporation of [MO_(4)]^(4-) tetrahedrons(M=Si,Ge,Sn,and Mn) into the crystal lattice can significantly reduce the band gap.In particular,this phenomenon was observed when the[MnO_(4)]^(4-) tetrahedron replaces the [PO_(4)]^(4-) tetrahedron because of the formation of a Mn 3 d-derived conduction band minimum(CBM) and interacts with other elements,leading to band broadening and obvious reduction of the band gap.This approach allowed us to propose a novel scheme in the band gap engineering of apatite-based compounds toward an entire spectral range modification.
文摘Environmental safety issues involved in transgenic plants have become the concern of researchers, practitioners and policy makers in recent years. Potential differences between Bt maize(ND1324 and ND2353 expressing the insecticidal Cry1Ab protein) and near-isogenic non-Bt varieties(ND1392 and ND223) in their influence on the composite microbial system of MC1 during the fermentation process were studied during 2011-2012. Cry1Ab protein in Bt maize residues didn't affect characteristics of lignocellulose degradation by MC1, pH of fermentation broth decreasing at initial stage and increasing at later stage of degradation. The quality of various volatile products in fermentation broth showed that no signifi cant difference of residues fermentation existed between Bt maize and non-Bt maize. During the fermentation MC1 efficiently degraded maize residues by 83%-88%, and cellulose, hemicelluloses and lignin content decreased by 70%-72%, 72%-75% and 30%-37%, respectively. Besides that, no consistent difference was found between Bt and non-Bt maize residues lignocellulose degradation by MC1 during the fermentation process. MC1 degraded 88%-89% Cry1Ab protein in Bt maize residues, and in the fermentation broth of MC1 and bacteria of MC1 Cry1Ab protein was not detected. DGGE profi le analyses revealed that the microbial community drastically changed during 1-3 days and became stable until the 9th day. Though the dominant strains at different fermentation stages had signifi cantly changed, no difference on the dominant strains was observed between Bt and non-Bt maize at different stages. Our study indicated that Cry1Ab protein did not infl uence the growth characteristic of MC1.