X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS） analyses were carried out to investigate the surface species and interfacial reactions during bioleaching of chalcopyrite by different strains of ...X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS） analyses were carried out to investigate the surface species and interfacial reactions during bioleaching of chalcopyrite by different strains of moderately thermophilic bacteria （45 °C）. Results show that monosulfide （CuS）, disulfide （S22？）, polysulfide （Sn2？）, elemental sulfur （S0） and sulfate （SO42？） are the main intermediate species on the surface of chalcopyrite during bioleaching byA. caldus,S. thermosulfidooxidans andL. ferriphilum. The low kinetics of dissolution of chalcopyrite inA. caldus can be mainly attributed to the incomplete dissolution of chalcopyrite and the passivation layer of polysulfide. Polysulfide and jarosite should be mainly responsible for the passivation of chalcopyrite in bioleaching byL. ferriphilumorS. thermosulfidooxidans. However, elemental sulfur should not be the main composition of passivation layer of chalcopyrite during bioleaching.展开更多
Drought is a bottleneck for worldwide soybean production which is getting more serious as the climate continues to worsen. Dehydration responsive element binding（DREB） is a kind of transcription factor that regulate...Drought is a bottleneck for worldwide soybean production which is getting more serious as the climate continues to worsen. Dehydration responsive element binding（DREB） is a kind of transcription factor that regulates the expression of stress tolerance-related genes in response to drought, high salinity and cold stress in plant. Soybean with DREB gene possesses the drought resisting capability which is helpful to increase the yield. However, the potential risk of genetically modified plants（GMPs） on soil microbial community is still in debate. In order to understand the effects of transgenic DREB soybean on the nitrogen-fixing bacteria, the diversity of nif H gene in pot experiments planted transgenic soybean and near-isogenic nontransgenic soybean under normal water condition and drought stress condition was analyzed by PCR-DGGE and sequence analysis. The results showed that transgenic soybean under normal water condition decrease the diversity of the nitrogen-fixing bacteria in the seeding stage and flowering stage, but had no notable effect in other stages. Under drought stress, transgenic soybean reduced the diversity of the nitrogen-fixing bacteria in the flowering stage, but had no notable effects on other stages. Phylogenic analysis revealed that g7, g13, g15 and g19 had a close relationship with Alphaproteobacteria, g12 had a close relationship with Azonexus, others were related to Betaproteobacteria and Burkholderia.展开更多
Three different packaging materials of (37 cm × 25 cm) size (Sealed Transparent Polythene Bag (STPB) Sealed Paper Bag (SPB) (Brown envelope), Open Mouth Polythene Bag (OMPB) (Black incolour)) were used for Oreoch...Three different packaging materials of (37 cm × 25 cm) size (Sealed Transparent Polythene Bag (STPB) Sealed Paper Bag (SPB) (Brown envelope), Open Mouth Polythene Bag (OMPB) (Black incolour)) were used for Oreochromisniloticus (O), Clariasgariepinus (C) and Mormyrusrume (M). Twenty fish samples per species (averaging 250 gm) were hot smoked dried whole for 36 hours at an average temperature of 100?C. Packaged hot at the rate of 6 fishes per package for each species (three packs for each packaging treatment i.e. 18 pieces were packed while the remaining 2 pieces were used for initial bacteria load and microbial load). Microbial load (Total Viable Count (TVC), Total Coliform Count (TCC) and Total Fungi Count (TFC)) for the fresh fish was initial hot smoked and finally at the end of 12 weeks was monitored. The TVC (bacterial load) of O. niloticus dropped from (10.6 - 8.4) × 104 (fresh state-hot smoked) and M. rume (9.8 - 7.0) × 104, while C. gariepinus slightly increased from (12.4 - 12.6) × 104. After hot smoking, highest TVC of 8.6 × 104 (OMPBC), 8.3 × 104 (SPBC) and 8.2 × 104 (STPBC) were recorded in C. gariepinus among the 9 packag- ing at 12 weeks. However highest tendency for heavy TVC is in all OMPB with highest bacteria load in the OMPBC (8.6 × 104), 7.6 × 104 (OMPBO) and 6.6 × 104 (OMPBM). After 12 weeks highest ranged TFC of (0.6 - 0.7) × 104 was recorded in M. rume as against 0.2 × 104 recorded in the initial smoked for all. TCC was highest in C. gariepinus (4.0 - 4.3) × 104. Packaging did not limit the existence of micro-organisms. Six bacteria species (Micrococcus (acidiophilus, luteus), Bacillus (subtilis, cereus, aureus), Staphylococcus aureus, Streptococcus lactis, Proteus (vulgaricus, morganii), Pseudomonas aureginosa) and three fungi species (Aspergillus (niger, tamari), Rhizopusnigricans, fusariumoxysporum) were represented in all the packages. On the average five bacteria and two fungi species were represented, excepting for OMPBM and OMPBO with six bacteria species.展开更多
This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications mini...This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications minimize the use of herbicides and maximize the competitive interactions of native species. The management method includes two seasons of application of organic fertilizer （4-1-4）, an initial herbicide （Pasture Gard, Dow Agro） application, and mowing, where mowing was a necessary treatment to control secondary growth in prairie habitats, to control high density patches of Lespedeza （L.） Cuneata, in a completely randomized factorial experiment. The herbicide was effective in reducing L. Cuneate stem density 0 stems/m^2 from an initial 88 stems/m^2 with cover reduced to 0% from 16%. The fertilizer only treatment reduced L. Cuneata percent cover to 6% from initial cover of 16%, but did not reduce the number of stems. The management strategy is an effective fast step in restoring a native prairie invaded by a nitrogen-fixing plant.展开更多
In this study,the hydrothermal method was employed to grow submicron CuS on carbon cloth(CC),and the photoreduction method was used to grow Ag nanoparticles on the CuS submicron flowers,thus forming the Ag/CuS/CC cata...In this study,the hydrothermal method was employed to grow submicron CuS on carbon cloth(CC),and the photoreduction method was used to grow Ag nanoparticles on the CuS submicron flowers,thus forming the Ag/CuS/CC catalytic electrode.The application of Ag/CuS/CC electrode-coupled dielectric barrier discharge(DBD)plasma in the disinfection of pathogenic bacteria in water was studied.The Ag/CuS/CC electrode exhibits strong antibacterial activity,and under an external voltage of 30 V,the degradation efficiency of Bacillus subtilis reaches 99.99%within 15 min without regeneration.After five cycles,the inactivation rate of Bacillus subtilis reached 99.99%within 25 min.The practical applicability of the Ag/CuS/CC-coupled DBD system for treating actual wastewater was evaluated,and the changes in biological toxicity were investigated.The results indicate that the prepared Ag/CuS/CC coupled DBD has great potential for safe disinfection of pathogenic bacteria in water through integrated processes.展开更多
Ferula spp. are traditional medicinal plants found in arid land. Large-scale excavation for extracting bioactive compounds from the plants in arid regions of Xinjiang over the last few years has, however, significandy...Ferula spp. are traditional medicinal plants found in arid land. Large-scale excavation for extracting bioactive compounds from the plants in arid regions of Xinjiang over the last few years has, however, significandy decreased their distributions. Due to the urgent need for preservation of these plant resources, along with the need of searching for alternative source of the useful metabolites, it is important to screen the endophytic microbial resources associated with the plant Ferula sinkiangensis K. M. Shen. In the study, a total of 125 endophytic bacteria belonging to 3 phyla, 13 orders, 23 families, and 29 genera were isolated based on 16S rRNA gene sequencing data. Among the different isolates, three strains isolated from roots were potential novel species of the genera Porphyrobacter, Paracoccus and draycofatopsis. In this study, 79.4% and 57.1% of the total isolates were capable of producing indole-3-acetic acid （IAA） and siderophore, respectively. And, 40.6% of the strains inhibit the growth of fungal pathogen Afternaria alternata, 17.2% and 20.2% strains were positive for antagonism against Vertidllium dahlia 991 and V. dahlia 7, respectively. These results demonstrated that E sinkiangensis is a rich reservoir of endophytic bacterial resources with potential for production of biologically important functions such as plant growth-promoting factors.展开更多
Discrimination of different types of sulfur-containing species not only helps us to deeply understand how sulfur affects cellular signaling,but also contribute to the early diagnosis of diseases.However,the current in...Discrimination of different types of sulfur-containing species not only helps us to deeply understand how sulfur affects cellular signaling,but also contribute to the early diagnosis of diseases.However,the current investigation about sulfur-containing species discrimination is mainly concentrated in biothiols,which is relatively limited for practical application.Toward circumventing this limitation,herein,a convenient sensor array consisting of three kinds of Au NCs-Cu2+ for simultaneous and rapid identification of different types of sulfur-containing species is reported.Based on the fingerprint-like fluorescence responses generated by competitive binding between Au NCs-Cu2+ and different sulfurcontaining species,not only ten different types of sulfur-containing species separately but also their binary or ternary randomly selected mixtures can be well discriminated even in human urine and serum samples.It is worth noting that it only takes 2 min to obtain the best response signals for sulfurcontaining species discrimination.Most importantly,serums from cancer patients(such as liver cancer and breast cancer) and healthy people as well as sulfur-oxidizing bacteria(SOB) and sulfur-free bacteria can be both effectively and rapidly identified within 2 min,respectively,making it a promising approach for point-of-care disease diagnostic.展开更多
基金Projects(51374248,51320105006)supported by the National Natural Science Foundation of ChinaProject(NCET-13-0595)supported by the Program for New Century Excellent Talents in University,ChinaProject(2014T70692)supported by China Postdoctoral Science Foundation
文摘X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS） analyses were carried out to investigate the surface species and interfacial reactions during bioleaching of chalcopyrite by different strains of moderately thermophilic bacteria （45 °C）. Results show that monosulfide （CuS）, disulfide （S22？）, polysulfide （Sn2？）, elemental sulfur （S0） and sulfate （SO42？） are the main intermediate species on the surface of chalcopyrite during bioleaching byA. caldus,S. thermosulfidooxidans andL. ferriphilum. The low kinetics of dissolution of chalcopyrite inA. caldus can be mainly attributed to the incomplete dissolution of chalcopyrite and the passivation layer of polysulfide. Polysulfide and jarosite should be mainly responsible for the passivation of chalcopyrite in bioleaching byL. ferriphilumorS. thermosulfidooxidans. However, elemental sulfur should not be the main composition of passivation layer of chalcopyrite during bioleaching.
基金Supported by the Special Scientific Fund for Non-profit Environmental Industry(2010467038)
文摘Drought is a bottleneck for worldwide soybean production which is getting more serious as the climate continues to worsen. Dehydration responsive element binding（DREB） is a kind of transcription factor that regulates the expression of stress tolerance-related genes in response to drought, high salinity and cold stress in plant. Soybean with DREB gene possesses the drought resisting capability which is helpful to increase the yield. However, the potential risk of genetically modified plants（GMPs） on soil microbial community is still in debate. In order to understand the effects of transgenic DREB soybean on the nitrogen-fixing bacteria, the diversity of nif H gene in pot experiments planted transgenic soybean and near-isogenic nontransgenic soybean under normal water condition and drought stress condition was analyzed by PCR-DGGE and sequence analysis. The results showed that transgenic soybean under normal water condition decrease the diversity of the nitrogen-fixing bacteria in the seeding stage and flowering stage, but had no notable effect in other stages. Under drought stress, transgenic soybean reduced the diversity of the nitrogen-fixing bacteria in the flowering stage, but had no notable effects on other stages. Phylogenic analysis revealed that g7, g13, g15 and g19 had a close relationship with Alphaproteobacteria, g12 had a close relationship with Azonexus, others were related to Betaproteobacteria and Burkholderia.
文摘Three different packaging materials of (37 cm × 25 cm) size (Sealed Transparent Polythene Bag (STPB) Sealed Paper Bag (SPB) (Brown envelope), Open Mouth Polythene Bag (OMPB) (Black incolour)) were used for Oreochromisniloticus (O), Clariasgariepinus (C) and Mormyrusrume (M). Twenty fish samples per species (averaging 250 gm) were hot smoked dried whole for 36 hours at an average temperature of 100?C. Packaged hot at the rate of 6 fishes per package for each species (three packs for each packaging treatment i.e. 18 pieces were packed while the remaining 2 pieces were used for initial bacteria load and microbial load). Microbial load (Total Viable Count (TVC), Total Coliform Count (TCC) and Total Fungi Count (TFC)) for the fresh fish was initial hot smoked and finally at the end of 12 weeks was monitored. The TVC (bacterial load) of O. niloticus dropped from (10.6 - 8.4) × 104 (fresh state-hot smoked) and M. rume (9.8 - 7.0) × 104, while C. gariepinus slightly increased from (12.4 - 12.6) × 104. After hot smoking, highest TVC of 8.6 × 104 (OMPBC), 8.3 × 104 (SPBC) and 8.2 × 104 (STPBC) were recorded in C. gariepinus among the 9 packag- ing at 12 weeks. However highest tendency for heavy TVC is in all OMPB with highest bacteria load in the OMPBC (8.6 × 104), 7.6 × 104 (OMPBO) and 6.6 × 104 (OMPBM). After 12 weeks highest ranged TFC of (0.6 - 0.7) × 104 was recorded in M. rume as against 0.2 × 104 recorded in the initial smoked for all. TCC was highest in C. gariepinus (4.0 - 4.3) × 104. Packaging did not limit the existence of micro-organisms. Six bacteria species (Micrococcus (acidiophilus, luteus), Bacillus (subtilis, cereus, aureus), Staphylococcus aureus, Streptococcus lactis, Proteus (vulgaricus, morganii), Pseudomonas aureginosa) and three fungi species (Aspergillus (niger, tamari), Rhizopusnigricans, fusariumoxysporum) were represented in all the packages. On the average five bacteria and two fungi species were represented, excepting for OMPBM and OMPBO with six bacteria species.
文摘This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications minimize the use of herbicides and maximize the competitive interactions of native species. The management method includes two seasons of application of organic fertilizer （4-1-4）, an initial herbicide （Pasture Gard, Dow Agro） application, and mowing, where mowing was a necessary treatment to control secondary growth in prairie habitats, to control high density patches of Lespedeza （L.） Cuneata, in a completely randomized factorial experiment. The herbicide was effective in reducing L. Cuneate stem density 0 stems/m^2 from an initial 88 stems/m^2 with cover reduced to 0% from 16%. The fertilizer only treatment reduced L. Cuneata percent cover to 6% from initial cover of 16%, but did not reduce the number of stems. The management strategy is an effective fast step in restoring a native prairie invaded by a nitrogen-fixing plant.
基金funded by the National College Student Innovation and Entrepreneurship Training Program(No.GJ202323011)。
文摘In this study,the hydrothermal method was employed to grow submicron CuS on carbon cloth(CC),and the photoreduction method was used to grow Ag nanoparticles on the CuS submicron flowers,thus forming the Ag/CuS/CC catalytic electrode.The application of Ag/CuS/CC electrode-coupled dielectric barrier discharge(DBD)plasma in the disinfection of pathogenic bacteria in water was studied.The Ag/CuS/CC electrode exhibits strong antibacterial activity,and under an external voltage of 30 V,the degradation efficiency of Bacillus subtilis reaches 99.99%within 15 min without regeneration.After five cycles,the inactivation rate of Bacillus subtilis reached 99.99%within 25 min.The practical applicability of the Ag/CuS/CC-coupled DBD system for treating actual wastewater was evaluated,and the changes in biological toxicity were investigated.The results indicate that the prepared Ag/CuS/CC coupled DBD has great potential for safe disinfection of pathogenic bacteria in water through integrated processes.
基金supported by the National Natural Science Foundation of China(U1403101,31200008)the China Postdoctoral Science Foundation(2016M602566)+3 种基金the Visiting Scholar Grant of State Key Laboratory of Biocontrol,Sun Yat-Sen University(SKLBC14F02)the West Light Foundation of the Chinese Academy of Sciencessupported by Hundred Talents Program of the Chinese Academy of SciencesGuangdong Province Higher Vocational Colleges & Schools Pearl River Scholar Funded Scheme(2014)
文摘Ferula spp. are traditional medicinal plants found in arid land. Large-scale excavation for extracting bioactive compounds from the plants in arid regions of Xinjiang over the last few years has, however, significandy decreased their distributions. Due to the urgent need for preservation of these plant resources, along with the need of searching for alternative source of the useful metabolites, it is important to screen the endophytic microbial resources associated with the plant Ferula sinkiangensis K. M. Shen. In the study, a total of 125 endophytic bacteria belonging to 3 phyla, 13 orders, 23 families, and 29 genera were isolated based on 16S rRNA gene sequencing data. Among the different isolates, three strains isolated from roots were potential novel species of the genera Porphyrobacter, Paracoccus and draycofatopsis. In this study, 79.4% and 57.1% of the total isolates were capable of producing indole-3-acetic acid （IAA） and siderophore, respectively. And, 40.6% of the strains inhibit the growth of fungal pathogen Afternaria alternata, 17.2% and 20.2% strains were positive for antagonism against Vertidllium dahlia 991 and V. dahlia 7, respectively. These results demonstrated that E sinkiangensis is a rich reservoir of endophytic bacterial resources with potential for production of biologically important functions such as plant growth-promoting factors.
基金support from the National Nature Science Foundation of China(Nos.21675093,21505081 and 21974075)the Natural Science Foundation of Shandong Province of China(No.ZR2019YQ13)+1 种基金the Science and Technology Support Plan for Youth Innovation of Colleges and Universities in Shandong Province(No.2019KJC007)the Taishan Scholar Program of Shandong Province,China(No.ts20110829)。
文摘Discrimination of different types of sulfur-containing species not only helps us to deeply understand how sulfur affects cellular signaling,but also contribute to the early diagnosis of diseases.However,the current investigation about sulfur-containing species discrimination is mainly concentrated in biothiols,which is relatively limited for practical application.Toward circumventing this limitation,herein,a convenient sensor array consisting of three kinds of Au NCs-Cu2+ for simultaneous and rapid identification of different types of sulfur-containing species is reported.Based on the fingerprint-like fluorescence responses generated by competitive binding between Au NCs-Cu2+ and different sulfurcontaining species,not only ten different types of sulfur-containing species separately but also their binary or ternary randomly selected mixtures can be well discriminated even in human urine and serum samples.It is worth noting that it only takes 2 min to obtain the best response signals for sulfurcontaining species discrimination.Most importantly,serums from cancer patients(such as liver cancer and breast cancer) and healthy people as well as sulfur-oxidizing bacteria(SOB) and sulfur-free bacteria can be both effectively and rapidly identified within 2 min,respectively,making it a promising approach for point-of-care disease diagnostic.
