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Low-Temperature Synthesis of Nano-AlN Based on Solid Nitrogen Source by Plasma-Assisted Ball Milling
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作者 Zhuoli Yang Xianbin Hou Leyang Dai 《Journal of Renewable Materials》 SCIE EI 2023年第6期2941-2951,共11页
Plasma-assisted ball milling was carried out on the Al+C3H6N6 system and Al+C_(4)H_(4)N_(4) system,respectively.The phase structure,functional groups and synthesis mechanism were analyzed by XRD and FT-IR,and the diff... Plasma-assisted ball milling was carried out on the Al+C3H6N6 system and Al+C_(4)H_(4)N_(4) system,respectively.The phase structure,functional groups and synthesis mechanism were analyzed by XRD and FT-IR,and the differences in the synthesis process of nano-AlN with different solid nitrogen sources were discussed.The results show that C3H6N6 has a stable triazine ring structure,and its chemical bond is firm and difficult to break,so AlN cannot be synthesized directly by solid-solid reaction at room temperature.However,there are a large number of nitrile groups(-CN)and amino groups(-NH_(2))in C_(4)H_(4)N_(4) molecules.Under the combined action of plasma bombardment and mechanical energy activation,C_(4)H_(4)N_(4) molecules undergo polycondensation and deamination,so that the ball milling tank is filled with a large number of active nitrogen-containing groups such as N=,≡N,etc.These groups and ball milling activated Al can synthesize nano-AlN at room temperature,with a conversion rate of 92%.SEM,DSC/TG analysis showed that the powder obtained by ball milling was formed by soft agglomeration of many fine primary particles about 50–80 nm.The surface morphology of the powder was loose and porous,and it had strong activity.After annealing at 800℃,the conversion rate of the Al+C_(4)H_(4)N_(4) system reached 99%. 展开更多
关键词 Plasma-assisted ball milling solid nitrogen source melamine(C_(3)H_(6)N_(6)) aluminum nitride(AlN) low-temperature synthesis
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The pH change in rhizosphere of Pinus koraiensis seedlings as af-fected by different nitrogen sources and its effect on phosphorus availability
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作者 陈永亮 韩士杰 +2 位作者 邹春静 周玉梅 于霞 《Journal of Forestry Research》 SCIE CAS CSCD 2001年第4期247-249,277,共4页
Root mat method described by Kuchenbuch and Jungk was used to study the rhizosphere processes. The experi-ment was carried out on two years old Pinus koraiensis seedlings. Soil samples collected from the upper 20-cm s... Root mat method described by Kuchenbuch and Jungk was used to study the rhizosphere processes. The experi-ment was carried out on two years old Pinus koraiensis seedlings. Soil samples collected from the upper 20-cm soil layer in Changbai Mountain were treated with three different forms of nitrogen fertilizers: NO3--N, NH4+-N and NH4NO3. The results showed that the soil pH and available P near the roots were all lower than in the bulk soil in control treatment. NH4+-N applica-tion greatly decreased the soil pH near the roots compared to the control treatment and promoted the absorption of phosphorus, which led to a more remarkable depletion region of available P. On the contrary, the rhizosphere soil pH was higher than in the bulk soil in treatments with NO3--N and retarded the P absorption, which led to a nearly equal available P contents to the bulk soil. In treatment with NH4NO3, the rhizosphere soil pH was only a little lower than that in the control treatment and its effects on P absorption is mediate between the treatments with NH4+-N and NO3--N. 展开更多
关键词 nitrogen sources Rhizosphere pH Available P
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The Effects of Three Mineral Nitrogen Sources and Zinc on Maize and Wheat Straw Decomposition and Soil Organic Carbon 被引量:8
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作者 Ogunniyi Jumoke Esther GUO Chun-hui +2 位作者 TIAN Xiao-hong LI Hong-yun ZHOU Yang-xue 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第12期2768-2777,共10页
The incorporation of straw in cultivated ifelds can potentially improve soil quality and crop yield. However, the presence of recalcitrant carbon compounds in straw slow its decomposition rate. The objective of this s... The incorporation of straw in cultivated ifelds can potentially improve soil quality and crop yield. However, the presence of recalcitrant carbon compounds in straw slow its decomposition rate. The objective of this study was to determine the effects of different nitrogen sources, with and without the application of zinc, on straw decomposition and soil quality. Soils were treated with three different nitrogen sources, with and without zinc: urea (CO(NH2)2), ammonium sulfate ((NH4)2SO4), and ammonium chloride (NH4Cl). The combined treatments were as follows:maize (M) and wheat (W) straw incorporated into urea-, ammonium sulfate-, or ammonium chloride-treated soil (U, S, and C, respectively) with and without zinc (Z) (MU, MUZ, WU, WUZ;MS, MSZ, WS, WSZ;MC, MCZ, WC, WCZ, respectively);straw with zinc only (MZ, WZ);straw with untreated soil (MS, WS);and soil-only or control conditions (NT). The experiment consisted of 17 treatments with four replications. Each pot contained 150 g soil and 1.125 g straw, had a moisture content of 80%of the ifeld capacity, and was incubated for 53 days at 25°C. The rates of CO2-C emission, cumulative CO2-C evolution, total CO2 production in the soils of different treatments were measured to infer decomposition rates. The total organic carbon (TOC), labile organic carbon (LOC), and soil microbial biomass in the soils of different treatments were measured to infer soil quality. All results were signiifcantly different (P〈0.05) with the exception of the labile organic carbon (LOC). The maize and wheat straw showed different patterns in CO2 evolution rates. For both straw types, Zn had a synergic effect with U, but an antagonistic effect with the other N sources as determined by the total CO2 produced. The MUZ treatment showed the highest decomposition rate and cumulative CO2 concentration (1 120.29 mg/pot), whereas the WACZ treatment had the lowest cumulative CO2 concentration (1 040.57 mg/pot). The addition of NH4Cl resulted in the highest total organic carbon (TOC) concentration (11.59 mg kg-1). The incorporation of wheat straw resulted in higher microbial biomass accumulation in soils relative to that of the maize straw application. The results demonstrate that mineral N sources can affect the ability of microorganisms to decompose straw, as well as the soil carbon concentrations. 展开更多
关键词 nitrogen sources ZINC carbon fractions straw mineralization wheat straw maize straw LOC
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Studies on optimization of nitrogen sources for astaxanthin production by Phaffia rhodozyma 被引量:7
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作者 NI Hui CHEN Qi-he +5 位作者 RUAN Hui YANG Yuan-fan LI Li-jun WU Guang-bin Hid Yang HE Guo-qing 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2007年第5期365-370,共6页
Fermentation of Phaffia rhodozyma is a major method for producing astaxanthin, an important pigment with industrial and pharmaceutical application. To improve astaxanthin productivity, single factor and mixture design... Fermentation of Phaffia rhodozyma is a major method for producing astaxanthin, an important pigment with industrial and pharmaceutical application. To improve astaxanthin productivity, single factor and mixture design experiments were used to investigate the effects of nitrogen source on Phaffia rhodozyma cultivation and astaxanthin production. Results of single factor experiments showed nitrogen source could significantly affect P. rhodozyma cultivation with respect to carbon source utilization, yeast growth and astaxanthin accumulation. Further studies of mixture design experiments using (NH4)2SO4, KNO3 and beef extract as nitrogen sources indicated that the proportion of three nitrogen sources was very important to astaxanthin production. Validation experiments showed that the optimal nitrogen source was composed of 0.28 g/L (NH4)2SO4, 0.49 g/L KNO3 and 1.19 g/L beef extract. The kinetic characteristics of batch cultivation were investigated in a 5-L pH-stat fermentor. The maximum amount of biomass and highest astaxanthin yield in terms of volume and in terms of biomass were 7.71 mg/L and 1.00 mg/g, respectively. 展开更多
关键词 Phaffia rhodozyma ASTAXANTHIN nitrogen source OPTIMIZATION
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Preliminary Study on the Responses of Three Marine Algae,Ulva pertusa(Chlorophyta),Gelidium amansii(Rhodophyta)and Sargassum enerve(Phaeophyta),to Nitrogen Source and Its Availability 被引量:5
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作者 LIUDongyan AmyPickering SUNJun 《Journal of Ocean University of China》 SCIE CAS 2004年第1期75-79,共5页
An experiment was designed to select economically valuable macroalga species with high nutrient uptake rates. Such species cultured on a large scale could be a potential solution to eutrophication. Three macroalgae sp... An experiment was designed to select economically valuable macroalga species with high nutrient uptake rates. Such species cultured on a large scale could be a potential solution to eutrophication. Three macroalgae species, Ulva pertusa (Chlorophyta), Gelidium amansii (Rhodophyta) and Sargassum enerve (Phaeophyta), were chosen for the experiment because of their economic values and availability. Control and four nitrogen concentrations were achieved by adding NH + 4 and NO - 3. The results indicate that the fresh weights of all species increase faster than that of control after 5 d culture. The fresh weight of Ulva pertusa increases fastest among the 3 species. However, different species show different responses to nitrogen source and its availability. They also show the advantage of using NH + 4 than using NO - 3. U. pertusa grows best and shows higher capability of removing nitrogen at 200 μmol L -1 , but it has lower economical value. G. amansii has higher economical value but lower capability of removing nitrogen at 200 μmol L -1 . The capability of nitrogen assimilation of S. enerve is higher than that of G. amansii at 200 μmol L -1 , but the former’s increase of fresh weight is lower than those of other two species. Then present preliminary study demonstrates that it is possible to use macroalgae as biofilters and further development of this approach could provide biologically valuable information on the source, fate, and transport of N in marine ecosystems. Caution is needed should we extrapolate these findings to natural environments. 展开更多
关键词 MACROALGAE nitrogen source EUTROPHICATION nutrient uptaking
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Effects of Different Nitrogen Sources and Metal Ions on Biogas Generation by Corn Stalk Fermentation
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作者 齐辉阳 黄世臣 +1 位作者 王慧 李文浩 《Agricultural Science & Technology》 CAS 2016年第11期2525-2528,共4页
[Objective] The present study was conducted to explore the effects of dif- ferent nitrogen sources and metal ions on the biogas production process and biogas yield by fermentation of corn stalk powder using self-desig... [Objective] The present study was conducted to explore the effects of dif- ferent nitrogen sources and metal ions on the biogas production process and biogas yield by fermentation of corn stalk powder using self-designed anaerobic fermenta- tion system. [Method] The biogas produced during fermentation was collected by water displacement, and measured by ignition. [Result] Ammonium bicarbonate, urea and yeast extract powder all increased biogas yield. Among them, ammonium bi- carbonate was the best nitrogen source. Ammonium dihydrogen phosphate showed an inhibitory effect on biogas production. Biogas yield was significantly increased by adding NaCl, KCl, MgCl2 or CaCl2, among which, NaCl had the best effect. [Conclu- sion] It is not conducive to the growth and development of methanogenic flora in the production of biogas using corn stalks as the only material in fermentation. The biogas yield can be increased by adding exogenous nitrogen, which reduces the carbon to nitrogen (C:N) ratio of fermentation materials. The biogas yield can be significantly increased by adding appropriate types and amount of electrolytes, with appropriate C:N ratio. The methanogenic flora is more tolerant to NaCl and KCl than to MgCl2 and CaCl2. Moreover, NaCl can not only significantly increase the biogas production, but also shorten startup period of methanogenic flora, thereby shortening the gas producing cycle. 展开更多
关键词 FERMENTATION Corn stalk BIOGAS nitrogen source Metal ion
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Effect of Nitrogen Sources on the Growth and Docosahexaenoic Acid Accumulation in Crypthecodinium cohnii 被引量:3
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作者 王菊芳 吴海珍 +1 位作者 梁世中 陈峰 《Marine Science Bulletin》 CAS 2002年第1期87-92,共6页
The effect of various nitrogen sources on the growth and docosahexaenoic acid (DHA) yield is determined in Crypthecodinium cohnii ATCC30556. Single nitrogen tryptone and peptone are suitable to growth, the dry weight ... The effect of various nitrogen sources on the growth and docosahexaenoic acid (DHA) yield is determined in Crypthecodinium cohnii ATCC30556. Single nitrogen tryptone and peptone are suitable to growth, the dry weight biomass is up to 2.78 g/L and 2.70g/L respectively on medium containing 0.34 g/L nitrogen. Peptone is a favorable nitrogen source for DHA accumulation, DHA yield increases up to 338.56 mg/L. Using peptone and KNO3 as a multiple nitrogen source, the highest biomass and DHA yield are obtained from media containing 0.34 g/L nitrogen in which the ratio of peptone-N:NO3--N is 1:2,and the biomass and DHA yield are 2.98 g/L(DW) and 527.97mg/L respectively. 展开更多
关键词 nitrogen sources Crypthecodinium cohnii DHA BIOMASS
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Influence comparison of N2 and NH3 nitrogen sources on AlN films grown by halide vapor phase epitaxy 被引量:1
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作者 Jing-Jing Chen Jun Huang +2 位作者 Xu-Jun Su Mu-Tong Niu Ke Xu 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第7期428-432,共5页
A comparison of the nitrogen sources(N2 and NH3)influence on AlN films grown by high-temperature halide vapor phase epitaxy(HVPE)is reported.The x-ray rocking curves(XRCs)indicate that the full width at half maximum(F... A comparison of the nitrogen sources(N2 and NH3)influence on AlN films grown by high-temperature halide vapor phase epitaxy(HVPE)is reported.The x-ray rocking curves(XRCs)indicate that the full width at half maximum(FWHM)of(0002)plane for AlN films using N2 as nitrogen source is generally smaller than that using NH3.Optical microscope and atomic force microscope(AFM)results show that it is presently still more difficult to control the crack and surface morphology of AlN films with thicknesses of 5-10µm using N2 as the nitrogen source compared to that using NH3.Compared with one-step growth,two-step growth strategy has been proved more effective in stress control and reducing the density of threading dislocations for AlN epilayers using N2 as the nitrogen source.These investigations reveal that using N2 as nitrogen source in HVPE growth of AlN is immature at present,but exhibits great potential. 展开更多
关键词 aluminum nitride halide vapor phase epitaxy surface structure nitrogen source
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Effects of Carbon and Nitrogen Additions on Soil Microbial Biomass Carbon and Enzyme Activities Under Rice Straw Returning 被引量:1
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作者 Dai Jian-jun Liu Li-zhi +4 位作者 Wang Xiao-chun Fang Qiu-na Cheng Ye-ru Wang Dan-ni Peng Xian-long 《Journal of Northeast Agricultural University(English Edition)》 CAS 2021年第3期21-30,共10页
The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw retur... The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw returning to the field,and the mechanism of the decomposition of rice straw returning to the field was discussed.Completely randomized experiment of the two factors of the three levels was designed,and a total of nine treatments of indoor soil incubation tests were conducted.Full amount of rice straw was applied to the soil in this simulation experiment and different amounts of brown sugar and urea were added in the three levels of 0(no carbon source and nitrogen source),1(low levels of carbon and nitrogen sources)and 2(high levels of carbon and nitrogen sources),respectively.The results showed that the addition of different amounts of carbon and nitrogen sources to the rice straw could increase the soil carbon content.Compared with T0N0,the microbial biomass carbon of T2N2 was increased significantly by 170.48%;the dissolved organic carbon content of T1N2 was significantly increased by 58.14%and the free humic acid carbon contents of T0N2,T1N1 and T2N0 were significantly increased by 56.16%and 45.55%and 47.80%,respectively;however,there were no significant differences among those of treatments at later incubation periods.The addition of different carbon and nitrogen sources could promote the soil enzyme activities.During the incubation period,all of the soil enzyme activities of adding sugar and urea were higher than those of T0N0 treatment.Therefore,the addition of different amounts of carbon and nitrogen sources to rice straw returning could improve soil microbial biomass carbon content,dissolved organic carbon and soil enzyme activities. 展开更多
关键词 rice straw returning carbon and nitrogen sources microbial biomass carbon dissolved organic carbon soil enzyme activity
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Non-Point-Source Nitrogen and Phosphorus Loadings from a Small Watershed in the Three Gorges Reservoir Area 被引量:25
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作者 ZHU BO WANG Zhenhua +1 位作者 WANG Tao DONG Zhixin 《Journal of Mountain Science》 SCIE CSCD 2012年第1期10-15,共6页
Non-point-source pollution has become a major threat to the water quality of the Three Gorges Reservoir(TGR);however,nutrient loadings from terrestrial sources are unclear due to a lack of in situ monitoring.A represe... Non-point-source pollution has become a major threat to the water quality of the Three Gorges Reservoir(TGR);however,nutrient loadings from terrestrial sources are unclear due to a lack of in situ monitoring.A representative small watershed in the central part of the TGR area was selected to monitor the loss of nitrogen(N) and phosphorous(P) continuously along with the runoff from 2007 through 2009 to understand the exact sources and loadings.Results show that the non-point-source nitrogen and phosphorus comes mainly from the storm runoff from residential areas,citrus orchards and sloping croplands,which contributes up to 76% of the loadings in this watershed.Thus,a crucial measure for controlling non-point-source pollution is to intercept storm runoff from the three sources.Paddy fields provide a sink for non-point-source N and P by intercepting the runoff and sediment along with their different forms of nitrogen and phosphorus.The N and P removal efficiency by paddy fields from residential areas is within the range of 56% to 98%.Paddy fields are an important land-use option for reducing the non-point-source loading of N and P in the TGR area. 展开更多
关键词 Non-point-source pollution Source and sink nitrogen Phosphorus Paddy fields Three Gorges Reservoir area China
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Influence of nitrogen sources on growth and mycotoxin production by isolates of Pyrenophora tritici-repentis from wheat
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作者 Noureddine Bouras Michael D.Holtz +1 位作者 Reem Aboukhaddour Stephen E.Strelkov 《The Crop Journal》 CAS CSCD 2016年第2期119-128,共10页
The fungus Pyrenophora tritici-repentis(Died.) Drechs. infects the leaves and kernels of wheat,causing tan spot and red smudge, respectively. Isolates of P. tritici-repentis have been reported to be both phytopathogen... The fungus Pyrenophora tritici-repentis(Died.) Drechs. infects the leaves and kernels of wheat,causing tan spot and red smudge, respectively. Isolates of P. tritici-repentis have been reported to be both phytopathogenic and mycotoxigenic. This research investigates the influence of nitrogen sources on growth and production of mycotoxins by eight different isolates of P. tritici-repentis. A synthetic agar medium(SAM) was used with different nitrogen sources, both inorganic [(NH4Cl, NH4NO3and(NH4)2SO4)] and organic(L-alanine, L-histidine, and L-lysine), at a concentration of 37.5 mmol L-1. Individual isolates exhibited different growth rates that varied according to the nitrogen source added to the medium. The choice of nitrogen source also had a major effect on production of the mycotoxins emodin, catenarin and islandicin. The highest concentrations of emodin, 54.40 ± 4.46 μg g-1, 43.07 ± 23.39 μg g-1and28.91 ± 4.64 μg g-1of growth medium, were produced on the complex medium(V8-potato dextrose agar) by the isolates Alg-H2, 331-2 and TS93-71 B, respectively. A relatively high concentration of emodin also was produced by isolates Az35-5(28.29 ± 4.71 μg g-1of medium)and TS93-71B(27.03 ± 4.09 μg g-1of medium) on synthetic medium supplemented with L-alanine. The highest concentrations of catenarin(174.54 ± 14.46 μg g-1and 104.87 ±6.13 μg g-1of medium) were recorded for isolates TS93-71 B and Alg-H2 on synthetic medium supplemented with L-alanine and NH4 Cl, respectively. The highest concentration of islandicin(4.64 ± 0.36 μg g-1medium) was observed for isolate 331-2 in the presence of L-lysine. There was not a close relationship between mycelial growth and mycotoxin production by the fungal isolates. This is the first report on the influence of nitrogen sources on the production of mycotoxins by P. tritici-repentis. 展开更多
关键词 Catenarin EMODIN Islandicin nitrogen source Tan spot Triticum aestivum
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A NEW FACILE METHOD FOR THE SYNTHESIS OF AZACROWN ETHERS BY USING BENZYLSULFONAMIDE AS A SOURCE OF NITROGEN
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作者 Shu HUANG Bao Zhi TIAN Department of Chemistry,Sichuan University,Chengdu 610064 Shou Jun HOU Shu Mian LI Department of Chemical Engineering Chemistry,Zhengzhou Light Industry Institute,Zhengzhou 450002 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第12期963-964,共2页
Benzylsulfonamide was used as a source of nitrogen in the syn- thesis of azacrown ethers,and the cyclic intermediates were easily deben- zylsulfonylated by treating with CaF_2/H_2SO_4 to afford the azacrown ethers.
关键词 AS A NEW FACILE METHOD FOR THE SYNTHESIS OF AZACROWN ETHERS BY USING BENZYLSULFONAMIDE AS A SOURCE OF nitrogen
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Effects of Medium Nutrients on Fusarium oxysporum Schl. f.sp 被引量:1
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作者 苏贤岩 王齐 +2 位作者 王学峰 蒋春荣 韩金先 《Agricultural Science & Technology》 CAS 2012年第1期162-167,共6页
[Objective] To study the effects of different culture conditions on the Fusarium oxysporurn SchL f. sp. [Method] Based on species identification of the pathogenic organism of Fusarium oxysporum Schl. f. sp, effects of... [Objective] To study the effects of different culture conditions on the Fusarium oxysporurn SchL f. sp. [Method] Based on species identification of the pathogenic organism of Fusarium oxysporum Schl. f. sp, effects of different cultures and different nutrients on the mycelial growth and conidial production of Fusarium oxysporum SchL f. sp were studied. [Result] The mycelial growth and conidial pro- duction of Fusarium oxysporum SchL f. sp was different under different culture con- ditions. PDA medium was the most suitable medium for the mycelial growth and had the highest conidial production; and the mycelial grew the fastest on the medium with maltose as carbon source or peptone as nitrogen source, which also had the highest conidial production. [Conclusion] This study provided experimental basis for the study of Fusarium oxysporum SchL f. sp and also provided theoretical basis for the study and control of Fusarium oxysporum Schl. f. sp. 展开更多
关键词 Fusarium oxysporum Schl f. sp MEDIUM Carbon source nitrogen source Mycelial growth Conidial production
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Optimal Controlling for Fermentation Process of Threonine-producing Strain Overexpressing rhtB Gene
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作者 孔晶 贾建波 +2 位作者 吴洁 赵玉萍 陈军 《Agricultural Science & Technology》 CAS 2012年第4期701-703,共3页
[Objective] The aim was to construct threonine-producing strain M122 overexpressing key gene rhtB for transporter protein to transport threonine to the extracellular, and to investigate effects of different carbon or ... [Objective] The aim was to construct threonine-producing strain M122 overexpressing key gene rhtB for transporter protein to transport threonine to the extracellular, and to investigate effects of different carbon or nitrogen sources and pH values on L-threonine production caused by the recombinant strain. [Method] The fermentation process of L-threonine-producing strain was analyzed by different carbon or nitrogen sources, and carbon or nitrogen sources and pH in fermentation medium were also optimized in this study. [Result] After direct modification, the uti- lization efficiency of threonine-producing strain on nutrients increases. When sucrose was used as carbon source for fermentation, Lothreonine yield via shaking culture was 28.1 g/L When (NH4)2SO4 or yeast powder was used as nitrogen source for fermenta- tion, L-threonine yield was 27.8 and 28.2 g/L respectively, which were all higher than that of other nitrogen sources. The study on optimal pH value showed that it was more beneficial for strain growth and L-threonine yield on neutral condition. [Conclusion] The best carbon source for threonine-produing strain M122 was sucrose, while the best nitrogen source was (NH4)2804 or yeast powder, and the most suit- able pH value was 7.0. 展开更多
关键词 rhtB gene L-THREONINE FERMENTATION Carbon source nitrogen source
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Characteristics and Culture Conditions of a Bioflocculant Produced by Penicillium sp. 被引量:12
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作者 LI-FAN LIU WEN CHENG 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2010年第3期213-218,共6页
Objective To study the characteristics of a bioflocculant named MBF7 produced by Penicillum strain HHE-P7 and the effects of cultivation conditions on bioflocculant production. Methods The chemical group in the bioflo... Objective To study the characteristics of a bioflocculant named MBF7 produced by Penicillum strain HHE-P7 and the effects of cultivation conditions on bioflocculant production. Methods The chemical group in the bioflocculant molecules was shown by Fourier transform infrared (FTIR) spectra, and the average molecular weight of MBF7 was estimated by gel permeation chromatography. The effects of medium components on bioflocculant production and flocculating activity were studied. Results Phospho-, amino-, hydroxyl, and carboxyl groups were the major fractions of MBF7, and the molecule weight was about 3.0 × 10^5 Da. In addition, the carbon and nitrogen sources favorable for the bioflocculant production were glucose and yeast extract respectively. When the initial pH of the medium was adjusted to 5.0, high flocculant efficiency could be achieved. Conclusion The bioflocculant MBF7 is a new macromolecule with high flocculating efficiency for Kaolin suspension, and could be produced under appropriate culture conditions. 展开更多
关键词 BIOFLOCCULANT Penicillium sp. Flocculating activity Carbon and nitrogen sources
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Enhancement of Laccase Activity by Marine-derived Deuteromycete Pestalotiopsis sp. J63 with Agricultural Residues and Inducers 被引量:10
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作者 冯晓雨 陈慧英 +1 位作者 薛栋升 姚善泾 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第10期1182-1189,共8页
Pestalotiopsis sp. J63, producing a high activity of laccase, is a new marine-derived fungus isolated from the oceanic sediment of the East China Sea. Since the marine environment is oligotrophic nutrient, marine deri... Pestalotiopsis sp. J63, producing a high activity of laccase, is a new marine-derived fungus isolated from the oceanic sediment of the East China Sea. Since the marine environment is oligotrophic nutrient, marine derived fungi may use small amount of nutrients to grow and produce laccases. Agricultural residues that are mainly composed of lignin, cellulose and hemicellulose are difficult to be degraded and few microbes can take them as substrates, so they are considered as oligotrophic nutrient and have the potential to be used to produce value added products. In this study, the ability of Pestalotiopsis sp. J63 to use agricultural residues to produce laccases was tested in the submerged fermentation. The combination of 3 g·L 1maltose and 20 g·L 1rice straw was the best carbon sources and 8 g·L 1ammonium sulfate was the best nitrogen source under the condition without inducers. The effects of five inducers, the feeding time and concentration of inducer on laccase production were investigated.Adding 0.09 mmol·L 1phenol after 24 h of incubation led to high laccase activity(5089 U·L 1), while with 0.09mmol·L 1phenol in the medium and wheat bran as the nitrogen source, the laccase activity could reach 5791.7U·L 1. Native-PAGE results showed that two laccase isozymes were present in the cultures. One existed in both induced and non-induced culture filtrates, while the other was only found in the fermentation with the addition of phenol, guaiacol and veratryl alcohol. 展开更多
关键词 laccase isozyme Pestalotiopsis sp. marine microorganism carbon and nitrogen source inducer
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Production of polyhydroxybutyrate by the marine photosynthetic bacterium Rhodovulum sulfidophilum P5 被引量:2
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作者 才金玲 魏莹 +2 位作者 赵宇鹏 潘光华 王广策 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第4期620-626,共7页
The effects of different NaCl concentrations, nitrogen sources, carbon sources, and carbon to nitrogen molar ratios on biomass accumulation and polyhydroxybutyrate (PHB) production were studied in batch cultures of ... The effects of different NaCl concentrations, nitrogen sources, carbon sources, and carbon to nitrogen molar ratios on biomass accumulation and polyhydroxybutyrate (PHB) production were studied in batch cultures of the marine photosynthetic bacterium Rhodovulum sulfidophilum P5 under aerobic-dark conditions. The results show that the accumulation of PHB in strain P5 is a growth-associated process. Strain P5 had maximum biomass and PHB accumulation at 2%-3% NaCl, suggesting that the bacterium can maintain growth and potentially produce PHB at natural seawater salinity. In the nitrogen source test, the maximum biomass accumulation (8.10±0.09 g/L) and PHB production (1.11±0.13 g/L and 14.62%±2.25% of the cell dry weight) were observed when peptone and ammonium chloride were used as the sole nitrogen source. NH^-N was better for PHB production than other nitrogen sources. In the carbon source test, the maximum biomass concentration (7.65±0.05 g/L) was obtained with malic acid as the sole carbon source, whereas the maximum yield of PHB (5.03±0.18 g/L and 66.93%± 1.69% of the cell dry weight) was obtained with sodium pyruvate as the sole carbon source. In the carbon to nitrogen ratios test, sodium pyruvate and ammonium chloride were selected as the carbon and nitrogen sources, respectively. The best carbon to nitrogen molar ratio for biomass accumulation (8.77±0.58 g/L) and PHB production (6.07±0.25 g/L and 69.25%±2.05% of the cell dry weight) was 25. The results provide valuable data on the production of PHB by R. sulfidophilum P5 and further studies are on-going for best cell growth and PHB yield. 展开更多
关键词 POLYHYDROXYBUTYRATE Rhodovulum sulfidophilum nitrogen source carbon source carbon tonitrogen molar ratio
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Influences of dietary protein sources and crude protein levels on intracellular free amino acid profile in the longissimus dorsi muscle of finishing gilts 被引量:13
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作者 Chunfu Qin Ping Huang +4 位作者 Kai Qiu Wenjuan Sun Ling Xu Xin Zhang Jingdong Yin 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2016年第2期184-193,共10页
Background: The current study was carried out to determine effects of dietary protein source and crude protein(CP)level on carcass characteristics, meat quality, and muscle amino acid(AA) profile in finishing gil... Background: The current study was carried out to determine effects of dietary protein source and crude protein(CP)level on carcass characteristics, meat quality, and muscle amino acid(AA) profile in finishing gilts. The experiment was designed as a 2 × 2 factorial arrangement with two sources of dietary proteins(cottonseed meal, CSM vs. soybean meal, SBM) and two levels of CP(12 % vs. 14 %, as-fed basis). Seventy-two crossbred gilts(89.5 ± 0.9 kg) were allotted to one of four dietary treatments in a randomized complete block design for a period of 28 d. All diets were formulated to be isoenergetic and similar concentrations of standardized ileal digestible essential AA covering the nutrient requirements of pigs.Results: Growth, carcass characteristics and meat quality were not affected by dietary protein source nor crude protein level(P &gt; 0.10) except that average daily feed intake was increased by CSM diets(P = 0.03). Gilts offered reduced protein diets had lower muscle p H45min(P 〈 0.05). Neither dietary protein source nor crude protein level influenced N deposition. However, reduced protein diets decreased N intake, N excretion, and serum urea nitrogen content, whilst improved N efficiency(P 〈 0.01). CSM diets increased N intake(P = 0.04),but did not depress N efficiency. The concentrations of phenylalanine, tryptophan, cysteine and tyrosine(P 〈 0.05) of the longissimus muscle were decreased when gilts offered CSM diets, while muscle intracellular free valine concentration was increased(P = 0.03). The gilts offered reduced protein diets had greater intracellular concentrations of free methionine, lysine, and total AA in muscle(P 〈 0.05).Conclusion: These results suggest that CSM could replace SBM as a primary protein source in finishing pig diets in terms of performance, N efficiency, carcass characteristics, and meat quality, but decrease the concentrations of muscle specific AA. Furthermore, the reduced protein diet played an important role in increasing muscle intracellular concentrations of specific free amino acids(FAA), and in reducing the relative ratios of specific FAA to lysine in longissimus dorsi muscle of pig, whose biological meaning needs further studies. 展开更多
关键词 Dietary protein source Finishing gilt Muscle free amino acids nitrogen efficiency Performance Pork quality
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Optimization of C/N ratio preparation of protein-rich and multi-enzymes feed thallus through synergic fermentation of mixed distillers'grains
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作者 LiZY ZhouD 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2002年第1期141-144,共4页
A new procedure of determining optimal C/N (the rate of carbon source to nitrogen source) of mixed distillers' grains for combined bacteria synergic fermentation is established. At the same time an improved method... A new procedure of determining optimal C/N (the rate of carbon source to nitrogen source) of mixed distillers' grains for combined bacteria synergic fermentation is established. At the same time an improved method evaluating bacteria growth, called method of dry cell weighing by filtering is developed. For each combination of C and N, their initial and residual contents before and after fermentation respectively are determined. Then followed the calculation of utilization of C and N sources by the compound bacteria. The optimal C/N is finally located from among the utilization of C and N of several combinations and the weight of produced mass of oven dried thallus. The conditions of fermentation are: inoculum size 10%, temperature 30 0℃, rotational speed 170 r/min, shake culture time 48h. The best results obtained from orthogonal experiments are: maximum mass of oven dried thallus is 14 693g in a liter liquid medium, maximum utilization rate of carbon source is 98 13% and maximum utilization rate of nitrogen is 78 14%. Optimal C/N is 5 1. 展开更多
关键词 optimal C/N fermentation distillers' grains utilization rate of carbon source transformation rate of nitrogen source
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Biological Characteristics and Culture Conditions of Hericium coralloides(Scop.)Pers.
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作者 Tong YANG Jianrui WANG Weihang PENG 《Medicinal Plant》 CAS 2020年第5期32-35,40,共5页
[Objectives]To study the biological characteristics and culture conditions of Hericium coralloides(Scop.)Pers.[Methods]The wild H.coralloides strain of Changbai Mountain was used as the experimental material to conduc... [Objectives]To study the biological characteristics and culture conditions of Hericium coralloides(Scop.)Pers.[Methods]The wild H.coralloides strain of Changbai Mountain was used as the experimental material to conduct a single factor test on its biological characteristics.[Results]The ideal available carbon source and nitrogen source are glucose and ammonium sulfate,respectively,the pH is 3.5-4.0,and the temperature is 20-22℃.Through the orthogonal experiment of 4 factors and 4 levels,it is found that the degree of influence of the 4 factors on H.coralloides is temperature>pH>nitrogen source>carbon source.[Conclusions]The optimum conditions for the mycelium culture of H.coralloides:the carbon source is glucose,and the nitrogen source is yeast extract or peptone,and pH is 3.5-4.0,and temperature is 20-22℃. 展开更多
关键词 Hericium coralloides(Scop.)Pers. Biological characteristics Carbon source nitrogen source PH TEMPERATURE
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