Carbon and nitrogen isotopes analysis and sources of organic matter in surface sediments from the Sanggou Bay and its adjacent areas, China

Naturally existing stable carbon and nitrogen isotopes are important in the study of sedimentary organic matter sources. To identify the sources of sedimentary organic matter in Sanggou Bay and its adjacent areas, which is characterized by high-density shellfish and seaweed aquaculture, the grain size, organic carbon （OC）, total nitrogen （TN）, carbon and nitrogen isotopic composition （δ13C andδ15N） of organic matter in the surface sediment were determined. The results showed that, in August, sedimentary OC and TN ranged from 0.17% to 0.76% and 0.04% to 0.14%, respectively. In November, OC and TN ranged from 0.23% to 0.87% and 0.05% to 0.14%, respectively. There was a significant positive correlation between OC and TN （R=0.98, P＆lt;0.0001）, indicating that OC and TN were homologous. In August, theδ13C andδ15N of organic matter varied from -23.06‰ to -21.59‰ and 5.10‰ to 6.31‰, respectively. In November,δ13C andδ15N ranged from -22.87‰ to -21.34‰ and 5.13‰ to 7.31‰, respectively. This study found that the major sources of sedimentary organic matter were marine shellfish biodeposition, seaweed farming, and soil organic matter. Using a three-end-member mixed model, we estimated that the dominant source of sedimentary organic matter was shellfish biodeposition, with an average contribution rate of 65.53% in August and 43.00% in November. Thus, shellfish farming had a significant influence on the coastal carbon cycle.

The Effects of Three Mineral Nitrogen Sources and Zinc on Maize and Wheat Straw Decomposition and Soil Organic Carbon

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.

Spatial distributions of organic carbon and nitrogen and their isotopic compositions in sediments of the Changjiang Estuary and its adjacent sea area

The spatial distribution patterns of total organic carbon and total nitrogen show significant correlations with currents of the East China Sea Shelf. Corresponding to distributions of these currents, the study area could be divided into four different parts. Total organic carbon, total nitrogen, and organic carbon and nitrogen stable isotopes in sediments show linear correlations with mean grain size, respectively, thus ＂grain size effect＂ is an important factor that influences their distributions. C/N ratios can reflect source information of organic matter to a certain degree. In contrast, nitrogen stable isotope shows different spatial distribution patterns with C/N and organic carbon stable isotope, according to their relationships and regional distributions. The highest contribution （up to 50%） of terrestrial organic carbon appears near the Changjiang Estuary with isolines projecting towards northeast, indicating the influence of the Changjiang dilution water. Terrestrial particulate organic matter suffers from effects of diagenesis, benthos and incessant inputting of dead organic matter of plankton, after depositing in seabed. Therefore, the contribution of terrestrial organic carbon to particulate organic matter is obviously greater than that to organic matter in sediments in the same place.

Fabrication, characterization and response surface method optimization for quantum efficiency of fluorescent nitrogen-doped carbon dots obtained from carboxymethylcellulose of oil palms empty fruit bunch

Bio based nitrogen doped carbon dots(N-CDs)were obtained from empty fruit bunch carboxymethylcellulose and ethylenediamine(EDA)through one-pot hydrothermal carbonization route.The optimum as-formed NCDs were thoroughly characterized via Transmission electron microscopy(TEM),high-resolution TEM(HRTEM),Fourier transform infrared(FTIR),X-ray photoelectron spectra(XPS),UV–vis spectra(UV–Vis)and Fluorescence spectra(PL).Response surface methodology was statistically used to assess three independent variables that have major influence on the fluorescence quantum yield(QY),including temperature(230–270℃),time(2–6 h)and EDA mass(10%–23.3%).Based on analysis of variance(ANOVA)results,synthesis temperature was found to be the most influential factor on the QY,followed by time and EDA mass.Higher temperature,long synthesis time and high amount of EDA were satisfactorily enough for efficient carbonization conversion rate and obtaining highest QY of N-CDs.The obtained quadratic model(R^2=0.9991)shows a good correlation between the experimental data and predicted values.The optimum synthetic parameters are of 270℃temperature,6 h reaction time and 23.3%of EDA mass.The optimized as-made N-CDs exhibited blue photoluminescence with both excitation dependent/independent phenomena and high nitrogen content.The maximum emission intensity was 426 nm at a maximum excitation wavelength of 320 nm,with a QY of up to 22.9%.XPS and FTIR data confirmed the existence of polar containing groups,such as carbonyl,carboxyl,hydroxyl and amino groups over the surface of N-CDs whereas nitrogen species in the form of(pyridinic and graphitic-N)were introduced in the aromatic carbon domains,which imparts the hydrophilic and photostability of N-CDs.Taking into account the low-cost and sustainable production of N-CDs,this method considered a feasible route for converting low quality waste into value-added nanomaterials and utilizing for different functionalization processes and analytical applications.

Effects of Carbon and Nitrogen Additions on Soil Microbial Biomass Carbon and Enzyme Activities Under Rice Straw Returning

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.

Impact of external carbon source on A2/O system and its biological phosphorus and nitrogen removal efficiency before and after restoration

以啤酒废水作为外加碳源，研究了不同浓度外加碳源对A2／O系统的冲击情况，并通过调节工艺参数对系统进行修复，对比了修复前后系统的脱氮除磷效果。结果表明，投加低浓度（COD为50mg／L）外加碳源没有影响系统的正常运行，且有助于提高系统的脱氮除磷效率；用COD为150mg／L的啤酒废水对系统进行冲击时，总氮、氨氮、总磷和COD的去除率均有所下降，依次下降了31．53、16．38、7．61、10．19百分点；经过修复后，与冲击前相比较，各分析指标的去除率略有降低。用高浓度（COD为250nag／L）的啤酒废水冲击A2／O系统，冲击期间各分析指标显著下降，且产生轻微的污泥膨胀，修复后各分析指标去除率依次降低了11．75、9．56、21．20、20．79百分点。实验表明，啤酒废水可以作为外加碳源用以调节系统的C／N，且A0／o系统对浓度变化的冲击具有一定的抵抗力。

Application o f 210 Pb, Carbon and Nitrogen Isotope in Tracing of Changes and Burial Effect of Endogenous and Terrigenous Organic Matter in the Bering Sea over the Past 100 Years

By using the multi-tube sediment samples collected from NB01 station in the Bering Sea during the period of the fourth Chinese Arctic research expedition in 2010,as well as the dating technique of radioisotope ^(210)Pb in sedimentary strata,based on the exponential decay trend of ^(210)Pb exwith the column sample depth,relative stable modern sedimentary environment in the investigation area was reflected. The results show that the deposition rate of modern marine sediment S was 0. 27 cm/a,and correlation coefficient R was 0. 96( n = 17),while time span was 107 a(1903-2010). Meanwhile,carbon,nitrogen and isotopes were used to trace the sources of materials in the Bering Sea. It is found that the content of organic carbon and nitrogen in the column samples from NB01 station in the Bering Sea was 1. 18%-1. 80% and 0. 16%-0. 28% respectively,and C/N ratio ranged from 5. 13 to 8. 31. Total organic carbon( TOC) and total organic nitrogen( TON) were preserved well in sedimentary strata and had good consistency,showing that sources of organic matter were consistent. Moreover,their changes positively correlated with^(210)Pb. Organic carbon isotope( δ13 C) ranged from-22. 45‰ to-21. 82‰,and its changing trend was similar to that of C/N ratio; organic nitrogen isotope(δ15 N) varied from 7. 53‰ to 8. 54‰,indicating that organic matter was mainly from remaining marine organisms after being decomposed,into which a certain quantity of terrigenous materials were mixed. In the 100 years,the overall trend of terrigenous materials became increasingly obvious,showing that the input and burial of organic carbon from seas and land in the Bering Sea were changing. According to the burial rate of surface sediment and content of organic carbon,the apparent burial flux of sedimentary organic carbon in the column sample from NB01 station in the Bering Sea was estimated,about 1 450 mmol C/( m^2·a). It is suggested that the high burial flux of sedimentary organic carbon in the regions was mainly related to the high primary productivity of the water body,the high output efficiency of organic carbon in the photic zone,favorable preservation and metabolic mechanism of organic matter,and high deposition rate.

Studies on optimization of nitrogen sources for astaxanthin production by Phaffia rhodozyma

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.

Influence of Carbon Source on Biological Nitrogen Removal by Immobilised Bacteria

Acetate, ethanol, and hydrolysed rice were used as external carbon sources in an ammonium removal process employing immobilised bacteria. The influence of the carbon source on the occurrence of free cells and total nitrogen removal efficiency was examined at C/N ratios of 1.5 (low), 2.5 (medium), and 3.5 (high). At the low C/N ratio, no free cells were found in the reactors and the use of acetate as the carbon source resulted in the highest total nitrogen removal efficiency, followed by ethanol and hydrolysed rice. The occurrence of free cells in reactors fed with acetate and ethanol led to a negligible increase in the total nitrogen removal efficiency with increasing C/N ratio. The results suggest that acetate is the most appropriate carbon source for nitrogen removal and that the number of free cells should be minimized to achieve the highest efficiency during long-term operation.

Effects of Different Carbon Sources on the Water of Aristichthys nobilis Richardson Aquaculture by Biofloc

In order to explore the effects of different carbon sources on the water of Aristichthys nobilis Richardson culture by biofloc as well as regular,glucose,sucrose,dextrin,brown sugar and molasses 5 soluble carbon source were added into the water of Aristichthys nobilis Richardson culture containing a certain amount of ammonia nitrogen,nitrite nitrogen to research their effects on pH value,dissolved oxygen,ammonia-nitrogen,nitrite nitrogen value.The results showed that sucrose had the best effect in converting ammonia nitrogen and nitrite nitrogen;glucose and dextrin had significant effect in converting ammonia nitrogen.However,compared with sucrose,glucose and dextrin had bad effect in converting nitrite nitrogen molasses had bad effect in converting ammonia nitrogen and nitrite nitrogen,and had little effect on pH value and dissolved oxygen;glucose,sucrose and dextrin had significant effect in decreasing pH value and dissolved oxygen;brown sugar had good effect in converting nitrite nitrogen,whereas it had little effect in converting ammonia nitrogen.Therefore,sucrose was the best carbon source,and if the cost factor was taken into account,glucose also had a high cost performance.

Characteristics and Culture Conditions of a Bioflocculant Produced by Penicillium sp.

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.

Enhancement of Laccase Activity by Marine-derived Deuteromycete Pestalotiopsis sp. J63 with Agricultural Residues and Inducers

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.

Effects of culture media and three metal ions on the accumulation of lanosterol and ergosterol in cultured mycelia of Inonotus obliquus

Lanosterol and ergosterol are the active principles with potential pharmacological activities in Inonotus obliquus. However, the two sterols are less accumulated in cultured mycelia of the fungus. In this study, different carbon and nitrogen sources and pH levels together with three metal ions were assayed for their effects on accumulation of the two sterols in the fungus. Among the tested media the growth medium consisting of glucose (1.5%), rice powder (0.5%), yeast extract (0.4%), wheat bran (0.1%), KH2PO4 (0.01%) and MgSO4·7H2O (0.05%) with pH level at 6.5 yielded a maximum production of the two sterols, which can further be increased following the treatment of Ag+, Cu2+ and Ca2+. Supplementing Ag+ at concentrations of 0.28 and 0.35μmol partially inhibited ergosterol biosynthesis, leading to an enhanced accumulation of lanosterol, the presence of intermediates of ergosterol biosynthetic pathway and a reduced accumulation of ergosterol in cultured mycelia of I.

Optimization of C/N ratio preparation of protein-rich and multi-enzymes feed thallus through synergic fermentation of mixed distillers'grains

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.

Biological Characteristics and Culture Conditions of Hericium coralloides(Scop.)Pers.

[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℃.

Carbon and nitrogen isotopes analysis and sources of organic matter in the upper reaches of the Chaobai River near Beijing,China

The carbon and nitrogen isotopes in the surface sediments,plants,and soil in the upper reaches of the Chaobai River have been researched.The results showed 27.75‰-21.58‰ and 1.32‰-6.74‰ for carbon and nitrogen isotopic ratios in the surface sediments,respectively.The sources of sedimentary organic matter in this area are soil organic matter,aquatic vascular plants,and riverine plankton,respectively,and a significant contributor to sediment in the Chaohe River,the Baihe River,and the Miyun Reservoir areas is soil organic matter.Furthermore,part of sedimentary organic matter in the Miyun Reservoir is attributed to the input from the Chaohe River and the Baihe River,the other is from C4 vegetation growing around individual point stations at the Miyun Reservoir.Compared with the situation in Hebei Province,the contribution of soil organic matter decreased significantly and river plankton and aquatic vascular plants increased significantly in Beijing municipal areas.This study reveals that the source of organic matter has a close relationship with the soil erosion.

Effects of Medium Nutrients on Fusarium oxysporum Schl. f.sp

[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.

Optimal Controlling for Fermentation Process of Threonine-producing Strain Overexpressing rhtB Gene

[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.

假丝酵母Candida rugosa产脂肪酶条件的优化(英文)

对假丝酵母Candidarugosa产脂肪酶的条件进行了优化.比较实验证明,碳源是影响酶产量的主要因素.其中,糖类使细胞生长良好,但酶产量较低,而脂类是较为适合的碳源.本实验首次发现长链的不饱和脂肪酸酯,三油酸甘油酯是最好的碳源.氮源的影响较小.而添加物的使用是有效提高脂肪酶产量的另一种方法.PVA可促进碳源的乳化,从而提高脂肪酶产量.吐温虽没有促进细胞生长,但却大幅度提高了酶的产量.将以上优化的结果应用于发酵罐中,分批流加操作时,脂肪酶产量高达每毫升128.2单位,为目前报道的最高值.

Treatment of coke plant wastewater by SND fixed biofilm hybrid system

In this article, coke plant wastewater was treated by a simultaneous nitrifying and denitrifying （SND） fixed biofilm hybrid system. The results showed that suitable parameters of the system were important for the performance of the bio-degradation system. The chemical oxygen demand （COD） removal efficiency in this system was satisfactory, higher than 94%, and ammonia nitrogen was higher than 95%. The effluent COD concentration could meet the discharge standard, except for very few situations. The results showed that a sufficient carbon source was important for making ammonia nitrogen concentration meet the discharge standard. Then the TiN removal efficiency in this system can be brought higher than 94%. Dissolved oxygen （DO） is very important to the performance of the SND bio-degradation system, and the suitable DO is about 3.5-4.0 mg/L at the forepart of reactor. In addition, the performance of the system was almost not affected by pH value. The results show that the system is feasible to treat coke plant wastewater.