Understanding the global economic crisis: A biophysical perspective

The recent economic meltdown worldwide has reinforced our understanding of the effects of decoupling economic growth, monetary policy, and resources. Concern for peak oil and suggestions that it may have contributed to the global economic woes as well as over concern for the banking fraud may be adding confusion over the underlying causes and sending a misleading message to the public and ultimately to policy makers. Viewing the economy as simply a circulation of money that can be manipulated to increase spending and therefore consume our way out of the current economic situation, is courting disaster by deluding the public that the solution lies in simple adjustments to the current monetary system. Similarly, emphasizing that energy is the problem and that the solution can be found with another energy source is probably counterproductive in the short run and may be disastrous in the long run. The recent nuclear accident in Japan seriously calls into question increased dependence on nuclear energy and renewable energy sources, in the majority, have low net yields and are unevenly distributed worldwide.In this paper we frame the economic system as a subsystem of the larger more encompassing geobiosphere and suggest that within this context, neoclassical economics is unlikely to provide sufficient explanation of the recent economic melt-down. From a biophysical perspective, increasing the amount or speed of money circulation as well as extracting more energy from whatever source is available will only compound the problems and relying on growth as the solution to what ails the global economy is not a desirable nor a tenable solution.     

Dssimilatory Fe(Ⅲ) reduction characteristics of paddy soil extract cultures treated with glucose or fatty acids

Dissimilatory Fe(Ⅲ) reduction is a universal process with irreplaceable biological and environmental importance in anoxic environments. Our knowledge about Fe(Ⅲ) reduction predominantly comes from pure cultures of dissimilatory Fe(Ⅲ) reducing bacteria (DFRB). The objective of this study was to compare the effects of glucose and a selection of short organic acids (citrate, succinate, pyruvate, propionate, acetate, and formate) on Fe(Ⅲ) reduction via the anaerobic culture of three paddy soil solutions with Fe(OH)3 as the sole electron acceptor. The results showed significant differences in Fe(Ⅲ) reduction among the three paddy soil solutions and suhstrate types. Bacteria from the Sichuan paddy soil responded quickly to substrate supply and showed higher Fe(Ⅲ) reducing activity than the other two soil types. Bacteria in the Jiangxi paddy soil culture solution could not use propionate as a source of electrons for Fe(Ⅲ) reduction. Similarly, bacteria in the Jilin paddy soil culture could not use succinate effectively. Pyruvate was readily used by cultures from all three paddy soil solutions, thus indicating that there were some similarities in substrate utilization by bacteria for Fe(Ⅲ) reduction. The use of glucose and citrate as substrate for dissimilatory Fe(Ⅲ) reduction indicates important ecological implications for this type of anoxic respiration.     

一株硝化脱氮除臭菌的筛选鉴定及其多途径氮代谢功能的研究

从江门某污水处理厂活性污泥中分离出一株能够高效脱除氨气的菌株JN-4.通过菌株形态观察、生理生化及16SrDNA分子鉴定,发现菌株JN-4与枯草芽孢杆菌(Bacillus subtilis)亲缘关系最为接近,同源性达到99%,认为JN-4为一株枯草芽孢杆菌(Bacillus subtilis).好氧培养条件下,以葡萄糖为碳源,JN-4在32h内对NH4+-N和NO2--N的总削减率能够达98.51%和84.50%,体系中总氮的削减率达到63.1%和16.9%,N2的产生量分别为3.72mmol·L-1和0.62mmol·L-1.好氧培养条件下,以KNO3为唯一氮源,NO3--N初始浓度为82.47mg·L-1,32h内体系中NO3--N的总削减率达到96.54%,体系中总氮的削减率达49.6%,产生1.44mmol·L-1的N2,反应中检测到有NH4+-N迅速积累,但会随着时间进行同步转化,可见JN-4不仅能够高效硝化脱氨,同时具有高效好氧反硝化的能力.JN-4在厌氧以及乙酸钠作为碳源的条件下,利用NH4+-N效率大大降低,但是能够在NO3--N存在时进行NO3--N还原(反硝化).JN-4能够进行多途径氮代谢,为一株异养硝化-好氧反硝化偶联的菌株,具有重要的应用价值.     

F/M对ASBR中基质的吸收、储存和利用影响

研究了不同F/M（COD/VSS）下以葡萄糖为基质时厌氧序批式反应器（ASBR）中的微生物代谢规律.结果表明,在序批操作条件下,水解产酸菌对葡萄糖的代谢存在2条并列的途径,即直接代谢为VFA和首先转化为胞内储存物糖原,然后糖原再被转化为VFA.前者约占进水COD的34%～38%,而后者则高达41%～46%.F/M越高,糖原的储存量越大,当F/M分别为0.27、 0.20和0.14时,单位质量污泥糖原的最大储存量分别为116.8、 81.1和62.4 mg/g.糖原的储存减缓了VFA的积累,为ASBR反应器的高效和正常运行创造了条件.     

基于能值分析的城市物质代谢研究

采用能值分析方法,构建了基于城市物质代谢通量指标、代谢存量指标和代谢效率指标的城市物质代谢指标体系,并以北京、天津、上海和重庆四个直辖市为例计算了2005年四城市物质代谢状况。分析结果表明:北京市代谢效率最低;上海市代谢通量和代谢存量最大,但是代谢效率不容乐观;重庆市代谢通量和代谢存量在四个城市中居于末位,但是代谢效率最高;天津市在四个城市中代谢呈中等水平。最后根据分析结果对城市今后的可持续发展提出了意见和建议。     

Bioconcentration kinetics of PCBs in various parts of the lifecycle of the tadpoles Xenopus laevis

Polychlorinated biphenyls （PCBs） in Xenopus laevis have been reported only for a few congeners. Additionally, there is very little information on the ability of Xenopus laevis to bioconcentrate PCBs. To address these issues, the tadpole Xenopus laevis was exposed to Aroclor 1254 mixtures in water at room temperature for 110 d followed by an additional 110 d of nonspiked PCBs in the water for the control group. During the whole process, bioconcentration factors （BCFs） of PCBs ranged from 1180 to 15670. For most PCB congeners, the highest and lowest bioconcentrations of the kinetic curves were found to be remarkably simultaneous, respectively. All 141 PCB congeners under the same experimental conditions had no linear correlation on the lgBCF versus lgKow relationship. The relationship between lgBCFs and lgKow followed a parabolic pattern indicative of selective bioconcentration, suggesting that the kinetic curves of the PCB congeners observed in the lifecycle of the tadpoles may be concentrated due to the amphibian special species and internal metabolism. In contrast, lgBCFs for PCBs were inversely related to lgKow, suggesting that a metabolism of the higher Kow PCB congeners occurred. These results support the author＇s conclusion that the tadpole Xenopus laevis plays major roles in the bioconcentration of PCB congeners, and demonstrated that the exposure kinetic curves of PCB congeners are complex. Besides the amphibian metamorphous development, the lifecycle of the tadpole Xenopus laevis also may be of importance in determining the bioconcentration of PCB congeners.     

镉对罗非鱼鳃线粒体结构和能量代谢的影响

为探明水环境镉对罗非鱼(Oreochromis niloticus)鳃线粒体结构和能量代谢的影响及其作用机理,本研究采用室内模拟方法,将罗非鱼在Cd²⁺浓度为0　μg/L、50　μg/L和500　μg/L的水中暴露7　d后,观察鳃线粒体超微结构并测定线粒体超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量和鳃组织中磷酸果糖激酶(PFK)、ATP酶(ATPase)活性、乳酸(LD)、ATP、ADP、AMP含量及血浆中Na⁺、K⁺、Ca²⁺浓度和渗透压,并计算能荷值(EC).结果表明,50　μg/L组鱼鳃线粒体结构未受损, 除SOD酶活性被显著诱导外,其余测定指标与对照组相比无显著差异(p>0.05); 而500　μg/L组鱼鳃线粒体严重受损, LD、MDA、ADP、AMP和血浆K⁺含量显著高于对照组, SOD和ATPase活性显著低于对照组(p<0.05), PFK和渗透压无显著变化(p>0.05),但有降低趋势.结果表明,高浓度镉短期暴露将降低鱼鳃线粒体SOD活性而导致线粒体氧化损伤,同时抑制ATPase和PFK活性,影响鳃的能量供应和利用,最终降低鳃血浆渗透压和离子浓度调节能力可能是其毒性机理之一.     

好氧颗粒污泥处理青霉素废水研究

青霉素在其生产过中产生大量的废水,其COD值较高,生化性较差,成分复杂,微生物难以降解,其处理技术是世界性难题。文章采用以葡萄糖模拟废水培养的好氧颗粒污泥为接种体,经青霉素废水逐步驯化后,使其完全处理青霉素废水。实验结果表明,应用好氧颗粒污泥技术,处理青霉素废水,COD,NH3-N,TP去除率较高,具有很好的处理效果。     

外加营养源作用下微生物黏结剂对土壤团聚体的影响

通过室内培养实验研究了外加营养源条件下微生物黏结剂(真菌菌丝和微生物胞外多糖)对土壤稳定性的影响以及微生物在不同粒径团聚体中的分布.所加营养源分别为葡萄糖(以C计)和硝酸铵(以N计),实验周期为30 d.实验设计包括对照(0.5 mg.g-1)、CN5(0.5 mg.g-1,0.1 mg.g-1,C/N=5)、CN10(0.5 mg.g-1,0.05 mg.g-1,C/N=10)3个水平.结果表明,3个处理的土壤呼吸速率十分接近,最大值都在3.10 mg.(h.kg)-1左右,说明无机氮肥的施加短期内对葡萄糖的矿化作用不明显.除培养第5 d CK的大团聚体形成量(15.67%)显著低于CN5(25.32%)和CN10(24.63%)外,其余培养期间3个处理的团聚体含量总体无显著性差异,表明本实验中葡萄糖对微生物的影响较大,覆盖了施加无机氮的影响,从而导致团聚体含量之间差异不显著.