包头南海湖不同湖区春季沉积物细菌群落结构

[目的]探究包头南海湖不同功能区域春季沉积物细菌群落多样性。[方法]采用高通量测序技术对进水口区、旅游开发区、湖心区和水草区共4个采样点表层沉积物细菌进行测定。[结果]不同区域物种丰富度和均匀度表现为水草区>进水口区>湖心区>旅游开发区。从门水平来看,沉积物细菌主要为变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi)、拟杆菌门(Bacteroidetes)、酸杆菌门(Acidobacteria)和蓝藻门(Cyanobacteria)等;从属水平分析,优势类群集中在硫杆菌属(Thiobacillus)、norank-f-anaerolineaceae。对沉积物细菌群落与环境因子做相关性分析,TN、TP、TOC对沉积物细菌群落结构影响较大。[结论]Thiobacillus在南海湖春季沉积物中广泛存在,其在地球生化循环中发挥着重要作用,而且极有可能诱发黑臭水体出现,应在以后研究中得到更多关注,并控制TN、TP以及TOC量,为预防南海湖黑臭水体的发生提供理论依据和基础数据。     

硫杆菌和元素硫在治理重金属污染中的应用研究进展

硫杆菌和元素硫在治理土壤和沉积物中重金属已经有了较多的研究。本文论述了利用硫杆菌和元素硫治理土壤和沉积物中的重金属污染的应用进展。主要包括了利用硫杆菌和元素硫去除重金属的优缺点及主要的影响因素,如温度、pH、细菌种类、元素硫浓度等。     

氧化亚铁硫杆菌烟气脱硫的研究进展

结合近年来国内外氧化亚铁硫杆菌烟气脱硫的相关研究,论述了氧化亚铁硫杆菌烟气脱硫的机理,重点阐述了基于氧化亚铁硫杆菌双重氧化系统脱硫的直接作用和间接作用原理。     

氧化亚铁硫杆菌的磁性及铁源种类对磁小体合成的影响

氧化亚铁硫杆菌,通过氧化二价铁或还原态无机硫化物获得能量,在细胞内能合成磁性纳米颗粒。通过扫描电镜和透射电镜对氧化亚铁硫杆菌菌体进行分析。探讨了该菌的趋磁性以及不同铁源对菌体生长和磁小体合成的影响。结果表明:生长于9K培养基的细菌能够合成磁小体,单个细胞的磁小体数目大概为2个;干燥菌体和湿菌体都能被磁铁吸附;当有外加磁场时,细菌在半固体平板和光学显微镜下均可见趋磁性;氧化亚铁硫杆菌生长和磁小体合成的最佳铁源均为硫酸亚铁。     

Effect of Repeated Applications of Elemental Sulfur on Microbial Population,Sulfate Concentration,and pH in Soils

Abstract

Though there exists a wide spectrum of sulfur‐oxidizing microorganisms in soils, the oxidation rate of soil‐applied elemental sulfur (S⁰) is regularly limited because of a restricted population size. An incubation experiment was conducted to determine the effect of repeated S⁰ applications on different microbial populations, sulphate (SO₄ ^2?)‐S concentration, and soil pH. Elemental sulfur was applied repeatedly at a rate of 15 mg S g^?1 soil in a 15‐day interval cycle of 7 times. After each cycle, 7.5 mg lime (CaCO₃) g^?1 soil was applied to adjust the soil pH to an optimum range. Soil pH and 0.025 M potassium chloride (KCl)–extractable SO₄ ^2?‐S were determined every 3 days. The population of Thiobacillus spp. and aerobic heterotrophic sulfur‐oxidizing bacteria were counted 3 and 15 days after each S⁰ application. The results showed that the soil pH decreased rapidly from an initial value of 7.6 to 5.3, 15 days after the first S⁰ application. Lime applications successfully counterbalanced the acidifying effect of S⁰ oxidation, and soil pH values were maintained in the optimum range with a pH of about 6.4. The 0.025 M KCl–extractable SO₄ ^2?‐S content increased with repeated applications of S⁰, showing a maximum value of 3,800 mg S kg^?1 soil after the sixth S⁰ application. Thereafter, the SO₄ ^2?‐S concentration decreased significantly. The Thiobacillus spp.count increased consistently with repeated S⁰ applications. The number of Thiobacillus spp. at the first application of S⁰ was significantly lower than the count after all other applications. A maximum Thiobacillus spp. count of 1.0 · 10⁸ g^?1 soil was observed after the seventh application of S⁰. The fastest S⁰ oxidation rate was found after the second application of S⁰. The population of aerobic heterotrophic sulfur‐oxidizing bacteria increased also with repeated S⁰ applications, showing a maximum count of 5.0 · 10⁴ g^?1 soil after the fourth S⁰ application. Thereafter, the population declined steadily. Significant relationships between SO₄ ^2?‐S concentration and count of Thiobacillus spp. (R²=0.85, p<0.01) and aerobic heterotrophic sulfur‐oxidizing bacteria (R²=0.63, p<0.01) were found. Based on these results, it may be concluded that repeated S⁰ applications decrease soil pH, increase Thiobacillus spp. counts, and thus increase extractable SO₄ ^2?‐S concentration in soils. The results further suggest that soils that receive regular S⁰ applications have a higher Thiobacillus spp. count and thus have conjecturally a higher S⁰ oxidation potential than soils that have never received S⁰. This again indicates a priming effect of S⁰ oxidation by Thiobacillus spp., which needs to be confirmed under field conditions.     

脱硫混合菌系在传代和硫化氢脱除中的稳定性

为研究由嗜酸氧化亚铁硫杆菌[Acidithiobacillus ferrooxidans(A.ferrooxidans)]和嗜酸氧化硫硫杆菌[Acidithiobacillus thiooxidans(A.thiooxidans)]按数量1∶2配比的一组脱硫混合菌系的硫化氢脱除效果及在传代和硫化氢脱除过程中的稳定性,采用ATP分析法和qRT-PCR分别检测ATP浓度和细菌gyr B基因拷贝数及其比例。结果表明,在传代培养中,ATP含量较为稳定,其值在1.09×10-6~1.54×10-6mol·L~(-1)的小范围内变化,A.ferrooxidans和A.thiooxidans的gyr B基因拷贝数也相对稳定,在最佳脱硫条件下,硫化氢的脱除效率可达99.4%。在脱硫过程中,体系p H值为2.29~2.62。此外,不同时间点的ATP含量和细菌基因拷贝数也相对稳定。在传代培养和硫化氢脱除的过程中,A.ferrooxidans和A.thiooxidans的gyr B基因拷贝数的比例一直维持在1∶2左右。本研究结果为脱硫混合菌系在生物燃气脱除硫化氢中的应用提供了依据。     

硫细菌对黄绵土养分活化作用的研究

分析了氧化硫硫杆菌的产酸力及其对黄绵土中Ｐ、Ｚｎ、Ｍｎ养分的活化作用结果表明,氧化硫硫杆菌可使环境ＰＨ值降低１－３个单位;接种于黄绵土垢可显著增加土壤中Ｃａ２－Ｐ、Ｃａ８－Ｐ、Ａｌ－Ｐ的含量,土壤中有效Ｚｎ、Ｍｎ量也明显提高。ｔ检验均达显著或极显著水平;田间试验表现显著的增产效果。     

二甲基硫醚氧化菌的分离鉴定及其对猪粪堆肥的影响

从污水处理厂活性污泥中分离得到一株二甲基硫醚(DMS)氧化菌AM2,经16S rDNA检测鉴定其为那不勒斯硫杆菌(Thiobcillus neapolitanus)。AM2的最适生长温度为30℃最适pH为7.0。以猪粪和秸秆粉为原料进行肥料堆肥试验,通过检验菌株AM2对堆肥过程中DMS排放量、堆肥温度、可培养微生物和酶活性的影响,来探究菌株AM2对堆肥的影响。结果表明:接入菌株AM2的实验组DMS释放量显著(P0.05)少于对照组,在30 d的实验中有20 d减少60%以上;显著提高了(P0.05)可培养微生物数量,同时将物料温度高于50℃的天数延长至13 d;实验各组的脲酶、脱氢酶、过氧化氢酶、蛋白酶和纤维素酶酶活都显著高于对照组。综合判断,菌株AM2能够有效降低堆肥过程中DMS的排放量并促进肥料腐熟。     

氧化亚铁硫杆菌(Thiobacillus ferrooxidans)对重金属富集植物腐蚀作用研究

为了获得重金属富集植物生物法预处理的最佳工艺条件,实现其资源化利用,以黑麦草(Lolium perenne)为材料,探究氧化亚铁硫杆菌(Thiobacillus ferrooxidans,T.f)在不同接种量和不同浓度底物添加剂(S0、Na2S2O_3、Fe SO4、Fe S和Fe0)条件下对黑麦草的腐蚀作用,通过扫描电镜进一步观察其对细胞壁的破坏情况。结果表明:氧化亚铁硫杆菌对黑麦草具有较好的腐蚀作用,各接种量(5%~15%)之间差异较小,反应第10 d,10%接种量处理组中黑麦草的纤维素降解率达40.97%,半纤维素降解率达77.49%,木质素降解率达19.33%。投加底物添加剂后,氧化亚铁硫杆菌对纤维素降解率有明显提高。总体来看,添加14 g·L~(-1)的S0对黑麦草的降解效果较好,纤维素、半纤维素及木质素的降解率分别达到81.31%、82.29%、26.02%,此条件下铀、铬、镉的浸出效率均较高。在氧化亚铁硫杆菌及底物添加剂的作用下,除Fe S、Fe0处理组外,其他各处理组的pH值均呈下降趋势,反应10 d后,pH值最低降至1.0左右,pH值的降低能有效提高半纤维素降解率,但与纤维素及木质素的降解率无明显关系。扫描电镜结果表明氧化亚铁硫杆菌对黑麦草细胞壁有较强的破坏作用。氧化亚铁硫杆菌对黑麦草具有很好的腐蚀效果,并且能充分利用底物添加剂提高黑麦草中纤维素降解率。后期需进一步考虑提高氧化亚铁硫杆菌对木质素的降解效率及黑麦草中重金属的回收率。     

Bioresource Efficacy of Phosphate Rock,Sulfur, and Thiobacillus Inoculum in Improving Soil Phosphorus Availability

In order to improve the effectiveness of phosphate rock as phosphorus fertilizer, elemental sulfur and Thiobacillus have been evaluated as amendments. First, Thiobacillus was isolated from different soil samples. Then, a greenhouse pot experiment was conducted using a completely randomized factorial design with three factors included: elemental sulfur at four levels of 0, 1000, 2000, and 5000 mg kg^?1; phosphate rock at three levels of 0, 1000 and 2000 mg kg^?1; four Thiobacillus inoculums (T₁, T₂, T₃, T₄) and without inoculation (T₀) in three replications. Results showed that all the four Thiobacillus inoculums increased significantly extractable soil-P. Combined application of phosphate rock and sulfur in equal proportion (1:1) along with inoculum Thiobacillus had a significant effect in improving phosphorus availability in soil. Combined application of sulfur (at rates of 1000 and 2000 mg kg^–1) and Thiobacillus significantly increased phosphorus uptake by plants as compared to the control.