Single-species microbial biofilm screening for industrial applications

While natural microbial biofilms often consist of multiple species, single-species biofilms are of great interest to biotechnology. The current study evaluates biofilm formation for common industrial and laboratory microorganisms. A total of 68 species of biosafety level one bacteria and yeasts from over 40 different genera and five phyla were screened by growing them in microtiter plates and estimating attached biomass by crystal violet staining. Most organisms showed biofilm formation on surfaces of polystyrene within 24 h. By changing a few simple conditions such as substratum characteristics, inoculum and nutrient availability, 66 strains (97%) demonstrated biofilm formation under at least one of the experimental conditions and over half of these strains were classified as strong biofilm formers, potentially suitable as catalysts in biofilm applications. Many non-motile bacteria were also strong biofilm formers. Biofilm morphologies were visualized for selected strains. A model organism, Zymomonas mobilis, easily established itself as a biofilm on various reactor packing materials, including stainless steel.     

翻压山黧豆绿肥与氮肥减施对水稻生长及其养分吸收与产量的影响

为探明种植翻压山黧豆绿肥与减施氮肥下的水稻生产潜力,通过3年田间定位试验,设置冬闲+不施肥(NF)、山黧豆绿肥(GM)、冬闲+常规氮肥(100%N,CK)、山黧豆绿肥+80%常规氮肥(GM+80%N)、山黧豆绿肥+70%常规氮肥(GM+70%N)、山黧豆绿肥+60%常规氮肥(GM+60%N)6个处理,研究不同处理对水稻生长、养分吸收及产量的影响。结果表明：(1)与CK相比,翻压山黧豆绿肥并减施氮肥处理均能够显著提升水稻株高、增加水稻分蘖数、提高水稻干物质积累量,其中以GM+70%N施肥处理提升效果最为明显。(2)GM+70%N施肥处理下,不同生育时期水稻株高、有效分蘖数分别较对照常规施肥(100%N)提升了13.32%~ 15.73%和33.98%~59.47%,水稻干物质积累量提高了23.19%~144.18%,且随着生育时期的推进增加速率依次降低。(3)种植翻压山黧豆绿肥并减施氮肥处理下水稻产量均有所提高,其中GM+70%N和GM+80%N处理显著提高,增产分别达13.84%,7.25%,且GM+70%N处理下水稻植株和籽粒养分吸收更为全面。研究发现,种植翻压山黧豆并适量减施氮肥能有效促进水稻生长和养分的吸收积累,显著提高水稻产量,说明翻压山黧豆绿肥可替代稻田30%~40%的氮肥施入量,并可在避免水稻旺长的同时实现水稻高产,是四川水稻种植较好的耕作措施。     

承气活血通腑汤联合穴位贴敷治疗粘连性肠梗阻的疗效及对胃肠功能和血清炎性因子的影响

目的:探讨承气活血通腑汤联合穴位贴敷治疗粘连性肠梗阻的疗效及对胃肠功能和血清炎性因子的影响.方法:选取2018年2月到2020年7月期间于我院接受诊治的粘连性肠梗阻患者60例.分组方法采用随机数字表法,将入选患者分为对照组(n=30,常规治疗)、研究组(n=30,对照组的基础上给予承气活血通腑汤联合穴位贴敷治疗),对比...     

木霉属真菌的系统学及其应用研究

介绍了木霉属真菌的分类系统 ,有关木霉种系发育的分子生物学研究进展 ,以及在酶制剂、农业和环境保护中的应用概况。     

The effect of treating seed potato tubers with benzimidazole, imidazole and phenylpyrrole fungicides on the control of rot and skin blemish diseases

Over 6 yr the effectiveness of imazalil, prochloraz and fenpiclonil, applied either alone or in a mixture, in controlling gangrene, dry rot, skin spot and silver scurf on potato tubers in store was compared with that of 2-aminobutane and thiabendazole. An assessment was also made of their efficiency in controlling the development of these diseases on the daughter tubers of seed tubers treated at harvest or before planting. Overall, 2-aminobutane was more effective in controlling gangrene (Phoma foveata) in store than the spray-applied fungicides. Deposits of imazalil, thiabendazole and fenpiclonil were greater when sprays were applied with an electrostatic sprayer than with a hydraulic sprayer. The opposite was found with the mixture of prochloraz Mn and tolclofos-methyl. More effective gangrene control was associated with the highest deposits. Fenpiclonil and the mixture of thiabendazole and imazalil were more effective in controlling dry rot (Fusarium solani var. coeruleum) than imazalil alone. The development of dry rot was, however, increased by 2-aminobutane treatment on eight out of 14 stocks. 2-aminobutane gave the greatest reduction (83%) in the severity of skin spot during storage whereas thiabendazole alone, and the mixture of thiabendazole and imazalil, gave mean reductions of 70% and 65% respectively. This mixture and fenpiclonil gave the greatest reduction in the severity of silver scurf although, in general, reductions in silver scurf with fungicide treatment were less than with skin spot. The type of sprayer used to apply a fungicide did not affect the effectiveness of the fungicides in controlling either skin spot or silver scurf on tubers in store, or on the daughter tubers. The incidence of gangrene and dry rot on daughter tubers was not reduced consistently by fungicide treatment of seed tubers of the six stocks tested. However, the severity of skin spot and silver scurf was reduced by fungicide treatments of all eight stocks but the reduction in disease was greater for skin spot than for silver scurf. All fungicides gave reductions in the severity of skin spot, and fenpiclonil and the mixture of thiabendazole and imazalil were the most effective for silver scurf. The effectiveness of the fungicides in controlling these diseases was similar for seed treated at harvest and that treated before planting.     

污水污泥土地投放重金属的环境效应研究进展

本文综述了污水污泥土地投放中重金属的环境效应研究方面的进展,重点就污水污泥土地投放中对植物生长的影响、对土壤微生物、土壤酶及昆虫生长的影响、重金属向地下水中的迁移情况、重金属在土壤中的生物活性变化及其影响因素、污水污泥土地投放后重金属的长期变化及土壤修复剂对重金属毒性的控制等方面的研究进展进行综述。     

超氧化物岐化酶在医学领域的研究现状

超氧化物歧化酶(SOD)是生物体内清除超氧阴离子自由基(O2-.)的一种重要金属酶,具有重要的生理功能,在医药、食品等方面有广泛的应用前景,是目前医学、分子生物学领域研究的热点之一。现对SOD的分类、分布、结构、性质、在相关疾病中的研究进展、临床应用等方面做一综述。     

Enantiomeric separation of triazole fungicides with 3-μm and 5-μml particle chiral columns by reverse-phase high-performance liquid chromatography

This study used chiral columns packed with 3‐μm and 5‐μm particles to comparatively separate enantiomers of 9 triazole fungicides, and Lux Cellulose‐1 columns with chiral stationary phase of cellulose‐tris‐(3,5‐dimethylphenylcarbamate) were used on reverse‐phase high‐performance liquid chromatography with flow rates of 0.3 and 1.0 mL min⁻¹ for 3‐μm and 5‐μm columns, respectively. The (+)‐enantiomers of hexaconazole ( 1 ) , tetraconazole ( 4 ) , myclobutanil ( 7 ) , fenbuconazole ( 8 ) and the (−)‐enantiomers of flutriafol ( 2 ) diniconazole ( 3 ) , epoxiconazole ( 5 ) , penconazole ( 6 ) , triadimefon ( 9 ) were firstly eluted from both columns, the elution orders identified with an optical rotation detector didn't change with variety of column particles and mobile phases (acetronitrile/water and methanol/water). The plots of natural logarithms of the selectivity factors (ln α) for all fungicides except penconazole ( 6 ) versus the inverse of temperature (1/T) were linear in range of 5–40°C. The thermodynamic parameters (ΔH°, ΔS°, ΔΔH° and ΔΔS°) were calculated using Van't Hoff equations to understand the thermosynamic driving forces for enantioseparation. This work will be very helpful to obtain good enantiomeric separation and establish more efficient analytical method for triazole fungicides. Chirality, 2011. © 2011 Wiley‐Liss, Inc.     

股骨头缺血坏死介入治疗的临床应用研究

目的:探讨介入治疗股骨头缺血坏死的临床应用价值。方法:采用Seldinger技术对28例患者行超选择股骨头供血动脉插管,动脉造影、溶通治疗。结果:28例患者治疗后髋部疼痛及关节功能障碍均有不同程度的减轻及改善,有效率96.4%;治疗后病变区血管分支增多、增粗;影像随访显示股骨头骨质不同程度修复。结论:介入治疗具有创伤小、并发症低、血管再通率高、临床症状改善明显的优势,能有效的改善股骨头的局部血液循环和髋关节的疼痛、活动功能,应大力推广。     

Enhanced Phytoremediation Capacity of Chenopodium album L. Grown on Pb-Contaminated Soils Using EDTA and Reduction of Leaching Risk

Leaching of metals due to enhanced mobility during ethylenediaminetetraacetic acid (EDTA)-assisted phytoextraction has been demonstrated as one of the potential hazards associated with this technology. This study was conducted to determine phytoextraction efficiency of Chenopodium album L. for Pb and EDTA-assisted (1.5, 3, and 9 mmol kg^?1) phytoextraction and potential for leaching of Pb. The results demonstrated that BCF_shoot (bioconcentration factor) was relatively higher than the BCF_root. Translocation factor in the shoot was higher than the roots. Thus, plant species would be applicable for Pb phytoextraction. EDTA enhanced translocation of Pb from roots to shoots. Lead content in the plant parts was maximum in the shoot and root of 9EDTA and 3EDTA, respectively. However, there was no significant difference between 3EDTA and 9EDTA. Lead concentration in the plant parts increased significantly from vegetative stage into flowering stage. Lead content taken up by the plant was lowest when EDTA was applied in a single dose. Therefore, application of EDTA in several increments rather than a single split reduced the leaching risk. Totally, optimum phytoextraction was observed when 3 mmol kg^?1 EDTA was added in triple dosage 60 days after the plant cultivation under triple application mode. The results indicated the plant has the potential for Pb phytoextraction, but it should not be used unless the biomass containing such accumulated metal is removed for disposal. Significant improvement over current ETDA-assisted phytoextraction of Pb may be possible but should be implemented cautiously because of environmental risk.