药渣发酵再次利用研究初探

以提取皂苷后的黄姜药渣作为主要原材料,通过添加有益微生物、腐植酸钾、沸石粉等辅料,研究发酵制得生物有机肥料的原料及配比。结果表明,黄姜药渣50%、沸石粉21%、豆饼17.5%、过磷酸钙10%、腐植酸钾1%、红糖0.5%,添加少量巨大芽孢杆菌、胶质芽孢杆菌、圆褐固氮菌、EM菌,在30~42℃环境下发酵20天,获得发酵成品,经检测符合生物有机肥料标准。通过此法制得的生物有机肥,生产成本低,同时减少了药渣对环境造成的污染,使药渣变废为宝。     

Effects of La and Nd on the Fermentation of Alginic Acid Produced from the Strain 342 of Azotobacter Vinelandii

It is reported that fermentative liquids with various concentrations of La and Nd affect the fer-mentation of alginic acid from the strain 342 of Azotobacter vinelandii.The results are as follows:When theconcentration of La or Nd was up to 100 ppm,the cell growth is stimulated and the production of alginic acidis promoted.The La or Nd in concentration higher than 200 ppm or 150 ppm inhibits the fermentation,respectively.As the concentration range of La is 0～100 ppm or that of Nd is 0～150 ppm,the yield of fixednitrogen increases,and the ratio of c_M to c_G(c_M/c_G)decreases with the raise of the concentration of La orNd.When the concentration range of La is 100～400 ppm and that of Nd is 150～400 ppm,the conclusion iscontrary to the above mentioned result.     

膜电位调控棕色固氮菌表达新生理特性的研究

膜电位对棕色固氮菌整体细胞固氮活性有调控作用。外加扫描电位能调控缺固氮酶活性中心、无固氮活性的棕色固氮菌突变菌株 CA30表达略高于天然棕色固氮菌的固氮活性。     

Enhanced bioremediation of crude oil‐contaminated soil by a Pseudomonas species and mutually associated adapted Azotobacter vinelandii

A mixed culture of compatible hydrocarbonoclastic and diazotrophic bacteria, each at a density of 10⁸ organisms cm^?3, was developed for optimised bioremediation of crude oil‐contaminated soil. The hydrocarbonoclastic bacterium, Pseudomonas sp and the diazotroph, Azotobacter vinelandii, were both isolated from a previously crude oil‐contaminated soil and thereafter modelled as a unit of mutualistic consortium in situ. Stabilisation of the consortium and hence the optimised bioremediation process occurred when the bacterial growth attained a pseudo‐steady state condition. This was considered to be as a result of a symbiotic association between A vinelandii and the Pseudomonas sp in which A vinelandii produced the required concentration of fixed nitrogen compounds required for the growth of the Pseudomonas sp. Enhancement in biodegradation, due to stimulated growth of Pseudomonas sp and co‐metabolic activity of A vinelandii, was mathematically evaluated as the difference in the specific growth rates (µ) between the consortium Pseudomonas sp/A vinelandii and Pseudomonas sp alone. The proportion of petroleum hydrocarbons degraded by the consortium from the contaminated soil ranged between 66.83 and 69.6% as compared with that of a pure culture of Pseudomonas sp (23.2–44.45%). Hence, beyond their role in biological nitrogen fixation, diazotrophs may be used to contribute to bioremediation of crude oil‐contaminated land. Copyright © 2004 Society of Chemical Industry     

Azotobacter vinelandii metal storage protein: "classical" inorganic chemistry involved in Mo/W uptake and release processes

The release of Mo (as molybdate) from the Mo storage protein (MoSto), which is unique among all existing metalloproteins, is strongly influenced by temperature and pH value; other factors (incubation time, protein concentration, degree of purity) have minor, though significant effects. A detailed pH titration at 12 degrees C revealed that three different steps can be distinguished for the Mo-release process. A proportion of approximately 15% at pH 6.8-7.0, an additional 25% at pH 7.2-7.5 and ca. 50% (up to 90% in total) at pH 7.6-7.8. This triphasic process supports the assumption of the presence of different types of molybdenum-oxide-based clusters that exhibit different pH lability. The complete release of Mo was achieved by increasing the temperature to 30 degrees C and the pH value to >7.5. The Mo-release process does not require ATP; on the contrary, ATP prevents, or at least reduces the degree of metal release, depending on the concentration of the nucleotide. From this point of view, the intracellular ATP concentration is suggested to play-in addition to the pH value-an indirect but crucial role in controlling the extent of Mo release in the cell. The binding of molybdenum to the apoprotein (reconstitution process) was confirmed to be directly dependent on the presence of a nucleotide (preferably ATP) and MgCl2. Maximal reincorporation of Mo required 1 mM ATP, which could partly be replaced by GTP. When the storage protein was purified in the presence of ATP and MgCl2 (1 mM each), the final preparation contained 80 Mo atoms per protein molecule. Maximal metal loading (110-115 atoms/MoSto molecule) was only achieved, if Mo was first completely released from the native protein and subsequently (re-) bound under optimal reconstitution conditions: 1 h incubation at pH 6.5 and 12 degrees C in the presence of ATP, MgCl2 and excess molybdate. A corresponding tungsten-containing storage protein ("WSto") could not only be synthesized in vivo by growing cells, but could also be constructed in vitro by a metalate-ion exchange procedure by using the isolated MoSto protein. The high W content of the isolated cell-made WSto (approximately 110 atoms/protein molecule) and the relatively low amount of tungstate that was released from the protein under optimal "release conditions", demonstrates that the W-oxide-based clusters are more stable inside the protein cavity than the Mo-oxide analogues, as expected from the corresponding findings in polyoxometalate chemistry. The optimized isolation of the W-loaded protein form allowed us to get single crystals, and to determine the crystal X-ray structure. This proved that the protein contains remarkably different types of polyoxotungstates, the formation of which is templated in an unprecedented process by the different protein pockets. (Angew. Chem. Int. Ed. 2007, 46, 2408-2413).     

Role of diazotrophic bacteria in the bioremediation of crude oil‐polluted soil

Nitrogen is one of the most limiting inorganic nutrients in the process of bioremediation of crude oil‐polluted environments. Enhanced remediation of crude oil polluted soil was achieved, in situ, by accelerating the biodegradation process through seeding with adapted Azotobacter which not only acted as supplier of fixed nitrogen to the indigenous crude oil‐degrading bacteria, but also performed some co‐metabolic activities. This work describes the capability of Azotobacter in providing activities that are useful in the bioremediation of crude oil‐polluted soil and biological nitrogen fixation when in association with indigenous oil‐degrading bacteria. © 1999 Society of Chemical Industry     

固氮菌β-C1株类胡萝卜素分离提取工艺优化的研究

本文主要报导了破壁方法、浸提溶剂和工艺条件对从固氮菌β-C1菌株中提取类胡萝卜素影响的实验结果.用酸热法对β-C1菌株进行破壁处理最有利类胡萝卜提取,用正交实验法得出的最佳破壁工艺为:盐酸的浓度3mol/L,盐酸的加量30ml/g,破壁时间2min,破壁温度100℃.氯仿、丙酮、甲醇及乙醇等多种溶剂能取得良好的提取效果,但综合考虑,乙醇最理想;用正交实验优化乙醇浸取的最佳条件为:乙醇加量30ml/g菌体,浸提温度为50℃,浸提时间45min,在优化后的条件下进行破壁提取β-C1菌中的类胡萝卜素,提取得率为3.45mg/g(干菌体).