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1.
Biodegradation of crude oil by Pseudomonas aeruginosa in the presence of rhamnolipids 总被引：3，自引：0，他引：3
INTRODUCTION Oily wastewater, especially from oil field, hasposed a great hazard for terrestrial and marine eco-systems. The traditional treatment of oily wastewater,such as containment and collection using floatingbooms, adsorption by natural or synthetic materials,etc., can not degrade the crude oil thoroughly (Ollis,1992). So far, biodegradation suggests an effectivemethod. During biodegradation, crude oil is used asan organic carbon source by a microbial process,resulting in the brea… 相似文献
2.
Hong-zi Zhang Xu-wei Long Ru-yi Sha Guo-liang Zhang Qin Meng 《Journal of Zhejiang University. Science. B》2009,10(11):852-859
Oily wastewater generated by various industries creates a major ecological problem throughout the world. The tra-ditional methods for the oily wastewater treatment are inefficient and costly. Surfactants can promote the biodegradation of pe-troleum hydrocarbons by dispersing oil into aqueous environment. In the present study, we applied rhamnolipid-containing cell-free culture broth to enhance the biodegradation of crude oil and lubricating oil in a conventional aerobically-activated sludge system. At 20 ℃, rhamnolipids (11.2 mg/L) increased the removal efficiency of crude oil from 17.7% (in the absence of rham-nolipids) to 63%. At 25 ℃, the removal efficiency of crude oil was over 80% with the presence of rhamnolipids compared with 22.3% in the absence of rhamnolipids. Similarly, rhamnolipid treatment (22.5 mg/L) for 24 h at 20 ℃ significantly increased the removal rate of lubricating oil to 92% compared with 24% in the absence of rhamnolipids. The enhanced removal of hydrocarbons was mainly attributed to the improved solubility and the reduced interracial tension by rhamnolipids. We conclude that a direct application of the crude rhamnolipid solution from cell culture is effective and economic in removing oily contaminants from wastewater. 相似文献
3.
ZHU Yong GAN Jun-jiang ZHANG Guo-liang YAO Bin ZHU Wen-jie MENG Qin 《浙江大学学报(A卷英文版)》2007,8(9):1514-1520
In this work,rhamnolipid production was investigated using waste frying oil as the sole carbon source. By culture in shaking flasks,a naturally isolated strain synthesized rhamnolipid at concentration of 12.47 g/L and its mutant after treatment by UV light increased this productivity to 24.61 g/L. Fermentation was also conducted in a 50 L bioreactor and the productivity reached over 20 g/L. Hence,with a stable and high productive mutant strain,it could be feasible to reuse waste frying oil for rhamnolipid production on industrial scale. 相似文献
4.
优良菌对原油降解性能的试验研究 总被引：1，自引：0，他引：1
以原油为唯一碳源,从长期被石油污染土壤的浸泡液中分离、筛选出二株降解原油的优良菌SY4和SY6,初步鉴定为:SY4和SY6为芽孢杆菌属;通过降解性能实验的研究得出:2株菌对原油都有较强的降解能力,在摇床实验中,单一菌株在5天后的原油降解率都高于60%.摇床实验和静态曝气实验都得出:SY6的降解能力比SY4强.实验研究结果为其实际应用提供了一定的生物基础. 相似文献
5.
以苯酚作为唯一碳源和能源的无机盐培养液对从绝缘材料厂排放的活性污泥进行驯化,从中分离筛选到1株苯酚降解菌,编号为JY04.采用正交实验设计方法优化了该菌株固定化条件,并且考察了该固定化细胞降解苯酚的最适条件.结果表明:在固定化条件为海藻酸钠(SA)浓度为5%,湿菌重/包埋剂为6/30,CaCl2浓度为3%时,固定化时间为8 h,降解率可达82.6%,并具有较好的机械强度.确定其对苯酚降解最适条件为pH 7.0,苯酚浓度为400 mg/L,温度32℃,接种量为25 g,培养时间42 h,其苯酚的降解率可达97.3%.该菌株固定化细胞的降解苯酚能力和耐受苯酚能力均大于游离细胞.固定化菌株对苯酚有较强的降解和耐受能力,是处理苯酚废水的良好菌种资源. 相似文献
6.
丙烯菊酯农药的微生物生物修复作用研究 总被引：3，自引：0，他引：3
通过富集驯化培养,获得了降解丙烯菊酯的混合微生物．研究结果表明,该混合微生物发挥最优降解力的温度是35℃,pH为7．0,培养时间为72h．丙烯菊酯降解速度和混合培养微生物生长速度对外加碳源有较强的依赖性．在培养液中添加1g／L葡萄糖时,72h丙烯菊酯去除率可达76％;而采用丙烯菊酯作为培养菌生长的唯一碳源、氮源和能源时,72h丙烯菊酯去除率为55％． 相似文献
7.
A newly isolated strain EL31410, producing elastase (E. C3. 4. 4. 7) with high elastolytic activity was identified asBacillus sp. In the medium optimization, it was found that wheat bran and soybean flour hydrosate were the best crude carbon and nitrogen
source for enzyme production, respectively. Addition of corn steep flour can affect the bacterium growth and elastase production.
A fractional factorial design was applied to study the main factors that affect the enzyme production, and central composite
experimental design and response surface methodology were adopted to derive a statistical model for the effect of wheat bran
and soybean flour hydrosate on elastase production. The experimental results showed that wheat bran had positive effect but
soybean flour hydrosate had negative effect, on enzyme production. An initial concentration of 3.4% (w/v) wheat bran and 9.4%
(v/v) soybean flour hydrosate were found to be optimal for enzyme production in batch culture. The time course of elastase
production in the optimized medium composition was also described.
Project (No. 300024) supported by the Zhejiang Provincial Natural Science Foundation of China 相似文献
8.
INTRODUCTION The difficulties associated with large-scaleproduction of biotherapeutics provide a constantchallenge to the biotechnology industry. FDA hadadded “therapeutic DNA plasmid vectors” to the listof well-characterized biotechnology product (DoHHs,1996), and gene therapy has moved rapidly fromlaboratory scale to clinical trials. It is urgent to de-velop new protocols to obtain high-quality plasmidswith high yields and minimal or no contamination ofRNA and chromosomal D… 相似文献
9.
木霉菌的许多种属都能够产生脂类物质,并且已经被用来研究脂类物质的生产.本研究主要探索光照和肌醇对木霉生物量积累和油脂量积累的作用.结果表明：与遮光处理组相比,正常光照培养条件更易于菌株成熟孢子的形成,并且正常光照培养也利于菌株L1生物量和油脂量的积累;肌醇的添加会促进菌株生物量的积累,但是对菌株L1油脂量的积累有一定的抑制作用,对菌株L2,相比无肌醇添加组,肌醇的添加在一定的培养时间上有利于油脂的形成.同时发现光照和肌醇能够影响木霉的脂类构成. 相似文献
10.
以饲料为原料筛选出一株既产乳酸又产芽孢的益生菌,经过分子生物学鉴定为凝结芽孢杆菌(Bacillus coagulans),命名为T-8。从培养基碳源、氮源、有机物浸出液、培养基pH、培养温度、培养时间等方面对菌株T-8展开发酵特性研究,结果表明,最优培养基配方为:玉米粉6 g/L、豆粕粉15 g/L、小麦麸皮浸出液60%、酵母粉5 g/L、蛋白胨10 g/L、氯化钠10 g/L,pH 5.0。以5%的接种量将种子液转接至最优培养基,在47℃的摇床中以200 r/min的转速振荡培养28 h,菌株T-8的细胞密度达到4.8×109 CFU/mL,芽孢率达到95.2%。本试验可为益生菌凝结芽孢杆菌应用于饲用微生物菌剂的工业化生产提供参考。 相似文献
11.
The production of elastase by Bacillus sp. EL31410 at various temperatures was investigated. In order to study the effect of temperature on elastase fermentation,
different cultivation temperatures, ranging from 39 °C to 28 °C, were evaluated in shake flask. The result indicated that
37 °C was best for cell growth at earlier stage; while maximum elastase activity was obtained when the cells were cultivated
at 30 °C. This result was verified by batch fermentation in 5-L bioreactor under 37 °C and 30 °C temperature, respectively.
The specific cell growth rate at 37 °C was higher than that at 30 °C during earlier stage of cultivation. The maximum value
[5.5 U/(h·g DCW)] of elastase formation rate occurred at 24 h at 30 °C compared to 4.6 U/(h·g DCW) at 30 h at 37 °C. Based
on these results, two-stage temperature shift strategy and oscillatory temperature cultivation mode were evaluated in the
next study. When compared to single temperature of 37 °C or 30 °C, both two-stage temperature shift strategy and oscillatory
temperature strategy improved biomass but did not yield the same result as expected for elastase production. The maximum biomass
(both 8.6 g/L) was achieved at 30 h at 37 °C, but at 42 h using two-stage temperature cultivation strategy. The highest elastase
production (652 U/ml) was observed at 30 °C in batch process. It was concluded that cultivation at constant temperature of
30 °C was appropriate for elastase production by Bacillus sp. EL31410.
Project (No. 20276064) supported by the National Natural Science Foundation of China 相似文献
12.
在不同的酸碱度、光环境和营养等条件下对粉红聚端孢菌的菌落形态和孢子大小进行了研究．结果表明：该菌在不同条件下培养后,菌落颜色、形态以及分生孢子的大小有一定差异,病原菌分生孢子长圆形或洋梨形,无色或半透明,孢基偏乳头突起,双细胞,隔膜处略缢缩;在pH近中性及光照条件下,分生孢子大型化现象最显著;该菌能利用所有供试碳源,孢子大型化的最适碳源为木糖醇,在可溶性淀粉培养基上产生的孢子最小;在供试氮源中。孢子大型化最适氮源为甘氨酸,在L-胱氨酸、尿素、氯化铵培养基上不产孢子． 相似文献
13.
从沉积物的潜在降解活性、外加不同碳源后一定时间内所得到的多环芳烃降解菌的数量及其生物总量这几方面，对泉州湾海域沉积物中微生物对多环芳烃的降解活性进行研究，以期对泉州湾海域的污染有更深的了解，找到更好的方法对沿海多环芳烃污染进行治理。 相似文献
14.
黑皮鸡枞菌液体培养基优化 总被引：1，自引：0，他引：1
试验比较不同pH条件及培养基配方对黑皮鸡枞菌丝体（球）生长的影响以探讨最佳液体培养黑皮鸡枞最佳的pH及配方条件．通过预实验筛选出玉米粉、麸皮、大豆粉、K2HPO4、MgSO4为碳源、氮源及微量营养因子;用四因素四水平正交表进行试验,以菌丝体的干物质量为基准比较．结果表明：液体培养条件下,获得最高黑皮鸡枞菌丝体生物量的最佳配方为：麸皮14g／L·玉米粉11g／L·大豆粉2g／L·KH：PO4 1.2g／L·MgSO40．9g／L;最适pH为6．0． 相似文献
15.
Aquilaria agallocha can produce fragrant agarwood used for incense, traditional medicine and other products. An efficient plant regeneration
system was established via organogenesis from shoots developed from seedlings ofAquilaria agallocha. Shoots generated many buds on MS medium supplemented with 1.3 μmol/L BA (6-benzylaminopurine) in the first 7 weeks, and
the buds elongated on MS medium with 1.3 μmol/L BA+0.5 μmol/L NAA (naphthaleneacetic acid) in another 7 weeks, 2.3 shoots
2 cm in length per explant were obtained within 14 weeks. Plantlets were rooted on 1/2 MS medium after being immersed in 5
μmol/L NAA for 48 h, 96.7% of the roots grew up two weeks later. All plantlets that survived acclimatization grew well in
the pots.
Project supported by the National Natural Science Foundation of China (No. 30070066) and the Science and Technology Project
of Guangzhou City (No. 2003J1-C0241), China 相似文献
16.
FENG Dao-lun WU Zu-cheng WANG Da-hui 《浙江大学学报(A卷英文版)》2007,8(11):1846-1852
Culture of Arthrospira platensis (Spirulina platensis) in human urine was investigated to get valuable biomass. NO3-N was the proper N source, in comparison with other N source, including urea, NH4-N and NO2-N. As a result, aerobic nitrification of human urine was performed, with above 93.6% nitrification percentage finally achieved with total-N (TN) load of 46.52 mg/(L·d), in which Arthrospira platensis was successfully grown. The main compositions of the obtained biomass are close to those in Zarrouk medium. Thus, it is possible to culture Arthrospira platensis in nitrified human urine for food production within bioregenerative life support systems (BLSSs). 相似文献
17.
Studies on optimization of nitrogen sources for astaxanthin production by <Emphasis Type="Italic">Phaffia rhodozyma</Emphasis> 总被引：2，自引：0，他引：2
Ni H Chen QH Ruan H Yang YF Li LJ Wu GB Hu Y He GQ 《Journal of Zhejiang University. Science. B》2007,8(5):365-370
Fermentation ofPhaffia 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. 相似文献
18.
19.
Nitrateremovalfromdrinkingwaterisoneofthemainproblemsinwaterresearch. Severalnitrateremovalmethodssuchasionexchange, reverseosmosis, electrodialysis, distillation, chemicalreductionandbio denitrificationhavebeenemployedwithdifferentratesofefficiency[1, 2]. Bio denitrificationhasbeenprovedtobeoneofthemostfeasible, advanced,selectiveandcosteffectiveprocessesforremovingnitratebydissimilationreduction[3], whichtransformsnitrateintonitrogengas[4]. Thisprocesshasbeenappliedtonitrogenremovalofwas… 相似文献
20.
对14份土样和7株实验室保藏菌株经初筛、摇瓶复筛,得到1株油脂产量较高的酵母菌,其油脂含量为7.34%。对影响该菌体产油脂的条件进行了单因素和正交实验,得出摇瓶发酵培养的最佳产油脂条件:发酵周期为4d,酵母膏和硫酸铵混合物为氮源,接种量为12%。在该条件下测得的菌体生物量为12.211g/L,油脂产量为1.524g/L,油脂含量为12.48%。 相似文献