Bioemulsification and Microbial Community Reconstruction in Thermally Processed Crude Oil.

Utilization of low-cost, environmental-friendly microbial enhanced oil recovery (MEOR) techniques in thermal recovery-processed oil reservoirs is potentially feasible. However, how exogenous microbes facilitate crude oil recovery in this deep biosphere, especially under mesophilic conditions, is scarcely investigated. In this study, a thermal treatment and a thermal recurrence were processed on crude oil collected from Daqing Oilfield, and then a 30-day incubation of the pretreated crude oil at 37 °C was operated with the addition of two locally isolated hydrocarbon-degrading bacteria, Amycolicicoccus subflavus DQS3-9A1T and Dietzia sp. DQ12-45-1b, respectively. The pH, surface tension, hydrocarbon profiles, culture-dependent cell densities and taxonomies, and whole and active microbial community compositions were determined. It was found that both A. subflavus DQS3-9A1T and Dietzia sp. DQ12-45-1b successfully induced culture acidification, crude oil bioemulsification, and residual oil sub-fraction alteration, no matter whether the crude oil was thermally pretreated or not. Endogenous bacteria which could proliferate on double heated crude oil were very few. Compared with A. subflavus, Dietzia sp. was substantially more effective at inducing the proliferation of varied species in one-time heated crude oil. Meanwhile, the effects of Dietzia sp. on crude oil bioemulsification and hydrocarbon profile alteration were not significantly influenced by the ploidy increasing of NaCl contents (from 5 g/L to 50 g/L), but the reconstructed bacterial communities became very simple, in which the Dietzia genus was predominant. Our study provides useful information to understand MEOR trials on thermally processed oil reservoirs, and proves that this strategy could be operated by using the locally available hydrocarbon-degrading microbes in mesophilic conditions with different salinity degrees.

Transcriptional response of Thialkalivibrio versutus D301 to different sulfur sources and identification of the sulfur oxidation pathways.

The genus Thialkalivibrio plays an essential role in the biological desulfurization system. However, to date, the sulfur oxidation pathways of Thialkalivibrio are not clearly understood. Here, we performed transcriptomic analysis on Thialkalivibrio versutus D301 with either thiosulfate or chemical sulfur as the sulfur source to understand it. The results show that T. versutus D301 has a higher growth rate and sulfur oxidation activity when thiosulfate is utilized. The use of chemical sulfur as sulfur source leads to decreased expression of genes involved in carbon metabolism, ribosome synthesis and oxidative phosphorylation in T. versutus D301. Potentially due to the adsorption to sulfur particles, the genes related to flagellum assembly and motivation are significantly induced in T. versutus D301 in the presence of chemical sulfur. In the periplasm, both thiosulfate and polysulfide from the chemical sulfur are oxidized to sulfate via the similar truncated Sox system (SoxAXYZB). Then, part of polysulfide reached to cytoplasm through an unidentified route is oxidized to sulfite by the Dsr-like system. The sulfite in the cytoplasm is further catalyzed to sulfate by SoxB or SoeABC. Overall, the difference in the oxidation rates of D301 can be mainly attributed to the bioavailability of the two sulfur sources, not the sulfur oxidation pathways.

Efficient production of succinic acid from macroalgae hydrolysate by metabolically engineered Escherichia coli.

In this study, microbial production of succinic acid from macroalgae (i.e., Laminaria japonica) was investigated for the first time. The engineered Escherichia coli BS002 exhibited higher molar yield of succinic acid on mannitol (1.39±0.01mol/mol) than glucose (1.01±0.05mol/mol). After pretreatment and enzymatic hydrolysis, L. japonica hydrolysate was mainly glucose (10.31±0.32g/L) and mannitol (10.12±0.17g/L), which was used as the substrate for succinic acid fermentation with the recombinant BS002. A final 17.44±0.54g/L succinic acid was obtained from the hydrolysate after 72h dual-phase fermentation. The yield was as high as 1.24±0.08mol/mol total sugar, which reached 73% of the maximum theoretical yield. The results demonstrate that macroalgae biomass represents a novelty and economical alternative feedstock for biochemicals production.

Performance of a haloalkaliphilic bioreactor and bacterial community shifts under different COD/SO4²â» ratios and hydraulic retention times.

Sulfur dioxide from flue gas was converted into sulfate after the absorption of alkaline solutions. Haloalkaliphilic microorganisms have been used in reducing sulfate to decrease expenses and avoid sulfide inhibition. The effects of different COD/SO4(2-) ratios and hydraulic retention times (HRTs) on the sulfate removal efficiency and bacterial community were investigated in model experiments. Ethanol showed better performance as an electron donor than lactate. The optimum COD/SO4(2-) ratio and HRT were 4.0 and 18 h, respectively, with respective sulfate removal efficiency and rate of 97.8 ± 1.11% and 6.26 ± 0.0710 g/Ld. Sulfide concentrations reached 1,603 ± 3.38 mg/L. Based on denaturing gradient gel electrophoresis analysis of 16S rDNA, the major sulfate-reducing bacterium (SRB) was Desulfonatronovibrio sp., which was only detected at a COD/SO4(2-) ratio of 4.0 using ethanol as an electron donor. Different HRTs had no significant effect on the band corresponding to this species. PCR results show that methane-producing archaea (MPA) were from the acetoclastic methanogenic family Methanosarcinaceae. Quantitative real-time PCR did not demonstrate any significant competition between SRB and MPA. The findings of this study indicate that sulfate reduction, nitrate reduction, and sulfide oxidization may occur in the same bioreactor.

A randomized controlled trial of single point acupuncture in primary dysmenorrhea.

BACKGROUND: Acupuncture is often used for primary dysmenorrhea. But there is no convincing evidence due to low methodological quality. We aim to assess immediate effect of acupuncture at specific acupoint compared with unrelated acupoint and nonacupoint on primary dysmenorrhea. METHODS: The Acupuncture Analgesia Effect in Primary Dysmenorrhoea-II is a multicenter controlled trial conducted in six large hospitals of China. Patients who met inclusion criteria were randomly assigned to classic acupoint (N = 167), unrelated acupoint (N = 167), or non-acupoint (N = 167) group on a 1:1:1 basis. They received three sessions with electro-acupuncture at a classic acupoint (Sanyinjiao, SP6), or an unrelated acupoint (Xuanzhong, GB39), or nonacupoint location, respectively. The primary outcome was subjective pain as measured by a 100-mm visual analog scale (VAS). Measurements were obtained at 0, 5, 10, 30, and 60 minutes following the first intervention. In addition, patients scored changes of general complaints using Cox retrospective symptom scales (RSS-Cox) and 7-point verbal rating scale (VRS) during three menstrual cycles. Secondary outcomes included VAS score for average pain, pain total time, additional in-bed time, and proportion of participants using analgesics during three menstrual cycles. FINDINGS: Five hundred and one people underwent random assignment. The primary comparison of VAS scores following the first intervention demonstrated that classic acupoint group was more effective both than unrelated acupoint (-4.0 mm, 95% CI -7.1 to -0.9, P = 0.010) and nonacupoint (-4.0 mm, 95% CI -7.0 to -0.9, P = 0.012) groups. However, no significant differences were detected among the three acupuncture groups for RSS-Cox or VRS outcomes. The per-protocol analysis showed similar pattern. No serious adverse events were noted. CONCLUSION: Specific acupoint acupuncture produced a statistically, but not clinically, significant effect compared with unrelated acupoint and nonacupoint acupuncture in primary dysmenorrhea patients. Future studies should focus on effects of multiple points acupuncture on primary dysmenorrhea.

Performance of a haloalkaliphilic bioreactor under different NO3(-)/SO4(2-) ratios.

Effects of NO3(-)/SO4(2-) ratio on denitrification and sulfate removal efficiency were investigated in model experiments applying haloalkaliphilic bioreactor. The reduction of both substrates performed well at different NO3(-)/SO4(2-) ratios ranging from 17.6 to l.5. The removal rates of nitrate and sulfate were 6 and 1.39kgm(-3)d(-1), respectively, at NO3(-)/SO4(2-) ratio 3.0, while sulfide concentration reached up to 703gm(-3). The major sulfate-reducing and denitrifying bacteria were Desulfonatronovibrio sp. and Halomonas campisalis, respectively. Decrease in NO3(-)/SO4(2-) ratio led to obvious changes in bacterial community. Although the sulfate reducers became dominant, the population of denitrifying ones also increased as it was demonstrated by analysis of PCR-amplified 16S rDNA fragments, which suggested that SRB and DB coexisted well in bioreactor.

Does Traditional Chinese Medicine pattern affect acupoint specific effect? Analysis of data from a multicenter, randomized, controlled trial for primary dysmenorrhea.

OBJECTIVES: This study assessed the importance of the Traditional Chinese Medicine (TCM) pattern on an acupoint-specific effect. DESIGN: This was a TCM pattern subdivision analysis of the first intervention data from a multicenter, randomized, controlled trial (ISRCTN24863192) (the main trial). SETTINGS: The main trial recruited participants from six hospitals in three provinces in China. SUBJECTS: Five hundred and one (501) participants diagnosed with primary dysmenorrhea (PD) were enrolled in the main trial. INTERVENTIONS: The main trial randomly and equally divided participants into three treatment groups with bilateral electroacupuncture at three sites, respectively: Sanyinjiao (SP6), Xuanzhong (GB39), and an adjacent nonacupoint. Participants were diagnosed with TCM patterns before the treatment. The intervention was carried out when the visual analogue scale (VAS) score of participant's menstrual pain was ≥ 40 mm on the first day of menstruation and lasted for 30 minutes. OUTCOME MEASURES: The immediate improvement of pain was measured with a 100-mm VAS before the intervention, at 5 minutes, 10 minutes, and 30 minutes during the intervention, and at 30 minutes after the completion of this intervention. RESULTS: Three (3) TCM patterns (n=320) were eligible for analysis, including Cold and Dampness Stagnation pattern (n=184), Qi and Blood Stagnation pattern (n=84), and Qi and Blood Deficiency pattern (n=52). In Cold and Dampness Stagnation pattern, the SP6 group had a significant reduction in VAS scores compared with the GB39 group (mean difference -7.6 mm) and the nonacupoint group (mean difference -8.2 mm), respectively. There was no difference between the latter two groups. There were no group differences in VAS scores in the other two patterns. CONCLUSIONS: It suggested that TCM pattern might affect acupoint specific effect on the immediate pain relief obtained for participants with PD.

Xiaopiyishen Herbal Extract Granule Improves the Quality of Life among People with Fatigue-Predominant Subhealth and Liver-Qi Stagnation and Spleen-Qi Deficiency Syndrome.

To observe the effects of Xiaopiyishen Herbal Extract Granule (XPYS-HEG) on the quality of life in people with fatigue-predominant subhealth (FPSH) and liver-qi stagnation and spleen-qi deficiency syndrome, the participants were allocated randomly to the treatment group (XPYS, n = 100) and the control group (placebo, n = 100) in this study. The study period was 18 weeks (6 weeks for the intervention and 12 weeks for followup). The results show that there were no differences between the two groups for the scores of eight factors on the SF-36 (Chinese version of the SF-36 universal quality-of-life scale) at baseline. Compared with the baseline score, intervention with XPYS-HEG led to a significant increase in scores for the factor of bodily pain at the end of the 6th week. Compared with the score at the end of the 6th week, the score for the factor of mental health in the XPYS group significantly increased at the end of the 18th week. Therefore, XPYS-HEG could partially improve the quality of life for people with FPSH and liver-qi stagnation and spleen-qi deficiency syndrome, which can ease bodily pain, stimulate a positive mood, and ease a negative mood.

Optimization of succinic acid fermentation with Actinobacillus succinogenes by response surface methodology (RSM).

Succinic acid is considered as an important platform chemical. Succinic acid fermentation with Actinobacillus succinogenes strain BE-1 was optimized by central composite design (CCD) using a response surface methodology (RSM). The optimized production of succinic acid was predicted and the interactive effects between glucose, yeast extract, and magnesium carbonate were investigated. As a result, a model for predicting the concentration of succinic acid production was developed. The accuracy of the model was confirmed by the analysis of variance (ANOVA), and the validity was further proved by verification experiments showing that percentage errors between actual and predicted values varied from 3.02% to 6.38%. In addition, it was observed that the interactive effect between yeast extract and magnesium carbonate was statistically significant. In conclusion, RSM is an effective and useful method for optimizing the medium components and investigating the interactive effects, and can provide valuable information for succinic acid scale-up fermentation using A. succinogenes strain BE-1.

Cloud point extraction of aloe anthraquinones based on non-ionic surfactant aqueous two-phase system.

Non-ionic surfactant-based aqueous two-phase system had been investigated to extract aloe anthraquinones. It had the advantage of using a single auxiliary chemical to induce phase separation above cloud point at a low concentration. Non-ionic surfactant Triton X-114 was chosen for its excellent phase-separating ability and low cloud point. The main factors affecting the cloud point extraction were discussed such as equilibrium temperature and time, concentrations of surfactant and inorganic electrolytes, pH, etc. Under the optimised conditions, the highest extraction yield 96.93% was obtained. The reverse extraction of anthraquinones from surfactant-rich phase was achieved with a recovery of 70.35% by adjusting pH. Compared with conventional purification methods, this CPE technique can be completed in one operation; besides, it is a low-cost method and an environment friendly one.

[Effects of Xiaopi Yishen herbal extract granules in treatment of fatigue-predominant subhealth due to liver-qi stagnation and spleen-qi deficiency: a prospective, randomized, placebo-controlled and double-blind clinical trial].

BACKGROUND: The demand for effective intervention for subhealth conditions is growing with increasing numbers of people being in a state of subhealth with a poor quality of life. Future research and evaluation of the treatment methods for subhealth conditions from the perspective of traditional Chinese medicine (TCM) may provide an important direction for developing effective management of these conditions. OBJECTIVE: To evaluate the efficacy and safety of Xiaopi Yishen herbal extract granules (XPYS-HEG), a compound traditional Chinese herbal medicine for relieving fatigue and promoting a cheerful spirit for the treatment of people with fatigue-predominant subhealth due to liver-qi stagnation and spleen-qi deficiency. DESIGN, SETTING PARTICIPANTS AND INTERVENTIONS: A multi-center, randomized, double-blinded, placebo-controlled clinical study was undertaken. The study period was 18 weeks, including 6 weeks for intervention and 12 weeks for follow-up. Participants were recruited from medical center and outpatient clinics of three hospitals in China, i.e. Xiaotangshan Hospital of Beijing, the First Affiliated Hospital of Henan University of TCM and the Affiliated Hospital of Liaoning University of TCM. Two hundred participants who met the criteria of fatigue-predominant subhealth and liver-qi stagnation and spleen-qi deficiency in TCM were allocated randomly to the treatment group (XPYS, n=100) and control group (placebo, n=100). MAIN OUTCOME MEASURES: The total score of Fatigue Scale-14 (FS-14) was used to evaluate the fatigue status of subjects and the extent of liver-qi stagnation and spleen-qi deficiency syndrome was also recorded. RESULTS: Three cases in the XPYS group withdrew from the trial. There were 200 subjects who entered to full analysis set (FAS) analysis and 197 subjects fitted in the per-protocol set (PPS) analysis. (1) According to the score changes of FS-14, the effectiveness rates in the XPYS and placebo group were as follows: 14.0% vs 9.0% (FAS) and 14.4% vs 9.0% (PPS) for complete remission, 19.0% vs 15.0% (FAS) and 19.6% vs 15.0% (PPS) for obvious effects, 39.0% vs 26.0% (FAS) and 39.2% vs 26.0% (PPS) for effective, and 72.0% vs 50.0% (FAS) and 73.2% vs 50.0% (PPS) for complete efficacy. The efficacy of XPYS-HEG was superior to the placebo statistically (P<0.05). (2) According to the score changes of TCM syndrome, the effectiveness rates in the XPYS group and placebo group were as follows: 1.0% vs 0.0% (FAS) and 1.0% vs 0.0% (PPS) for complete remission, 20.0% vs 7.0% (FAS) and 19.6% vs 7.0% (PPS) for obvious effects, 29.0% vs 24.0% (FAS) and 29.9% vs 24.0% (PPS) for effective, and 50.0% vs 31.0% (FAS) and 50.5% vs 31.0% (PPS) for complete efficacy. The efficacy of XPYS-HEG was superior to that of placebo statistically (P<0.05). (3) The follow-up results at 12 weeks and 18 weeks showed that the efficacy of XPYS-HEG was superior to that of placebo statistically (P<0.05). (4) No adverse effects were found in the XPYS group. CONCLUSION: It can be concluded that XPYS-HEG is effective and safe for the treatment of people with fatigue-predominant subhealth due to liver-qi stagnation and spleen-qi deficiency.

Immediate analgesia effect of single point acupuncture in primary dysmenorrhea: a randomized controlled trial.

BACKGROUND: Acupuncture is often used for primary dysmenorrhea. OBJECTIVE: To assess the efficacy of a single point of acupuncture in the management of primary dysmenorrhea compared with sham acupuncture and no acupuncture. METHODOLOGY: Patients with primary dysmenorrhea were randomly assigned to acupoint group (n=50), unrelated acupoint group (n=50), nonacupoint group (n=46), or no acupuncture group (n=48). Acupuncture and sham acupuncture were administered once-daily for 3 days with electro-acupuncture at Sanyinjiao (SP6) that was specifically designed to treat primary dysmenorrhea, or an unrelated acupoint (Xuanzhong, GB39), or nonacupoint location. The primary outcome was pain intensity as measured by a 100-mm visual analog scale (VAS) at baseline; 5, 10, 30, and 60 minutes following the start of the first intervention. Cox retrospective symptom scale (RSS), verbal rating scale (VRS), pain total time, and proportion of participants using analgesics were also recorded during three menstrual cycles. RESULTS: The primary comparison of VAS scores demonstrated that patients receiving acupuncture (-15.56 mm, 95% CI -22.16 to -8.95, P<0.001), unrelated acupoint (-18.14 mm, 95% CI -24.81 to -11.47, P<0.001), and nonacupoint (-10.96 mm, 95% CI -17.62 to -4.30, P=0.001) treatment presented significant improvements compared with no acupuncture group. There were no significant differences among the four groups with respect to secondary outcomes. CONCLUSION: Acupuncture was better than no acupuncture for relieving the pain of dysmenorrhea following a single point of acupuncture, but no differences were detected between acupoint acupuncture and unrelated acupoint acupuncture, acupoint acupuncture and nonacupoint acupuncture.

[Clinical observation of pentazocine for postoperative intravenous analgesia in patients with lumbar herniation].

OBJECTIVE: To observe the effects and side effects of Pentazocine for postoperative intravenous analgesia in patients with lumbar herniation, and to investigate the difference of Pentazocine with different doses. METHODS: From January 2009 to December 2009, sixty patients undergone laminectomy and pedicle internal fixation, who using equal analgesic dosage of Pentazocine and Sulfentanil, were retrospectively analysed. The patients including 34 males and 26 females, aged 40 to 65 (average 59), weighted 60 to 80 kg (average 71 kg), ASA I-II, were divided into Sufentanil group and Pentazocine group I and Pentazocine group II, with 20 cases each. The regimens of the three groups included: Sufentanil of 2 g/kg; Pentazocine group I of 3 mg/kg; Pentazocine group II of 5 mg/kg. All were diluted with saline into 100 ml and were continuously infused at the rate of 2 ml/h. Visual analogue scale (VAS), Ramsay sedation scale and side effects were recorded at 4, 8, 12, 24, 36, and 48 h postoperatively. RESULTS: The three groups had no significant difference in analgesic effects, VAS of all groups were below 3. The sedation scale of Pentazocine group II at 4, 8, 12 h was higher than that at 4 h, significantly different than the other two groups. The incidence of nausea, vomiting and pruritus in Sufentanil group were higher than that in the other two groups. The incidence of respiratory depression in Sufentanil group and Pentazocine group II were higher than that in Pentazocine group II. The incidence of dizziness in Pentazocine group II were higher than that in the other two groups. CONCLUSION: Pentazocine can produce reliable postoperative analgesia for patients with lumbar herniation, as same as the effect of sulfentanil in equal dose. And Pentazocine has fewer adverse effects compared with sufentanil. 3 mg/kg of Pentazocine is an optimal dose for postoperative intravenous patient-control analgesia.

A comparative study on the immediate effects of electroacupuncture at Sanyinjiao (SP6), Xuanzhong (GB39) and a non-meridian point, on menstrual pain and uterine arterial blood flow, in primary dysmenorrhea patients.

OBJECTIVE: The objective of this study was to compare the effects of Sanyinjiao (SP6), Xuanzhong (GB39), and an adjacent non-meridian point on menstrual pain and uterine arterial blood flow in primary dysmenorrhea patients. DESIGN: The design of the study was a prospective, randomized controlled trial. SETTING: The setting of the study was the Shandong Institute of Medical Imaging, Jinan, China. PATIENTS: The patients were 52 women with primary dysmenorrhea. INTERVENTIONS: Women received electroacupuncture (EA) at SP6 (n=13), GB39 (n=14), and an adjacent non-meridian point (n=12), respectively, for 10 minutes when scored ≥40 on a 100-mm visual analog scale (VAS), and for 30 minutes on the next 2 days. There was no EA in the waiting list group (n=13). OUTCOME MEASURES: Primary outcomes were menstrual pain, resistance index (RI), and the ratio between peak systolic to end-diastolic flow velocity (S/D) in uterine arteries. Secondary outcomes included verbal rating scale (VRS) and retrospective symptom scale (RSS). RESULTS: The SP6 group had a highly significant reduction in VAS scores compared with the waiting list group (-23.19mm, 95% confidence interval [CI]-32.06 to -14.33, P<0.0001), GB39 group (-18.58mm, 95% CI -27.29 to -9.88, P<0.0001) and the non-meridian point group (-20.78mm, 95% CI -29.82 to -11.73, P<0.0001), respectively. A significant reduction in VRS scores was found in the SP6 group compared with the GB39 group (P=0.034) and the non-meridian point group (P=0.038). There were no significant differences of RI, S/D-values and RSS scores among the four groups (P>0.05). CONCLUSIONS: EA at SP6 can immediately relieve menstrual pain and minimize the influence of pain on daily life compared with GB39 and an adjacent non-meridian point. The data preliminarily show the specificity of SP6 for the immediate pain relief of primary dysmenorrhea.

pH neutralization while succinic acid adsorption onto anion-exchange resins.

Succinic acid is a useful chemical and its purification from fermentation broth by ion-exchange resins has widely drawn attention. In this study, pH neutralization in the process of adsorption of succinic acid from model solutions and fermentation broth by anion-exchange resin NERCB 04 has been tested. Adsorption capacity of NERCB 04 was about 0.41 g succinic acid/g resin at concentrations of succinic acid in the range of 10-50 g/L in packed column. In the process of succinic acid removal, pH of the system could also be neutralized. The neutralizing ability of the resin as a neutralizing agent has also been studied in the model cycle system and in the real fermentation cycle process. It was found that NERCB 04 showed stable adsorption capacity and pH neutralization ability after each regeneration. A certain amount of anion-exchange resin could neutralize the low pH values (pH 2-5) and maintain the system around pH 7.0. This means the anion-exchange resins have the function of neutralizing reagent in the process of adsorbing succinic acid.

[Study on the pH-sensitive secondary structure of gamma-PGA embedded with magnetite nanoparticles].

The conformational transition of poly gamma-glutamic acid (gamma-PGA) embedded with magnetite nanoparticles under various pH conditions was investigated by Fourier transform infrared spectroscopy (FTIR). The secondary structure content was determined through the analysis of amide I bands of Fourier deconvolution spectra, secondary derivative spectra and the Gaussian curve fitting of the original infrared spectra. The results showed that the conformation of the gamma-PGA was affected by solution pH. The total contents of beta-sheet and beta-turn were higher than 65%, while alpha-helix and random coil were low. The content of beta-turn increased with increasing pH, while the beta-sheet decreased. Additionally, the zeta potential results showed that the pH-sensitive secondary structure of gamma-PGA had influence on the stability of suspension of magnetic gamma-PGA nanospheres. The minimum value of zeta potential (-35. 4 mV) was obtained at pH 10.2.

Purification of aloe polysaccharides by using aqueous two-phase extraction with desalination.

A PEG6000/(NH4)2SO4 aqueous two-phase system was chosen as the separation system. The effects of NaCl, Gu(SCN)2 and pH on the partitioning of aloe polysaccharide and bovine serum albumin (BSA) were studied. The result shows that the recovery of aloe polysaccharide was decreased with the increase in pH and the recovery of protein was not changed; NaCl and Gu(SCN)2 can change the partitioning behaviour of the BSA. The separation of BSA and aloe polysaccharides was also carried out. Then, the aloe polysaccharides were obtained by using ultrafiltration membrane. The composition of the polysaccharides was analysed by gas chromatography. The results show that mannose is mainly monosaccharide, and it only contains a few glucose.

Recovery and purification of nicotine from waste tobacco by aqueous two-phase system/reverse extraction.

A two-step process has been developed for the purification of nicotine from waste tobacco using an aqueous two-phase system and solvent reverse extraction. The partitioning behavior of nicotine was investigated in an isopropyl alcohol/(NH4)2SO4 aqueous two-phase system. The effects of the addition of salt, pH and temperature on the partitioning behavior of nicotine were studied. The recovery rate of nicotine was 96.1% with a purity of above 99% when optimal conditions were used [(NH4)2SO4 25%, pH 9, temperature 35 degrees C, isopropyl alcohol 5 mL].

In situ magnetic separation and immobilization of dibenzothiophene-desulfurizing bacteria.

In situ cell separation and immobilization of bacterial cells for biodesulfurization were developed by using superparamagnetic Fe(3)O(4) nanoparticles (NPs). The Fe(3)O(4) NPs were synthesized by coprecipitation followed by modification with ammonium oleate. The surface-modified NPs were monodispersed and the particle size was about 13 nm with 50.8 emu/g saturation magnetization. After adding the magnetic fluids to the culture broth, Rhodococcus erythropolis LSSE8-1 cells were immobilized by adsorption and then separated with an externally magnetic field. The maximum amount of cell mass adsorbed was about 530 g dry cell weight/g particles to LSSE8-1 cells. Analysis showed that the nanoparticles were strongly absorbed to the surface and coated the cells. Compared to free cells, the coated cells not only had the same desulfurizing activity but could also be easily separated from fermentation broth by magnetic force. Based on the adsorption isotherms and Zeta potential analysis, it was believed that oleate-modified Fe(3)O(4) NPs adsorbed bacterial cells mainly because of the nano-size effect and hydrophobic interaction.

Separation and purification of Aloe polysaccharides by a combination of membrane ultrafiltration and aqueous two-phase extraction.

A two-step process was developed for the purification of polysaccharides from the pulp of Aloe varavia using aqueous two-phase system (ATPS) extraction and a novel copolymer ultrafiltration membrane. The first step was ATPS under optimal separations conditions using a total composition of 18% PEG2000, 25% ammonium sulfate, pH 3.0, and 0.3 M NaCl. To form the copolymer membrane, poly(acrylonitrile-acrylamide-styrene) was prepared by solution polycondensation using azoisobutyronitrile as initiator. Then, membranes were formed from the dissolved copolymer by the phase inversion method. Copolymer structure was investigated by infrared spectrum and thermogravimetric analysis (TGA). The copolymer membrane surface and cross section were observed by scanning electron microscopy. The water flux of this membrane was 26.33 mL/(cm(2) h), and retention was 96% for bovine serum albumin and 34% for dextran T40000. The separation and purification of aloe polysaccharide were carried using this copolymer membrane following ATPS. The TGA of aloe polysaccharide demonstrated a high purity of the polysaccharide. By gas chromatographic analysis, it was shown that mannose is the main monosaccharide in the aloe polysaccharide, and only a few glucose residues are present.