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The effect of magnetic Fe3O4 particles on cellulase in the enzymatic hydrolysis of sunflower seed hull was studied in different adding ways and additive amount. In the process of enzymatic hydrolysis of sunflower seed hull, the variations of cellulase activity, reducing sugar concentration and cellulose conversion were evaluated. After the reaction, the analysis of pH and surface tension of hydrolysate were also used to determine the mechanisms of cellulase by the magnetic effect. The results indicated that after adding magnetic Fe3O4, the cellulase activity, reducing sugar concentration and conversion of cellulose had an increased between the 0.5 g/L and 2.0 g/L cases after 48 h. When the additive amount of magnetic Fe3O4 was 2 g/L, the cellulase activity at 60 h was improved significantly by 25.9%. It was found that the concentration of reducing sugar was increased from 6.950 mg/mL to 8.775 mg/mL with magnetic Fe3O4 1.5 g/L. Simultaneously, compared with the blank, which the conversion of cellulose was 47.932%, the maximum celluloseconversion of samples with adding magnetic Fe3O4 was 60.531%. Besides, the stability of cellulase activity adding in times was better than in one time. After the reaction, the final surface tension of hydrolysate with 1.5 g/L magnetic Fe3O4 was the lowest in comparison with the blank. However, no significant differences were observed in the final pH of the hydrolysate.
ABSTRACT
Sulfate-reducing bacteria (SRB) are widespread in the environment. SRB are obligate anaerobes and capable of dissimilatory reduction of sulfate. SRB have application prospects in the control of environmental pollution due to that many pollutants can be removed by SRB. The biological characteristics and metabolic mechanisms of SRB are introduced, and the application of SRB in the treatment of environmental pollution is described in this paper. The research progress of Cr(Ⅵ ) reduction and Cr(Ⅵ ) removal from wastewater by SRB is reviewed, and future direction of research on the control of Cr(Ⅵ ) pollution by SRB is also analysed.
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12 strains of H2-producing bacteria were isolated and purified from anaerobic sludge, aerobic sludge and river bottom sludge by Hungate method. A new species of high efficient hydrogen production bacterium Enterococcus sp. LG1 (registration number: EU258743 ) was studied deeply. It was showed that the Enterococcus sp. LG1 was an anaerobic and Gram-negative bacterium. Sequence analysis of this type of clones showed that it was affiliated with the genus Enterococcus and it was not reported yet in other paper at present. Meanwhile, batch tests of anaerobic fermentative hydrogen production by Enterococcus sp. LG1 were investigated by using sterilization pretreated sludge as substrate. The changes of soluble COD, protein, carbohydrate and pH value during hydrogen fermentation were monitored. It was found that only hydrogen and carbon dioxide were produced by this strain and no methane was detected during fermentation. The maximal hydrogen yield was 36.48 mL/g TCOD and the hydrogen concentration in the gas phase was 73.5%. The Enterococcus sp. LG1 was a butyrate fermentation bacteria analyzed by metabolites.
ABSTRACT
<p><b>OBJECTIVE</b>To isolate the bioflocculant-producing bacteria from activated sludge and investigate the flocculating characteristics of the newly isolated bioflocculant.</p><p><b>METHODS</b>Bacteria were screened from activated sludge samples to isolate bioflocculant-producing bacteria. Flocculating activity was used as a measure of the flocculating capability of the bioflocculant.</p><p><b>RESULTS</b>A novel bioflocculant-producing bacterium was isolated, which was identified to belong to genus Aeromonas and named as Aeromonas sp. N11. Flocculating activity increased in the presence of K+, Na+, or Ca2+. The highest flocculating activities for kaolin suspension were obtained in acidic pH ranges, and optimum pHs for it were 3.0, 4.0, and 5.0 with 1 mmol/L K+, Ca+, and Na+ present, respectively. The highest flocculating activities for soil suspension were observed at pH 8.0. The bioflocculant had a good flocculating activity and could achieve a flocculating activity of 92.4% for kaolin suspension at a dosage of only 1 mgxL(-1), and its activity in kaolin suspension was decreased by only 9.2% after heating at 100 degrees C for 60 min.</p><p><b>CONCLUSION</b>The bioflocculant produced by Aeromonas sp. N11 has strong flocculating activity and high stability, which affords high possibility of its practical use.</p>
Subject(s)
Aeromonas , Metabolism , Culture Media , Flocculation , Hydrogen-Ion Concentration , KaolinABSTRACT
The effects of surfactants on the production of cellulase by Trichoderma viride in liquid substrate fermentation process were investigated. Straw was used as the sole carbon source and the surfactants were biosurfactant rhamnolipid from Pseudomonas aeruginosa and Tween 80. The changes of FPA,CMCase,Avicelase and surface tension with time were analyzed under different concentrations of the two surfactants. The results showed that the surfactants can enhance the enzyme activity of Trichoderma viride. The FPA,CMCase,Avicelase were promoted 1.08,1.6 and 1.03 times higher than the controls by rhamnolipid. The enhancement of the enzyme activity by rhamnolipid was much higher than that of Tween 80. At the same time,rhamnolipid was not degraded prior to other substrate.
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With the development of immunoassay and sensing technologies and the solid waste compost technologies being paid more and more attention,the method of immunosensor can’t be interfered by some interference factors of the commonly used analytical methods,it is of great significance to apply the immunosensor technologies in monitoring,and real-time,online measurement during compost process. The working mechanism and classification of immunosensor are briefly introduced,and the components of the complex compost system are divided into solid phase,liquid phase and gas phase. The development and application of immunosensor in compost is introduced. The latest progress in immunosensor for determination of trace toxicants is reviewed. The application of immunosensor in environmental monitoring and its future development are also discussed.
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<p><b>OBJECTIVE</b>To observe the millimeter wave therapy responses in patients with burning mouth syndrome.</p><p><b>METHODS</b>Eighty patients were randomized divided into 4 groups. The first group was treated with both millimeter wave irradiation and routine medication, the second group with millimeter wave irradiation, the third with pretending millimeter wave irradiation and routine medication and the fourth with routine medication. Pain, extravasated blood level and autonomic nerve system condition were double-blindly evaluated either before or after the treatment.</p><p><b>RESULTS</b>Statistically significant difference (P < 0.05) was found as the degree of pain was compared before and after treatment of all the 4 groups. The first and second group, which were affected by the millimeter wave irradiation, had obvious improvements in the extravasated blood level and autonomic nerve system condition (P < 0.05). When the 4 groups were compared with each other, there were significant differences (P < 0.05) between the first and the fourth groups, and the second and the fourth groups regarding the reduction of pain. According to extravasated blood level, significant differences (P < 0.05) were found in the first and third or fourth groups, the second and third or fourth groups.</p><p><b>CONCLUSIONS</b>The irradiation of holographic point by millimeter wave can improve the patients' pain, extravasated blood level and autonomic nerve system condition. It might provide a new treatment method for burning mouth syndrome.</p>
Subject(s)
Humans , Acupuncture Points , Burning Mouth Syndrome , Therapeutics , Microwaves , Therapeutic Uses , Treatment OutcomeABSTRACT
The endophytic microorganisms found widely in many kinds of plants mediate various effects to theirs hosts. In this study, seven different dominant endophytes (SDE01 to 07) isolated from a Hy-peraccumulator-Solanum nigrum L. were resistant to Cd2+, and the strain SDE06 survived even in the medium containing 80 mg/L of Cd2+. Bacteria strain SDE06 was identified as Bacillus sp.. The removal of Cd2+ of SDE06 in different conditions were studied. Under the optimal conditions, the incubating time was 36 h, the solution pH 6.0, the temperature was 37?C and the Cd2+ concentration of medium was 20 mg/L, the highest removal rate was up to 80.2% at this condition.
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The fast development of the molecular biology and the further research on the nucleic acid set a solid foundation for the development of genosensor.Genosensor is the result of combining molecular biology with microelectronics,electrochemistry,optics and etc,which will build a bridge between the life science and the information science and become one of the most important technologies for DNA information analysis and detection.The working principle,classification of genosenor and the recent research on its application in the detection of functional genes of environmental microorganisms are discussed according to the latest literature.And it is pointed out that the application in the determination of microorganism functional genes in compost is an important development orientation of genosensor.
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In order to find an easy and rapid quantitative analytical method to detect rhamnolipid produced by Pseudomonas aeruginosa, three methods, H_ 2 SO_ 4 -anthrone analysis method, L-cysteine-H_ 2 SO_ 4 method and phenol-H_ 2 SO_ 4 method, were compared in the present paper, and the influence factors were also considered.The results showed that H_ 2 SO_ 4 -Anthrone analysis method was better than the others and its optimal reaction condition was obtained.The influence to the quantitative analysis of rhamnolipid from the residual glucose and the top clean liquid layer in the ferment solution could be ignored.But the influence from the bacterial body and the middle layer of the ferment solution reached a certain degree.Thus, the bacterial body should be removed before measuring.However, the influence from the middle layer of the ferment solution could be avoided by making a standard curve which was made by using a rhamnose mixed with the middle layer ferment solution.
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Ergosterol is the important component of the fungal membrane, and having stable structure. This makes it a suitable indicator for growth of fungi. In the paper, isolation and determination techniques of ergosterol as the indicator of the fungal biomass were reviewed. The methods of extracting ergosterol include traditional saponification and refluxing, rapid physical disruption, rapid ultrasonication, supercritical fluid extraction and so on. The ergosterol determination methods are high performance liquid chromatography, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, and thin-layer chromatography, et al. The application of these techniques was also introduced. Finally, the paper prospected the feasibility of applying the ergosterol as the indicator of fungal biomass in composting.
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White-rot fungi is a kind of basidiomycetes making wood rotten. For their particular metabolism and extracellular degrading ability, they can degrade a lot of organic pollutants, and then become the hot point of international academic research. This paper reviews the recent research progress in many aspects,such as the sort and degradation mechanism of white rot fungus, advances in applied research for white rot fungi on industry and environmental pollution disposal and so on. In addition, some suggestions on the prospective application in the composting of municipal solid waste are presented in the end.