Changes in calcium accumulation and utilization efficiency and their impact on recycling,immobilization,and export across the oil palm cycle

Effective calcium(Ca)management is crucial for optimizing oil palm cultivation and enhancing crop yield.This study aimed to gain insights into the dynamics of Ca concentration,accumulation,exportation,immobilization,and recycling in various oil palm organs relative to plant age.The experiment was conducted at the Agropalma enterprise site in the northeastern region of Para State,Brazil,evaluating seven plant age treatments:2,3,4,5,6,7,and 8 years old.Employing a completely randomized design with four replications.The results demonstrated an age-related increase in Ca concentration in petioles,rachis,arrows,male inflorescences,peduncles,and fruits.Furthermore,Ca accumulation exhibited an upward trend in all organs with progressing plant age.Notably,the study revealed an enhanced Ca use efficiency across all plant organs in correlation with the age of oil palm cultivation.These findings underscore the dynamic nutritional demands of oil palm,influencing Ca immobilization,cycling,and export throughout its developmental stages.

Construction of Fusion Expression Vector of α-galactosidase-EGFP in Cucumber

[Objective] The research aimed to construct the fusion protein expression vector of α-galactosidase-EGFP （enhanced green fluorescent protein） in cucumber controlled by CaMV35S promoter.[Method] CaMV35S promoter sequence and the coding region of EGFP were amplified by polymerase chain reactions （PCR） with vector pCambia 1303 as the template.Using reverse transcript PCR technology,with total RNAs of cucumber as template,the coding region of acid α-galactosidase Ⅰ in cucumber was amplified.The above three fragments were inserted into the multiple cloning sites of expression vector pCambia 1381c.The fusion expression vector of α-galactosidase-EGFP located at the C-terminal of the target genes was constructed.[Result] After enzyme digestion and sequencing,the fusion expression of α-galactosidase-EGFP in cucumber was constructed successfully.[Conclusion] The research laid the experimental basis for further study on the subcellular localization of α-galactosidase in cucumber.

β-Galactosidase的应用研究

本文综述了β-galactosidase的国内外研究概况、作用机理以及来源，着重论述了β-galactosidase在畜牧生产、食品工业、制药工业等领域的应用。

Immobilization of activated sludge using improved polyvinyl alcohol (PVA) gel

The microbial immobilization method using polyvinyl alcohol （PVA） gel as an immobilizing material was improved and used for entrapment of activated sludge. The oxygen uptake rate （OUR） was used to characterize the biological activity of immobilized activated sludge. Three kinds of PVA-immobilized particles of activated sludge, that is, PVA-boric acid beads, PVA-sodium nitrate beads and PVA-orthophosphate beads were prepared, and their biological activity was compared by measuring the OUR value. The bioactivity of both autotrophic and heterotrophic microorganisms of activated sludge was determined using different synthetic wastewater media （containing 250 mg/L COD and 25 mg/L NH4^＋ -N）. The experimental results showed that the bioactivity and stability of the three kinds of immobilized activated sludge was greatly improved after activation. With respect of the bioactivity and the mechanical stability, the PVA-orthophosphate method may be a promising and economical technique for microbial immobilization.

Immobilization study of biosorption of heavy metal ions onto activated sludge

Activated sludge was immobilized into Ca-alginate beads via entrapment, and biosorption of three heavy metal ions, copper(Ⅱ), zinc(Ⅱ), and chromimum(Ⅱ), from aqueous solution in the concentration range of 10\_100 mg/L was studied by using both entrapped activated sludge and inactivated free biomass at pH≤5. A biphasic metal adsorption pattern was observed in all immobilized biomass experiments. The biosorption of metal ions by the biosorbents increased with the initial concentration increased in the medium. The adsorption rate of immobilized pre-treated activated sludge(PAS) was much lower than that of free PAS due to the increase in mass transfer resistance resulting from the polymeric matrix. Biosorption equilibrium of beads was established in about 20 h and the adsorbed heavy metal ions did not change further with time. No significant effect of temperature was observed in the test for free biomass while immobilized PAS appeared to be strong temperature dependent in the test range of 10 and 40℃. Besides, the content of activated sludge in the calcium alginate bead has an influence on the uptake of heavy metals. The sorption equilibrium was well modeled by Langmuir isotherm, implying monomolecular adsorption mechanism. Carboxyl group in cell wall played an important role in surface adsorption of heavy metal ions on PAS.

Immobilization of organophosphorus hydrolase enzyme by covalent attachment on modified cellulose microfibers using different chemical activation strategies:Characterization and stability studies

The plant cellulose powder was activated by two different methods using 1,4-butanediol diglycidyl ether(BTDE)and 1,1′-Carbonyldiimidazole(CDI) as the chemical coupling agents.Organophosphorus hydrolase(OPH) from Flavobacterium ATCC 27551 was immobilized on any of activated support through covalent bonding.The optimal conditions of affecting parameters on enzyme immobilization in both methods were found, and it was demonstrated that the highest activity yields of immobilized OPH onto epoxy and CDI treated cellulose were 68.32%and 73.51%, respectively.The surface treatment of cellulose via covalent coupling with BTDE and CDI agents was proved by FTIR analysis.The kinetic constants of the free and immobilized enzymes were determined, and it was showed that both immobilization techniques moderately increased the Kmvalue of the free OPH.The improvements in storage and thermal stability were investigated and depicted that the half-life of immobilized OPH over the surface of epoxy modified cellulose had a better growth compared to the free and immobilized enzymes onto CDI treated support.Also, the pH stability of the immobilized preparations was enhanced relative to the free counterpart and revealed that all enzyme samples would have the same optimum pH value for stability at 9.0.Additionally, the immobilized OPH onto epoxy and CDI activated cellulose retained about 59% and 68% of their initial activity after ten turns of batch operation, respectively.The results demonstrated the high performance of OPH enzyme in immobilized state onto an inexpensive support with the potential of industrial applications.

Human sperm immobilization effect of Carica papaya seed extracts: an in vitro study

Aim: To examine if the seed extracts of Carica papaya, which showed anfispermatogenic/sperm immobilizationproperties in animal models, could cause human sperm immobilization in vitro. Methods: Chloroform extract, ben-zene chromatographic fraction of the chloroform extract, its methanol and ethyl acetate sub-fractions and the isolatedcompounds from the sub-fractions i. e., ECP 1 & 2 and MCP 1 & 2, of the seeds of Carica papaya were used at con-centrations of 0.1%, 0.5%, 1% and 2%. Sperm motility was assessed immediately after addition of extracts and ev-ery 5 minutes thereafter for 30 minutes. Results: There were dose-dependent spermicidal effects showing an instantfall in the sperm motility to less than 20% at 2% concentration. Isolated compounds ECP 1 & 2 were more effective in-ducing a motility of less than 10%. Many of the spermatozoa became vibratory on the spot. Total inhibition of motilitywas observed within 20-25 rain at all concentrations of all products. Scanning and transmission electron microscopyrevealed deleterious changes in the plasma membrane of the head and mid-piece of spermatozoa. Sperm viability testand the number of abnormal spermatozoa after completion of incubation suggested that the spermatozoa were infertile.The effects were spermicidal but not spermiostatic as revealed by the sperm revival test. Conclusion: The results re-veal spermicidal activity in vitro of the seed extracts of Carica papaya.

Inhibition of acid mine drainage and immobilization of heavy metals from copper flotation tailings using a marble cutting waste

Acid mine drainage （AMD） with high concentrations of sulfates and metals is generated by the oxidation of sulfide beating wastes. CaCO3-rich marble cutting waste is a residual material produced by the cutting and polishing of marble stone. In this study, the feasibility of using the marble cutting waste as an acid-neutralizing agent to inhibit AMD and immobilize heavy metals from copper flotation tailings （sul- fide-beating wastes） was investigated. Continuous-stirring shake-flask tests were conducted for 40 d, and the pH value, sulfate content, and dissolved metal content of the leachate were analyzed every 10 d to determine the effectiveness of the marble cutting waste as an acid neu- tralizer. For comparison, CaCO3 was also used as a neutralizing agent. The average pH value of the leachate was 2.1 at the beginning of the experiment （t = 0）. In the experiment employing the marble cutting waste, the pH value of the leachate changed from 6.5 to 7.8, and the sul- fate and iron concentrations decreased from 4558 to 838 mg/L and from 536 to 0.01 mg/L, respectively, after 40 d. The marble cutting waste also removed more than 80wt% of heavy metals （Cd, Cr, Cu, Ni, Pb, and Zn） from AMD generated by copper flotation tailings.

Preparation of Magnetic Chitosan Nanoparticles and Immobilization of Laccase

The magnetic chitosan nanoparticles were prepared by reversed-phase suspension method using Span-80 as an emulsifier, glutaraldehyde as cross-linking reagent. And the nanoparticles were characterized by TEM, FT-IR and hysteresis loop. The results show that the nanoparticles are spherical and almost superparamagnetic. The laccase was immobilized on nanoparticles by adsorption and subsequently by cross-linking with glutaraldehyde. The immobilization conditions and charac-terizations of the immobilized laccase were investigated. The optimal immobilization conditions were as follows： 10 mL of phosphate buffer （0.1 M, pH 7.0） containing 50 mg of magnetic chitosan nanoparticles, 1.0 mg·mL-1 of laccase and 1% （v/v） glutaraldehyde, immobilization temperature of 4 ℃ and immobilization time of 4 h. The immobilized laccase exhibited an appreciable catalytic capability （480 units·g-1 support） and had good storage stability and operation stability. The Km of immobilized and free laccase for ABTS were 140.6 and 31.1 μM in phosphate buffer （0.1 M, pH 3.0） at 37 ℃, respectively. The immobilized laccase is a good candidate for the research and development of biosensors based on laccase catalysis.

Synthesis and Heavy Metal Immobilization Behaviors of Fly Ash based Gepolymer

Two aspects of studies were carried out： 1） synthesis of geopolymer by using fly ash and metakaolin; 2） Immobilization behaviors of fly ash based geopolymer in a presence of Pb and Cu ions. As for the synthesis of fly ash based geopolymer, 4 different fly ash content （10%, 30%, 50%, 70%） and 3 types of curing regimes （standard curing, steam curing and autoclave curing） were investigated to obtain the optimum synthesis condition based on the compressive and flexural strength. The experimental results show that geopolymer, containing 30% fly ash and synthesized at steam curing （80 ℃ for 8 h）, exhibits higher mechanical strengths. The compressive and flexural strengths of fly ash based geopolymer reach 32.2 MPa and 7.15 MPa, respectively. Additionally, Infrared （IR） and X-ray diffraction （XRD） techniques were used to characterize the microstructure of the fly ash geopolymer. IR spectra shows that the absorptive band at 1086 cm^-1 shifts to lower wave number around 1033 cm^-1, and the 6-coordinated Al transforms into 4-coordination during the syn-thesis of fly ash based geopolymer. The resulting geopolymeric products were X-ray amorphous materials. As for immobilization of heavy metals, the leaching tests were employed to investigate the immobilization behaviors of the fly ash based geopolymer synthesized under the above optimum condition. The leaching tests showed that fly ash based geopolymer can effectively immobilize Cu and Pb heavy metal ions, and the immobilization efficiency reached 90% greater when heavy metals were incorporated in the fly ash geopolymer in the range of 0.1% to 0.3%. The Pb exhibits better immobilization efficiency than the Cu, especially in the case of large dosages of heavy metals.

Surface Modification of Polypropylene Microporous Membrane by Atmospheric-Pressure Plasma Immobilization of N,N-dimethylamino Ethyl Methacrylate

Surface modification of polypropylene microporous membrane （PPMM） was performed by atmospheric pressure dielectric barrier discharge plasma immobilization of N,Ndimethylamino ethyl methacrylate （DMAEMA）. Structural and morphological changes on the membrane surface were characterized by attenuated total reflection-Fourier transform infrared spectroscopy （FT-IR/ATR）, X-ray photoelectron spectroscope （XPS） and field emission scanning electron microscopy （FE-SEM）. Water contact angles of the membrane surfaces were also measured by the sessile drop method. Results reveal that both the plasma-treating conditions and the adsorbed DMAEMA amount have remarkable effects on the immobilization degree of DMAEMA. Peroxide determination by 1,1-diphenyl-2-picrvlhydrazyl （DPPH） method verifies the exsistence of radicals induced by plasma, which activize the immobilization reaction. Pure water contact angle on the membrane surface decreased with the increase of DMAEMA immobilization degree, which indicates an enhanced hydrophilicity for the modified membranes. The effects of immobilization degrees on pure water fluxes were also measured. It is shown that pure water fluxes first increased with immobilization degree and then decreased. Finally, permeation of bovine serum albumin （BSA） and lysozyme solution were measured to evaluate the antifouling property of the DMAEMA-modified membranes, from which it is shown that both hydrophilicity and electrostatic repulsion are beneficial for membrane antifouling.

Sperm immobilization activity of Allium sativum L. and other plant extracts

<abstract>Aim: To identify possible spermicidal agents through screening a number of edible medicinal plants with antimicrobial activity. Methods: Initial screening was made on the basis of ram cauda epididymal sperm immobilization immediately after addition of extracts. The most potent extract was selected and was evaluated on both ram and human spermatozoa. To unravel its mode of action several sperm functional tests were carried out, namely viability of cells, hypo-osmotic swelling test for membrane integrity and assays of membrane-bound enzyme 5'-nucleotidase and acrosomal marker enzyme acrosin. Results: The crude aqueous extract of the bulb of Allium sativum L. showed the most promising results by instant immobilization of the ram epididymal sperm at 0.25 g/mL and human ejaculated sperm at 0.5 g/mL. Sperm immobilizing effects were irreversible and the factor of the extract responsible for immobilization was thermostable up to 90 癈. On boiling at 100 癈 for 10 minutes, this activity was markedly reduced. Moreover, this extract was able to cause aggregation of ram sperms into small clusters after 30 minutes of incubation at 37 癈. However this property was not found in human spermatozoa. More than 50 % reduction in sperm viability and hypo-osmotic swelling occurred in treated sperm as compared with the controls, indicating the possibility of plasma membrane disintegration which was further supported by the significant reduction in the activity of membrane bound 5'-nucleotidase and acrosomal acrosin. Conclusion: The crude aqueous extract of A. sativum bulb possesses spermicidal activity in vitro.

Immobilization of microorganisms using carrageenan gels coated with chitosan and application to biodegradation of 4-chlorophenol

A new cell immobilization method based on the replacement of KCl by KCl+chitosan as the gelling agent was developed. The experimental results showed that through addition of chitosan into gelling agent, the mechanical strength and the thermal stability of the carrageenan gel were greatly improved. The new immobilization method was used to entrap a chlorophenol degrading microorganism. The immobilized microbial cells were applied for chlorophenol biodegradation. The experiments demonstrated that immobilized cells exhibit a higher bioactivity in the degradation of chlorophenol than free cells.

Neuropeptide Y and leptin receptor expression in the hypothalamus of rats with chronic immobilization stress

In this study, Sprague-Dawley rats were immobilized to a frame for 3 hours a day for 21 days to establish a model of chronic immobilization stress. The body weight and food intake of rats subjected to chronic immobilization stress were significantly decreased compared with the control group. Dual-labeling immunofluorescence revealed that the expression of leptin receptor and the co-localization coeffient in these leptic receptor neurons in the arcuate nucleus of the hypothalamus were both upregulated, while the number of neuropeptide Y neurons was decreased. Chronic immobilization stress induced high expression of leptin receptor in the arcuate nucleus and suppressed the synthesis and secretion of neuropeptide Y, thereby disrupting the pathways in the arcuate nucleus that regulate feeding behavior, resulting in diminished food intake and reduced body weight.

Non-Fusion and Fusion Expression of β-Galactosidase from Lactobacillus bulgaricus in Lactococcus lactis

Objective To construct four recombinant Lactococcus lactis strains exhibiting high β-galactosidase activity in fusion or non-fusion ways, and to study the influence factors for their protein expression and secretion. Methods The gene fragments encoding β-galactosidase from two strains of Loctobacillus bulgaricus, wch9901 isolated from yogurt and 1.1480 purchased from the Chinese Academy of Sciences, were amplified and inserted into lactococcal expression vector pMG36e. For fusion expression, the open reading frame of the β-galactosidase gene was amplified, while for non-fusion expression, the open reading frame of the β-galactosidase gene was amplified with its native Shine-Dalgarno sequence upstream. The start codon of the β-galactosidase gene partially overlapped with the stop codon of vector origin open reading frame. Then, the recombinant plasmids were transformed into Escherichia coli DH5α and Lactococcus lactis subsp, lactis MG1363 and confirmed by determining β-galactosidase activities. Results The non-fusion expression plasmids showed a significantly higher β-galactosidase activity in transformed strains than the fusion expression plasmids. The highest enzyme activity was observed in Lactococcus lactis transformed with the non-fusion expression plasmids which were inserted into the β-galactosidase gene from Lactobacillus bulgaricus wch9901. The β-galactosidase activity was 2.75 times as high as that of the native counterpart. In addition, β-galactosidase expressed by recombinant plasmids in Lactococcus lactis could be secreted into the culture medium. The highest secretion rate （27.1%） was observed when the culture medium contained 20 g/L of lactose. Conclusion Different properties of the native bacteria may have some effects on the protein expression of recombinant plasmids. Non-fusion expression shows a higher enzyme activity in host bacteria. There may be a host-related weak secretion signal peptide gene within the structure gene of Lb. bulgaricus β-galactosidase, and its translation product may introduce the enzyme secretion out of cells in special hosts.

In-situ Leaching-immobilization of Lead in Soilvegetable System Based on Coupling of Remediation & Production

[Objective] The aim was to seek effective soil remediation technologies suitable for soils slightly or moderately polluted. [Method] In-situ leaching-immobi- lization was used to research remediation soil and vegetable contaminated by lead in vegetable bases in Chongqing. [Result] By tartaric acid-based leaching-sodium sulphide-based immobilization, vegetable Pb reduction rate was 46.4%, soil Pb reduction rate was 8.45% and Pb immobilization rate was 9.3% in deeper horizons. EDTA leaching did reduce lead content in vegetables, but reduced vegetable yield simultaneously. [Conclusion] The coupling remediation technology brought heavy metal contents down in vegetables without affecting productions. Therefore, it guarantees vegetable safety and reduces vegetable farmer＇s economic loss. It is a remediation technology suitable for soils slightly or moderately contaminated by heavy metals.

Hydration Characteristics and Immobilization of Cr(Ⅵ) in Slag Cement-CKD Pastes under Hydrothermal Treatment

The effect of hydrothermal curing regimes on the hydration characteristics of slag cement containing different ratios of cement kiln dust has been studied. The samples for this study were combination of slag cement and cement kiln dust(5%-25%) without and with immobilization of 5% Cr(VI) by mass. Pastes were hydrothermally treated at 180 ℃ for different periods(2-24 h) in well closed stainless steel capsule. The hydration characteristics of these pastes were studied by measuring the compressive strength, bulk density, total porosity and combined water content. The findings were further supported by XRD and SEM analysis. The results indicated that the hydration characteristics of slag cement paste containing cement kiln dust 10% by mass were enhanced, especially at later ages(24 h) of hydration. That is due to the hydrothermal curing regimes of immobilized pastes accelerating hydration reactions and precipitation of Ca Cr O4, indicating that Cr(VI) can be solidified in the cement paste. This precipitation leads to pore formation in hydrated slag cement pastes.

Photochemical surface modification of poly(arylsulfone) ultrafiltration membrane and covalent immobilization of enzyme

The sensitivity of poly(arylsulfone)(PSf) for UV irradiation in different solvents(water and ethanol) was investigated. It is confirmed that acrylic acid(AA) and acrylamide(AAm) are grafted only onto the surface of the membrane instead of the interior by FTIR and scanning electron microscope(SEM). The membrane performance(Δ J/J 0 and contact angle θ ) after photografting was studied. In the range of conditions used, the grafting yield increases with irradiation time and monomer concentration growing. After photografting and N 3 dimethyl aminopropyl N' ethycarbodiimide hydrochloride(EDC) activation, PSf membrane was immobilized with hydrogen peroxide oxidoreductase, and showed a higher activity than the control membrane.

Synthesis of phosphate-embedded calcium alginate beads for Pb(Ⅱ) and Cd(Ⅱ) sorption and immobilization in aqueous solutions

The phosphate-embedded calcium alginate beads were successfully synthesized based on sodium alginate, calcium dihydrogen phosphate and sodium hydrogen carbonate. Scanning electron microscopy, Fourier transformed infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were conducted to characterize the morphology and structure of the phosphate-embedded calcium alginate beads. The effects of pH and the initial concentration of the metal ions on Pb(II) and Cd(II) sorption by the beads were investigated. The optimal pH values for Pb(II) and Cd(II) sorption are 4.0 and 5.5, respectively. The optimal initial concentrations of Pb(II) and Cd(II) are 200 mg/L and 25 mg/L, correspondingly, and the removal efficiencies are 94.2% and 80%,respectively. The sorption mechanism is that the heavy metal ions accessed the beads firstly due to the large surface area, combinedwith OH?, and then precipitated with phosphate radical, which was proven by FTIR and XRD. The sorption of Pb(II) and Cd(II) isfitted to Langmuir isotherm model with R2 values of 0.9957 and 0.988, respectively. The sorption capacities of Pb(II) and Cd(II) are263.16 mg/g and 82.64 mg/g, respectively. The results indicate that the phosphate-embedded calcium alginate beads could be appliedto treating Pb(II)/Cd(II)-containing wastewater and it could be implied that the synthesized beads also could be used as a kind of soil ameliorant for remediation of the heavy metal contaminated paddy soil.

Immobilization of Bovine Serum Albumin on Poly(ether ether ketone) for Surface Biocompatibility Improvement

UV-induced graft polymerization of acrylic acid（AA） on poly（ether ether ketone）（PEEK） films was carried out to introduce ―COOH for the subsequent immobilization of bovine serum albumin（BSA）.BSA was introduced on PEEK surface based on the condensation reaction between ―NH 2 and ―COOH.The modified surface（PEEK-BSA） was characterized by energy-disperse spectrometry（EDS）,X-ray photoelectron spectroscopy（XPS）,water contact angle measurement and UV spectrum analysis.The contact angle was found to decrease from 104° for the virgin PEEK films to 63° for the BSA-immobilized PEEK films,demonstrating a significant improvement of surface hydrophilicity.Moreover,the appearance of nitrogen on PEEK film confirmed by XPS and EDS indicates the immobilization of BSA on PEEK surface.