Preparation and Application of Immobilized Cells from the Fungus Mucor miehei

A laboratory bioreactor was developed for functionalizing immobilized cells of the mycelial fungusMucor miehei.The ability to use the cells to purify wastewaters from the oil-refining industry is demonstrated. With proper operation of the reactor, immobilized cells (1 g) can purify >100 l of wastewater containing 0.10-0.15% of lipid-like substances.     

Bioflocculant Exopolysaccharide Production by Azotobacter indicus Using Flower Extract of Madhuca latifolia L

Efficacy of Azotobacter indicus ATCC 9540 strain for production exopolysaccharide (EPS) bioflocculant was investigated. Mahua flower extract (Madhuca latifolia L), a natural substrate at the concentration of 20 g L^?1, gave maximum recovery of EPS followed by sucrose and mannitol as compared to other carbon sources after 172 h. Yeast extract was found to be the most effective nitrogen source as compared to beef extract, sodium nitrate, ammonium sulfate, casein hydrolysate, and urea for the production of EPS. EPS production was increased in presence of nitrogen (5.51 g L^?1) as compared to nitrogen-free medium (3.51 g L^?1), and fermentation time was also reduced by 28 h. Maximum EPS production (6.10 g L^?1) was found in the presence of 20 g L^?1 flower extract and 0.5 g L^?1 yeast extract containing Ashby’s media with 180 rpm at 30 °C at 144 h, under controlled conditions in 2.5 L fermenter using optimized medium. The isolated EPS showed cation-dependent flocculating activity. Concentration of EPS played an important role in bioflocculating activity which increased in a concentration-dependent manner up to a certain limit, with the maximum flocculation of 72% at 500 mg L^?1 concentration but remained almost static after this concentration. Extracted polymer was characterized by different chemical tests, FT-IR spectroscopy, and TLC which showed presence of uronic acids, O-acetyl groups, and Orcinol with suggestive indication of alginate like polymer. This study suggests that use of M. latifolia L. flowers can be a potential alternative bioresource for production of exopolysaccharide.     

磷酸基团在环丙沙星光敏损伤DNA中的作用

利用紫外-可见稳态吸收光谱, 稳态荧光发射光谱和激光光解瞬态光谱实验方法研究了磷酸基团在环丙沙星(CPX)光敏损伤DNA中的作用. 紫外-可见和稳态荧光光谱实验证实了磷酸根离子影响环丙沙星的稳态吸收和发射谱, 实验结果表明磷酸根是通过弱相互作用与环丙沙星结合. 我们还利用激光闪光光解实验分别研究了鸟苷(Gua), 脱氧鸟苷(dG)以及脱氧鸟苷酸(dGMP)对环丙沙星三线态(³CPX^*)的影响, 通过对比实验证实了在环丙沙星光敏损伤dGMP中, 由于磷酸基团的存在, 导致了环丙沙星三线态吸收峰的改变, 从而改变了光敏损伤反应的途径. 通过研究发现, 光敏损伤途径的改变是由于dGMP结构上磷酸基团通过氢键与环丙沙星结合所造成的. 最后, 根据实验结果并对比Gua, dG和dGMP的结构, 提出了一个合理的磷酸基团的作用机理.     

Optimization of Biodiesel Production Catalyzed by Fungus Cells Immobilized in Fibrous Supports

A circulating packed-bed bioreactor system using fibrous nonwoven fabric as the immobilization matrix was suitable for simultaneous cell growth and immobilization of Rhizopus oryzae fungus cells, which could be used for lipase-mediated production of biodiesel by methanolysis of soybean oil. Response surface methodology and 5-level-5-factor central composite rotatable design was proved to be a powerful tool for the optimization of methanolysis conditions catalyzed by immobilized R. oryzae whole cell biocatalyst. A quadratic polynomial regression model was used to analyze the relationship between the yield and the significant reaction parameters. The analysis confirmed that water content, molar ratio of methanol to oil, cell weight, and reaction time were the significant factors affecting the yield at a 95% confidence level (p?<?0.05). Under the optimum condition at 10.97% (w/w) water content, 0.64 molar ratio of methanol to oil, 2.25% (w/w) cell weight, and 23.3 h reaction time, the predicted value of yield was 72.6%. Validation experiments with yields of 70.77?±?2.46% verified the availability and the accuracy of the model.     

Effect of ethanol extract of Sphaeranthus indicus on cisplatin-induced nephrotoxicity in rats

Cisplatin is an anticancer drug extensively used against a variety of cancers. Cisplatin chemotherapy is found to manifest dose-dependent nephrotoxicity. Depletion of the renal antioxidant defence system has been suggested to be the main cause of cisplatin-induced nephrotoxicity. The purpose of this study is to investigate whether the ethanol extract of entire plant of Sphaeranthus indicus could reduce the intensity of toxicity in albino rats. Nephrotoxicity was assessed by determining the serum creatinine and urea levels and renal antioxidant status in rats after cisplatin administration (12?mg?kg(-1)?body weight, i.p.). The ethanol extract of S. indicus (150 and 300?mg?kg(-1)?body weight) was administered orally from the sixth day onwards for 10 days after cisplatin administration. The extract significantly reduced the elevated serum creatinine and urea levels. Renal antioxidant defence systems, such as superoxide dismutase, catalase, glutathione peroxidase activities and reduced glutathione level that are depleted by cisplatin therapy were restored to normal by treatment with the extract. Cisplatin-induced lipid peroxidation was also found to be markedly reduced by treatment with the extract. These results suggest that S. indicus has protective effect against cisplatin-induced nephrotoxicity, which may be attributed to its antioxidant potential.     

Production of Polyether Polyols Using Phosphate Calcium Salt

The synthesis of bifunctional polyols using glycerol phosphate calcium salt hydrate as initiator and caesium hydroxide and potassium tert-butoxide as catalyst by means of anionic polymerization was achieved. If a phosphate salt is used as initiator, this reaction allows us to obtain polyols with phosphate groups in its structure not previously described. The relationship to catalyst type was also studied. The kinetic studies revealed that there was a linear relationship between the propylene oxide consumption and time. Both the polydispersity indexes of the polyol and the reaction time decreased using caesium hydroxide instead of potassium tert-butoxide under the same synthesis conditions. The incorporation of phosphorus in the polyol chain was confirmed by MALDI-TOF spectra and ³¹P-NMR spectra. GPC analyses showed an additional small peak in the product, attributed to the allyl adduct. The purification procedure of polyether polyols was also studied by means of liquid-liquid extraction, desorption and ion exchange.     

Efficient Enantioselective Biocatalytic Production of a Chiral Intermediate of Sitagliptin by a Newly Filamentous Fungus Isolate

(S)-3-Hydroxy-1-(3-(trifluoromethyl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)-4-(2,4,5-trifluorophenyl)butan-1-one ((S)-HTPP) is a crucial intermediate for the synthesis of Sitagliptin. A fungal strain ZJPH1308, capable of the biocatalysis of ketoamide 4-oxo-4-[3-(trifluoromethyl)-5,6-dihydro-[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-one (OTPP) to (S)-HTPP with excellent enantioselectivity, was isolated from a soil sample and identified as Rhizopus microsporus var. rhizopodiformis ZJPH1308 based on its morphological characteristics and internal transcribed spacer (ITS) sequence. Some key reaction parameters involved in the bioreduction catalyzed by isolate ZJPH1308 were then optimized. It demonstrated that the bioreduction of OTPP was effective conducted at relative high temperature (45 °C), along with distilled water as reaction medium and glycerol-coupling approach for cofactor regeneration. Under the optimal conditions, the preparative-scale bioreduction gave a 93.2 % yield (with >99.9 % of enantiomeric excess (ee)) at 15 mM of OTPP and 45 °C, reaction for 24 h. The results indicated that fungal isolate ZJPH1308 can afford a thermostable carbonyl reductase and is a promising biocatalyst for clean and efficient production of valuable chiral intermediate.     

磷酸钙料浆性质对雾化干燥羟基磷灰石微球的影响

以甲烷火焰为干燥介质,将3种不同性质的磷酸钙料浆利用火焰-雾化干燥法制备出不同形态和性能的羟基磷灰石(HA)微球。对比分析了料浆成分、温度、结晶程度等参数对所得HA微球形貌、相组成、结晶度、比表面积以及孔隙分布等的影响。结果表明,料浆中的氨水在雾化干燥过程中会聚集突释,得到具有“爆破状”开口的形态的HA微球。低温并且结晶程度较低的磷酸钙料浆经过火焰-雾化快速干燥后,得到结构松散、结晶度较低、比表面积及孔体积较大的HA微球,说明料浆的性质将会直接影响火焰-雾化干燥后HA微球的特性。     

高效液相色谱法快速检测氨基葡萄糖含量

应用高效液相色谱法,建立了硫酸氨基葡萄糖氯化钾胶囊中氨基葡萄糖含量的快速测定方法。采用Hedera NH2色谱柱（250 mm ×4.6 mm,5 μm）,流动相为乙腈-磷酸缓冲液（ 65∶35）,流速为 1.0 mL/min,可变波长紫外检测器,检测波长为195 nm。 结果表明,在上述色谱条件下,氨基葡萄糖浓度在1.6~2.4 g/L范围内线性关系良好,检出限为7.81 mg/L,精密度（RSD,n=6）为0.53%;平均加标回收率为 100%,相对标准偏差为1.1%。该法准确、可靠,无需衍生反应,适用于硫酸氨基葡萄糖氯化钾胶囊中氨基葡萄糖的含量测定。     

Lipid Accumulation by Pelletized Culture of Mucor circinelloides on Corn Stover Hydrolysate

Microbial oil accumulated by fungal cells is a potential feedstock for biodiesel production, and lignocellulosic materials can serve as the carbon source to support the fungal growth. The dilute acid pretreatment of corn stover can effectively break down its lignin structure, and this process generates a hydrolysate containing mostly xylose at very dilute concentration and numerous by-products that may significantly inhibit the cell growth. This study utilized corn stover hydrolysate as the culture media for the growth of Mucor circinelloides. The results showed that Mucor cells formed pellets during the cell growth, which facilitates the cell harvest from dilute solution. The results also showed that the inhibitory effect of furfural, 5-hydroxymethylfurfural (HMF), and acetic acid could be avoided if their concentration was low. In fact, all these by-products may be assimilated as carbon sources for the fungal growth. The results proved the feasibility to reuse the cultural broth water for acid pretreatment and then use for subsequent cell cultivation. The results will have a direct impact on the overall water usage of the process.     

铬离子掺杂对LiFePO4电化学性能的影响

采用机械球磨和共沉淀的方法合成了两种Cr3＋掺杂的LiFePO4. 通过对合成样品的XRD、SEM及其电化学性能（循环性能、大电流放电性能）的研究表明，少量Cr3＋的掺杂未影响到LiFePO4的晶体结构，但显著改善了它的电化学性能，在低放电倍率（0.1 C）时，机械球磨掺杂和共沉淀掺杂Cr3＋的LiFePO4的放电容量分别为144和158 mAh•g－1，而当放电倍率提高到2 C时，两种掺杂的LiFePO4仍分别具有110和130 mAh•g－1的放电容量，且循环性能良好.同时表明通过铁源共沉淀掺杂是一条改善离子掺杂效果的有效途径.     

Effect of Phosphate Fertilization on Micronutrient Content of Maize Plant

Abstract

The effect of fertilization and irrigation on phosphate and metal content in maize was studied in an arable land plot experiment on fertilization effects. A field plot experiment was carried out at the Látókép Farm 15 km from Debrecen. Each treatment consisted of 46 m² plots, arranged in a randomized block design with four replication, where the basic treatment was fertilization; the additional treatments were crop rotation, irrigation and cultivation. The soil is Calcareous Chernozem with 2.8–3.0% humus content. The depth of the humus layer is 70–90 cm. The N-content and original P-content of the soil is average, but it is rich in K. Besides macroelements, there is no shortage of trace elements. The element content of maize was determined with a Labtam 8440M inductively coupled plasma atomic emission spectrometer after digestion. A relationship between phosphate and microelement contents in plant was studied. A linear relationship between phosphate and magnesium, and some microelement contents can be found. Linear correlation in P and Mg content of maize was found strongest (Fig 1.).     

Chemical Profile of Launaea nudicaulis Ethanolic Extract and Its Antidiabetic Effect in Streptozotocin-Induced Rats

Launaea nudicaulis is used in folk medicine worldwide to treat several diseases. The present study aimed to assess the antidiabetic activity of L. nudicaulis ethanolic extract and its effect on diabetic complications in streptozotocin-induced hyperglycemic rats. The extract was orally administrated at 250 and 500 mg/kg/day for 5-weeks and compared to glibenclamide as a reference drug at a dose of 5 mg/kg/day. Administration of the extract exhibited a potential hypoglycemic effect manifested by a significant depletion of serum blood glucose concurrent with a significant elevation in serum insulin secretion. After 5-weeks, extract at 250 and 500 mg/kg/day decreased blood glucose levels by about 53.8 and 68.1%, respectively, compared to the initial values (p ≤ 0.05). The extract at the two dosages prevented weight loss of rats from the 2nd week till the end of the experiment, compared to diabetic control rats. The extract further exhibited marked improvement in diabetic complications including liver, kidney and testis performance, oxidative stress, and relative weight of vital organs, with respect to diabetic control. Histopathological examinations confirmed the previous biochemical analysis, where the extract showed a protective effect on the pancreas, liver, kidney, and testis that degenerated in diabetic control rats. To characterize extract composition, UPLC-ESI–qTOF-MS identified 85 chromatographic peaks belonging to flavonoids, phenolics, acyl glycerols, nitrogenous compounds, and fatty acids, with four novel phenolics reported. The potential anti-diabetic effect warrants its inclusion in further studies and or isolation of the main bioactive agent(s).     

氨基葡萄糖衍生物钌络合物催化苯乙酮氢化反应

基于D-氨基葡萄糖氨基及羟基的反应,制备了缩醛化氨基葡萄糖衍生物L1及磺酰胺基葡萄糖衍生物L2~L4.将其与Ru(Ⅱ)化合物原位组成催化体系,考察了该催化体系在苯乙酮氢化反应中的催化活性,结果表明,有机基团的引入提高了氨基葡萄糖参与氢化反应的催化活性.研究了反应温度、时间及碱的种类对RuCl2(PPh3)3/L4催化苯乙酮氢化反应的影响.动力学研究结果表明,催化反应对苯乙酮为一级反应,表观活化能为37.13 kJ/mol,并提出了可能的反应机理.     

Integrated Use of Maize Bran Residue for One-Step Phosphate Bio-Fertilizer Production

Applied Biochemistry and Biotechnology - The development of bio-fertilizer inoculants is important and desirable. Two phosphate-solubilizing Bacillus subtilis strains were inoculated onto maize...     

Photogeneration of Silver Nanoparticle Facilitated by Pluronic F127 Surfactant in Ethanolic Solution

In the present study, the photo-generation of silver nanoparticles in ethanolic solution and in the presence of F127 block copolymer using UV irradiation have been investigated. The aim of the present study is preparing the green, facile and much faster method than previous studies. The kinetics of silver nanoparticles formation has been investigated by using UV-vis spectroscopy. The two-dimensioanl map technique has been used to estimate the switching time between the nucleation and growth of Ag nanoparticles. The results show that the dispersed Ag nanoparticle in ethanol can be formed by high intensity ultraviolet exposure within few minutes.     

Ester synthesis catalyzed by Mucor miehei lipase immobilized on magnetic polysiloxane-polyvinyl alcohol particles

Mucor miehei lipase was immobilized on magnetic polysiloxane-polyvinyl alcohol particles by covalent binding with high activity recovered. The performance of the resulting immobilized biocatalyst was evaluated in the synthesis of flavor esters using heptane as solvent. The impact on reaction rate was determined for enzyme concentration, molar ratio of the reactants, carbon chain length of the reactants, and alcohol structure. Ester synthesis was maximized for substrates containing excess acyl donor and lipase loading of 25 mg/mL. The biocatalyst selectivity for the carbon chain length was found to be different concerning the organic acids and alcohols. High reaction rates were achieved for organic acids with 8 or 10 carbons, whereas increasing the alcohol carbon chain length from 4 to 8 carbons gave much lower esterification yields. Optimal reaction rate was determined for the synthesis of butyl caprylate (12 carbons). Esterification performance was also dependent on the alcohol structure, with maximum activity occurring for primary alcohol. Secondary and tertiary alcohols decreased the reaction rates by more than 40%.