Properties of Rice Straw Extract after Subcritical Water Treatment

Rice straw was separated into four parts: the upper, middle, and lower parts of the stem, and the leaf. They were treated with subcritical water at 140 to 260 °C. The yield, carbohydrate, protein, and phenolic contents were obtained as well as the UV-Vis absorption spectra and the radical scavenging activity of the extracts. The extracts obtained from the stem parts had almost the same characteristics and were different from those of the leaf part. The extracts, prepared at higher temperature, exhibited higher radical scavenging ability. The radical scavenging ability and the phenolic content showed a correlation (R ²=0.92), suggesting that the phenolic substances in the extract cause its antioxidant ability.     

Variation in Biomass Properties among Rice Diverse Cultivars

Biomass properties of rice straws were compared among eight cultivars that formed a mini diverse set. The ethanol productivity from rice straws was evaluated employing a laboratory-scale method based on dilute acid-hydrolysis pretreatment. The results indicated significant variation in biomass properties among the cultivars.     

Subcritical and supercritical technology for the production of second generation bioethanol

There is increased interest in reducing our reliance on fossil fuels and increasing the share of renewable raw materials in our energy supply chain due to environmental and economic concerns. Ethanol is emerging as a potential alternative to liquid fuels due to its eco-friendly characteristics and relatively low production costs. As ethanol is currently produced from commodities also used for human and animal consumption, there is an urgent need of identifying renewable raw materials that do not pose a competitive problem. Lignocellulosic agricultural residues are an ideal choice since they can be effectively hydrolyzed to fermentable sugars and integrated in the context of a biorefinery without competing with the food supply chain. However, the conventional hydrolysis methods still have major issues that need to be addressed. These issues are related to the processing rate and generation of fermentation inhibitors, which can compromise the quality of the product and the cost of the process. As the knowledge of the processes taking place during hydrolysis of agricultural residues is increasing, new techniques are being exploited to overcome these drawbacks. This review gives an overview of the state-of-the-art of hydrolysis with subcritical and supercritical water in the context of reusing agricultural residues for the production of suitable substrates to be processed during the fermentative production of bioethanol. Presently, subcritical and/or supercritical water hydrolysis has been found to yield low sugar contents mainly due to concurrent competing degradation of sugars during the hydrothermal processes. In this line of thinking, the present review also revisits the recent applications and advances to provide an insight of future research trends to optimize on the subcritical and supercritical process kinetics.     

通过根癌农杆菌介导的共转化获得具有蜡质基因反义片段的转基因水稻

在构建剔除潮霉素抗性基因的反义蜡质基因重组质粒p13W8的基础上,用分别携带p13W8质粒和有潮霉素抗性基因的pCAMBIA1300质粒的根癌农杆菌,在不同处理条件下对粳稻3个品种进行共转化.试验结果显示,共感染混合液中pCAMBIA1300菌液比例高,抗性愈伤组织的转化频率也较高;抗性愈伤组织的PCR检测结果表明,潮霉素抗性基因的阳性检测率为98%,反义蜡质基因的阳性检测率为68%.在105株转基因植株中,反义蜡质基因阳性株为30株,占转基因植株的28.6%.乙酰丁香酮处理组的平均转化频率略高于未处理组;在乙酰丁香酮的各种处理中,直接浸泡愈伤组织的转化频率稍高于其它处理方式.     

Optimizing the Production of Antioxidant and Antibacterial Alkaloids from Macleaya cordata by Subcritical Water Extraction Technology

In this work, the subcritical water extraction technology was used to extract alkaloids from Macleaya cordata, and the effects of extraction temperature and time on its yield were investigated to find the best extraction conditions. Moreover, the antioxidant capacity and antibacterial activity of Macleaya cordata extract were studied. Furthermore, through the single-factor method, it was found that properly increasing the extraction temperature and prolonging the extraction time was conducive to increasing alkaloid yield. Still, a considerable amount of alkaloids might be decomposed by heat, resulting in a decrease in their yield. The results showed that the optimal extraction temperature of alkaloids from Macleaya cordata with subcritical water is 190 °C, the time is 45 min, and the corresponding maximum yield is 35.19±0.12 mg/g (sanguinarine equivalent in raw materials). In addition, the antioxidation and bacteriostasis abilities of subcritical water extract are better than those of traditional hot water extract, indicating that it is a feasible method to extract alkaloids from Macleaya cordata with subcritical water.     

不同品种水稻秸秆的理化特性及酶解产糖的研究

本研究以不同品种水稻秸秆为原料,测定分析了三大主要组分纤维素、半纤维素和木质素含量及理化特性的差异,并分析对比了经碱预处理后酶解及直接酶解的产糖率差异。利用X-射线衍射仪测定分析了结晶度和晶粒尺寸的异同,红外光谱仪定性评估了特定基团的差异,扫描电镜观察分析了表面形态结构的差异。综合考虑理化特性和酶解产糖率结果,与a(常规水稻黄华占)相比,5种不同品种的超级杂交水稻秸秆中,b(杂交水稻Y两优1)、c(杂交水稻隆两优2010)和f(杂交水稻Y两优143)三个品种的秸秆材料比较适合作为酶解产糖的原材料。     

Remediation of Gulf War Oil Spill Contaminated Soil by a Subcritical Water Extraction Process: Oil Removal,Recovery, and Degradation

Due to the unique properties of subcritical water (marked change in water's dielectric constant and viscosity), the extraction by subcritical water offers a great opportunity to remediate soil contaminated with organic pollutants as an alternative and green remediation method. In this study, subcritical water extraction is proposed as an efficient remediation technique for the Gulf War oil spill contaminated soil. The subcritical water extraction experiment was carried out in a lab-scale continuous flow apparatus. The three major operating factors, temperature, time and water flow rate, were evaluated in terms of optimum removal efficiency. The results show that crude oil removal depended largely on water temperature, whereas an extraction run time higher than 1 h and a water flow rate higher than 1.5 mL/min marginally or negatively affected removal efficiency. During subcritical water treatment at 300°C for 1 h at a flow rate of 1.5 mL/min, removal efficiency was almost 95%. Under these operating conditions, the subcritical water treatment demonstrated a similar removal efficiency to those of organic solvents like acetone. In contrast, the efficiency of oil recovery decreased with an increase in extraction temperature, due to degradation by a water self-oxidizing agent. Several degradation products identified in the treated soil and in the effluent sample (which initially were absent in the contaminated soil) were oxygen-containing aromatic compounds, confirming the oxidation-degradation.     

乙醇对瘤胃液接种稻秸的体外发酵产物及细菌群落结构的影响

旨在研究乙醇对山羊瘤胃液与水稻秸秆厌氧共培养的影响。利用频繁传代的体外发酵技术和高通量测序方法,分析了短链脂肪酸(SCFA)产量和细菌群落的变化。结果表明,经体外培养传代8次的稻秸发酵液的总短链脂肪酸产量显著高于瘤胃液(P<0.01);与未添加乙醇的稻秸发酵液相比,添加乙醇显著提高了乙酸、戊酸和己酸的比例,降低了丙酸和丁酸的比例(P<0.01),总SCFA产量及异丁酸和异戊酸比例无显著差异。与瘤胃液相比,稻秸发酵液的拟杆菌门(Bacteroidetes)相对丰度下降,厚壁菌门(Firmicutes)相对丰度升高(P<0.05),且添加乙醇显著提高了厚壁菌门和放线菌门(Actinobacteria)的相对丰度(P<0.05);添加乙醇使双歧杆菌属(Bifidobacterium)、未定性的毛螺菌属(unidentified Lachnospiraceae)、产琥珀酸菌属(Succiniclasticum)、脱硫弧菌属(Desulfovibrio)和未定性的梭菌属(unidentified Clostridiales)的相对丰度显著升高(P<0.05)。乙醇使稻秸发酵液的显著性差异物种(Biomarker)增加;稻秸发酵液与瘤胃液亲缘关系较近,而添加乙醇显著改变了细菌区系;短链脂肪酸比例在稻秸发酵液细菌群落多样性中具有重要作用。研究表明,体外频繁传代和添加乙醇可以提高稻秸发酵液的乙酸、戊酸和己酸产量,乙醇改变了稻秸发酵液的细菌群落结构。     

Phytoremediation of Parboiled Rice Mill Wastewater Using Water Lettuce (Pistia Stratiotes)

Phytoremediation is an emerging technology applied for treatment of wastewater. It is a suitable option notably in developing countries as it is simple, sustainable and cost effective. In the present lab-based batch study the free floating aquatic plant water lettuce (Pistia stratiotes) is used for treatment of parboiled rice mill wastewater having low pH, high chemical oxygen demand (COD), nitrogen, and phosphate. In raw rice mill wastewater (undiluted) growth of water lettuce is found to be inhibited. Later on, two different dilution approaches (raw and facultative pond effluent 1:1; raw and tap water 1:1) are applied in order to effectively use this technology. In all cases a control (without plant) is maintained to compare the performance with the Aquatic Plant based Treatment (APT) system. In the APT system results reveal that removal of soluble COD (SCOD), ammoniacal nitrogen (NH₄-N), nitrate nitrogen (NO₃-N), and soluble phosphorus (sol. P) are upto 65%, 98%, 70%, and 65% respectively. The study highlights the efficacy of water lettuce in removing organics and nutrients from parboiled rice mill wastewater.     

Convergence Properties of Monte Carlo Simulations on Fluids

Convergence properties of standard Monte Carlo simulations for various fluid systems are studied both theoretically and experimentally. It turns out that pseudo-dynamic behaviour found for homogeneous fluids with periodic boundary conditions differs substantially from that for fluids at interfaces and for other inhomogeneous, anisotropic or less than three-dimensional systems. The results are applied to the problems of error estimation and the optimum frequency of measurement of the quantities.     

Subcritical Water Extraction of Phenolic Compounds from Vaccinium Dunalianum Wight Leaves and Their Antioxidant and Tyrosinase Inhibitory Activities in Vitro

Subcritical water extraction was used to extract bioactive phenolic compounds from Vaccinium dunalianum Wight leaves. The optimal extraction conditions were determined as an extraction temperature of 150 °C, an extraction time of 40 min, and a liquid-solid ratio of 35 : 1 mL/g. The total phenolic content reached 21.35 mg gallic acid /g, which was 16 % higher than that by hot water extraction. The subcritical water extraction extract exhibited strong scavenging activity of DPPH free radical and ABTS⁺ free radical, as well as significant tyrosinase inhibitory activity. The study suggests that subcritical water extraction can alter the composition of the extracts, leading to the production of various phenolic compounds, effective antioxidants, and tyrosinase inhibitors from Vaccinium dulciana Wight leaves. These findings confirm the potential of Vaccinium dunalianum Wight as a natural antioxidant molecule source for the medicine and food industries, and for the therapy of skin pigmentation disorders.     

Screening of Rice Genes from the cDNA Catalog Using the Data Obtained by Protein Sequencing

The partial amino acid sequences of 121 rice proteins separated by two-dimensional gel electrophoresis (2D-PAGE), were determined for a protein sequence data file. In the Rice Genome Research Program (RGP), more than 20,000 cDNA clones randomly selected from rice cDNA libraries have been sequenced to construct a cDNA catalog. Complimentary DNAs encoding about 30% of proteins in the protein sequence data file could be identified in the catalog by computer search. It was deduced that 20,000–40,000 genes are present in the rice genome. Only half of about 20,000 cDNAs sequenced in the RGP, corresponding to 1/4–1/2 of genes present in the entire rice genome, should have unique sequences after considering gene redundancy. This is consistent with the fact that the cDNAs encoding about 30% of the sequenced proteins could be identified in the catalog. If the size of the cDNA catalog is enlarged further, cDNAs encoding all proteins separated by 2D-PAGE could be easily identified from the catalog by using the protein sequence data.     

利用热稳定蛋白特异条带鉴别籼粳稻的方法研究

以85份栽培稻为材料,利用SDS-聚丙烯酰胺凝胶电泳和蛋白免疫印迹技术分析籼稻和粳稻热稳定蛋白的表达差异.探讨利用特异蛋白来建立籼粳稻的鉴别方法.结果表明,在籼粳稻品种之间存在热稳定蛋白的差异表达,尤其在分子量约42～47kD范围.其中45.2kD条带(Band I)和46.5 kD(Band Ⅱ)条带为典型粳稻特异蛋白(Os03g0168100)的标志带,42.0kD条带(Band Ⅲ)为典型籼稻特异蛋白(OsI_10172)的标志带.以这3条带作为鏊别方法,并与程氏指数法进行比较,典型籼稻和粳稻的一致度分别为80.0%和86.4%,表明热稳定蛋白标志带法在一定程度上可用于鉴别典型的籼稻和粳稻.     

麦秸与稻秸浸提液对油菜及2种靶标杂草种苗生长影响的差异性研究

采用室内培养皿生物测定的方法,测试不同质量浓度（0、0.02、0.03、0.05、0.08、0.10 g·mL^-1）麦秸、稻秸浸提液对油菜及油菜田2种常见靶标杂草野燕麦（Avena fatua Linn）、播娘蒿 ［Descurainia sophia（L.）Schur］种子萌发及幼苗生长的影响。结果表明,在供试质量浓度下,麦秸与稻秸浸提液对3种受体材料种苗生长的影响存在显著差异,二者对油菜种苗生长安全的最高质量浓度分别为0.08 g·mL^-1和0.05 g·mL^-1,可以用来开发研制油菜田肥料;在对油菜安全的质量浓度下,麦秸浸提液对野燕麦种苗生长无抑制作用;而稻秸浸提液对野燕麦种苗生长的抑制作用明显,可以用来开发研制油菜田防除野燕麦的生物抑草肥;在油菜的安全的质量浓度下,麦秸、稻秸浸提液对播娘蒿种苗生长均有很强的抑制作用,且麦秸的抑制作用强于稻秸,具有开发研制油菜田治理播娘蒿的生物抑草肥料的应用前景。     

用无启动子的GUS报告基因捕获水稻基因启动子

构建了嵌合质粒p13DGUTs,它是在Ds转座子中插入了无启动子的B．葡萄糖醛酸酶报告基因(GUS),用于分离水稻基因启动子。将p13DGUTs转化粳稻品种中花11的胚性愈伤组织,获得了496个转基因植株。抗性愈伤组织与转基因植株的GUS染色与PCR分析表明整合在水稻染色体上的Ds因子都发生了随机跳跃。转基因植株T0代与部分T1代的GUS染色结果表明,M92转基因植株中Ds转座子整合位置上游的水稻基因启动子指导GUS基因的表达及表达的特性是可遗传的。文章对此方法在分离水稻基因启动子与基因上的应用进行了讨论。     

应用寡核苷酸芯片分析水稻花序相关基因在花序发育中的表达谱

从Internet、国内外文献中查询了50个水稻花序的相关基因,制备成水稻花序相关基因的寡核苷酸芯片。对3个不同生长阶段的水稻花序材料进行了表达谱检测,用ScanArray3000对杂交结果进行扫描,得到了不同的基因表达谱。用ImaGene 4.0软件对获得的表达谱进行分析,获得基因表达差异的散点图及饼图。 图像分析表明,候选基因在水稻花序3个不同发育阶段的材料中,表达水平有显著差异。这些结果将有助于研究水稻花序的发育机理。 Abstract:In this paper we chose 50 rice inflorescence genes from Internet,references.Rice oligonucleotide microarray was prepared by printing the target rice inflorescence genes oligonucleotide.Expression patterns of 50 genes from rice inflorescence in three different development phase were obtained by scanning using ScanArray3000 after array hybridization.The scatter plots and scale maps of the images were acquired after the acquired gene expression patterns were analyzed by ImaGene4.0 software.The scatter plots and scale maps show that there existed a significant difference in the expression of these candidate genes in rice inflorescences with different development phase.Further analysis of those candidate gene expression patterns will be helpful to understand the developmental mechanism of rice inflorescence.     

利用低温水浴鉴定水稻苗期耐寒性

高效准确鉴定苗期耐寒性是水稻(Oryza sativa)耐寒研究的前提。基于流动水浴温度均一这一特性, 建立了一种恒温水浴鉴定水稻幼苗耐寒性方法。该方法中环境温度设定为20°C, 水浴温度设定为4°C。根据对2个水稻亚种不同材料的处理结果, 总结出几种常见品种的低温处理时间与存活率参考值, 并对操作过程中的一些注意事项进行了说明。     

水稻主茎叶片出生与温度关系

水稻叶片生长与分蘖、根系、穗分化、节间伸长存在规律性的同伸规律［２，３．９］。水稻主茎每出一张叶片都形成和生长相应的器官。因此，可根据叶龄预报分蘖发生与成穗、节间伸长时间、穗分化进程。以此为依据可指导水稻高产栽培和杂交水稻制种的父母本播栽期。但目前水...     

基因枪转化获得的转基因水稻中外源基因整合与表达规律研究

通过基因枪法将cecropin B和bar基因共转化水稻,获得多个水稻优良品系的转化材料,对转基因的结构和表达的系统分析,发现外源基因的整合模式多种多样,有简单也有复杂,其中插入位点数的变化范围为1－7个,拷贝数的变化范围为1－10个,转基因拷贝数的多少与其表达和沉默不存在必然的联系,相同整合模式的转基因事件中基因的表达存在较大的差异,选择标记基因bar比非选择标记基因cecropin B的表达框的完整性和转录概率要高,但是发现大部分表达框完整的bar基因发生基因沉默,而在终止子发生序列丢失的cecropin B基因的表达则明显提高。