Responses of Sesbania rostrata and S. cannabina to Pb, Zn, Cu and Cd toxi-cities

Responses of Sesbania rostrata and S. cannabina to Pb, Zn, Cu and Cd toxicities were assessed by a seed-suspending seedbed(SSS) approach. The results showed that the SSS approach was suitable for testing the tolerance of a plant to the stress of toxic metals. The endpoints include seed germination success, straightened radicle and hypocotyl of the seedlings from the seeds. The measurements could be done easily and accurately. It was found that the elongation of radicle was the most sensitive indicator to the stress of heavy metals among the endpoints. When exposure to lower or medium concentrations of Pb, Zn, and Cd, the development of the lateral roots were favorable. Species of S. rostrata was more tolerant than S. cannabina to the heavy metals, especially to Zn and Cd. The ED 50 of Pb, Zn, Cu and Cd were 32.90, 5.32, 4.40 and 12.00 μg/ml for S. rostrata, respectively, and they were 30.11, 2.87, 4.05 and 4.94 μg/ml respectively for S. cannabina.

Cd、Cu对长喙田菁Sesbania rostrata各器官亚显微结构的影响

研究了重金属镉和铜处理了6d的长喙田菁根和叶细胞亚显微结构的变化。结果表明,无论是镉还是铜的处理,亚显微结构的变化均相似,而且植株外观形态变化与亚显微结构的变化相吻合。通过实验可看到,0.10mmol·L-1是镉和铜处理长喙田菁的临界浓度。而细胞中已破坏的细胞器和未被破坏的细胞器的共存表明,长喙田菁细胞中存在对镉和铜的耐性机理,使植物在镉和铜的处理下仍能生长。

愈伤组织悬浮培养法研究长喙田菁(Sesbania rostrata)根、茎、叶的重金属抗性

通过悬浮培养长喙田菁 (Sesbaniarostrata)愈伤组织 ,分别研究长喙田菁根、茎、叶各器官对重金属胁迫的反应 ,并量化各器官的重金属抗性 .研究结果表明 ,愈伤组织悬浮培养方法能够有效测定植物根、茎、叶的重金属抗性 ;长喙田菁根愈伤组织对Pb、Zn、Cu和Cd的抗性远高于茎和叶愈伤组织 ,叶愈伤组织则对各重金属较为敏感 ,其抗性只有根的 1/ 8～ 1/ 4.Pb对根、茎、叶的半抑制质量浓度分别为 80 ,40和 15mg/L ,Zn则分别为 80 ,30和 10mg/L ,Cu分别为 2 0 ,8和 4mg/L ,Cd分别 15 ,8和 6mg/L .

Telomere-to-telomere genome of the allotetraploid legume Sesbania cannabina reveals transposon-driven subgenome divergence and mechanisms of alkaline stress tolerance

Alkaline soils pose an increasing problem for agriculture worldwide,but using stress-tolerant plants as green manure can improve marginal land.Here,we show that the legume Sesbania cannabina is very tolerant to alkaline conditions and,when used as a green manure,substantially improves alkaline soil.To understand genome evolution and the mechanisms of stress tolerance in this allotetraploid legume,we generated the first telomere-to-telomere genome assembly of S.cannabina spanning~2,087 Mb.The assembly included all centromeric regions,which contain centromeric satellite repeats,and complete chromosome ends with telomeric characteristics.Further genome analysis distinguished A and B subgenomes,which diverged approximately 7.9 million years ago.Comparative genomic analysis revealed that the chromosome homoeologs underwent large-scale inversion events(>10 Mb)and a significant,transposon-driven size expansion of the chromosome 5A homoeolog.We further identified four specific alkali-induced phosphate transporter genes in S.cannabina;these may function in alkali tolerance by relieving the deficiency in available phosphorus in alkaline soil.Our work highlights the significance of S.cannabina as a green tool to improve marginal lands and sheds light on subgenome evolution and adaptation to alkaline soils.

Enhanced adaptability of Sesbania rostrata to Pb/Zn tailings via stem nodulation

Sesbania rostrata is wellknown for its stem nodulation, but the roles of stem nodulation in root nodulation and adaptation of S. rostrata to Pb/Zn-enriched tailings environment has been poorly understood. We investigated the effects of inoculating （with stem nodule treatment） and non-inoculating （without stem nodule treatment） Azorhizobium caulinodans on the growth, root nodulation, and N fixation of S. rostrata grown on three different types of soil substrata： Pb/Zn tailings, garden soil amended tailings, and garden soil. The results showed that plant height, stem basal diameter, biomass, chlorophyll content, nitrogen content and N-accumulation per plant were 2.3%-4.9%, 2.2%-7.7%, 27.8%-72.2%, 17.1%-23.5%, 12.3%-34.2%, and 43.1%-131.2%, respectively, higher in treatments with stem nodule than those without stem nodule for the same soil substrate. With respect to soil substrata, all measurements had consistently higher values in tailings than in amended tailings and garden soil, indicating that the poorer the soil condition, the greater the contribution of stem nodule. In contrast, the number and fresh weight of root nodules on plants without stem nodule were 6.9-11.6 times and 5.8-29.0 times higher than those with stem nodule, respectively, especially with respect to the plants grew on Pb/Zn tailings. In general, stem nodulation favored plant growth and nitrogen fixation of S. rostrata, but suppressed root nodulation. With the ability of stem and root nodulation, S. rostrata can be used as a pioneer plant species for remediation of Pb/Zn tailings.

Bioprospecting for anti-Streptococcus mutans:The activity of 10% Sesbania grandiflora flower extract comparable to erythromycin

Objective:To search an herbal material,capable of inhibiting plaque producing bacteria Streptococcus mutans.Methods:Twenty materials comprising 10 flowers and 10 rhizomes were extracted with70% ethanol.Their activity was then examined at a concentration of 10%(w/v) against Streptococcus mutans in vitro on Mueller–Hinton media.Erythromycin(Oxoid,20 mg disc) was used as a positive control.Meanwhile,to establish a fingerprint guide for authentication or quality control,the most potent material was further analyzed regarding its chemical constituents by means of reversed phase-high performance liquid chromatography(HPLC) and thin-layer chromatography(TLC).Results:Of the tested samples,Sesbania grandiflora(S.grandiflora) flower and Costus speciosus rhizome extracts showed the most potent activity with inhibited zone diameters of 18.5 and 14.8 mm,respectively.On the other hand,other extract plants showed a diameter zone in the range of 0.5–10.6 mm or being inactive(diameter=0 mm).The activity of S.grandiflora was comparable to that of erythromycin(diameter=18.0 mm).The best separation was achieved on HPLC system with acetonitrile-water with a ratio of2:8,and a flow rate at 0.5 m L/min.TLC,meanwhile,was featured on chloroform–methanol(8.5:1.5) as a mobile system.Conclusions:S.grandiflora flower is a promising material to be developed as the active ingredient of anti-plaque toothpaste as well as mouthwash solution.The developed HPLC and TLC system can be used for a further standard in its material authentication as well as for a fingerprinting of quality control during the manufacturing process.

不同豆科田菁属(Sesbania spp)绿肥对酸性土壤有机碳含量的影响

豆科植物是热带、亚热带地区重要的绿肥资源,为了探明我国豆科绿肥的培肥效果,笔者通过田间试验,研究施用7份野生豆科田菁属绿肥后酸性土壤有机碳含量随时间的动态变化。结果表明,施用绿肥后,不同种质绿肥对土壤有机碳含量的影响不同,且不同绿肥对土壤有机质碳含量的影响效果随着施用时间的变化而不断变化;虽然不同田菁绿肥对土壤有机质含量影响的效果不一,但在施用1年内均能显著(P<0.05)增加土壤有机碳的含量,并在施用1个月后效果最好,但随着时间的延长,土壤有机碳含量不断降低。

Endophytic fungi of wild legume Sesbania bispinosa in coastal sand dunes and mangroves of the Southwest coast of India

Evaluation of 450 surface sterilized tissue segments of a seasonal wild legume, Sesbania bispinosa （Jacq.）, of coastal sand dunes and mangroves of southwest India yielded 546 isolates comprising 39 endophytic fungi with six dominant taxa （Aspergillus flavus, Aspergillus niger, Cladosporium tenuissimum, Fusarium moniliforme, Penicillium chrysogenum and morpho sp. 1）. A consortium of saprophytic, pathogenic and toxigenic fungi exists as endophytes in S. bispinosa. Number of segments colonized, number of isolates obtained, species richness and diversity were higher in S. bispinosa in mangroves compared to coastal sand dunes. Seeds yielded more fungal isolates, but species richness and diversity were low. In spite of low fungal colonization in root segments, the diversity was high. Up to 30-40 % endophytic fungi of S. bispinosa differed between coastal sand dunes and mangroves revealing partial host- and habitat-specificity. As S. bispi- nosa is extensively used as green manure and forage in southwest India, further studies especially on the bioactive compounds of its endophytic fungi might broaden its range of uses. In addition to conventional morphologicaltechniques, molecular tools would provide precise insight on the endophytic fungi of coastal sand dunes and mangroves.

Interaction of Glufosinate and <i>Colletotrichum truncatum</i>on Ammonia Levels and Glutamine Synthetase Activity in Hemp Sesbania

The use of microbes and microbial products as bioherbicides has been studied for several decades, and combinations of bioherbicides and herbicides have been examined to discover possible synergistic interactions to improve weed control efficacy. Bioassays were conducted to assess possible interactions of the herbicide glufosinate [2-amino-4-(hydroxymethylphosphinyl) butanoic acid] and Colletotrichum truncatum (CT), a fungal bioherbicide to control hemp sesbania (Sesbania exaltata)]. Glufosinate acts as a glutamine synthetase (GS) inhibitor that causes elevated ammonia levels, but the mode of action of CT is unknown. GS has also been implicated in plant defense in certain plant-pathogen interactions. The effects of spray applications of glufosinate (1.0 mM) orbioherbicide (8.0 × 104 conidia ml-1), applied alone or in combination were monitored (88 h time-course) on seedling growth, GS activity and ammonia levels in hypocotyl tissues under controlled environmental conditions. Growth (elongation and fresh weight) and extractable GS activity were inhibited in tissues by glufosinate and glufosinate plus CT treatments as early as 16 h, but CT treatment did not cause substantial growth reduction or GS inhibition until after ~40 h. Generally, ammonia levels in hemp sesbania tissues under these various treatments were inversely correlated with GS activity. Localization of hemp sesbania GS activity on electrophoretic gels indicated a lack of activity after 30 h in glufosinate and glufosinate plus CT-treated tissue. Untreated control tissues contained much lower ammonia levels at 24, 64, and 88 h after treatment than treatments with CT, glufosinate or their combination. CT alone caused elevated ammonia levels only after 64 - 88 h. Glufosinate incorporated in agar at 0.25 mM to 2.0 mM, caused a 10% - 45% reduction of CT colony radial growth, compared to fungal growth on agar without glufosinate, and the herbicide also inhibited sporulation of CT. Although no synergistic interactions were found in the combinations of CT and glufosinate at the concentrations used, further insight on the biochemical action of CT and its interactions with this herbicide on hemp sesbania was achieved.

Biological Control of the Weed Sesbania exaltata Using a Microsclerotia Formulation of the Bioherbicide <i>Colletotrichum truncatum</i>

Colletotrichum truncatum, grown on rice grain (3 to 4 weeks, 22°C to 24°C) produced a fungus-infested rice mixture of microsclerotia and conidia (spores) in a ratio of ~9:1, respectively. Greenhouse tests of this formulation (0.4 to 50 mg finely-ground fungus-rice product) which applied pre-emergence to 5 cm2 of soil surface, caused 22% to 96% hemp sesbania plant mortality, after 14 days. Post-emergence treatment (fungus-rice aqueous formulation;2.4 × 105 microsclerotia ml-1, 30% unrefined corn oil and 0.2% Silwet L-77 surfactant) of weeds surviving the pre-emergence application, resulted in 93% mortality, after 14 days. Based on greenhouse results, field tests were undertaken: 1) pre-emergence treatment (fungus-rice formulation at 2.4 × 105 microsclerotia cm-2), 2) post-emergence (fungus-rice product in 30% unrefined corn oil, 0.2% Silwet) only treatment, applied 15 days after planting and 3) pre-emergence treatment followed by post-emergence treatment (fungus-rice product in 30% unrefined corn oil, 0.2% Silwet) applied 15 days after planting to surviving weeds. Control treatments were: 1) autoclaved rice product sans fungus, 2) unrefined corn oil (30% unrefined corn oil, 0.2% Silwet in water) and 3) untreated plants. Planting dates were: early season (April-May), early-mid season (June-July), late-mid season (July-August), and late season (September-October). Weed mortality was recorded at 15 days for the pre-plus post-treatment, and at 30 days after planting for the pre-emergence only and the post-treatment only. The early season, pre-emergence treatment caused 67% hemp sesbania mortality (3-yr average) within 15 days and the post-emergence treatment caused 91% mortality of the surviving weeds. In the late-mid-season, pre-emergence treatment caused minimal (<5%) mortality at 15 days, but mortality in the post-emergence treatment was >80%. Results suggest that seasonal environmental conditions are important in the efficacy of this C. truncatum-rice product formulation when applied pre- or post-emergence to this onerous weed.

Biological and physiological parameters of <i>Bulinus truncatus</i>snails exposed to methanol extract of the plant <i>Sesbania sesban</i>plant

The effects of sublethal concentrations of methanol extract of sesbania sesban plant on survival rate, egg laying of Bulinus truncatus snails, hatchability of their eggs, infection rate with Schistosoma haemato- bium miracidia, cercarial production and certain physiological parameters of treated snails were stu- died. The sublethal concentrations of the tested plant extract (LC0, LC10 and LC25) caused considerable reduction in survival rates;egg production of B. runcates snails;hatchability of eggs as well as in the infectivity of Schistosoma haematobium miracidia to the snail. Also, the tested concentrations reduced the cercarial production per snail and the period of cer-carial shedding. The glucose level in haemolymph of exposed snails was elevated while the glycogen, pro-tein content and the activities of hexokinase (HK), pyruvatekinase (PK) and lactate dehydrogenase (LDH) showed a decrease in soft tissues when compared with the control group. It was concluded that the app lication of sublethal concentration of methanol ex- tracts of Sesania sesban may be helpful in snail con- trol as it interferes with the snails’ biology and phy- siology.

Sesbania grandiflora (L.) Pers.(Agati):its ethnobotanical knowledge,phytochemical studies,pharmacological aspects,and future prospects

The review focuses on the phytochemical and pharmacological aspects of the medicinalplant Sesbania grandiflora L. It has a limited lifespan with beneficial properties. Therasapanchaka properties provide a broad spectrum of traditional uses and benefits.Phytochemical studies and their isolated compounds (phenol, antiarol, erucic acid,isoflavonoids, kaempferol, etc.) have different therapeutic and pharmacological activities ondifferent diseases, such as antibacterial, antimicrobial, tuberculosis, ulcers, anti-arthritic,anti-cancer, etc. Different plant extracts are synthesised using different nanoparticles (Ag,CdO, ZnO, Au, etc.) to study their biological and physical properties and their effects ondifferent diseases. The plant is also known for its potential commercial applications, such asleaves as fodder, wood as firewood, and flowers as an ornamental ingredient. The study hasbeen carried out by referring to various research papers. The review highlights majorphytochemicals and their isolated compounds, their pharmacological properties,commercial and ethnobotanical uses, and their recent advances in research.

Phytochemical Screening and Acute Toxicity Evaluation of Leaves Extract of Two Fabaceae’s Species: <i>Sesbania pachycarpa</i>DC. and <i>Indigofera berhautiana</i>Gillett

Objective: The aim of this study is to screen chemical composition and to evaluate the acute general toxicity of leaves aqueous extracts from Sesbania pachycarpa DC. (Fabaceae), used in traditional medicine in Burkina Faso to treat malaria, helminthiasis, and aqueous extracts of the leaves from Indigofera berhautiana Gillet (Fabaceae) used to treat hepatitis and typhoid fever. Methods: Aqueous decoction of leaves from Sesbania pachycarpa DC. or Indigofera berhautiana Gillett which are the form of use recommended by traditional health practitioners, were used for tests. Aqueous extracts used to evaluate the acute toxicity, were studied on mice of strain NMRI. For the toxicity study, the doses of the aqueous extracts were respectively 5 mg/kg, 50 mg/kg, 300 mg/kg and 2000 mg/kg of body weight. Phytochemical screening was done to identify the phytochemicals contained in extracts. Results: Aqueous extracts of two species: Sesbania pachycarpa DC., Indigofera berhautiana Gillet were not toxic at the maximum dose of 2000 mg/kg of body weight. Phytochemical screening, showed coumarins, flavonoids, tannins, polyphenols compounds, steroids and/or triterpenes and saponosides in the aqueous extracts of the two species. Alkaloids were identified in Sesbania pachycarpa aqueous extract.

施氮对田菁翻压还田滩涂盐渍土碳氮及细菌群落结构的影响

为探讨不同施氮处理下田菁翻压还田对滩涂盐渍土的改良效果,通过田间小区试验研究了不同施氮水平下(CK、SN1、SN2、SN3、SN4对应的施氮量分别为0、90、135、180、225 kg/hm^(2))绿肥田菁还田对土壤碳氮、pH、水溶性盐和细菌群落结构的影响。结果表明:SN3处理下田菁生物量和碳、氮累积量最高,分别为41 882、3 756和101.5 kg/hm^(2)。作绿肥翻压还田后,则以SN2处理土壤有机碳、全氮含量最高,分别为6.51 g/kg和0.637 g/kg。各施氮处理下,田菁翻压后土壤微生物生物量碳氮含量低于CK处理。随田菁翻压量的增加,土壤pH呈逐步下降趋势,而土壤水溶性盐总量则随施氮水平和翻压量的增加而上升,但较种植前明显降低。不同施氮处理田菁翻压后,土壤中具有一定有机降解功能的变形菌门、酸杆菌门、拟杆菌门、放线菌门和绿弯菌门等细菌类群占据主导地位,且相对丰度随田菁翻压量的增加呈一定变化趋势,但细菌群落结构变化不明显。土壤门水平优势菌群相对丰度与土壤碳氮含量、pH和水溶性盐总量等指标均呈一定的相关关系,其中以拟杆菌门、厚壁菌门、蓝菌门、绿弯菌门和迷踪菌门相对丰度与土壤有机碳和全氮含量的相关性较显著。综上所述,SN2处理下田菁翻压还田可显著提升滩涂土壤有机碳和全氮含量;不同施氮水平下生长的田菁翻压还田后,土壤水溶性盐总量均较种植前显著降低,主要优势菌群均有利于绿肥降解与土壤培肥,改善滩涂土壤微生态环境。

田菁不同部位营养价值、分子结构特性和体外瘤胃降解率研究

本试验旨在研究田菁不同部位(包括叶、茎、根及全株)的营养价值、分子结构特征及体外瘤胃降解率,为反刍动物优质粗饲料资源的开发提供基础数据。试验按照概略养分分析法和康奈尔净碳水化合物和蛋白质体系(CNCPS)分析田菁叶、茎、根及全株的营养成分含量,同时利用傅立叶变换红外光谱(FTIR)技术对田菁不同部位的分子结构进行分析,最后进行体外瘤胃模拟发酵,分析田菁不同部位在瘤胃内的降解率以及产气量。结果表明:1)田菁不同部位间的蛋白质组成和二级结构光谱参数存在显著差异(P<0.05)。其中,叶的蛋白质成分含量较高,根的较低;叶的酰胺Ⅰ区和酰胺Ⅱ区的峰高和峰面积以及β-折叠峰面积较高,茎的酰胺Ⅰ区峰高和峰面积较低。2)田菁不同部位间的碳水化合物组成和分子结构光谱参数存在显著差异(P<0.05)。其中,根的中性洗涤纤维(NDF)、酸性洗涤纤维(ADF)和酸性洗涤木质素(ADL)含量较高,叶的较低;根的总碳水化合物峰高和峰面积较高。此外,田菁的蛋白质和碳水化合物组成与分子结构之间存在一定的相关性。3)田菁叶的体外发酵粗蛋白质和干物质降解率最高,显著高于全株、茎和根(P<0.05);叶的48 h总产气量显著高于茎和根(P<0.05)。由此可见,田菁不同部位的营养价值与分子结构之间具有一定的相关性;其中,叶和茎的营养价值及利用率相对较高,而根的营养价值及利用率较低。

阳离子田菁胶助染剂对纸张浆外染色效果的影响

本研究通过醚化反应制备了阳离子田菁胶(CSG)助染剂,并通过浆外浸渍染色法,探究了其对直接耐晒翠蓝GL染色效果的影响,并确定了最佳染色工艺。适度提高醚化剂用量,能获得更高取代度的CSG;CSG的热稳定性比未改性田菁胶(SG)较差。加入CSG后,染料分子和CSG可通过静电吸附作用,稳固地附着在纸张表面,染色效果显著。选用取代度0.22、N含量0.63%的CSG作为助染剂,染色时间30 s、染液pH值6、CSG用量0.8%、染液温度70℃时,CSG染色效果最佳,相比SG组染色效果提升168.9%。染纸水洗前后Δb^(*)值变化不大,说明CSG同时具有较好的固色效果。

田菁纳豆多酚提取工艺优化及其抗氧化活性

以田菁纳豆为原料,采用乙醇溶剂浸提田菁纳豆中的多酚,以田菁纳豆多酚提取量为评价指标,通过响应面试验设计优化提取工艺,并考察田菁纳豆多酚的体外抗氧化能力。经过优化得到4个因素的最佳参数为乙醇浓度30%、提取时间80 min、提取温度61℃、料液比1∶15(g/mL),该条件下田菁纳豆的实际多酚提取量为119.24 mg/g。抗氧化试验结果表明,田菁纳豆多酚对ABTS^(+)自由基、DPPH自由基、羟自由基都具有较好的清除能力,在最佳提取条件下,其最高清除率分别是53.47%、83.70%、62.18%,且对铁离子的最大还原力为3.12,表明田菁纳豆多酚具有较好的抗氧化活性。

蒙脱石与复合菌剂配施提高田菁改良盐渍土的效果

【目的】田菁具有较强的固氮和耐盐能力,因此已经成为改良盐碱地的先锋植物。通过蒙脱石与复合菌剂配施提升田菁的耐盐能力,为其更好地改良盐碱土壤提供技术支撑。【方法】采用盆栽试验方法进行研究。将供试土壤与蛭石、珍珠岩按照3∶1∶1的体积混匀并灭菌后,用于制备NaCl浓度为0、100、200 mmol/L的3组土壤,每组土壤中设置空白对照(CK)、加蒙脱石(M)、加复合菌剂(J)、加蒙脱石和复合菌剂(M+J)4个处理,田菁生长60天后收获,测量田菁生物量和土壤理化性质变化。【结果】复合菌剂中的假单胞菌Pseudomonadaceae sp.ST3和大肠杆菌Escherichia coli ND2B相比于其他内生菌有较强的促生能力。在盐浓度0、100、200 mmol/L土壤上,田菁植株高度、地上部干重及叶片叶绿素含量、净光合效率、酶活均表现为CK<M<J<M+J,M+J处理的以上几个指标值均显著高于CK、M处理,多数指标与J处理间差异显著(P<0.5),表明M+J的改良效果最为显著。在盐浓度为100和200 mmol/L的土壤上,M+J处理田菁生长及抗逆指标相较于CK的增加幅度分别为:株高157.2%和187.6%,茎秆重307.6%和286.9%,根长46.9%和40.7%,根表面积31.2%和25.0%,根干重60.7%和72.8%,叶绿素含量100.28%和138.00%,叶片净光合速率43.72%和40.81%,超氧化物歧化酶活性118.26%和192.11%,过氧化物酶活性138.24%和137.50%,过氧化氢酶活性222.96%和151.50%;M+J处理田菁叶片丙二醛含量分别显著降低了39.93%和38.41%;M+J处理土壤pH分别较CK显著降低3.82%和3.82%,土壤盐含量分别显著降低36.39%和39.04%,而土壤全氮含量分别显著增加92.83%和87.56%,速效磷含量分别显著增加35.40%和37.28%,速效钾含量分别显著增加27.53%和30.59%,有机碳含量分别显著增加17.95%和21.85%。【结论】蒙脱石、复合菌剂单独施用可不同程度地改善土壤理化性质,促进田菁生长和抗盐能力,降低土壤含盐量,增加土壤有机质和氮磷钾养分含量。而两者配施的效果更加显著且稳定,是提高田菁改良盐渍土效果的高效措施。

The Formation of SO_(2) and Emission Reduction Solutions in the Preparation of a Hydrogenation Catalyst Support

The key reason for SO_(2) formation during the production of a residue hydrogenation catalyst support was identified and subsequent emission reduction solutions were then investigated and verified systematically.The results demonstrated that carbon-containing organic materials,including sesbania powder and cellulose,did not completely decompose over the temperature range of 350−600℃during the heating stage of the calcination process,but rather underwent a condensation reaction within the same temperature range to form carbon-containing species with a lower ratio of hydrogen to carbon and a higher condensation degree,which promoted the decomposition of sulfate to form SO_(2).Systematic experimental work revealed that three different measures,i.e.,applying the staged calcination method,reducing the heating rate,and increasing the air flow rate,during the calcination process could all achieve the effect of reducing SO_(2) emissions.

田菁纳豆总黄酮提取工艺及抗氧化活性分析

通过单因素试验和正交试验对田菁纳豆总黄酮提取工艺进行优化,同时测定了田菁纳豆提取液DPPH自由基清除力、羟自由基清除能力及还原力。结果表明:各因素对田菁纳豆总黄酮含量的影响程度为提取温度>乙醇体积分数>提取时间>料液比,最佳提取工艺为乙醇体积分数60%、料液比1∶15(g/mL)、提取温度80℃、提取时间80 min,在此条件下田菁纳豆总黄酮含量为100.32 mg/g,田菁纳豆提取液对DPPH自由基和羟自由基的清除率分别为85.92%,41.97%,最大还原力为0.184,具有良好的抗氧化能力。