Green Synthesis of Silver Nanoparticles Using Extracts of <i>Ananas comosus</i>

The biosynthesis of nanoparticles has been proposed as a cost effective and environmental friendly alternative to chemical and physical methods. Plant mediated synthesis of nanoparticles is a green chemistry approach that intercom nects nanotechnology and plant biotechnology. In the present study, synthesis of silver nanoparticles (AgNPs) or (Green-Silver) has been demonstrated using extracts of Ananas comosus reducing aqueous silver nitrate. The AgNPs were characterized by Ultraviolet-Visible (UV-vis) Spectrometer, Energy Dispersive X-ray Analysis (EDAX), Selected Area Diffraction Pattern (SAED) and High Resolution Transmission Electron Microscopy (HRTEM). TEM micrographs showed spherical particles with an average size of 12 nm. The XRD pattern showed the characteristic Bragg peaks of (111), (200), (220) and (311) facets of the face center cubic (fcc) silver nanoparticles and confirmed that these nanoparticles are crystalline in nature. The different types of antioxidants presented in the pineapple juice synergistically reduce the Ag metal ions, as each antioxidant is unique in terms of its structure and antioxidant function. The re- action process was simple for formation of silver nanoparticles and AgNPs presented in the aqueous medium were quite stable, even up to 4 months of incubation. This work proved the capability of using biomaterial towards the synthesis of silver nanoparticle, by adopting the principles of green chemistry.

Physico-Chemical and Thermal Characterization of Some Lignocellulosic Fibres: <i>Ananas comosus</i>(AC), <i>Neuropeltis acuminatas</i>(NA) and <i>Rhecktophyllum camerunense</i>(RC)

This paper focuses on the study of the physical, biochemical, structural, and thermal properties of plant fibres of Rhecktophyllum camerunense (RC), Neuropeltis acuminatas (NA) and Ananas comosus (AC) from the equatorial region of Cameroon. The traditional use of these fibres inspired researchers to investigated their properties. This study aims at improving the state of knowledge with a view to diversifying applications. The fibres are extracted by retting. Then, their apparent density was measured following the ASTM D792 standard and their water moisture absorption and moisture content were also evaluated. Their molecular structure was studied by ATR-FTIR spectroscopy. A quantitative analysis of the biochemical composition was performed according to the analytical technique for the pulp and paper industry (TAPPI). A TGA/DSC analysis was also performed. The results reveal that the AC, NA and RC fibres have densities of 1.26 ± 1.06, 0.846 ± 0.13 and 0.757 ± 0.08 g·cm-3 respectively. They are also hydrophilic with a water absorption rate of 188.64 ± 11.94%, 276.16% ± 8.07% and 198.17% ± 20%. They have a moisture content of 12.21%, 10.36% and 9.37%. The studied fibres exhibit functional groups that are related to the presence of hemicellulose, pectin, lignin and cellulose. The cellulose crystallinity index was found to be 67.99%, 46.5% and 59.72% respectively. The fibres under study have the following chemical composition: an extractive content of 3.07%, 14.77% and 8.74%;a pectin content of 4.15%, 7.69% and 3.45%;a hemicellulose content of 4.90%, 15.33% and 7.42%;a cellulose content of 68.11%, 36.08% and 65.15%;a lignin content of 12.01%, 25.15% and 16.2%;and an ash content of 0.27%, 1.53% and 0.47% respectively. The thermal transitions observed on the thermograms correlate with the TAPPI chemical composition. It is observed that these fibres are thermally stable up to temperatures of 200°C, 220°C and 285°C. These results make it possible to envisage uses similar to those of sisal, hemp and flax fibres.

Design and Construction of a Pneumatic Temporary Immersion Bioreactor System for the Multiplication of <i>Ananas comosus</i>var. Trujillana Red

The present work initially identified the design parameters of a temporary immersion bioreactor to later scale it to a complete system for the in vitro multiplication of Ananas comosus var. Trujillana Red. Thus, a low-cost pneumatic temporary immersion bioreactor system was designed and built with 24 tanks of 2 L each. The automation of the system was designed and implemented by means of a timer circuit whose design parameters were: duration of the propagation process, which depends on the multiplication period of the crop and is an open variable, which means that the operator decides when to turn off the system;the duration of each dive, which for reasons of complexity of the algorithm was standardized as one minute;immersion frequency, which was programmed for intervals of 1, 2, 3, 4, 5, 6, 7, 8 hours respectively and duration of aeration, which from a test run times of 0.20 were chosen, 30, 40, 50, 60, 70, and 80 seconds that correspond to the time of delivery of compressed air;additionally, the multiplication rate of Ananas comosus var. Trujillana Red in the immersion system which was 6.5 times per propagative unit inoculated in thirty days.

Light Intensity Affects the Coloration and Structure of Chimeric Leaves of Ananas comosus var.bracteatus

Ananas comosus var.bracteatus is an important ornamental plant because of its green/white chimeric leaves.The accumulation of anthocyanin makes the leaf turn to red especially in the marginal part.However,the red fades away in summer and winter.Light intensity is one of the most important factors affecting leaf color along the seasons.In order to understand the effects of light intensity on the growth and coloration of the chimeric leaves,Ananas comosus var.bracteatus was grown under full sunlight,50%shade and 75%shade for 75 days to evaluate the concentration of pigments,the color parameters(values L^(*),a^(*),b^(*))and the morpho-anatomical variations of chimeric leaves.The results showed that a high irradiance was beneficial to keep the chimeric leaves red.However,prolonged exposure to high irradiance caused a damage,some of the leaves wrinkled and even burned.Shading instead decreased the concentration of anthocyanin and increased the concentration of chlorophyll,especially in the white marginal part of the leaves.Numerous chloroplasts were observed in the mesophyll cells of the white marginal part of the chimeric leaves under shading for 75 days.The increase in chlorophyll concentration resulted in a better growth of plants.In order to balance the growth and coloration of the leaves,approximately 50%shade is suggested to be the optimum light irradiance condition for Ananas comosus var.bracteatus in summer.

Preventive Effects of Ananas comosus Juice on Obesity Risk Factors in Female Wistar Rats

The present study aim was to assess the preventive effects of Ananas comosus juice consumption on the risk factors of obesity in female Wistar rats. 108 rats were tested for 90 days. After randomization, they were shared out into six groups including four experimental groups (GTc, GPlp, GEns and GBrS) and two control groups (). The control group consumed 1.20 ml of distilled water, the experimental rats received in oral, 1.20 ml of drinks made from the different parts of Ananas comosus fruit. The measurements of morphometric and biochemical parameters were carried out on Day 0 (D0), Day 30 (D30), Day 60 (D60) and Day 90 (D90). The analysis showed that compared to the positive control rats, the consumption of the various drinks slowed down significantly (P < 0.001);the evolution of the morphometric and biochemical parameters likely to induce obesity in experimental rats which have an increase in a protective factor (HDL;P < 0.001). These results indicate that consumption of different parts of Ananas comosus’s juices had preventive effects on risk factors related to obesity. Moreover, the fruit juice treatment has been found to be more effective.

Pineapple (<i>Ananas comosus</i>L. Merr.), Waste Streams, Characterisation and Valorisation: An Overview

Processing pineapple industry produces huge amounts of waste thus contributing to worsen the global environmental problem. Valorising pineapple waste through further processing until it is transformed into valuable products using environmentally friendly techniques is both, a challenge, and an opportunity. The aim of this review is to characterize and highlight the phytochemical constituents of pineapple peel, their biological activity, and to evaluate the current state-of-art for the utilization of pineapple waste from the processing industry for obtaining pharmaceuticals, food, and beverages, biocombustibles, biodegradable fibers, and other different usage. Pineapple residues are rich in many bioactive compounds such as ferulic acid, vitamin A and C as antioxidant, and containing alkaloids, flavonoids, saponins, tannins, cardiac glycoside, steroids, triterpenoids and phytosterols may provide a good source of several beneficial properties, as well as bromelain that showed significant anticancer activity. Also, pineapple processing residues contain important volatile compounds used as aroma enhancing products and have high potential to produce value-added natural essences. Pineapple peels can be used as nonpharmacological therapeutical in the form of processed food and instant drinks;its potent natural antimicrobial properties may be applied for food conservation and as potential leads to discover new drugs to control some infectious microbial. Pineapple waste is a promising source of metabolites for therapeutics, functional foods, and cosmeceutical applications.

营养元素缺乏对‘台农16号’菠萝组培幼苗生长的影响

为研究营养元素缺乏对‘台农16号’菠萝组培幼苗生长的影响,设计了缺氮、缺磷、缺钾、缺镁、缺铁、缺钙、缺微量元素和全素共8种处理,对不同缺素处理后的幼苗症状进行观测。结果表明:各缺素处理均对组培幼苗生长产生影响,其中缺素症状表现最为明显的是缺氮及缺钾处理,主要表现为幼苗生长变慢,矮小,叶片短小、失绿变黄,而其它5种处理虽有相应缺素症状出现,但均不明显;与全素处理相比,各缺素处理幼苗的D叶长、D叶宽、叶片SPAD值、地上部分鲜重、地下部分鲜重及总鲜重均降低;缺素处理中,缺氮处理的幼苗长势最弱,其次是缺钾处理,两者的新抽叶片数、株高增量、D叶长、D叶宽、叶片SPAD值、地上部分鲜重、地下部分鲜重及总鲜重均极显著地低于其它5种缺素处理和全素处理。

菠萝AcNINV家族全基因组分离及表达分析

【目的】鉴定出菠萝NINV家族全基因组成员,初步阐明NINV基因与蔗糖代谢的关系。【方法】采用生物信息学方法鉴定并分析菠萝NINV家族全基因组成员,通过实时荧光定量PCR分析其表达特性,利用HPLC对蔗糖含量进行测定。【结果】在菠萝中共鉴定出6个NINV基因,分布于5条不同染色体上,其二级结构主要由α-螺旋和无规则卷曲组成,该基因家族启动子区域光反应元件数量最多。AcNINV外显子数量介于4~6个之间,其中AcNINV3、6外显子的数量为6个,亚细胞定位预测发现这2个基因都分布于叶绿体,属于α亚族;AcNINV1、2、4、5外显子的数量为4个,亚细胞定位预测发现这4个基因都分布于质膜,属于β亚族。在果柄、果皮、果心中表达量最高的是AcNINV2基因,在果肉中表达量最高的是AcNINV6基因。蔗糖含量随着菠萝果实成熟呈先升高后降低的变化趋势,而AcNINV4基因在菠萝果实成熟过程中呈下调表达。【结论】AcNINV4可能是催化果实蔗糖降解的水解酶基因。

基于多传感器信息融合的菠萝果茎切割点位置检测方法

夹切一体的菠萝(Ananascomosus(L.)Merr.)采摘器在进行田间采摘作业时,需要自主确定果茎切割点位置,而菠萝果茎处容易被植株叶片和苞叶遮挡,采用单一图像处理的方法难以准确识别到果茎切割点位置,为此提出一种多传感器信息融合的菠萝果茎切割点位置检测方法。将深度相机和多组光电传感器结合,利用改进的YOLOv5目标检测算法融合RGB-D深度信息,实现对菠萝冠芽顶部至果实底部长度测量,再利用光电传感器信号变化判断菠萝采摘器是否到达冠芽顶部位置,并将冠芽顶部作为起始位置,控制采摘器下降速度和时间,从而保证采摘器底部安装的切割刀准确抵达果茎切割点位置。台架试验结果表明,该方法对真实菠萝果茎切割点检测成功率达到85%,满足菠萝采摘机器人作业过程中果茎切割点检测准确性要求。

不同催花处理对‘台农4号’菠萝出蕾率及果实品质的影响

用400倍40%乙烯利和1.5%电石对西双版纳地区‘台农4号’菠萝进行催花研究。结果表明:乙烯利处理的菠萝果实在果实纵径、果实横径、果形指数、果颈长、裔芽数、果基果瘤、果实重量、果肉重量上显著低于对照和电石处理,果眼纵径、冠芽重量、总酸显著高于对照和电石处理。各处理果心直径、冠芽高、出蕾率、果汁含量、可溶性固形物含量差异不显著。不同处理菠萝果实重量、果肉重量与果实横径呈极显著正相关。乙烯利和电石处理菠萝果形指数与果实纵径呈极显著正相关,对照菠萝果形指数与果实纵径呈显著正相关。

不同激素和基本培养基对菠萝组培苗生长的影响

为了解激素和基本培养基对菠萝组培苗生长的影响,试验用不同的分裂素和生长素及基本培养基对菠萝组培苗进行培养。结果表明:细胞分裂素6-BA能有效促进菠萝组培苗分蘖,但对株高及叶片、根的生长不利,浓度越高抑制越明显;KT不利于菠萝组培苗的分裂,有利于植株和根系的生长,但浓度不宜过高。生长素主要作用是促进根系生长及壮苗,其中IBA在株高和根长方面比NAA优势明显,更适合用于生根培养。1/2 MS基本培养基中菠萝组培苗的长势弱于MS基本培养基,不适合用于菠萝组培苗的培养。

菠萝不同品种对低温胁迫响应差异的生理代谢机制

为探明菠萝不同品种对低温胁迫响应差异的相关机理,本研究以耐寒性强的‘粤甜’和耐寒性弱的‘巴厘’品种为试材,对常温(25℃)及低温(5℃)处理48 h植株的叶片生理指标、基因相对表达量及差异代谢物等进行比较测定。结果表明,低温处理后‘粤甜’的可溶性蛋白、可溶性糖、脯氨酸含量及POD、SOD、CAT酶活性均显著高于‘巴厘’,丙二醛含量显著低于‘巴厘’;POD、CAT基因相对表达量显著高于‘巴厘’,ProDH基因显著低于‘巴厘’;内源生长素、细胞分裂素、茉莉酸、水杨酸及独角金内酯含量高于‘巴厘’,赤霉素、脱落酸含量低于‘巴厘’。代谢组分析表明,低温处理后‘粤甜’与‘巴厘’间共检测出差异代谢物262个,其中黄酮类代谢物最多。KEGG分析表明‘粤甜’‘巴厘’间差异代谢物主要富集在次生代谢物生物合成、类黄酮生物合成、黄酮与黄酮醇生物合成等代谢通路中。筛选出110个低温诱导的‘粤甜’与‘巴厘’差异代谢物,其中41个在常温下差异显著、低温处理后差异倍数增大,69个在常温下无显著差异、低温处理后差异显著;差异代谢物在‘粤甜’中的含量积累均显著高于‘巴厘’。由此可见,渗透调节及抗氧化活性、内源激素及代谢物积累的差异是‘粤甜’与‘巴厘’低温响应差异的重要原因。

菠萝黑心病发生过程中AcAPXs的表达分析及克隆

菠萝黑心病(internal browning,IB)严重制约菠萝产业发展,该病害的发生主要是过量活性氧(reactive oxygen species,ROS)引起膜损伤,打破质体多酚氧化酶(polyphenol oxidase,PPO)与液泡内酚类底物原有的区室化划分,使其接触氧化后聚合成醌类物质。抗氧化清除系统能够清除过量ROS,维持机体内ROS的动态平衡。本课题组前期用抗氧化剂抗坏血酸(ascorbic acid,AsA)处理采后‘巴厘’菠萝,能有效延缓黑心病的恶化,然而其作用机理尚不明确。抗坏血酸过氧化物酶(ascorbate peroxidase,APX,EC1.1.11.1)是I类血红素过氧化物酶,以抗坏血酸作为特定的电子供体,催化过氧化氢转化为水,参与植物的多种发育生理过程和胁迫反应。本研究筛选出6个AcAPX基因,对其黑心病发生过程以及AsA处理后的转录水平进行分析,发现AcAPX1基因在贮藏后期极显著响应AsA处理,9 d和12 d时显著上调表达;相关性分析发现,AsA处理后的菠萝黑心病指数与AcAPX1基因表达水平呈显著正相关。结果表明:AcAPX1显著响应AsA处理,可能在AsA延缓菠萝黑心病中发挥重要作用。为了进一步探究其作用机制,从菠萝果肉中克隆到AcAPX1基因,通过生物信息学分析方法对其理化性质、蛋白结构域等进行分析。结果表明:其开放阅读框长度为753 bp,编码250个氨基酸,蛋白分子量预测为27.41087 kDa,理论等电点为5.52,无跨膜螺旋区,属于稳定亲水性蛋白;氨基酸序列比对分析表明,菠萝AcAPX1与番木瓜、香蕉、椰子、油棕的序列相似性达85%以上,对AcAPX1基因进行功能结构域分析表明其具有血红素结合位点、K^(+)结合位点及底物结合位点(超家族:cl00196),属于植物过氧化物酶超家族的成员。AcAPX1基因的克隆对于研究其在菠萝中抗氧化能力中的分子机制及黑心病的防治具有重要意义。研究结果为进一步探究菠萝AcAPX1基因参与AsA清除ROS,延缓黑心病恶化的分子机制奠定基础。

红苞凤梨AbF3′5′H基因上游调控因子筛选

颜色是观赏植物最重要的性状之一,也是当前观赏园艺育种的一个重要方向。为研究红苞凤梨红蓝色彩的呈现机制,初步分析金边红苞凤梨(Ananas comosus var.bracteatus)不同组织中花青素种类与含量,用AbF3′5′H基因启动子构建诱饵载体,利用酵母单杂交(Y1H)文库筛选其上游调控转录因子;并采用酵母单杂交验证技术,验证筛选出的转录因子与AbF3′5′H启动子的互作关系。结果表明:花青素的种类组成和相对比例决定了组织的颜色性状,AbF3′5′H是花青素合成途径种类分支的关键基因,在花青素种类组成与相对比例调控中具有重要作用;AbBTB/POZ、AbHSP81-1和AbGLOX能够与AbF3′5′H的启动子结合而调控其转录,可能在红苞凤梨花青素合成代谢调控中发挥重要作用。研究结果对于进一步揭示红苞凤梨花青素合成代谢调控机理,研究红苞凤梨呈色机理,培育叶色新品种有着重要的理论和实践意义。

An updated review of pineapple and its bioactive compounds in breast cancer

Women are more likely than men to develop cancer of the breast.Most breast cancer drugs are highly toxic,and treatment can cause side effects.It is imperative to find safe alternative medicines in the pursuit of a cure for breast cancer.An extract of pineapple contains cysteine proteases known as bromelains.In general,pineapples are regarded as safe foods.From the fruit,stem,and of pineapples,bromelain is produced by multiple endopeptidases.As well as reducing the growth of tumors locally,bromelain severely impaired the cytotoxicity of monocytes in the immune system in the fight against cancer.Specifically,we investigated pineapple’s possible mechanisms of action and its bioactive compounds in breast cancer.

菠萝密码子使用偏好性分析

【目的】分析菠萝[Ananas comosus(L.)Merr.]基因组中编码CDS的密码子使用偏好性,为了解菠萝的密码子偏好性规律和进行分子改造提供理论基础,促进植物密码子的生物学研究。【方法】以菠萝基因组测序获得的30 663条编码CDS为数据来源,应用编写的perl脚本、CUSP和SPSS软件对序列进行密码子偏好性、双联密码子以及多元统计分析。【结果】菠萝基因组数据中的编码CDS的GC平均含量为52.09%,密码子中第3位核苷酸的GC平均含量(GC3S)为55.41%,有效密码子数(ENC)取值为58.41,绝大部分的ENC值都大于35。另外,确定了34种高频密码子(RSCU值大于1),其中仅有8个以AT碱基结尾,25个以CG碱基结尾;同时确定了31种高优越表达密码子。结合以上结果,最后筛选出13种最优密码子。通过与17种植物的GC3S和密码子使用频率进行比较,发现双子叶植物与单子叶植物的GC3S和密码子使用频率存在较大差异,而菠萝较其他单子叶植物与双子叶植物更接近。【结论】从不同基因、基因内不同位置以及不同植物3个层面对菠萝密码子的偏好性进行分析,筛选出13种菠萝最优密码子。该研究有助于更好地了解菠萝密码子偏好性规律,促进植物密码子生物学研究及基因组数据在非模式植物中的潜在应用。

菠萝叶中防晒成分的超声提取及其稳定性研究

采用超声辅助提取法从菠萝叶中提取防晒成分,以单因素实验考察防晒成分的最佳提取工艺条件,并且研究了提取液中防晒成分的稳定性。结果表明:以丙酮为溶剂,料液比0.1200∶25(g·m L^(-1)),提取温度50℃、提取时间90min、超声功率144W的条件下菠萝叶中防晒成分提取效果较佳,温度和光照对提取液的防晒活性没有明显的影响,菠萝叶中含有较强的紫外线吸收成分,是具有广谱防晒作用的植物。

热脱附-气相色谱/质谱分析菠萝果实香气研究

采用热脱附-气相色谱/质谱(TCT-GC/MS)联用技术,对动态顶空密闭循环吸附捕集的菠萝果皮及果肉的挥发物进行了检测,结果表明:菠萝果皮与果肉的香气中富含酯类化合物、尤其是甲酯类成分,含量最高的均为己酸甲酯、分别达到45.66%和64.45%;果皮挥发物中的2-甲基丁酸甲酯相对含量为8.03%、辛酸甲酯相对含量为6.44%,均比果肉中的含量(分别为6.50%和3.51%)高;果肉挥发物中未检出非酯类成分,而在果皮挥发物中检测到2,5-二乙烯基四氢吡喃(9.07%)和少量甲酸乙酸酐(0.87%)。

菠萝叶片色泽、色素及抗氧化活性的关系

以菠萝22个栽培品种的叶片为实验材料,测定其5种色泽参数(L*、a*、b*、c*和h*值)、5种色素(叶绿素、类胡萝卜素、花青苷、类黄酮和总酚)含量及3种抗氧化活性指标(ABTS、DPPH自由基和亚硝酸盐的清除能力),并进行相关性分析。研究结果显示,色泽参数a*和h*值可以作为菠萝叶片指示色泽、主要色素含量和抗氧化活性变化的重要指标;菠萝叶片主要色素组成是叶绿素、类黄酮和总酚,且含有少量的花青苷,几乎不含类胡萝卜素。相关性分析结果显示,菠萝叶片类黄酮和总酚含量均与3种抗氧化活性指标极显著正相关,而叶绿素含量与其它指标相关性未达到显著水平,类黄酮和总酚是菠萝叶片抗氧化活性的主要功效成分。

菠萝果实发育过程中糖积累与其代谢酶的关系

以菠萝[Ananas comosus(L.)Merr."]巴厘"和"台农11号"两个品种为试验材料,测定不同发育时期果实中蔗糖、葡萄糖和果糖含量以及蔗糖代谢相关酶——酸性转化酶(AI)、中性转化酶(NI)、蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)的活性,并对果实中糖积累与酶活性的关系进行分析。结果表明:2个品种果实中糖积累动态十分相似,即果实发育前期,糖积累缓慢;进入成熟期,蔗糖迅速积累,而己糖"巴厘"果实中前期变化较少,后期稍有积累,"台农11号"果实中前期稍有积累,后期基本不变。2个品种果实中蔗糖含量与SS和SPS活性相关系数分别达到正的显著或极显著水平,NI活性与2个品种果实中蔗糖含量呈极显著负相关,蔗糖含量与AI的活性相关性品种间差异明显。