Subcellular localization and isoenzyme pattern of peroxidase and polyphenol oxidase in beet root (Beta vulgaris L.)

The two enzymes involved in enzymatic browning reactions, polyphenol oxidase (PPO) and peroxidase (PO), have been partially purified and extracted from different fractions of beet root. PPO is mainly located in the membrane fraction, and it was also found in the soluble fraction. In both cases PPO was in its latent state. However, PO activity was higher in the soluble fraction than in the membrane fraction. Nevertheless, the highest values of specific activity for PO were obtained from the solubilized enzyme from acetone powders. Under native isoelectric focusing (IEF), several PPO isoenzymes were present in the pH range of 4.8-5.8. All of these isoenzymes shared a single band with a similar apparent mass under sodium dodecyl sulfate-polyacrylamide gel electrophoresis. PO was also analyzed by IEF, showing a complex isoenzyme pattern in all fractions. The characteristic basic PO isoenzyme of high pI found in both the soluble fraction and the solubilized enzyme from acetone powders was not detected in the membrane fraction. The kinetic characterization of PPO and PO from all fractions was carried out.     

Trace Element Emissions from some Cement Plants in Turkey

The cement industry has been one of the major sources of air pollution in the past and the Turkish Air Quality Protection Regulation has issued limits also to trace elementemissions to minimise the polluting effects of this industrialsector. In the present study, dust samples were obtained isokinetically from 18 main stacks of 10 cement plants locatedin different geographical areas of Turkey. The samples were analysed for trace elements Hg, Cd, Cr, Pb, Ni, Se, Te, TI, V, Sb, Ba, Zn, Co, Sr, Cu, Bi, Mo, Be, and As. The results are presented both as concentration in the dust samples as well as emissions per unit production, and concentration inthe stack gas. The trace element emissions of the main stacksagree to great extent with the values given in the literature. On the other hand, the trace element emissions of the plants considered are well below the limits set in the Turkish Air Quality Protection Regulation.     

Effect of the conservation procedure on the contents of phenolic compounds and organic acids in chanterelle (Cantharellus cibarius) mushroom

To check the influence of the conservation procedure in the chemical composition of chanterelle mushroom, phenolic compounds and organic acids of samples preserved under four different conditions (drying, freezing, conservation in olive oil and in vinegar) were determined. Phenolics and organic acids were analyzed by HPLC-DAD and HPLC-UV, respectively. The results showed that chanterelle is characterized by the presence of six phenolic compounds (3-, 4-, and 5-O-caffeoylquinic acid, caffeic acid, p-coumaric acid, and rutin) and five organic acids (citric, ascorbic, malic, shikimic, and fumaric acids). Samples preserved in olive oil also exhibited hydroxytyrosol, tyrosol, luteolin, and apigenin, whereas conservation in vinegar led to the detection of hydroxytyrosol, tyrosol, and tartaric acid in the analyzed samples. The conservation procedures to which chanterelle samples were subjected seem to affect the qualitative and quantitative phenolics and organic acids profiles.     

Occurrence of naturally acetylated lignin units

This work examines the occurrence of native acetylated lignin in a large set of vascular plants, including both angiosperms and gymnosperms, by a modification of the so-called Derivatization Followed by Reductive Cleavage (DFRC) method. Acetylated lignin units were found in the milled wood lignins of all angiosperms selected for this study, including mono- and eudicotyledons, but were absent in the gymnosperms analyzed. In some plants (e.g., abaca, sisal, kenaf, or hornbeam), lignin acetylation occurred at a very high extent, exceeding 45% of the uncondensed (alkyl-aryl ether linked) syringyl lignin units. Acetylation was observed exclusively at the gamma-carbon of the lignin side chain and predominantly on syringyl units, although a predominance of acetylated guaiacyl over syringyl units was observed in some plants. In all cases, acetylation appears to occur at the monomer stage, and sinapyl and coniferyl acetates seem to behave as real lignin monomers participating in lignification.     

Delineating site-specific management zones on pasture soil using a probabilistic and objective model and geostatistical techniques

Precision Agriculture - In recent years, different algorithms have been utilised to delineate management zones, areas with similar properties, within agricultural fields. However, there are few...     

Profile and Content of Residual Alkaloids in Ten Ecotypes of Lupinus mutabilis Sweet after Aqueous Debittering Process

Plant Foods for Human Nutrition - The evaluation of the level of alkaloids in edible Lupinus species is crucial from a food safety point of view. Debittering of lupin seeds has a long history;...     

小麦顶三叶与粒重关系的研究初报

研究了小麦不同摘叶方式下 ,顶三叶与粒重的关系及不同类型品种之间的差异。结果表明 :顶三叶的摘除对粒重的影响大小排序为旗叶 >倒二叶 >倒三叶 ,整株摘叶对粒重的影响高于主茎摘叶 ;多蘖型小麦品种主茎摘叶后千粒重降低得少 ,与整株摘叶后千粒重降低率相比差距大 ,而少蘖类型降低得多 ,降低率相比差距小     

大岗山人工针阔混交林与常绿阔叶林水文动态变化研究

采用定位观测方法与水集水区试验技术方法，利用1-6月份艰测数据，从土壤水分、坡面径流、集水区径流量等方面对大岗山地区人工针阔混交林、天然常绿阔叶林典型森林集水区的森林水文动态变化规律进行了研究。结果表明：⑴人工针阔混交林森林土壤水分量大值（51.8mm）出现在5月份，最小值（33.2mm）出现在3月份，且垂直变化幅度不大。⑵坡面径流量月变化较大，与一次性降水有密切关系，可用指数式y=0.1266e^0.0502x表示。⑶与人工针阔混交林相比，天然常绿阔叶林具有较强水土保持能力和显著水源涵养作用。