胞外酶对堆肥中微生物群落演替的影响

研究了添加黄孢原毛平革菌胞外酶对农业废物堆肥中木质纤维素降解及微生物群落演替的影响.结果表明,堆肥初期,胞外酶对微生物生长具有抑制作用,且随堆肥时间的延长逐渐减弱;堆肥后期,胞外酶可提高微生物群落的多样性和均匀性,并促进木质素和半纤维素的大量降解.醌指纹数据显示,胞外酶并未引起新的优势醌的出现,进入高温期后,以MK-7为主要醌类的微生物作为优势菌群,且这种优势一直存在;堆肥后期胞外酶对甲基萘醌影响较大,可促进长链甲基萘醌的出现.主成分分析表明,胞外酶对醌种类演替的影响主要作用在3d和40d,这与非相似性指数结果一致,并使真菌在整个体系中影响力加大.     

Effect of chromium on accumulation and antioxidants in Cucumis utillissimus L.: Response under enhanced bioavailability condition

This study compares the accumulation of Cr(VI) and biochemical changes (total chlorophyll, carotenoid, protein, malondialdehyde (MDA) and cysteine contents) and roles of antioxidant enzymes (superoxide dismutase (SOD), guaiacol peroxidase (GPX), ascorbate peroxidase (APX)) in tolerance to metal induced stress in Cucumis utillissimus L. grown in Cr contaminated soil (CS) with garden soil (GS). Furthermore, Cr bioavailability was enhanced by ethylene diamine tetra-acetic acid (EDTA) addition to the soil to forecast the plant’s accumulation pattern at elevated Cr environment. Accumulation of Cr in the leaves of the plant increased with increase in substrate metals concentration. It further increased with the addition of EDTA by 1437% and 487% in GS and CS, respectively at the highest treatment level. The lipid peroxidation increased proportionately with increase in Cr accumulation in the leaves. All the activity of antioxidant enzymes (SOD, GPX and APX) and the level of cysteine increased with dose dependant manner. SOD and cysteine were observed to be higher in the GS than in CS, but APX and GPX were found to be higher in CS than in GS. The increase in GPX and APX activities with the increase in Cr concentration could be assumed that these two enzymes have a major role in the defense mechanism towards stress induced by Cr in C. utillissimus.     

接种功能内生细菌对蔬菜亚细胞菲积累的削减作用

蔬菜多环芳烃(PAHs)污染威胁人群健康.通过水培试验,研究了接种具有菲降解功能的植物内生细菌Diaphorobacter sp.Phe15对空心菜及其亚细胞组分中菲积累的影响,揭示了空心菜体内多酚氧化酶(PPO)和过氧化物酶(POD)的响应及其与PAHs积累的相关关系.Phe15可定殖在空心菜体内,不同部位菌株Phe...     

Thiram‐induced toxic liver injury in male sprague‐dawley rats

Abstract

A single i.p. dose (120 mg/kg) of thiram given to male Sprague‐Dawley rats caused a significant increase in the activity of SGOT and SGPT 24 hr post‐treatment indicating liver damage. A considerable diminution in the serum cholinesterase activity was also noted in the treated rats as against the control animals. Additional evidence for thiram‐induced liver toxicity is provided by the observation that there was approximately 50% inhibition of the activity of hepatic microsomal benzphetamine N‐demethylase with a concomitant decrease in the concentration of cytochrome P‐450, an important component of the mixed‐function oxidase system. Although not significant, hepatic glutathione levels were also depleted by thiram, probably making the liver susceptible to toxic injury.     

不同类型植物凋落物参与下炼锌废渣对斑马鱼抗氧化酶和神经毒性的影响

为评价矿山生态修复过程中植物凋落物参与下炼锌废渣体系浸出液对水生生物抗氧化酶和神经毒性的影响,通过模拟添加不同类型代表性修复植物(三叶草、刺槐、构树和法国梧桐)凋落物处理黔西北土法炼锌废渣,检测在不同处理废渣浸出液中暴露28 d斑马鱼(Danio rerio)组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、丙二醛...     

Prenatal diagnosis of cystic fibrosis: I. Prospective study of 51 pregnancies

A prenatal diagnosis was performed in 51 pregnancies with a 1-in-4 risk of having a child with cystic fibrosis. The criteria for determining an affected fetus were based on the results of alkaline phosphatase (ALP) residual activity after inhibition by phenylalanine and by homoarginine, of total ALP activity, and of gamma-glutamyltranspeptidase (GGTP) activity in the amniotic fluid taken between 16 and 19 weeks of pregnancy. The chromosomal analysis of amniotic fluid cells showed trisomy 13 in one case which was excluded from the analysis of biochemical assays. The biochemical assays were in the normal ranges in the amniotic fluid of 35 pregnancies: 26 have reached term and a normal infant has been born, 9 are still in progress. A deficiency of the ALP phenylalanine-inhibitable form, depressed values of total ALP and GGTP were observed in the amniotic fluid of 15 pregnancies: one pregnancy went to term and the infant had CF, in 14 cases the pregnancy was terminated, and meconium ileus was observed in ten of these cases. It was observed that the changes towards abnormal values became more significant with advancing gestational age and that 18 weeks appeared to be the optimum time for diagnostic amniocentesis.     

A Functional Approach to the Assessment of the Nutritional Value of Particulate Organic Matter

Organic matter lability can be determined with different approaches, based on the quantitative and qualitative estimate of its nutritional value. the C/N ratio and the particulate organic matter (as the sum of protein, carbohydrate and lipid bulks) vs total suspended matter (POM/TSM) deal with a quantitative assessment of the organic matter bulk, while other indices such as proteins/carbohydrates ratio (PRT/CHO) may give also qualitative information. Gordon (1970) proposed a functional approach, based on organic carbon decrease after enzymatic digestion. Coupling Gordon's approach with the evaluation of the main biochemical components (proteins, carbohydrates and lipids) contained in the particulate organic matter, a simple method to assess lability and nutritional value of organic substrates is proposed.

Water samples were collected at the surface and close to the bottom in a shallow coastal station (10 m depth) in the Marconi Gulf (Ligurian Sea, NW Mediterranean). the difference between “total labile” and “hydrolyzed labile” organic matter (respectively before and after enzymatic digestion) suggests a relevant presence of resuspended refractory materials vs about 60% of labile hydrolyzed organic matter, thus confirming the importance of a more qualitative approach to organic matter studies.     

Larvae of Sand Smelts (Atherina hepsetus L.) as a Bioindicator of Pollution in the Black Sea Coastal Waters

The activity of antioxidant enzymes and electrophoretic protein spectra were studied in sand smelt larvae inhabiting from five Sevastopol bays with different degrees of anthropogenic impact. The activity of antioxidant enzymes and the heterogeneity of electrophoretic protein spectra proved to increase in the larvae from the most polluted waters. The possibility of using these parameters as biological markers for assessing the influence of pollution on the early stages of fish ontogeny and the marine environment are discussed.     

Metal-related oxidative stress in birds

Metals can cause oxidative stress by increasing the formation of reactive oxygen species (ROS), which render antioxidants incapable of defence against growing amounts of free radicals. Metal toxicity is related to their oxidative state and reactivity with other compounds. Our aim is to review the mechanisms on how metals cause oxidative stress and what is known about metal-induced oxidative stress in wildlife. Taking birds as model organisms, we summarize the mechanisms responsible for antioxidant depletion and give a view of how to detect metal-induced oxidative stress in birds by using different biomarkers. The mechanisms producing the harmful effects of oxidative stress are complex with different biomolecular mechanisms associated with ecotoxicological and ecological aspects. The majority of the studies concerning metals and ROS related to oxidative stress have focused on the biomolecular level, but little is known about the effects at the cellular level or at the level of individuals or populations.