Influence of glucose feeding on the ligninolytic enzyme production of the white-rot fungus Phanerochaete chrysosporium

The present work studied the influence of glucose feeding on the ligninolytic enzyme production of Phanerochaete chrysosporium in a nitrogen-limited (C/N ratio is 56/8.8 mmol/L) medium. Several sets of shaking flask experiments were conducted. The results showed that 2 g/L glucose feeding on the first day of the culture (24 h after the inoculation) simulated both fungal biomass growth and enzyme production. The manganese peroxidase (MnP) activity was 2.5 times greater than that produced in cultures without glucose feeding. Furthermore, the glucose feeding mode in fed-batch culture was also investigated. Compared to cultures with glucose feeding every 48 h, cultures with glucose feeding of 1.5 g/L (final concentration) every 24 h produced more enzymes. The peak and total yield of MnP activity were 2.7 and 3 times greater compared to the contrast culture, respectively, and the enzyme was kept stable for 4 days with an activity of over 200 U/L.     

汽爆麦草固态发酵木质素酶

木质素是地球上主要的可再生芳香族化合物 ,是地球上仅次于纤维素的第二丰富可再生天然资源 ,然而 ,对它的利用研究却很少 ,是天然高分子中未开发的领城[1] .80年代初发现了木质素过氧化物酶 (ＬｉＰ) [2 ,3] 和锰过氧化物酶 (ＭｎＰ) [4 ] 以后 ,木质素酶和木质素生物降解研究取得了一定进展 .但木质素微生物转化降解研究中仍存在许多问题 .( 1)由于木质素酶解是一种非专一性的、以自由基为基础的链反应过程[5] .因此 ,木质素酶在化学工业、煤化学和环境保护方面具有很大的开发前景 .而现在木质素酶的生产大多用合成培养基 ,必需添加昂贵的…     

多壁碳纳米管引起白鼠肺部毒性的评价(Comparative Pulmonary Toxic Assessment of Mutil-Wall Carbon Nanotubes in Rats)

以雄性Wistar大白鼠为研究对象,观察了多壁碳纳米管(MWNTs)体内暴露后肺部的病理学变化.采用气管注入方式将直径为40～60nm多壁碳纳米管(40～60MWNTs)和直径小于10nm的多壁碳纳米管(10MWNTs)暴露于大白鼠的体内,同时分别采用纳米二氧化硅(SiO2)和乙炔碳黑(Cb)作为阳性和阴性对照.实验结果表明:实验中采用的纳米颗粒均不同程度地引起了肺部的损伤,同剂量下损伤严重程度顺序为:Cb>10MWNTs>40～60MWNTs>SiO2.多壁碳纳米管对肺部损伤的程度与剂量呈依赖关系,当在低剂量(1mg·kg-1)时,40～60MWNTs仅仅对肺部引起了轻微的炎症损伤,随着剂量的增大,多壁碳纳米管对肺部的损伤越来越严重,出现明显的病理损伤.     

Surface characterization of acid-oxidized multi-walled carbon nanotubes

Multi-walled carbon nanotubes (MWNTs) oxidized with sulfuric acid, nitric acid, and the mixture of sulfuric and nitric acids were characterized by thermogravimetric analysis (TGA), Raman spectroscopy, elemental analysis, X-ray diffraction, and X-ray photoelectron spectroscopy. The TGA data showed that the MWNTs were more resistant to oxidation than C₆₀ or activated carbon fibers. Catalyst particles could be removed by the oxidants containing sulfuric acid, and thus indicative of the tip opening of MWNTs. The sulfuric acid had a propensity to create defect sites and introduce the surface oxides at those defects that already exist or be newly generated on MWNTs. However, the acid mixture could open the caps of MWNTs but preserve the structure homogeneity. The treatment with nitric acid gave rise to the highest bulk oxygen content in MWNTs, while the most abundant surface oxides were provided by sulfuric acid oxidation. In addition, nitric acid exhibited the best ability to transform the phenolic groups into carboxyl groups.     

Rehydration of desiccated intertidal brown algae: Release of dissolved organic carbon and water uptake

The release of dissolved organic carbon (DOC) by Ascophyllum nodosum (L.) Le Jol. and Fucus vesiculusus L. during rehydration was investigated after desiccation under experimental conditions. During 30 min of rehydration of plants which had lost up to 70% of their water, A. nodosum released about 2 to 10 mg C/100 g dry weight, while F. vesiculosus released 10 to 50 times more. When dried to water losses exceeding 70%, plants of both species yielded similar amounts of DOC, approximating 2 g C/100 g dry weight. Considerable variance in the amounts of DOC released by individual plant of both species was observed over the whole range of water losses tested. Among the DOC released, the portion of carbohydrate-C was O to 5% with A. nodosum but 2 to 47% with F. vesiculosus. This difference was most pronounced when less than 100 mg C/100 g dry weight were released. A. nodosum regained a smaller percentage of its original weight than F. vesiculosus after 30 min of rehydration when more than 30% of fresh weight were lost during desiccation. Curves were obtained which enable the estimation of water losses in naturally desiccated specimens within 30 min.     

High adsorption of dyes by water hyacinth fixed on alginate

Pollution from synthetic dyes has emerged to be a significant environmental issue over the past few decades. This has mainly been triggered by the increasing global dye production, possible toxic effects, undesirable colour and high persistence in the environment. Biosorption, which involves dye removal from aqueous solution by passive linkage in live and dead biomass, has shown great potential in removing dyes from aquatic environments. Among aquatic macrophytes, water hyacinth, Eichhornia crassipes, has shown great potential as a biosorbent. In this work, we investigated the removal of two basic dyes, methylene blue and crystal violet, using E. crassipes immobilized on alginate. Results showed that the Langmuir model better described the equilibrium sorption data when compared to the Freundlich model. Optimum amounts of methylene blue and crystal violet dyes were adsorbed in the alkaline pH range (8–10), 8 % biomass dose, and the amount of dye removed increased with increasing initial dye concentration. The equilibrium monocomponent adsorption capacities for the dyes were 111.1 and 43.5 mg/g, while the binary adsorption capacities were 26.1 and 11.6 mg/g for methylene blue and crystal violet, respectively. To conclude, we show for the first time that E. crassipes fixed on alginate beads can uptake and adsorb methylene blue and crystal violet dyes very effectively in batch systems and show great potential for dye removal from aquatic environments.     

The assimilation and chronic effects of sub-lethal concentrations of Endosulfan on condition and spawning in the common mussel Mytilus edulis

The rate of uptake of Endosulfan by Mytilus edulis L. exposed to pesticide concentrations of 0.1, 0.5, and 1.0 mg/l, and its subsequent elution on removal to clean sea water, was investigated. Higher residue levels were recorded for mussels exposed to higher concentrations of the pesticide, but concentration factors were reduced. There was a rapid initial fall in tissue residue levels on transfer to clean sea water due, it is suggested, to elution of Endosulfan adsorbed on particulate matter assimilated in the gut. The spawning period was prolonged at higher concentrations and, at 1.0 mg/l, the onset of spawning was delayed, possibly due to interference with gamonic action. At 0.1 mg/l, the minor protraction of the spawning period may reflect the effect of experimental tank conditions. No seasonal trend was obvious, and there was an exaggeration of the expected fall in condition in mussels exposed to higher concentrations of Endosulfan. In controls, the expected seasonal trend was reduced.     

Etude de l'absorption,de la concentration et du métabolisme du strontium 85 chez le crustacé décapode Caricinus maenas

Strontium is absorbed and retained by Carcinus maenas L. The variations of the specific activity rates due to the retention of ⁸⁵Sr have been studied for the whole animals as a function of its size and the activity of the contaminating water. The same study has been carried out as a function of the stages of the intermoult cycles for both the whole animal and the organs and tissues likely to affect the uptake, storing, or further metabolism of strontium in the hepatopancreas, hypoderm, blood, gills, muscle and exoskeleton. On the basis of the results, assumptions are made on the respective part played by these organs or tissues in the processes studied.     

Groundwater quality in the major industrial area of Thessaloniki,Greece part 1: Chemical composition‐geochemical processes

Adsorption rates of Sb(V) ions on an activated alumina (AA) were analyzed by batchwise experiments, while the continuous adsorption, desorption, regeneration of AA, and multiple reuse cycles were studied by flow column tests. The adsorption rates increased quickly with the increases of shaking speed and operation temperature. The adsorbed Sb(V) ions were desorbed easily by a 50 mM NaOH solution, and a 41–90 times concentrated Sb(V) solution was yielded correspondingly. AA was effectively regenerated by desorption operation and ca. 93% of the initial adsorption capacity was retained after six times adsorption/desorption cycles.     

A novel sequence batch membrane carbonation photobioreactor developed for microalgae cultivation

A novel SBM-C-PBR was constructed for microalgae cultivation. Membrane fouling was greatly mitigated by membrane carbonation. NH₄⁺ and P removal rates were around 80% in SBM-C-PBR. Biomass was completely retained by membrane. In this study, a novel sequence batch membrane carbonation photobioreactor was developed for microalgae cultivation. Herein, membrane module was endowed functions as microalgae retention and CO₂ carbonation. The results in the batch experiments expressed that the relatively optimal pore size of membranes was 30 nm, photosynthetically active radiation was 36 W/m² and the CO₂ concentration was 10% (v/v). In long-term cultivation, the microalgal concentration separately accumulated up to 1179.0 mg/L and 1296.4 mg/L in two periods. The concentrations of chlorophyll a, chlorophyll b and carotenoids were increased about 23.2, 14.9 and 6.3 mg/L respectively in period I; meanwhile, the accumulation was about 25.0, 14.5, 6.6 mg/L respectively in the period II. Furthermore, the pH was kept about 5.5–7.5 due to intermittent carbonation mode, which was suitable for the growth of microalgae. Transmembrane pressure (TMP) was only increased by 0.19 and 0.16 bar in the end of periods I and II, respectively. The pure flux recovered to 75%–80% of the original value by only hydraulic cleaning. Scanning electron microscope images also illustrated that carbonation through membrane module could mitigate fouling levels greatly.     

Plant-derived visual signals may protect beetle herbivores from bird predators

Insect herbivores often use chemical signals obtained from their food plants to deter enemies and/or attract sexual partners. Do plant-based visual signals act similarly, i.e., repel consumers' enemies and appeal to potential mates? We explored this question using the pollen-feeding beetle Pygopleurus israelitus (Glaphyridae), a specialized pollinator of Anemone coronaria's chemically defended red-morph flowers. We presented dead beetles, which had fed either on anemones or on cat food, to young domestic chicks on a red (anemone-like) or a green (leaf-like) background. We determined whether the beetles' background color and diet affected the chicks' feeding. Cuticle surface extracts from anemone-fed beetles, but not from cat food-fed beetles, contained a secondary metabolite characteristic of anemones. Latencies to the first picking up and consuming of beetles from green backgrounds were shorter than of beetles from red backgrounds. The picking up order of beetles also indicated that prey from the green background was preferred. The chicks retained this preference when re-tested, 3 days later. Handling times of anemone-fed beetles were longer than of cat food-fed beetles. A previous study showed that glaphyrids improve their mate-finding prospects by orienting to large red anemone flowers. Here, female beetles preferred cat food-fed to anemone-fed males in mate-choice assays, thus anemone-derived chemicals did not increase mating success. Instead, the combined results indicate that A. coronaria's red flowers provide a visual signal that may both deter its herbivore's predators and attract its mates. To our knowledge, this is the first experimental evidence for a potential protective role of plant-derived visual signals for insect herbivores/pollinators.     

Biodegradation of plasticizer di‐n‐butyl phthalate (DBP) by immobilized microbial cells

Microorganisms capable of degrading di‐n‐butyl phthalate (DBP) were isolated by acclimated and enrichment technique. The adaptation of microorganism to DBP was investigated. The microbial cells were immobilized on ceramic particles. The results showed that the biomass adsorbed on ceramic particles can reach 85 mg dry weight/g carrier. The immobilized microbial cells were used for the treatment of wastewater containing DBP. The results demonstrated that the DBP concentration of the outlet reached the stationary‐state level of less than 1.0 mg/1 within 2 days at inlet DBP concentration of 100mg/l and 12h of hydraulic retention time.     

Flow cytometric assessment of the effects of chlorine,chloramine, and UV on bacteria by using nucleic acid stains and 5-cyano-2,3-ditolyltetrazolium chloride

Flow cytometry (FCM) has been widely used in multi-parametric assessment of cells in various research fields, especially in environmental sciences. This study detected the metabolic activity of Escherichia coli and Staphylococcus aureus by using an FCM method based on 5-cyano-2,3-ditolyltetrazolium chloride (CTC); the accuracy of this method was enhanced by adding SYTO 9 and 10%R2A broth. The disinfection effects of chlorine, chloramine, and UV were subsequently evaluated by FCM methods. Chlorine demonstrated stronger and faster destructive effects on cytomembrane than chloramine, and nucleic acids decomposed afterwards. The metabolic activity of the bacteria persisted after the cytomembranewas damaged as detected using CTC. Low-pressure (LP) UV or medium-pressure (MP) UV treatments exerted no significant effects on membrane permeability. The metabolic activity of the bacteria decreased with increasing UV dosage, and MP-UV was a stronger inhibitor of metabolic activity than LP-UV. Furthermore, the membrane of Gram-positive S. aureus was more resistant to chlorine/chloramine than that of Gram-negative E. coli. In addition, S. aureus showed higher resistance to UV irradiation than E. coli.

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Studies on the uptake of cadmium by the crab Carcinus maenas in the laboratory. I. Accumulation from seawater and a food source

The crab Carcinus maenas (L.) was exposed to radioactively labelled cadmium dissolved in seawater at concentrations of 0.1, 1 and 10 ppm, the latter concentration being toxic to the crabs (50% mortality after 12.3 days). Net accumulation of cadmium from solution was proportional to the level and time period of cadmium exposure. Total absorbed cadmium levels reached 0.0043 and 0.0412 mg Cd g^-1 dry weight after 40 days exposure to 0.1 and 1 ppm Cd, respectively, and 0.1115 mg Cd g^-1 dry weight after 12.3 days average exposure to 10 ppm Cd. The highest tissue concentration was found in the midgut gland, reaching 0.786 mg Cd g^-1 dry weight after 12.3 days average exposure to 10 ppm Cd. The midgut gland only contained about 10% of the total cadmium absorbed from solution, while the exoskeleton contained the bulk of obsorbed cadmium (59 to 80%) probably passively adsorbed onto the surface. When cadmium was absorbed by the crabs from a food source, the midgut gland contained 16.9% of the total absorbed cadmium whereas the exoskeleton now contained only 22.2%. Ten percent of the cadmium available in the food source (Artemia salina) was accumulated by the crabs. When placed in cadmium-free seawater, crabs that had accumulated cadmium from solution lost 69% of the absorbed cadmium in 10 days, mostly from the exoskeleton which lost 78% of its original absorbed cadmium concentration.     

Dual-functional sites for synergistic adsorption of Cr(VI) and Sb(V) by polyaniline-TiO2 hydrate: Adsorption behaviors,sites and mechanisms

• PANI/Ti(OH)_n^(4–n)+ exhibited excellent adsorption capacity and reusability. • Adsorption sites of Cr(VI) were hydroxyl, amino/imino group and benzene rings. • Sb(V) was adsorbed mainly through hydrogen bonds and Ti-O-Sb. • The formation of Cr-O-Sb in dual system demonstrated the synergistic adsorption. • PANI/TiO₂ was a potential widely-applied adsorbent and worth further exploring. Removal of chromium (Cr) and antimony (Sb) from aquatic environments is crucial due to their bioaccumulation, high mobility and strong toxicity. In this work, a composite adsorbent consisting of Ti(OH)_n^(4–n)+ and polyaniline (PANI) was designed and successfully synthesized by a simple and eco-friendly method for the uptake of Cr(VI) and Sb(V). The synthetic PANI/TiO₂ composites exhibited excellent adsorption capacities for Cr(VI) and Sb(V) (394.43 mg/g for Cr(VI) and 48.54 mg/g for Sb(V)), wide pH applicability and remarkable reusability. The adsorption of Cr(VI) oxyanions mainly involved electrostatic attraction, hydrogen bonding and anion-π interactions. Based on X-ray photoelectron spectroscopy and FT-IR analysis, the adsorption sites were shown to be hydroxyl groups, amino/imino groups and benzene rings. Sb(V) was adsorbed mainly through hydrogen bonds and surface complexation to form Ti-O-Sb complexes. The formation of Cr-O-Sb in the dual system demonstrated the synergistic adsorption of Cr(VI) and Sb(V). More importantly, because of the different adsorption sites, the adsorption of Cr(VI) and Sb(V) occurred independently and was enhanced to some extent in the dual system. The results suggested that PANI/TiO₂ is a promising prospect for practical wastewater treatment in the removal of Cr(VI) and Sb(V) from wastewater owing to its availability, wide applicability and great reusability.     

Growth responses of the newly-discovered Cd-hyperaccumulator Rorippa globosa and its accumulation characteristics of Cd and As under joint stress of Cd and As

Rorippa globosa has been identified as a newly-found Cd-hyperaccumulating species. In the present study, growth responses of Rorippa globosa and its accumulation characteristics of Cd and As were examined under joint stress of Cd and As. The results showed that Cd and As had an antagonistic effect on enhancing the growth of Rorippa globosa plants and Cd uptake and accumulation under the low concentration Cd and As treatments. When the concentration of Cd in the soil was 10 mg/kg and the concentration of As was 50 mg/kg, the highest growing height of the plant was up to 35.9 cm and the dry weight of the shoots was up to 2.2 g/pot, respectively. Meanwhile, the accumulation of Cd in the leaves under the joint stress was higher than that at the same level under single Cd pollution. However, there were synergic adverse effects on plant growth and Cd uptake under the combined pollution from a high concentration of Cd and As. Meanwhile, the accumulation of As in the roots was greater than that in the shoots, the translocation factor (TF) was ?0.3 and the bioaccumulation factor (BF) was ?0.6, thus showing that Rorippa globosa had an excluding effect on As uptake. These results confirmed that Rorippa globosa had a strong tolerant ability to the joint stress of Cd and As, and the potential for phytoremediation of soils contaminated by Cd and As.     

Fragrant legs in Paysandisia archon males (Lepidoptera, Castniidae)

Paysandisia archon was accidentally introduced into Europe where it damages endemic and ornamental palms, also threatening the date palm from North Africa. Little was known about sex pheromones in the Castniidae day-flying moth before a recent paper that concluded on the absence of female sex pheromone in P. archon. A putative identification of a short-range male pheromone, present on fore- and hindwings, was reported. In this paper, we describe the original structure of the male androconia located on the tarsi of the mid-legs. The extracts of mid-legs were analysed by GC/MS and the chemical structure of the male androconia component was identified as E2,Z13-18:OH. After extraction in solvent, biological activity of the extracts was assessed by EAG. The chemistry and the morphology of the androconia reinforce the current classification of the Castniidae in the Cossoid/Sesioid assemblage and provide new information on the chemical ecology in day-flying Lepidoptera and suit the recent paper describing the courtship behaviour     

Biosorption and biotransformation of crystal violet by Aeromonas hydrophila DN322p

DN322p, an offspring of Aeromonas hydrophila DN322, has the capacity to adsorb and decolorize triphenylmethane dyes in wastewater simultaneously. As a common triphenylmethane dye, crystal violet (CV) was chosen to test the decolorization characteristics of DN322p. Within 0.5 h, the strain DN322p adsorbed a large amount of CV, producing a deep-colored cell pellet and colorless supernatant. The colors of the cell pellet and supernatant lightened over time. The supernatant and dichloromethane extract of the cell pellet both showed conspicuous CV and leuco CV (LCV) characteristic absorbance peaks at 590 nm and 260 nm, respectively, in the UV-vis spectral analysis. This finding indicated that the DN322p cells can adsorb the two dyes. A 99% (w/w) decolorization rate was achieved within 2.5 h with shaking at 30°C for 50 mg CV·L^?1. High Performance Liquid Chromatography (HPLC) analysis of the dichloromethane extract of the supernatant and cell pellet confirmed that CV was mainly converted into its leuco form. Dead cells had a similar adsorption capacity with living cells. About 90% of CV in the dye solution (50 mg·L^?1) was removed by autoclaved cells with an optical delnsity at 600 nm (OD₆₀₀) above 1.0.     

Fluoride concentrations in the pineal gland,brain and bone of goosander (Mergus merganser) and its prey in Odra River estuary in Poland

The aim of the study was to investigate fluoride concentrations in bone, brain and pineal gland of goosander Mergus merganser wintering in the Odra estuary (Poland) as well as in fish originating from its digestive tract. The fluoride concentrations were determined with potentiometric method. Medians of concentrations in goosander had the highest and the lowest values in pineal gland and brain (>760 and <190 mg/kg, respectively). Fluoride concentration in the pineal gland was significantly greater than in the bone and the brain of the duck. In fish, the fluoride concentration ranged from 37 to 640 mg/kg and significant correlation was revealed between the fluoride concentration and fish weight and length. Based on own results and data of other authors, a daily fluoride intake by the goosander in the Odra estuary was estimated at 15 mg. So high fluoride concentrations like in the duck have not been found in mammal brains.     

Fate and removal of typical pharmaceutical and personal care products in a wastewater treatment plant from Beijing: a mass balance study

The fate and removal of pharmaceuticals and personal care products (PPCPs) in wastewater treatment plants (WWTPs) has received great attention during the last decade. Numerous data concerning concentrations in the water phase can be found in the literature, however corresponding data from sludge as well as associated mass balance calculations are very limited. In the present study, the adsorbed and dissolved concentrations of 9 PPCPs were investigated in each unit of a WWTP in Beijing, China. Based on the calculation of mass balance, the relative mass distribution and removal efficiency of each target compound was obtained at each process. The amount of PPCPs entering into the WWTP ranged from 12 g·d^–1 to 3848 g·d^–1. Five target compounds (caffeine, chloramphenicol, bezafibrate, clofibric acid, and N,N-diethyl-meta-toluamide) were effectively removed, with rates of 57%–100%. Negative removal efficiencies were obtained for sulpiride, metoprolol, nalidixic acid, and carbamazepine, ranging from -19% to -79%. PPCPs mainly existed in dissolved form (≥92%) in both the raw influent and the final effluent. The sludge cake carried a much lower amount of PPCPs (17 g·d^–1) compared with the discharged effluent (402 g·d^–1). In A²/O treatment tanks, the anaerobic and anoxic tanks showed good performance for PPCPs removal, and the amount of adsorbed PPCPs was increased. The results reveal that both the dissolved and the adsorbed phases should be considered when assessing the removal capacity of each A²/O tank.