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关键词： Gastric evacuation   Blood biochemistry   Intestinal digestive enzyme   Appetite-related genes   TILAPIA OREOCHROMIS-NILOTICUS   FOOD-INTAKE   NEUROPEPTIDE-Y   RAINBOW-TROUT   GIANT GROUPER   PLASMA LEPTIN   FEEDING FREQUENCY   GROWTH-HORMONE   EXPRESSION   CORTISOL  

摘要： The proportion of remaining stomach meal (PSR), gastric evacuation model, serum cortisol and glucose levels, intestinal lipase, amylase, and chymotrypsin activities and the expression levels of neuropeptide Y (npy), orexin (ore) and leptins (lepa, lepb) of the hybrid grouper (Epinephelus moara female x E. lanceolatus male) during gastric evacuation were evaluated to determine the optimal feeding interval. Results showed that PSR significantly decreased by more than 60%, 70%, and 90% at postprandial 6 h, 9 h and 12 h, respectively. The cubic root curve was the most supported model and fitted all PSR data. The cortisol and glucose levels were significantly varied, and the highest values were obtained at postprandial 6 h. Cortisol and the glucose levels then gradually decreased from postprandial 9 h to postprandial 12 h. Intestinal lipase and chymotrypsin activities showed similar results to cortisol, whereas the amylase activity was not significantly different during gastric evacuation. The hypothalamic npy and ore mRNA levels were gradually up-regulated within postprandial 6 h, and then significantly down-regulated from postprandial 9 to postprandial 12 h. By contrast, hepatic lepa and lepb mRNA levels remained high levels within postprandial 6 h and significantly decreased from postprandial 9 to postprandial 12 h. These results indicated that food digestion in the intestine peaked at postprandial 6 h. Afterward, appetite returned and fully recovered at about postprandial 12 h. Therefore, on the basis of the aforementioned results and considering the fish management, postprandial 12 h is the optimal feeding interval of hybrid grouper (Epinephelus moara female x E. lanceolatus male). This feeding interval offers potential savings in time and labor spent in cultivating hybrid grouper in captivity.

关键词： Iron toxicity   Physiological responses   Ammonia excretion   Rh glycoprotein   Gene expression   Energy budget   FRESH-WATER   AMMONIA EXCRETION   RAINBOW-TROUT   FUNDULUS-HETEROCLITUS   K+-ATPASE   FISH   NA+   COPPER   BIOACCUMULATION   GLYCOPROTEINS  

摘要： Iron overload is a significant water quality issue in many parts of the world. Therefore, we evaluated the potential toxic effects of waterborne elevated iron on largemouth bass (Micropterus salmoides), a highly valued sport and aquaculture fish species. First, a 96 h-LC50 toxicity assay was performed to understand the tolerance limit of this species to iron; and was determined to be 22.07 mg/L (as Fe3+). Thereafter, to get a better insight on the fish survival during long-term exposure to high environmental iron (HEI) (5.52 mg/L, 25% of the determined 96 h-LC50 value), a suite of physio-biochemical, nitrogenous metabolic and ion-regulatory compensatory responses were examined at 7, 14, 21 and 28 days. Results showed that oxygen consumption dropped significantly at 21 and 28 days of HEI exposure. Ammonia excretion rate (J(amm)) was significantly inhibited from day 14 and remained suppressed until the last exposure period. The transcript concentration of Rhesus glycoproteins Rhcg2 declined; likely diminishing ammonia efflux out of gills. These changes were also reflected by a parallel increment in plasma ammonia levels. Under HEI exposure, ion-balance was negatively affected, manifested by reduced plasma [Na+] and parallel inhibition in branchial Na+/K+-ATPase activity. Muscle water content was elevated in HEI-exposed fish, signifying an osmo-regulatory compromise. HEI exposure also increased iron burden in plasma and gills. The iron accumulation pattern in gills was significantly correlated with a suppression of J(amm), branchial Rhcg2 expression and Na+/K+-ATPase activity. There was also a decline in the glycogen, protein and lipid reserves in the hepatic tissue from 14 days, 28 days and 21 days, respectively. Overall, we conclude that sub-lethal chronic iron exposure can impair normal physio-biochemical and ion-regulatory functions in largemouth bass. Moreover, this data set can be applied in assessing the environmental risk posed by a waterborne iron overload on

关键词： GH19 chitinase   Enzymatic conversion   Anti-fungi   CELLULOSE-BINDING DOMAIN   FAMILY-19 CHITINASE   N-ACETYLGLUCOSAMINE   AROMATIC RESIDUES   D-GLUCOSAMINE   ALPHA-CHITIN   SEQUENCE   HYDROLYSIS   EXPRESSION   MECHANISM  

摘要： Chitinases play crucial roles in enzymatic conversion of chitin and biocontrol of phytopathogenic fungi. Herein, a chitinase of glycoside hydrolase (GH) family 19, SaChiB, was cloned from Streptomyces alfalfae ACCC 40021 and expressed in Escherichia coli BL21(DE3). The purified SaChiB displayedmaximal activities at 45 degrees C and pH 8.0, and showed good stability up to 55 degrees C and in the range of pH 4.0-11.0, respectively. It exhibited substrate specificity towards chitin and chitooligosaccharides (degree of polymerization 3-6) with the endo-cleavage manner. In combination with the N-acetyl hexosaminidase SaHEX, it yielded a conversion rate of 95.2% from chitin powder to N-acetyl-D-glucosamine in 8 h and a product purity of >98.5%. Furthermore, the enzyme strongly inhibited the growth of tested pathogenic fungi. These results indicated that SaChiB has the great potential for applications in the conversion of raw chitinous waste in industries as well as the biocontrol of fungal diseases in agriculture. (C) 2020 Published by Elsevier B.V.

关键词： Epinephelus fuscoguttatus   Epinephelus polyphekadion   Feed fat   Biochemical   DIETARY-LIPID LEVEL   RAINBOW-TROUT   HEPATIC LIPOGENESIS   ACID PROFILES   FLESH QUALITY   SEA-BASS   JUVENILE   PROTEIN   ANTIOXIDANT   METABOLISM  

摘要： The growth of teleost fish can be enhanced by several means. A fat-enriched feed provides substantial energy for fish in aquaculture. However, fat is an expensive feed component and one of the highest cost components of the feed for cultured species in the aquaculture industry. Therefore, in recent years, nutritionists increasingly focus on improving the fat efficacy of feed components utilized in commercial feeds. To achieve this, precise, comprehensive, and homogeneous analytical procedures are required to quantify fat in feed components. This study assessed the influence of the feed fat level on growth performance, body composition, and serum biochemical indices of the 8 weeks old juvenile hybrid grouper (8 cm) with average body weight of 7.2 g. The results show that the level of feed fat has no substantial effect on the survival rate of the hybrid grouper, which indicates that hybrid grouper juveniles can tolerate high feed fat levels. In addition, the results also show that increasing the level of feed fat can increase the growth rate of fish and feed efficiency, while decreasing their ammonia nitrogen excretion rate. The suitable dietary fat level of hybrid grouper was identified to be 9.72-10.28%. This offers valuable insight into the effects of the feed fat level on the growth performance of the hybrid grouper, which can inform the culture of other species in aquaculture.

关键词： Graphene oxide   Eisenia fetida   Antioxidant enzymes   Lysosomal membrane   DNA damage   WALLED CARBON NANOTUBES   OXYGEN SPECIES GENERATION   NEUTRAL RED RETENTION   OXIDATIVE STRESS   SODIUM PENTACHLOROPHENATE   ANTIOXIDANT SYSTEM   LIPID-PEROXIDATION   LAYER GRAPHENE   EISENIA-ANDREI   EXPOSURE  

摘要： With the growing production and use of carbon nanomaterials (CNMs), the risk of their releases to the environment has drawn much attention. However, their potential effect on soil invertebrates has not yet been systematically assessed. Herein, the toxic effects of graphene oxide (GO) on earthworms (Eisenia fetida) were thoroughly investigated. Exposure to different doses of GO (0, 5, 10, 20, and 30 g kg(-1)) was conducted for 7, 14, 21, and 28 days. The results showed that enzymatic activity was stimulated at the early stages of exposure (7 days and 14 days) and inhibited after 14 days for catalase (CAT) and after 21 days for peroxidase (POD) and superoxide dismutase (SOD), especially at high GO doses. The content of MDA showed an increasing trend over the whole exposure period and was significantly elevated by GO from 21 days except at the dose of 5 g kg(-1) on day 21. Lysosomal membrane stability and DNA damage presented dose- and time-dependent relationships. Graphene oxide remarkably decreased lysosomal membrane stability except at the dose of 5 g kg(-1) on day 7. The tail DNA%, tail length and olive tail moment increased with increasing GO dose throughout the exposure duration, reaching maximum values at the end of exposure (28 days). These findings suggest that GO induces oxidative stress and genotoxicity in Eisenia fetida, resulting in lipid peroxidation, decreased lysosomal membrane stability and DNA damage. Therefore, attention should be paid to the potential pollution and risk associated with graphene oxide application. The results can provide valuable information for environmental safety assessment of graphene nanomaterials in soil. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Bivalve mollusc   Diclofenac   Nifedipine   Roundup   Heating   Biomarkers   MYTILUS-GALLOPROVINCIALIS   ELEVATED-TEMPERATURE   CORBICULA-FLUMINEA   STRESS RESPONSES   CATHEPSIN-D   METALLOTHIONEIN   ANTIOXIDANT   GLUTATHIONE   GLYPHOSATE   MUSSELS  

摘要： The priority list of freshwater pollutants is increasingly amended by pharmaceuticals. Their impact on the aquatic biota can be modulated by the presence of typical pollutants, like pesticides, and/or abnormal heating. The aim of this study was to elucidate potentially hazardous impact of combined environmental factors on the freshwater mussels by analyzing various sets of biochemical markers. We treated the bivalve molluscs of Unio tumidus with non-steroidal anti-inflammatory drug diclofenac (Dc, 2 nM), calcium antagonist and antihypertensive drug nifedipine (Nf, 2 nM) or organophosphonate glyphosate-based herbicide Roundup MAX (Rn, 79 nM of glyphosate) at 18 degrees C as well as with the mixture of these substances at 18 degrees C (Mix) or 25 degrees C (MixT) during 14 days. The concentrations used were correspondent to the environmentally relevant levels. The biomarkers of stress and toxicity were evaluated in digestive gland, except the lysosomal membrane stability measured in hemocytes. Exposures caused an oxidative stress due to the decreased SOD and GST activities and GSH/GSSG ratio, increased levels of thiobarbituric acid-reactive substances and protein carbonyls (with some exceptions). Dc increased cathepsin D activity in lysosomes. Nf increased lysosomal membrane stability and caspase-3 activity. Rn caused a dramatic distortion of metallo-thiolome due to increased levels of GSH and metallothionein-related thiols (MTSH) as well as depletion of Zn, Cu and Cd in the composition of metallothioneins, and decreased Zn/Cu molar ratio in the tissue. The particular toxicity of Rn was also attested by decreased lysosomal membrane stability and cholinesterase activity. Canonical discriminant analysis separated Rn-, Mix- and MixT-groups from the joint set of C-, Dc- and Nf-groups. Generally, compound-specific effects were expressed in U. tumidus responses to the mixtures, but in MixT-group some effects were particular or extremely strong. Multimarker approach and inte

关键词： Leaves   Hg2+ tolerance   Chelators   Cell death   Malondialdehyde   Quercetin   INDUCED OXIDATIVE STRESS   HEAVY-METAL STRESS   ANTIOXIDANT ACTIVITY   ZEA-MAYS   PHYTOREMEDIATION   PHYTOTOXICITY   RESPONSES   CADMIUM   ACCUMULATION   MECHANISMS  

摘要： The present study aimed to explore the effect of synthetic and naturally occurring chelators, EDTA and citric acid (CA), respectively, on changes in physiological and biochemical factors including cell death, level of mercury ions accumulation, malondialdehyde (MDA) content, total phenol and total flavonoids, anthocyanins and DPPH free radical scavenging activity, in the leaves of okra (Abelmoschus esculentus L.) plants exposed to mercury stress. In addition, polyphenolic compounds profile was assessed by high-performance liquid chromatography. The okras were planted in completely controlled hydroponic conditions (Hoagland solution). After they reached the four-leaf stage, they were treated simultaneously with different concentrations of HgCl2, EDTA and CA chelators, and their combination for one month. At the stage of maturity, the physiological and biochemical factors of the plant leaves were measured. The results showed that with the application of higher concentration of HgCl2, cell death, level of shoot and root Hg2+ content and root MDA, total phenols and total flavonoids, anthocyanin content, and DPPH free radical scavenging activity were increased. Also, the results indicated that okra plants have high biomass and a high rate of Hg mobilization and accumulation in the shoot versus the roots (TF = 2.152 for the plants treated with 60 mg L-1 Hg2+), hence, can be considered as Hg hyperaccumulator plant for the phytoremediation of Hg-polluted soils and waters. In the Hg-treated plants changes in their phenolic profile were induced, and the increase of chlorogenic acid, rosmaric acid, apigenin, quercetin and rutin content was observed. The application of EDTA and CA improved the toxic effects of Hg2+, by modifying phenolic compounds, chelating Hg2+, and its proper compartmentation, while EDTA outperformed CA in this respect. Based on the results, it could be concluded that due to the high biomass and growth of okra in the presence of Hg2+, this plant is suitable

关键词： Ecology   Filamentous algae   Surface waters   Multivariate approach   CLADOPHORA-GLOMERATA CHLOROPHYTA   ECOLOGICAL QUALITY   METAL POLLUTION   RUNNING WATERS   GREEN-ALGAE   PROLINE   COPPER   RIVER   MALONDIALDEHYDE   PIGMENTATION  

摘要： The present study aimed to investigate biochemical responses of filamentous algae integrated with surface waters in Yavuzeli-Araban catchment (the south-east of Turkey) by the use of a multivariate approach. This catchment having anthropogenic activities and different climate could affect environmental variables of surface waters, changed the biochemical compounds of filamentous species. A canonical correspondence analysis elucidated that heavy metals, water temperature, and nutrients were found to be major environmental factors governing the occurrence/succession and biochemical contents of filamentous algae. Cladophora glomerata is mainly linked with water temperature, antimony, orthophosphate, and conductivity, whereas Spirogyra majuscula related to nitrate and lead. Filamentous algae obtained from various sampling stations had different biochemical responses to different physicochemical factors. The biochemical responses of species were significantly different between sampling stations (p < 0.05) at different sampling seasons. Relatively high nutrients and low heavy metal contents stimulated the formation of pigments and total protein content by filamentous algae. On the other hand, increment in heavy metal ions in ecosystems lead to increase malondialdehyde, hydrogen peroxide, proline, total thiol group, and total phenolic compounds by filamentous algae. A significant positive relation between heavy metal ions and mentioned biochemical compounds observed from the Pearson correlation test. Besides, the surface structure of algal biomass changed concerning the different responses of species under various environmental conditions, indicated by the Fourier transform infrared analysis. Filamentous algal species showed different temporal and spatial occurrences in the region, which could be due to the biochemical responses of algae species to different complex environmental conditions. A significant increment in mentioned biochemical compound levels in filamentous al

关键词： Mycogenic   Nanoparticles   Tomato late blight   Resistance   Biostimulants   Defense response   PHYTOPHTHORA-INFESTANS   CHITOSAN NANOPARTICLES   SEVERE OUTBREAKS   BRASSICA-JUNCEA   STRESS   BIOSYNTHESIS   PROTEINS   POTATO   PLANTS   EFFICACY  

摘要： With the advent of rapid evolution of oomycete pathogen lineages, the need for sustainable agriculture practices has become the need of the hour. The late blight of tomato caused by Phytopthora infestans, has recently emerged as one such devastating disease in India that led to huge crop losses. Hence, in the present work seed priming with mycogenic selenium nanoparticles (SeNPs) for elicitation of resistance against tomato late blight disease is investigated. It also aims to understand the defense responses triggered by SeNPs at cellular, biochemical and transcriptomic levels. Enhanced plant growth parameters were observed in bioactive SeNPs-primed tomato plants as compared to control plants. SeNPs-primed and pathogen inoculated plants exhibited a significant protection of 72.9 % against late blight disease. The primed plants also recorded a remarkable accumulation of lignin, callose and hydrogen peroxide that serve as the cellular defense over the control plants. Further, an elevated level of lipoxygenase (LOX), phenylalanine lyase (PAL), beta-1,3-glucanase (GLU), superoxide dismutase (SOD) corroborated the biochemical defense in primed plants, which was also reflected in the corresponding transcriptome profiling of the genes encoding the enzymes. Thus, the present study represents an orchestrated correlation between resistance and defense responses incited by SeNPs against tomato late blight disease, which can be used as nano-biostimulant fungicide in protecting tomato plants.