Haematological profile of common carp spawners of various breeds

The goal of this study was to determine the basic haematological profile of common carp (Cyprinus carpio L.) spawners of eight breeds reared under identical conditions and sampled in spring after overwintering. Significant differences were found among the breeds for haemoglobin level (Hb), haematocrit value (PCV), mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) values. The number of red blood cells (RBC), mean corpuscular haemoglobin concentration (MCHC), number of leukocytes (WBC) and leukocyte differential count (WBC DIFF) did not differ significantly among the respective breeds. The highest Hb, PCV and MCH values were found for Ropsha scaly carp (ROP) and Amur wild carp (AS) (Hb 109 ± 17 and 106 ± 15 g l^?1; PCV 0.40 ± 0.06 and 0.40 ± 0.06 l l^?1; MCH 69 ± 7 and 69 ± 9 pg, respectively). The AS specimens and breeds that originated [ROP, Ukraine scaly carp (US), and Northern mirror carp (M72)] showed significantly higher values of Hb (P < 0.01), PCV (P < 0.01), MCV (P < 0.05) and MCH (P < 0.05), compared to the other four breeds: Hungarian mirror carp (M2), Israeli mirror carp (Dor 70), South Bohemian mirror carp (BV) and Tata scaly carp (TAT). Males showed significantly higher PCV, Hb and RBC values within individual breeds. This study demonstrated that Amur wild carp and breeds originating from it had significantly higher values of erythrocyte profile in comparison with the other breeds studied.     

Haematological and serum biochemical characterization and comparison of wild and cultured northern snakehead (Channa argus Cantor, 1842)

The objective of this study was to compare haematological and serum biochemical parameters of cultured and wild specimens of the northern snakehead, Channa argus, to establish baseline values. Thirty sexually immature and disease‐free wild fish (37.70 ± 13.68 cm total length, 555.3 ± 449.0 g weight) and 30 cultured fish (36.82 ± 1.72 cm total length, 450.5 ± 58.8 g weight) were examined. In cultured northern snakehead, the average values of alanine aminotransferases (370.1 IU L^?1), aspartate amino transferases (1145.3 IU L^?1), albumin (15.84 g L^?1), direct billuribin (6.15 μmol L^?1), urea (1.40 mmol L^?1), glucose (21.54 mmol L^?1) and cholesterol levels (6.60 mmol L^?1) were significantly higher (P < 0.05) than in the wild fish. In wild specimens the corresponding values were 9.81 IU L^?1, 394.1 U L^?1, 12.90 g L^?1, 2.57 μmol L^?1, 0.97, 2.36 and 4.38 mmol L^?1, respectively. No significant difference (P > 0.05) was found for total protein, globulin, total bilirubin, chromium, sodium, chloride or triglyceride levels between wild and cultured populations. The mean values of the red blood cell (RBC) counts, hematocrit, haemoglobin, and mean corpuscular volume (MCV) were significantly higher (P < 0.05) in the cultured population, while the values of the white blood cell (WBC) counts, erythrocyte sedimentation rate (ESR), mean corpuscular haemoglobin (MCH), and mean corpuscular haemoglobin concentration (MCHC) were significantly higher (P < 0.05) in the wild population. The study showed that the environmental conditions significantly impacted the status of the fish. It is suggested that these physiological parameters can be conveniently employed as health monitoring tools in fish culture practices.     

Fish as sources and sinks of nutrients in lakes

1. The release of total phosphorus (TP) and nitrogen (N in ammonium) was measured for the five most abundant fish species (>85% of biomass) in Mouse and Ranger Lakes, two biomanipulated, oligotrophic lakes in Ontario. 2. The specific release rate of both nutrients was significantly related to fish mass; log₁₀ TP release rate (μg h^?1) = 0.793 (±0.109) [log₁₀ wet mass (g)] + 0.7817 (±0.145), and log₁₀ N release rate (μg h^?1) = 0.6946 (±0.079) [log₁₀wet mass (g)] + 1.7481 (±0.108). 3. When fish nutrient release was standardized for abundance (all populations, 1993–95) and epilimnetic volume, fish were estimated to contribute 0.083 (±0.061) μg TP L^?1 day^?1, and 0.41 (±0.17) μg N L^?1 day^?1 in Mouse L., and 0.062 (±0.020) μg TP L^?1 day^?1 and 0.31 (±0.08) μg N L^?1 day^?1 in Ranger L. 4. In comparison, concurrent rates of total planktonic P regeneration were 1.02 (±0.45) μg L^?1 day^?1 (Mouse L.) and 0.85 (±0.19) μg L^?1 day^?1 (Ranger L.). Fish represented 8% of planktonic P release in Mouse L. and 7% in Ranger L. 5. Fish dry mass had mean elemental body compositions of 39.3% carbon, 10.9% nitrogen, and 4.0% phosphorus (all fish combined), with a mean molar C : N : P ratio of 27 : 6 : 1. This comprised about 55% and 23% of the total epilimnetic particulate P and N respectively. 6. Turnover times of P and N in fish were approximately 103 and 48 days respectively. In comparison, planktonic turnover times of particulate P in Mouse and Ranger Lakes were 4.3 and 4.4 days respectively. Given their high P content and low turnover rates, fish appear to be important P sinks in lakes.     

Polymorphism of microsatellite markers in Russian common carp (<Emphasis Type="Italic">Cyprinus carpio</Emphasis> L.) breeds

Using five microsatellite loci, genotyping and genetic diversity estimates were obtained for nine samples representing seven common carp breeds most widespread in Russia. For comparison, the samples of Amur wild common carp (Cyprinus carpio haematopterus) and a sample of European Hungarian carp were used. In the samples examined (n = 148) a total of 78 alleles were revealed. The highest mean allele number per locus (7.3) was identified in Amur wild common carp, while the lowest number was found in Cherepets carps (4.0). In different breeds, the observed heterozygosities varied from 0.819 (Altai carp) to 0.651 (Cherepets scaly carp). Three out of five microsatellite loci (MFW-24, MFW-28, and MFW-19) revealed a high level of population differentiation. In the dendrogram of genetic differences, all breeds clustered into two groups. One of these groups was composed of the two strains of Ropsha carp, Stavropol carp, Amur wild common carp, and the two samples of Cherepets carp. The second cluster included Altai carp (Priobskii and Chumysh populations), two Angelinskii carp breeds (mirror and scaly), and Hungarian carp. The pairs of breeds/populations/strains, having common origin, were differentiated. Specifically, these were two populations of Altai carp, two strains of Ropsha carp, as well as the breeds of Angelinskii and Cherepets carps. The reasons for genetic differentiation of Russian common carp breeds, as well as the concordance of the evolutionary histories of these breeds, some of which originated from the European breeds, while the others contain substantial admixture of the Amur wild common carp, are discussed.     

Effect of different doses of organic fertilizer (cow dung) on pond productivity and fish biomass in stillwater ponds

The effects of five (5 000, 10 000, 15 000, 20 000, 24 000 kg ha^?1 year^?1) different doses of organic fertilizer (cow dung) were studied on pond productivity in terms of plankton production and fish biomass in freshwater fish ponds. The grow out period was 60 days. Physico-chemical factors of pond waters were also monitored. With an increase in the fertilizer dose, biochemical oxygen demand (BOD) (1.7 ± 0.1 – 10.35 ± 0.05 mg L^?1), O-PO₄ (0.04 ± 0.0 – 0.77 ± 0.02 mg L^?1) and NH₄-N (0.03 ± 0.02 – 0.32 ± 0.02 mg L^?1) increased significantly (P < 0.05). Alkalinity (79.0 ± 1.6 – 164.0 ± 3.8 mg L^?1) also increased with the increase in fertilizer dose, declining after 60 and 75 days (48.8 ± 1.13 – 67.9 ± 2.1 mg L^?1). NO₃-N was maximum (1.66 ± 0.2 mg L^?1) in the ponds which received cow dung at 15 000 kg ha^?1 year^?1, and declined (0.94 ± 0.5 mg L^?1) at higher doses. Dissolved oxygen (DO) remained significantly high (4.7 mg L^?1) up to the third (15 000 kg ha^?1 year^?1) treatment. Highest plankton population (phytoplankton 17 350.0 ± 1 250.0 no L^?1), zooplankton (373.0 ± 22.0 no L^?1), species diversity (phytoplankton 3.0, zooplankton 2.3), fish biomass (4.45 kg) and specific growth rate (SGR) (2.36 % body weight (BW) d^?1) were also observed in ponds which were treated with fertilizer at 15 000 kg ha^?1 year^?1. However, at higher doses, a decline in these parameters (phytoplankton, 0.0 – 8 810.0 ± 690.0 no L^?1; zooplankton, 0.0 – 205.0 ± 25.0 no L^?1; fish biomass, 2.3 kg; SGR, 1.25 % body weight (BW) d^?1) was observed. Furthermore, with a decrease in the water temperature from 24 °C (on day 60) to 21 °C (on day 75), a decline in nutrient release, plankton population L^?1 and species diversity was observed. Sediment analysis indicated that with an increase in the fertilizer dosage, a significant and progressive increase in the accumulation of organic carbon (0.787 ± 0.006 – 0.935 ± 0.01), total nitrogen (0.877 ± 0.071 – 1.231 ± 0.03), NH₄-N (54.4 ± 0.57 – 68.95 ± 0.81), NO₃-N (78.5 ± 1.21 – 98.5 ± 0.35), total P (140.0 ± 0.50 – 151.0 ± 1.27) and soluble P (7.15 ± 0.18 – 10.1 ± 0.56) took place; similarly, electrical conductivity (EC) values of sediment also increased progressively (from 200.0 ± 7.1–300.0 ± 10.63 μ mhos cm^?1).     

Mitigating stress effects during transportation of matrinxã (Brycon amazonicus Günther, 1869; Characidae) through the application of calcium sulfate

This study verified the effects of CaSO₄ on physiological responses of the tropical fish matrinxãBrycon amazonicus (200.2 ± 51.1 g) in water containing CaSO₄ after a 4‐h transportation at concentrations of: 0, 75, 150, and 300 mg L^?1. Blood samples were collected prior to transportation (initial levels), immediately after packaging, at arrival, and 24 h and 96 h after transportation (recovery). Cortisol levels increased after packaging (118.2 ± 14.2 ng ml^?1), and decreased slightly after transportation in water containing CaSO₄ (106.8 ± 14.1), but remained higher than initial levels (21.0 ± 2.6 ng ml^?1). Fish kept at 150 mg L^?1 CaSO₄ reached the pre‐transportation levels at 24 h of recovery. Blood glucose increased after transportation in all treatments (8.2 ± 0.2 mmol L^?1) and declined after full recovery to values below initial levels (4.8 ± 0.1 mmol L^?1). Chloride levels did not change in CaSO₄ treatments; serum sodium concentrations decreased after packaging and after transportation. Serum calcium levels did not differ among treatments, but decreased after packaging and increased at 96 h of recovery. Hematocrit and the number of red blood cells were higher in all treatments after packaging and arrival, except in fish exposed to 300 mg L^?1 CaSO₄. Mean corpuscular volume increased in 75 mg L^?1 CaSO₄, which reached the higher VCM after transportation. Hemoglobin levels increased only after transportation, regardless of calcium sulfate levels. Handling before transportation and transportation itself were both stressful to fish; calcium sulfate at concentrations tested in the present work had a moderate influence in the reduction of stress responses.     

Development of an animal adaptability index: Application for dairy cows

The objective of this study was designed to evaluate the association between thermoregulatory responses, hormonal, hematological and serum biochemical values features aiming to propose an adaptability index (AI) for dairy cows under tropical conditions. Thirty adult dairy cows were used, including 15 Sindi and 15 Girolando breeds with mean weight of 338.52 ± 42.79 kg and 487.54 ± 60.67 kg, respectively. These data included rectal temperature (RT) and respiratory rate (RR). For the serum of blood sample, the levels of glucose (GLU), cholesterol (CHO), triglycerides (TRI), total protein (TP), creatinine (CRE), albumin (ALB), urea (URE), aspartate aminotrasferase (AST) and alanine aminotrasferase (ALT) and hormonal concentrations (triiodothyronine – T₃ and thyroxine – T₄). For the total blood samples were analyzed for hematology variables: red blood cell count (RBC); hemoglobin concentration (HC); packet cell volume (PCV); mean corpuscular volume (MCV); white blood cell (WBC). The AI was development using multivariate analysis to "weigh" the influence of each variable in the animal responses. The variables more important for adaptive aspects of Sindi and Girolando cows were respectively: GLU; MCV; AST; PCV; RBC; HE; TP; ALB; ALT; RR; T₄; RT; T₃; URE; CHO; TRI; CRE; WBC and ALB; GLU; TP; AST; RR; ALT; CRE; CHO; RT; RBC; T₄; HE; PCV; MCV; URE; TRI; WBC; T₃. The difference between breeds was just over 8% for AI. We developed a preliminary AI, able to measure the level of adaptability of dairy cows under tropical region. The methodological framework has potential to inform decision-makers on the adaptability animal conditions and high inference of the blood values from adaptability of cows.     

Regulation of Intracellular pH in Guinea Pig Cerebral Cortex Ex Vivo Studied by 31P and 1H Nuclear Magnetic Resonance Spectroscopy: Role of Extracellular Bicarbonate and Chloride

Abstract: The role of transmembrane processes that are dependent on external anions in the regulation of cerebral intracellular pH (pH_i), high-energy metabolites, and lactate was investigated using ³¹P and ¹H NMR spectroscopy in an ex vivo brain slice preparation. During oxygenated superfusion, removal of external HCO₃^?/CO₂ in the presence of Na⁺ led to a sustained split of the inorganic phosphate (P_i) peak so that the pH_i indicated by one part of the peak was 0.38 pH units more alkaline and by the other part 0.10 pH units more acidic at 5 min than in the presence of HCO₃^?. The pH in the compartment with a higher pH_i value returned to 7.29 ± 0.04 by 10.5 min of superfusion in a HCO₃^?-free medium, whereas the pH_i in an acidic compartment was reduced to 7.02. In the presence of 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid or the absence of external Cl^?, removal of HCO₃^? caused alkalinization without split of the P_i peak. Both treatments reduced the rate of pH_i normalization following alkalinization. Simultaneous omission of external HCO₃^? and Na⁺ did not inhibit alkalinization of the pH_i following CO₂ exit. All these data show that the acid loading mechanism at neutral pH_i is mediated by an Na⁺-independent anion transport. During severe hypoxia, pH_i dropped from 7.29 ± 0.05 to 6.13 ± 0.16 and from 7.33 ± 0.03 to 6.67 ± 0.05 in the absence and presence of HCO₃^?, respectively, in Na⁺-containing medium. Lactate accumulated to 18.7 ± 2.8 and 19.6 ± 1.5 mmol/kg under the respective conditions. In the HCO₃^?-free medium supplemented with 1 mM amiloride, the pH_i fell only to 6.94 ± 0.08 despite the lactate concentration of 18.9 ± 2.4 mmol/kg. Acidification caused by hypoxia was also small in the slice preparations superfused in the absence of both HCO₃^? and Cl^?, as the pH_i was 7.01 ± 0.12 at a lactate concentration of 24.5 ± 2.4 mmol/kg. These data indicate that apart from anaerobic glucose metabolism, separate acidifying mechanisms are functioning during hypoxia under these conditions. Recovery of phosphocreatine levels following reoxygenation was >75% relative to the prehypoxic level in the slice preparations superfused in the absence of HCO₃^? but <47% in those preparations superfused without HCO₃^? and Cl^?. This indicates that either neutral pH_i or absence of Cl^? during hypoxia was deleterious to the energy metabolism. The present data indicate that Cl^?/HCO₃^? exchange mechanisms have distinct roles in cerebral H⁺ homeostasis depending on the level of pH_i and energy state.     

Nonlinear response of stream ecosystem structure to low‐level phosphorus enrichment

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Microalgae for phosphorus removal and biomass production: a six species screen for dual‐purpose organisms

Microalgae biofuel production can be feasible when a second function is added, such as wastewater treatment. Microalgae differ in uptake of phosphorus (P) and growth, making top performer identification fundamental. The objective of this screen was to identify dual‐purpose candidates capable of high rates of P removal and growth. Three freshwater – Chlorella sp., Monoraphidium minutum sp., and Scenedesmus sp. – and three marine – Nannochloropsis sp., N. limnetica sp., and Tetraselmis suecica sp. – species were batch cultured in 250 mL flasks over 16 days to quantitate total phosphorus (TP) removal and growth as a function of P loads (control, and 5, 10, and 15 mg L^?1 enrichment of control). Experimental design used 100 μmol m^?2 s^?1 of light, a light/dark cycle of 14/10 h, and no CO₂ enrichment. Phosphorus uptake was dependent on species, duration of exposure, and treatment, with significant interaction effects. Growth was dependant on species and treatment. Not all species showed increased P removal with increasing P addition, and no species demonstrated higher growth. Nannochloropsis sp and N. limnetica sp. performed poorly across all treatments. Two dual‐purpose candidates were identified. At the 10 mg L^?1 treatment Monoraphidium minutum sp. removed 67.1% (6.66 mg L^?1 ± 0.60 SE) of TP at day 8, 79.3% (7.86 mg L^?1 ± 0.28 SE) at day 16, and biomass accumulation of 0.63 g L^?1 ± 0.06 SE at day 16. At the same treatment Tetraselmis suecica sp. removed 79.4% (6.98 mg L^?1 ± 0.24 SE) TP at day 8, 83.0% (7.30 mg L^?1 ± 0.60 SE) at day 16, and biomass of 0.55 g L^?1 ± 0.02 SE at day 16. These species merit further study using high‐density wastewater cultures and lipid profiling to assess suitability for a nutrient removal and biomass/biofuel production scheme.     

Enhancing ethanol production from cellulosic sugars using <Emphasis Type="Italic">Scheffersomyces (Pichia) stipitis</Emphasis>

Studies were performed on the effect of CaCO₃ and CaCl₂ supplementation to fermentation medium for ethanol production from xylose, glucose, or their mixtures using Scheffersomyces (Pichia) stipitis. Both of these chemicals were found to improve maximum ethanol concentration and ethanol productivity. Use of xylose alone resulted in the production of 20.68 ± 0.44 g L^?1 ethanol with a productivity of 0.17 ± 0.00 g L^?1 h^?1, while xylose plus 3 g L^?1 CaCO₃ resulted in the production of 24.68 ± 0.75 g L^?1 ethanol with a productivity of 0.21 ± 0.01 g L^?1 h^?1. Use of xylose plus glucose in combination with 3 g L^?1 CaCO₃ resulted in the production of 47.37 ± 0.55 g L^?1 ethanol (aerobic culture), thus resulting in an ethanol productivity of 0.39 ± 0.00 g L^?1 h^?1. These values are 229 % of that achieved in xylose medium. Supplementation of xylose and glucose medium with 0.40 g L^?1 CaCl₂ resulted in the production of 44.84 ± 0.28 g L^?1 ethanol with a productivity of 0.37 ± 0.02 g L^?1 h^?1. Use of glucose plus 3 g L^?1 CaCO₃ resulted in the production of 57.39 ± 1.41 g L^?1 ethanol under micro-aerophilic conditions. These results indicate that supplementation of cellulosic sugars in the fermentation medium with CaCO₃ and CaCl₂ would improve economics of ethanol production from agricultural residues.     

Optimization of D-xylose to xylitol biotransformation by Candida guilliermondii cells permeabilized with Triton X-100

Abstract

The effect of NADP⁺ and glucose-6-phosphate (G6P) on the biotransformation of D-xylose to xylitol by cells of Candida guilliermondii permeabilized with surfactant Triton X-100 was evaluated. The experimental runs were performed with 12 g L^?1 of permeabilized cells and a reaction medium composed of Tris–HCl buffer (0.1 M pH 7), D-xylose (57 g L^?1), and MgCl₂.6H₂O (5 mM). The levels of NADP⁺ (from 0.0 to 1.7 mM) and G6P (from 0.00 to 0.17 M) were varied according a 2²-full factorial composed design. Under optimized conditions (NADP⁺ 0.5 mM and 0.05 M G6P), the xylitol volumetric productivity (Q_P) and yield factor (Y_P/S) predicted were 1.86 ± 0.03 g L^?1 h^{? 1} and 0.64 ± 0.03 g g^?1, respectively. These values were 94% and 19% higher than those obtained with unpermeabilized cells under fermentation conditions (0.97 g L^?1 h^?1 and 0.53 g g^?1, respectively). On the basis of the results, it can be concluded that xylitol production by biotransformation with cells of C. guilliermondii permeabilized with Triton X-100 is a promising alternative to the fermentative process.     

Performance evaluation of an integrated constructed wetland used to treat a contaminated aquatic environment

The treatment performance of an integrated constructed wetland (ICW) that was in operation for 3 years was evaluated. Artificial neural network modeling was used to predict contaminant treatment efficiencies based on easily measured field parameters. The estimates for average yearly removals of total phosphorus (TP), total nitrogen (TN), chemical oxygen demand (COD), and total suspended solids (TSS) were 0.81 ± 0.18, 7.17 ± 1.62, 63.80 ± 17.41, and 126.12 ± 48.61 g m^?2 d^?1, respectively. Removal velocities of contaminants were determined from analyses of inlet–outlet datasets. The areal removal rate constants were 0.46, 0.73, 0.44, and 0.82 m d^?1 for TP, TN, COD, and TSS, respectively. The presence of high background concentrations of contaminants (TP: 0.01 mg L^?1, TN: 0.13 mg L^?1, COD: 6.43 mg L^?1, TSS: 14.83 mg L^?1) indicated that the water in the ICW was mesotrophic. Statistical methods (i.e., principal component analysis (PCA), forward selection, and correlation analysis) were used to select optimal input subsets for different contaminants. These data subsets were subsequently used for model development. To find the optimal network architectures, a genetic algorithm was introduced to the learning processes. The models were competent at providing reasonable matches between the measured and the predicted effluent concentrations of TP (R² = 0.9711), TN (R² = 0.8875), COD (R² = 0.9359), and TSS (R² = 0.9164). The results of the models provided information that will be useful for the design and modification of constructed wetlands.     

Phosphorus retention of forested and emergent marsh depressional wetlands in differing land uses in Florida,USA

The translocation of phosphorus (P) from terrestrial landscapes to aquatic bodies is of concern due to the impact of elevated P on aquatic system functioning and integrity. Due to their common location in depressions within landscapes, wetlands, including so-called geographically isolated wetlands (GIWs), receive and process entrained P. The ability of depressional wetlands, or GIWs, to sequester P may vary by wetland type or by land use modality. In this study we quantified three measures of P sorption capacities for two common GIW types (i.e., emergent marsh and forested wetlands) in two different land use modalities (i.e., agricultural and least impacted land uses) across 55 sites in Florida, USA. The equilibrium P concentration (EPC₀) averaged 6.42 ± 5.18 mg P L^?1 (standard deviation reported throughout); and ranged from 0.01–27.18 mg P L^?1; there were no differences between GIW type or land use modality, nor interaction effects. Significant differences in phosphorus buffering capacity (PBC) were found between GIW types and land use, but no interaction effects. Forested GIWs [average 306.64 ± 229.63 (mg P kg^?1) (µg P L^?1)^?1], and GIWs in agricultural settings [average 269.95 ± 236.87 (mg P kg^?1) (µg P L^?1)^?1] had the highest PBC values. The maximum sorption capacity (S_max) was found to only differ by type, with forested wetlands (1274.5 ± 1315.7 mg P kg^?1) having over three times the capacity of emergent GIWs (417.5 ± 534.6 mg P kg^?1). Classification trees suggested GIW soil parameters of bulk density, organic content, and concentrations of total P, H₂O-extractable P, and HCl-extractable P were important to classifying GIW P-sorption metrics. We conclude that GIWs have high potential to retain P, but that the entrained P may be remobilized to the wetland water column depending on storm and groundwater input P concentrations. The relative hydrologic dis-connectivity of GIWs from other aquatic systems may provide sufficient retention time to retain elevated P within these systems, thereby providing an ecosystem service to downstream waters.     

Interaction of the synthetic immunomodulatory dipeptide bestim with murine macrophages and thymocytes

The tritium-labeled dipeptide bestim (γ-D-Glu-L-Trp) with a specific activity of 45 Ci/mmol was obtained by high-temperature solid-state catalytic isotope exchange. It was found that [³H]bestim binds with a high affinity to murine peritoneal macrophages (K _d 2.1 ± 0.1 nM) and thymocytes (K _d 3.1 ± 0.2 nM), as well as with plasma membranes isolated from these cells (K _d 18.6 ± 0.2 and 16.7 ± 0.3 nM, respectively). The specific binding of [³H]bestim to macrophages and thymocytes was inhibited by the unlabeled dipeptide thymogen (L-Glu-L-Trp) (K _i 0.9 ± 0.1 and 1.1 ± 0.1 nM, respectively). After treatment with trypsin, macrophages and thymocytes lost the ability to bind [³H]bestim. Bestim in the concentration range of 10^?10 to 10^?6 M reduced the adenylate cyclase activity in the membranes of murine macrophages and thymocytes.     

Kinetics of chloride transport in the cyanobacterium Synechococcus R-2 (Anacystis nidulans, S. leopoliensis) PCC 7942

The kinetics of the light-driven Cl^? uptake pump of Synechococcus R-2 (PCC 7942) were investigated. The kinetics of Cl^? uptake were measured in BG-11 medium (pH_o, 7·5; [K⁺]_o, 0·35 mol m^?3; [Na⁺]_o, 18 mol m^?3; [Cl^?]_o, 0·508 mol m^?3) or modified media based on the above. Net³⁶Cl^? fluxes (?Cl^?_o,i) followed Michaelis-Menten kinetics and were stimulated by Na⁺ [18 mol m^?3 Na⁺ BG-11 ?Cl^?_max= 3·29±0·60 (49) nmol m^?2 s^?1 versus Na⁺-free BG-11 ?Cl^?_max= 1·02±0·13 (54) nmol m^?2 s^?1] but the Km was not significantly different in the presence or absence of Na⁺ at pH_o 10; the Km was lower, but not affected by the presence or absence of Na⁺ [Km = 22·3±3·54 (20) mmol m^?3]. Na⁺ is a non-competitive activator of net ?Cl^?_o,i. High [K⁺]_o (18 mol m^?3) did not stimulate net ?Cl^?_o,i or change the Km in Na⁺-free medium. High [K⁺]_o (18 mol m^?3) added to Na⁺ BG-11 medium decreased net ?Cl^?_o,i [18 mol m^?3K⁺ BG-11; ?Cl^?_max= 2·50±0·32 (20) nmol m^?2 s^?1 versus BG-11 medium; ?Cl^?_max= 3·35±0·56 (20) nmol m^?2 s^?1] but did not affect the Km 55·8±8·100 (40) mmol m^?3]. Na⁺-stimulation of net ?Cl^?_o,i followed Michaelis-Menten kinetics up to 2–5 mol m^?3 [Na⁺]_o but higher concentrations were inhibitory. The Km for Na⁺-stimulation of net ?Cl^?_o,i [K_1/2(Na⁺)] was different at 47 mmol m^?3 [Cl^?]_o (K_1/2[Na⁺] = 123±27 (37) mmol m^?3]. Li⁺ was only about one-third as effective as Na⁺ in stimulating Cl^? uptake but the activation constant was similar [K_1/2(Li⁺) = 88±46 (16) mmol m^?3]. Br^? was a competitive inhibitor of Cl^? uptake. The inhibition constant (Ki) was not significantly different in the presence and absence of Na⁺. The overall Ki was 297±23 (45) mmol m^?3. The discrimination ratio of Cl^? over Br^? (δCl^?/δBr^?) was 6·38±0·92 (df = 147). Synechococcus has a single Na⁺-stimulated Cl^? pump because the Km of the Cl^? transporter and its discrimination between Cl^? and Br^? are not significantly different in the presence and absence of Na⁺. The Cl^? pump is probably driven by ATP.     

Effect of periphyton on growth performance of grey mullet, Mugil cephalus (Linn.), in inland saline groundwater ponds

The present study attempts to assess the potential of artificial substrates to enhance fish production in inland saline groundwater ponds through periphyton production. Grey mullet, Mugil cephalus, was cultured for 100 days in ponds with substrate (treatment ponds) and without substrate (control ponds). To enhance the surface area, bamboo poles were used as substrate. The periphyton population, pigment concentration and hydrobiological characteristics of pond water were monitored. The studies revealed little difference in most of the water quality parameters observed in the two treatments. However, turbidity (27.0 ± 0.1–35.0 ± 0.1 Nephalo Turbidity Unit (NTU)), chlorophyll ‘a’ (6.6 ± 0.6–7.6 ± 0.6 μg L^?1), plankton population (phytoplankton 8.4 × 10³–9.4 ×10³ numbers L^?1; zooplankton 4.0 × 10³–5.1 × 10³ numbers L^?1) and NH₄–N (2.0 ± 0.2–2.3 ± 0.1 mg L^?1) were high in the treatment with no additional substrate; however, in the treatment with substrate the total Kjeldahl nitrogen (9.8 ± 0.8–10.8 ± 0.7 mg L^?1) and o‐PO₄ (0.1 ± 0.01–0.1 mg L^?1) remained significantly (P < 0.05) higher. Highest periphyton biomass in terms of dry matter (DM) (0.8 ± 0.01–1.4 ±0.01 mg cm^?2), ash free DM (0.4 ± 0.0–0.6 ± 0.01 mg cm^?2), chlorophyll ‘a’ (3.1 ± 0.2–8.1 ± 0.8 μg cm^?2) and pheophytin ‘a’ (1.9 ± 0.4–3.9 ± 0.5 μg cm^?2) was observed at 50 cm depth in ponds provided with additional substrate. Fifteen plankton genera showing periphytic affinity colonized the bamboo substrates. Fish growth (mean fish weight 524.3 ± 8.7 g and SGR 2.5 ± 0.1) was significantly (P < 0.05) higher in ponds provided with additional substrate compared with control ponds (387.2 ± 6.0). Length–weight relationship (LWR) (W = cLⁿ) also showed that the exponential value (‘n’) of length was high in substrate‐supported ponds (n = 2.36) in comparison with controls (n = 1.09). These studies suggest that a periphyton‐supported aquaculture system can be used successfully for the culture of herbivorous brackishwater fish species like M. cephalus in inland saline groundwaters and thus could contribute to the development of sound and sustainable aquaculture technology.     

Production of precursors for anti-Alzheimer drugs: Asymmetric bioreduction in a packed-bed bioreactor using immobilized D. carota cells

(S)-1-Phenylethanol derivatives, which are the precursors of many pharmacological products, have also been used as anti-Alzheimer drugs. Bioreduction experiments were performed in a batch and packed-bed bioreactor. Then, the kinetics constants were determined by examining the reaction kinetics in the batch system with free and immobilized carrot cells. Also, the effective diffusion coefficient (D_e) of acetophenone in calcium alginate-immobilized carrot cells was investigated. Kinetics constants for free cells, which are intrinsic values, are reaction rate V_max?=?0.052?mmol?L^?1?min^?1, and constants of the Michaelis–Menten K_M?=?2.31?mmol?L^?1. Kinetics constants for immobilized cells, which are considered apparent values, are V_{max, app}?=?0.0407?mmol?L^?1 min^?1, K_{M, app}?=?3.0472?mmol?L^?1 for 2?mm bead diameter, and V_{max, app}?=?0.0453?mmol?L^?1 min^?1, K_{M, app}?=?4.9383?mmol?L^?1 for 3?mm bead diameter. Average value of effective diffusion coefficient of acetophenone in immobilized beads was determined as 1.97?×?10^?6?cm²?s^?1. Using immobilized carrot cells in an up-flow packed-bed reactor, continuous production of (S)-1-phenylethanol through asymmetric bioreduction of acetophenone was performed. The effects of the residence time and concentrations of substrate were investigated at pH 7.6 and 33°C. Enantiomerically pure (S)-1-phenylethanol (ee?>?99%) was produced with 75% conversion at 4-hr residence time.     

The mixture of kresoxim‐methyl and boscalid,an excellent alternative controlling grey mould caused by Botrytis cinerea

Grey mould, caused by the fungus Botrytis cinerea, is one of the most destructive diseases in greenhouses for which serious fungicide resistance has developed. Between 2003 and 2005, 213 isolates of B. cinerea from two geographical regions were characterised for baseline sensitivity to kresoxim‐methyl. In the absence of salicylhydroxamic acid (SHAM), the mean 50% effective concentration (EC₅₀) values were 6.67 ± 0.61 (mean ± SD) and 0.37 ± 0.10 mg L^?1 during growth and germination, respectively. In the presence of 100 mg L^?1 SHAM, baseline sensitivities were distributed as unimodal curves with mean EC₅₀ values of 2.38 ± 0.21 and 0.28 ± 0.09 mg L^?1 for inhibiting growth and inhibiting germination, respectively. The mixture of kresoxim‐methyl and boscalid showed good control efficacy against strawberry grey mould disease. After the mixture was extensively used on strawberry for 2 years, 50 isolates were collected and determined for their sensitivity to kresoxim‐methyl and boscalid, respectively. The mean EC₅₀ of germination inhibition by boscalid was 0.39 ± 0.08 mg L^?1. The mean EC₅₀ of germination inhibition by kresoxim‐methyl was 0.26 ± 0.07 mg L^?1 in the presence of 100 mg L^?1 SHAM. Sensitivities of B. cinerea to both kresoxim‐methyl and boscalid did not show any significant decrease. These results suggest that their mixture is a satisfactory alternative candidate for management of grey mould disease in greenhouses.     

Effect of oxygen transfer rate on the composition of the pectolytic enzyme complex of Aspergillus niger

Optimal agitation and aeration conditions [assuring O₂ transfer rates (OTR) from 12 to 179 mmol L^?1 h^?1] were determined for pectin lyase (PL) synthesis of an Aspergillus niger strain. Components of the pectolytic enzyme complex were also investigated in order to determine whether their O₂ demand is identical with or different from that of pectin lyase. Should the latter be the case, a possibility would be given to produce enzyme complexes of different agitation and aeration conditions. According to our results, mycelium yield of Aspergillus niger attained a maximum at an OTR of 100 mmol L^?1 h^?1. The yields of the various pectolytic enzymes reached maxima at different OTRs. Pectin lyase production was the highest (0.555 µmol min^?1 mL^?1) at an OTR of 60 mmol L^?1 h^?1. Endopolygalacturonase (PG) production showed a maximum at the OTR of 49 mmol L^?1 h^?1 with a second peak at 100?135 mmol O₂ L^?1 h^?1. Pectin esterase (PE) synthesis showed a maximum at on OTR of 12?14 mmol L^?1 h^?1, while both apple juice clarifying and macerating activities gave two maxima at 14 and 60 mmol L^?1 h^?1 due to the optima of PE and endo-PG. Macerating activity showed a high value at OTR optimal for PL production as well.