Adsorption of Vancomycin on Amberlite XAD-16 in a Packed Bed Column

Vancomycin is a glycopeptide used in the prophylaxis and treatment of bacterial infections. It is obtained with fermentation of bacteria called Amycolatopsis orientalis. After fermentation, it is purified of coloured additions and inorganic salts by adsorption to a polymeric adsorbent Amberlite XAD-16. In this work, equilibrium adsorption studies to determine the adsorption capacity were done first. The experimental data fitted best with Langmuir isotherm. Maximum capacity was q0 = 53.76 kg m–3 resin at pH 7. Next, adsorption was studied in a laboratory packed bed adsorption column. A simple mathematical model taking into account axial dispersion was applied to describe the dynamics of the process with breakthrough curves. Experimental and predicted results were compared, and some parametric sensitivity analysis was made to better understand the process for the purpose of scale up

Adsorption of Vancomycin on Amberlite XAD-16 in a Packed Bed Column

Vancomycin is a glycopeptide used in the prophylaxis and treatment of bacterial infections. It is obtained with fermentation of bacteria called Amycolatopsis orientalis. After fermentation, it is purified of coloured additions and inorganic salts by adsorption to a polymeric adsorbent Amberlite XAD-16. In this work, equilibrium adsorption studies to determine the adsorption capacity were done first. The experimental data fitted best with Langmuir isotherm. Maximum capacity was q0 = 53.76 kg m–3 resin at pH 7. Next, adsorption was studied in a laboratory packed bed adsorption column. A simple mathematical model taking into account axial dispersion was applied to describe the dynamics of the process with breakthrough curves. Experimental and predicted results were compared, and some parametric sensitivity analysis was made to better understand the process for the purpose of scale up

Fertimetro, a Principle and Device to Measure Soil Nutrient Availability for Plants by Microbial Degradation Rates on Differently-Spiked Buried Threads

A novel patented method (PCT/IB2012/001157: Squartini, Concheri, Tiozzo, University of Padova) and the corresponding application devices, suitable to measure soil fertility, are presented. The availability or deficiency of specific nutrients for crops is assessed by monitoring the kinetics of progressive weakening of cotton or silk threads due to in situ microbial activity. The method is based on a nutrient-primed incremented substrate degradation principle. Threads are buried as is or pre-impregnated with N or P solutions, and the acceleration of the degradation rate for the N-supplemented or P-supplemented thread, in comparison to the untreated thread, is proportional to the lack of the corresponding nutrient in that soil. Tests were validated on corn crops in plots receiving increasing fertilizer rates in a historical rotation that has been established since 1962. The measurement carried out in May significantly correlated with the subsequent crop yields recorded in October. The analysis allows an early, inexpensive, fast, and reproducible self-assessment at field level to improve fertilization rates. The device is envisaged as a user-friendly tool for agronomy, horticulture, and any environmental applications where organic matter cycling, soil quality, and specific nutrients excess or deficiency are critical considerations

Effect of stocking density of fish on water quality and growth performance of European Carp and leafy vegetables in a low-tech aquaponic system

Aquaponics (AP) is a semi-closed system of food production that combines aquaculture and hydroponics and represents a new agricultural system integrating producers and consumers. The aim of this study was to test the effect of stocking densities (APL, 2.5 kg m-3; APH, 4.6 kg m-3) on water quality, growth performance of the European Carp (Cyprinus carpio L.), and yield of leafy vegetables (catalogna, lettuce, and Swiss Chard) in a low-technology AP pilot system compared to a hydroponic cultivation. The AP daily consumption of water due to evapotranspiration was not different among treatments with an average value of 8.2 L d-1, equal to 1.37% of the total water content of the system. Dissolved oxygen was significantly (p < 0.05) different among treatments with the lowest median value recorded with the highest stocking density of fish (5.6 mg L-1) and the highest median value in the hydroponic control (8.7 mg L-1). Marketable yield of the vegetables was significantly different among treatments with the highest production in the hydroponic control for catalogna (1.2 kg m-2) and in the APL treatment for Swiss Chard (5.3 kg m-2). The yield of lettuce did not differ significantly between hydroponic control and APL system (4.0 kg m-2 on average). The lowest production of vegetables was obtained in the APH system. The final weight (515 g vs. 413 g for APL and APH, respectively), specific growth rate (0.79% d-1 vs. 0.68% d-1), and feed conversion (1.55 vs. 1.86) of European Carp decreased when stocking density increased, whereas total yield of biomass was higher in the APH system (4.45 kg m-3 vs. 6.88 kg m-3). A low mortality (3% on average) was observed in both AP treatments. Overall, the results showed that a low initial stocking density at 2.5 kg m-3 improved the production of European Carp and of leafy vegetables by maintaining a better water quality in the tested AP system

Effects of mycorrhizal inoculation and digestate fertilisation on triticale biomass production using fungicide-coated seeds

peer-reviewedCrop fertilisation management using organic wastes and arbuscular mycorrhizal fungi (AMF) inoculation can play a crucial role in the sustainability of agroecosystems. However, in conventional agricultural systems, agrochemicals like fungicides could reduce the positive effect of AMF. The aim of this study was to evaluate the agronomic (biomass production) and environmental (soil CO2 emission) effects of AMF inoculation and digestate spreading on triticale cultivation using commercial seeds coated with fungicide. The field experiment was conducted in 2014–2015 at the University of Padua’s experimental farm (Italy), adopting a split-plot design, where the main plot factor was AMF inoculation (inoculated vs. uninoculated) and the subplot factor was fertilisation treatment (no fertilisation (NF), digestate liquid fraction (DL), digestate solid fraction (DS), mineral fertilisation (MF)). Low AMF root colonization was observed, likely due to the effect of fungicide; the only significant effect of AMF inoculation was a lower shoot density. Dry biomass production was significantly higher in the MF treatment (21.8 ± 1.04 Mg/ha) and lower in the NF treatment (14.5 ± 0.73 Mg/ha) compared to DS and DL treatments, which were not significantly different with an average yield of 17.2 ± 2.10 Mg/ha. During the cropping season, soil CO2 emissions were not significantly affected by either AMF inoculation or fertilisation treatment. The median value of soil CO2 emissions was 447.3 mg/m2 per hour

Adubação NPK do algodoeiro adensado de safrinha no cerrado de Goiás.

Esse estudo foi realizado com dois experimentos de campo conduzidos na safra 2009/10 com o objetivo de definir doses e níveis de adubação NPK para o algodão de safrinha adensado, nas condições do Cerrado de Goiás. O primeiro experimento constou de um fatorial NPK 3x3x3+3 resultante da combinação de três doses de nitrogênio (40, 80 e 120 kg/ha de N), três doses de fósforo (30, 60 e 90 kg/ha de P2O5) e três doses de potássio (40, 80 e 120 kg/ha de K2O), mais três tratamentos adicionais (0-0-0 N-P-K, 60-60-60 N-P-K, e 60-0-60 N-P-K). O outro experimento foi disposto no campo em esquema fatorial 4x4: 4 densidades de plantas (8, 10, 12 e 14 plantas por metro) e 4 níveis de adubação NPK (50, 75, 100 e 125 % da adubação recomendada para a cultura de algodão safra). Utilizou-se delineamento de blocos ao acaso com 4 repetições. Concluiu-se que: 1) Não há influência de população de plantas na resposta da cultura à adubação; e 2) A adubação de manutenção com 60 a 90 kg/ha de N, 60 kg/ha de P2O5 e 60 kg/ha de K2O garantem produtividade de até 3.500 kg/ha de algodão em caroço, em solos com a fertilidade corrigida

Physicochemical parameters and antibiotics residuals in Algerian honey

The aim of the present study was to evaluate the quality of 36 samples of different honey type supplied by local producers from Algeria in order to verify its compliance with the standards of Codex Alimentarius and  European Union (EU). For that, five physicochemical parameters were  analyzed using the HPLC method: hydroxyl-methyl furfural (HMF), sugars, diastase activity and search of antibiotic contamination with streptomycin and tetracycline. The physicochemical analyses of the Algerian honeys show that 56% of samples correspond to Codex standards and 44% not in  conformity with the standards required by the Codex Alimentarius and EU, because part of the samples had one or more defects. The percentage not in conformity was due to the high rates of hydroxyl-methyl furfural, sucroseand also to the low enzyme level. Analysis performed by the laboratory to detect residues of tetracycline and streptomycin in honey have revealed insignificant traces of oxytetracycline in two samples of honey (0.03 ppb). From the present study, it is observed that the Algerian honey samples is not completely in agreement with the requirements of international honey standards which could be caused by inappropriate actions during processing and storage steps.Key words: Honey quality, sugar, diastase activity, hydroxymethylfurfural, antibiotic residues