Land-use impact on soil solution constituents from an Ultisol of North Florida

Land use management is important to maximize nutrients use efficiency and reduce losses, especially on sandy soils. Nutrient cycling in pastoral systems is different as the grazing animals are excreting back to the pasture most of the ingested nutrients. The objective of this study was to evaluate N, P, K, Ca, Mg, and Na by monitoring elements’ concentrations in soil solution from bahiagrass (Paspalum notatum Flugge) pastures continually-stocked with cattle (CP) and rotationally-grazed by goats (GP) in comparison with arable land (AL). Samples were obtained by suction cup lysimeters randomly installed at three depths in an Ultisol of North Florida, USA. To evaluate nutrients in atmospheric deposition, surface and ground waters, samples from rain, nearby spring, lake and three wells on the farm were also analyzed. The results confirmed that land-use management had an effect on soil-solution N, P, K, Ca, Mg, and Na concentrations reflecting managerial and climatic conditions. The means of these nutrients ranged widely from 0.64 to 11.14 mg L⁻¹ for N, 0.03–0.45 mg L⁻¹ for P, 0.12–6.97 mg L⁻¹ for K, 0.37–33.91 mg L⁻¹ for Ca, 0.47–7.39 mg L⁻¹ for Mg, and 1.28–4.37 mg L⁻¹ for Na. The soil-solution N was higher from March through August (wet seasons) and lower and relatively constant between September and February (dry seasons). The N from shallow depth (0.6 m) of CP was fourfold higher than the deep (1.8 m) one and exceeded the maximum permissible level (MPL) of 10 mg L⁻¹. A 1.5-fold increase by depth of AL was detected, and a leaching of 53–98 kg N ha⁻¹ was identified for both AL and CP during the wet season vs. 4–5 kg ha⁻¹ leachable N from GP. Also, a 1–3 kg P ha⁻¹ may be leached from CP during the wet season. The nutrients in the soil solutions tended to be higher than those in rain, lake, sprint, well, and tap waters. In groundwater however, there were episodically N concentrations as high as those in the soil solution.     

Antimicrobial nanoparticles and biodegradable polymer composites for active food packaging applications

The food industry faces numerous challenges to assure provision of tasty and convenient food that possesses extended shelf life and shows long-term high-quality preservation. Research and development of antimicrobial materials for food applications have provided active antibacterial packaging technologies that are able to meet these challenges. Furthermore, consumers expect and demand sustainable packaging materials that would reduce environmental problems associated with plastic waste. In this review, we discuss antimicrobial composite materials for active food packaging applications that combine highly efficient antibacterial nanoparticles (i.e., metal, metal oxide, mesoporous silica and graphene-based nanomaterials) with biodegradable and environmentally friendly green polymers (i.e., gelatin, alginate, cellulose, and chitosan) obtained from plants, bacteria, and animals. In addition, innovative syntheses and processing techniques used to obtain active and safe packaging are showcased. Implementation of such green active packaging can significantly reduce the risk of foodborne pathogen outbreaks, improve food safety and quality, and minimize product losses, while reducing waste and maintaining sustainability.     

Biodegradation dynamics of high catechol concentrations by Aspergillus awamori

The biodegradation process of high catechol concentrations by Aspergillus awamori was investigated. The values of the kinetic constants for a model of specific growth rate at different initial conditions were determined. At 1.0 g/L catechol concentration, the biodegradation process proceeded in the conditions of substrate limitation. At higher catechol concentrations (2.0 and 3.0 g/L) a presence of substrate inhibition was established. The dynamics of the specific catechol degradation rate was studied and the values of catechol and biomass concentrations, maximizing the specific catechol degradation rate, were estimated analytically. The specified ratio catechol/biomass could serve as a starting base for determination of the initial conditions for a batch process, for specifying the moment of feeding for a fed-batch process, and for monitoring and control of a continuous process by the aim of time-optimal control.     

Verbesserte Synthese von 8-Amino-2-methyl-4-phenyl-1,2,3,4-Tetrahydroisochinolin

An Improved Synthesis of 8-Amino-2-methyl-4-phenyl-1,2,3,4-Tetrahydroisoquinoline The regioselectivity of the reaction of 2-nitrobenzylmethylamine ( 1 ) and styrenoxide ( 2 ) leading to a mixture of the isomeric aminoalcohols 3a and 3b has been studied. The course of the reaction strongly depends on the type of the solvent used as reaction medium. The highest selectivity ( 3a:3b = 9:1) was achieved with a combination of polar aprotic and protic solvents (DMFA and ethanol). ¹H n.m.r. spectroscopy was used for identification of the isomers as well as for the determination of their ratio in the crude reaction mixtures. The isomer ratio remains unaffected during catalytic reduction (Ra-Ni) of 3a/3b to a mixture of the corresponding aminoalcohols 4a and 4b . Pure 3a, 4a and 4b were independently synthesized for comparison. Cyclodehydration of crude 4a/4b mixtures gives 5 in a very good yield.