Project description:The unintentional release of nanoparticles in the atmosphere and their targeted application to improve plant productivity requires detailed study. The translocation features of copper and gold nanoparticles applied by spraying in the concentration range of 1-100 mg/L in Petroselinum crispum (Mill.) tissues during a 10-day experiment were investigated. Atomic absorption spectrometry and inductively coupled plasma atomic emission spectroscopy showed that copper and gold nanoparticles applied to the leaves' surface could accumulate in plant organs. A dose-dependent increase in the content of copper and gold in the aerial parts of parsley was revealed. The content of copper in leaves treated with nanoparticles was 1-2.3 times higher than the control, while the content of gold exceeded control values 2-116 times. The effect of nanoparticles on plants' biochemical composition was assessed. The antioxidant tests showed an ambiguous response at exposure to metal nanoparticles. Copper nanoparticles at the applied concentration consistently reduced both chlorophyll and carotenoid content. Gold nanoparticles enhanced the chlorophyll and carotenoid level at low concentrations (1 mg/L) and significantly inhibited it at higher concentrations. The parsley exposed to nano-copper remained safe for human consumption, but parsley containing more than 14.9 mg/kg of gold may adversely affect human health.
Project description:The biocatalytic synthesis of L- and D-phenylalanine analogues of high synthetic value have been developed using as biocatalysts mutant variants of phenylalanine ammonia lyase from Petroselinum crispum (PcPAL), specifically tailored towards mono-substituted phenylalanine and cinnamic acid substrates. The catalytic performance of the engineered PcPAL variants was optimized within the ammonia elimination and ammonia addition reactions, focusing on the effect of substrate concentration, biocatalyst:substrate ratio, reaction buffer and reaction time, on the conversion and enantiomeric excess values. The optimal conditions provided an efficient preparative scale biocatalytic procedure of valuable phenylalanines, such as (S)-m-methoxyphenylalanine (Y = 40%, ee > 99%), (S)-p-bromophenylalanine (Y = 82%, ee > 99%), (S)-m-(trifluoromethyl)phenylalanine (Y = 26%, ee > 99%), (R)-p-methylphenylalanine, (Y = 49%, ee = 95%) and (R)-m-(trifluoromethyl)phenylalanine (Y = 34%, ee = 93%).
