Agriculture is a signifi cant source of gaseous pollutants such as ammonia, methane, nitrous oxide and volatile organic compounds. Ammonia is particularly important due to the high emission and local, as well as global impact on the environment. The release of NH3 is one of the main ways of nitrogen emission to the atmosphere and it contributes to its subsequent deposition. The aim of the study was to analyze ammonia emissions from animal production in Poland in 2005–2017, its regional diversity and possibilities of its reduction in agriculture. The ammonia emission was calculated for the animal production groups according to the NFR classifi cation. The values of ammonia emission were calculated based on ammonia emission factors used by KOBIZE, in accordance with the EMEP/EEA methods. In 2017, the NH3 emission from Polish agriculture amounted 288 Gg and it accounted for 96% of the emission in 2005. Ammonia emission from livestock production, in 2005–2017, on average accounted for 79.8% of agricultural emissions. The largest share had the cattle (51%) and swine (30%) production. The NH3 emissions differed strongly between provinces. The emission density (kg NH3·km-2·year-1) in provinces with intensive livestock production was about 5.5 times higher than in regions, where livestock production was the lowest. The mitigation strategies should be implemented primarily in provinces where reduction potential is the largest. The assessment of the reduction potential should take into account the NH3 emission per 1 km2 and the low
NH3 emission technologies, which are already applied in the regions.
Phylloplane microbes have been studied as strategic tools in management against plant pathogens. Non-pathogenic bacteria and fungi have been applied as crop protectants against various plant diseases. The present study aimed at evaluating the potentiality of Aspergillus niger spores in altering the activity of four key enzymes related to defense in tomato. The experiment was designed such that two groups of 50 tomato plants were considered: group 1 – sprayed with autoclaved distilled water (control) and group 2 – sprayed with A. niger spores. Spraying was carried out under aseptic conditions. The experimental parameters included analysis of the activity of peroxidase (POX), polyphenol oxidase (PPO), phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL) as well as expression of POX and PPO isoforms. The results demonstrated an inductive effect of A. niger on the activity of POX, PPO, PAL and TAL. Enhanced expression of POX and PPO isoforms was also observed. The results indicated that A. niger can be considered probiotic for the management of tomato against its phytopathogens.
A novel absorbing pervaporation hybrid technique has been evaluated experimentally for the recovery of ammonia from the gas mixture in a recycle loop of synthesis plants. This process of hybridization brings together the combination of energy-efficient membrane gas separation based on poly(dimethylsiloxane) poly(diphenylsilsesquioxane) with a high selective sorption technique where a water solution with polyethylene glycol 400 (PEG-400) was used as the liquid absorbent. Process efficiency was studied using the pure and mixed gases. The influence of PEG-400 content in aqueous solutions on process selectivity and separation efficiency was studied. The ammonia recovery efficiency evaluation of an absorbing pervaporation technique was performed and compared with the conventional membrane gas separation. It was shown that the absorbing pervaporation technique outperforms the conventional membrane method in the whole range of productivity, producing the ammonia with a purity of 99.93 vol.% using the PEG 80 wt.% solution. The proposed method may be considered as an attractive solution in the optimization of the Haber process.
Most satellites stationed in space use catalytic propulsion systems for attitude control and orbit adjustment. Hydrazine is consumed extensively as liquid monopropellant, in the thrusters. Catalytic reactor is the most important section in the catalytic thruster. Ammonia and nitrogen gases are produced as a result of complete catalytic decomposition of hydrazine in the reactor, causing an increase in temperature and a rise in specific impulse. Ammonia is subsequently decomposed, leading to nitrogen and hydrogen gases. Decomposition of ammonia leads to a decrease in temperature, molecular weight and specific impulse. The latter phenomenon is unavoidable. The effect of ammonia decomposition on the reactor temperature, molecular weight of gaseous products and conclusively on specific impulse was studied in this article. At adiabatic state, thermodynamic analysis revealed that the maximum and minimum temperatures were 1655 K and 773 K, respectively. The highest molecular weight was obtained at ammonia conversion of zero and the lowest when ammonia conversion was 100%. The maximum specific impulse (305.4 S) was obtained at ammonia conversion of zero and completely conversion of ammonia, the minimum specific impulse (about 213.7 s) was obtained. For specific impulse, the result of thermodynamic calculation in this work was validated by the empirical results.
Barley phylloplane is seriously colonized by Drechslera graminea, the causal agent of leaf
stripe disease in the hos. The present study involved the elucidation of alterations induced
in the protein content of the host due to Drechslera infection. Naturally growing barley
plants were obtained from fields and Drechslera graminea was isolated and identified from
diseased plants’ leaves. After identification and preparation of the pure culture, the pathogen
was inoculated on plants grown under aseptic and controlled laboratory conditions.
Changes in the total soluble cytoplasmic proteins and defense enzymes of the host such
as polyphenol oxidase (PPO), peroxidase (POX), phenylalanine lyase (PAL) and tyrosine
ammonia lyase (TAL) were observed up to 5 h after inoculation. The results demonstrated
a significant effect of the pathogen on the cytoplasmic protein expression of the host as well
as in its defense system.
This study examined the effects of UV-B radiation and allelochemical stress induced by ferulic acid (FA) on the activity of phenylalanine ammonia lyase (PAL; EC 4.3.1.5) at metabolic and molecular levels in two cucumber genotypes differing in tolerance to cold and disease, in order to determine any interaction between stress effects and genotype response. Stresses were applied simultaneously, sequentially, and singly. In both genotypes, several days of UV radiation retarded growth up to 36%. The effect of FA was not significant. The response to a particular stress, including the effect on PAL activation, was enhanced by simultaneous application of the two stresses. PAL transcription was not correlated with the increase of PAL activity. Exposure to UV-B, FA, and combined UV-B and FA was detrimental to both genotypes but to different extents. The response was not correlated with the genotype of cold and disease sensitivity. PAL activity and its transcription seem to be involved in UV and allelochemical stress, but not related to the plants' tolerance of these stresses.
Ammonia-oxidizing bacteria communities were evaluated in a completely mixed, laboratory scale membrane reactor (MBR) working under anoxic conditions for 5 months. The microorganisms in activated sludge were fed a synthetic medium containing 66-150 mg NH4 +-N/l. The age of the activated sludge in MBR was 50 days and the hydraulic retention time (HRT) was 3.3 days. The estimation of the diversity and complexity of the AOB community together with the identification of the dominant bacteria in the activated sludge under anoxic conditions were performed using denaturing gradient gel electrophoresis (DGGE) and DNA sequencing. Molecular analysis of the microbial community carried out with two microbial molecular markers, 16S rRNA gene and amoA gene, suggested that nitrification was led by a Nitrosomonas-like species. In the biocenosis of the investigated bioreactor, oxygen was the crucial selective parameter. The results obtained in this work showed that amoA gene research is more suitable to study the stability and effectiveness of ammonia oxidation. This information emphasizes the necessity of the usage of molecular markers based on functional genes instead of ribosomal ones in order to present the actual state of the process performed in bioreactors. It was also stated that Nitrosomonas -like bacteria are able to perform nitritation even in anoxic environment, that is probably the reason why these bacteria are the most common AOB in different bioreactors.
Root associated bacteria were isolated from Suaeda nudiflora and two isolates were selected for this study: rhizospheric Bacillus megaterium and endophytic Pseudomonas aeruginosa. These isolates were inoculated into maize variety Narmada Moti during its germination. TTC (2, 3, 5-triphenyl tetrazolium chloride) staining was used to confirm the association of the isolates with the maize root. The effects of these root associated bacteria were tested alone and in combinations for cell wall reinforcement and the induction of defense enzymes such as phenylalanine ammonia lyase (PAL) and β-1,3-glucanase in the presence of fungal pathogen Aspergillus niger in maize. The results indicated that the rhizospheric bacteria had a greater fight response to fungal infection than the endophhytic bacteria due to cell wall lignification as well as the rapid induction of higher concentrations of defense related enzymes.