Recovery of nitrogen removal by N2H4 after nitrite inhibited anammox reaction

<p>A pilot-scale sequencing batch reactor (SBR) for anaerobic ammonium oxidation (anammox) of bacteria culture was used along with a batch experimental reaction device to study the effect of NO2--N concentration on the activity of anammox bacteria and the recovery of N2H4 on anammox bacteria after inhibition by high concentrations of NO2--N. The optimal influent NO2--N concentration in the pilot-scale reactor was 72.0 mg/L, with its total nitrogen consumption being approximately 40.0 g/d. Influent water NO2--N concentrations greater than 100 mg/L had a serious inhibitory effect on the anammox bacteria. At an influent NO2--N concentration of 120.35 mg/L, the addition of 10.0-15.0 mg/L of N2H4, restored the activity of granular anammox bacteria; the total nitrogen consumption was increased by 69.96%. Microbiological analysis showed that a change in NO2--N concentration within the range of 18.87-115.39 mg/L did not affect the microbial population structure of the pilot-scale reactor, wherein Candidatus Kuenenia was the dominant bacterial species. In samples collected at stages A0 (sludge inoculation), A20 (the number indicates the NO2--N concentration, which, in this stage, was 20 mg/L), A40, A60, A80, and A100, the proportion of Candidatus Kuenenia was 27%, 23%, 36%, 26%, 34%, and 33%, respectively.</p>

THE NITROGEN CONSUMPTION BY ALFALFA CROPS DEPENDING ON THE NITROGEN NUTRITION PATTERN

Приведены результаты полевых исследований потребления азота посевами люцерны в зависимости от режима азотного питания и симбиотической активности посевов за 2017…2019 годы. Опыты с люцерной синегибридной проведены в экологических условиях предгорной зоны РСО-Алания на черноземе выщелоченном с близким залеганием галечника. Сравнивались минеральный и симбиотрофный режимы азотного питания растений люцерны. Установлено, что в год посева потребление азота посевами люцерны составило от 105,0 до 135,4 кг/га, при этом к первому укосу потребление было в 1,1…1,2 раза больше, чем ко второму укосу. На второй и третий годы пользования посевами потребление азота выросло в 1,7…1,9 раза в сравнении с показателями года посева. Показатели вариантов с естественными условиями (контроль) и внесением стартовых доз азотных удобрений (N30) были практически идентичными. Показатели вариантов с инокуляцией семян высокогорным инокулюмом (Ин-1800) и внесением стартовых доз азотных удобрений на фоне инокуляции (N30 + Ин) во второй и третий годы пользования посевами были практически идентичными. Объемы потребления азота в указанных вариантах составили свыше 235 кг/га, или на 25,6…27,1 % выше показателей контрольного варианта. В сумме за три года исследований посевы люцерны в контрольном варианте усвоили 483,3 кг/га азота. Стартовые дозы азотных удобрений (N30) увеличили данный показатель всего на 1,4 %. Предпосевная инокуляция семян способствовала увеличению потребления азота во всех вариантах: в варианте с промышленным штаммом ризоторфина (Шт. 425а) – на 17,8 %, с высокогорным инокулюмом на фоне внесения стартовых доз минеральных азотных удобрений (N30 + Ин) – на 24,6 %, с высокогорным инокулюмом в чистом виде (Ин-1800) – на 27,1 %. Ключевые слова: люцерна, режим питания, симбиотическая активность, минеральный азот, биологический азот, потребление азота. The results of field studies of nitrogen consumption in alfalfa crops depending on the nitrogen nutrition pattern and symbiotic activity of crops for 2017...2019 are presented. Experiments with the alfalfa purple were carried out in the ecological conditions of the foothill zone of the North Ossetia-Alania, on leached chernozem with a close occurrence of gravel. Mineral and symbiotrophic patterns of nitrogen nutrition of alfalfa plants were compared. It was found that in the year of planting, the nitrogen consumption of alfalfa crops ranged from 105.0 to 135.4 kg/ha, and by the first mowing, the consumption was 1.1...1.2 times bigger than by the second mowing. In the second and third years of crop use, nitrogen consumption increased by 1.7...1.9 times compared to the year of planting. The parameters of the options with natural conditions (control) and the addition of starting doses of nitrogen fertilizers (N30) were almost identical. In the second and third years of use of crops, parameters of options with inoculation of seeds with high-altitude inoculum (In-1800) and the addition of starting doses of nitrogen fertilizers within the background of inoculation (N30 + in) were almost identical. In these options, the amount of nitrogen consumption was more than 235 kg/ha, or 25.6...27.1 % higher than in the control variant. In total, over three years of research, in the control option alfalfa crops took 483.3 kg/ha of nitrogen. Starting doses of nitrogen fertilizers (N30) increased this indicator by only 1.4 %. Pre-planting inoculation of seeds contributed to an increase in nitrogen consumption in all options: in the option with the industrial strain of risotorphine (St. 425a) – by 17.8 %, with high-altitude inoculum within the background of adding starting doses of mineral nitrogen fertilizers (N30 + In) – by 24.6 %, with high-altitude inoculum in pure form (In-1800) – by 27.1 %.

Nitrogen Preferences during Alcoholic Fermentation of Different Non-Saccharomyces Yeasts of Oenological Interest

Non-Saccharomyces yeasts have long been considered spoilage microorganisms. Currently, oenological interest in those species is increasing, mostly due to their positive contribution to wine quality. In this work, the fermentative capacity and nitrogen consumption of several non-Saccharomyces wine yeast (Torulaspora delbrueckii, Lachancea thermotolerans, Starmerella bacillaris, Hanseniaspora uvarum, and Metschnikowia pulcherrima) were analyzed. For this purpose, synthetic must with three different nitrogen compositions was used: a mixture of amino acids and ammonium, only organic or inorganic nitrogen. The fermentation kinetics, nitrogen consumption, and yeast growth were measured over time. Our results showed that the good fermentative strains, T. delbrueckii and L. thermotolerans, had high similarities with Saccharomyces cerevisiae in terms of growth, fermentation profile, and nitrogen assimilation preferences, although L. thermotolerans presented an impaired behavior when only amino acids or ammonia were used, being strain-specific. M. pulcherrima was the non-Saccharomyces strain least affected by the nitrogen composition of the medium. The other two poor fermentative strains, H. uvarum and S. bacillaris, behaved similarly regarding amino acid uptake, which occurred earlier than that of the good fermentative species in the absence of ammonia. The results obtained in single non-Saccharomyces fermentations highlighted the importance of controlling nitrogen requirements of the wine yeasts, mainly in sequential fermentations, in order to manage a proper nitrogen supplementation, when needed.

Influence of weather conditions of the year and variety features on nitrogen consumption and formation of winter wheat grain quality

Influence of weather conditions of the year and variety features on nitrogen consumption and formation of winter wheat grain quality The article discusses the influence of two factors on the quality of winter wheat grain – the characteristics of the variety and weather conditions of the year. Varietal differences in the nitrogen supply to winter wheat grains were studied. A greater influence of the genetic characteristics of winter wheat varieties than weather conditions on the accumulation of nitrogen in wheat grain was revealed. The dependence of high quality wheat grain on arid weather conditions were confirmed. Varieties such as Arctis and Panonicus have shown more stable indicators of nitrogen content, so the grain of these varieties is the most conditioned. Keywords: nitrogen content, winter wheat, varietal features, protein content, weather conditions.