Skate-Skin Mucin, Rich in Sulfated Sugars and Threonine, Promotes Proliferation of Akkermansia muciniphila in Feeding Tests in Rats and In Vitro Fermentation Using Human Feces

Dietary factors, affect Akkermansia muciniphila (AM) abundance in the colon, have attracted attention, driven by the inverse correlation between AM abundance and metabolic disorders. We prepared skate-skin mucin (SM), porcine stomach mucin (PM), and rat gastrointestinal mucin (RM). SM contained more sulfated sugars and threonine than PM or RM. Rats were fed a control diet or diets including SM, PM, or RM (15 g/kg), or SM (12 g/kg) from five different threonine contents for 14 d. Cecal total bacteria and AM were less and more numerous, respectively, in SM-fed rats than the others, but SM did not affect microbial species-richness. Low-threonine SM did not induce AM proliferation. The in vitro fermentation with human feces showed that the rate of AM increase was greater with SM than PM. Collectively, heavy SM sulfation facilitates a priority supply of SM-derived amino sugars and threonine that promotes AM proliferation in rats and human feces.

Justification of the possibility for obtaining meat culinary products using objects of marine origin

Обоснована возможность получения мясных кулинарных продуктов с добавлением компонентов морского происхождения (макруруса малоглазого, тепловых экстрактов из голотурий - трепанга и кукумарии). В качестве основного сырья использованы мясо индейки и курицы, баранина и говядина. Критериями для оценки данного направления в технологии служили результаты органолептического исследования образцов и показателей биологической ценности. Установлено, что рациональным количеством при производстве котлет из мяса птицы мышечной ткани макруруса малоглазого является 25 % от основного ингредиента рецептуры; биологическая ценность готового изделия при этом увеличивается почти на 20 %. Тепловые экстракты из голотурий (трепанга и кукумарии), применяемые практически вместо воды в составе рецептур котлет из говядины или баранины, способствуют повышению органолептической оценки, а также положительно влияют на биологическую ценность, которая выше, чем у контроля, почти на 18 %. Использование тепловых экстрактов из морского сырья (голотурий) приводит к обогащению продукции растворимыми коллагеновыми фрагментами (установлено по увеличению количества свободного оксипролина), биологически активными аминокислотами (глутаминовая и аспарагиновая, аланин, глицин, пролин), аминосахарами и тритерпеновыми гликозидами. The possibility of obtaining meat culinary products with the addition of components of marine origin (small-eyed macrurus, thermal extracts from holothurium-trepang and cucumaria) is justified. Turkey and chicken meat, lamb and beef are used as the main raw materials. The criteria for evaluating this direction in the technology were the results of organoleptic examination of samples and indicators of biological value. It is established that the rational amount in the production of cutlets from poultry meat of muscle tissue of small - eyed macrurus is 25 % of the main ingredient of the recipe; the biological value of the finished product increases by almost 20 %. Thermal extracts from holothurias (trepang and cucumaria), used instead of water in the recipes of beef or lamb cutlets, contributes to an increase in organoleptic evaluation, and also positively affects the biological value, which is higher than that of the control by almost 18 %. The use of thermal extracts from marine raw materials (holothurias) leads to the enrichment of products with soluble collagen fragments, biologically active amino acids (glutamic and aspartic, alanine, glycine, proline), amino sugars and triterpene glycosides.

Effect of crop rotation and cropping history on net N mineralization dynamics of a clay loam soil

Estimating soil N mineralization is critical to being able to balance fertilizer N requirements and their environmental impacts. In this study, net N mineralization was examined in soils under different crop rotations with each phase of the rotation present every year with biologically-based incubations in 2011 and 2015. Net N mineralization was significantly different among treatments when the current crop was soybean and the effect was dependent upon the previous crop and the cropping sequence. In particular, net increases in inorganic N were greater when the previous crop was winter wheat with/without red clover than if it were corn, and greater for the first year of soybean compared to the second year for rotations with two consecutive years of soybean in the 2011 incubation. However, cropping history did not influence net soil N mineralization when the current crop was either corn, winter wheat, or winter wheat + red clover. In 2015, the presence of red clover in the rotation increased net N mineralization in all phases of the rotation. These results suggest both current and previous crops should be considered when estimating the N supplying capacity (net mineralization) of the soil. Net mineralizable N was found to be significantly correlated with total amino sugars (P < 0.001), glucosamine (P < 0.001), and galactosamine (P = 0.003), which suggests that amino sugars could be used as an indicator of the N supplying capacity of soil.

Divergent Accumulation of Microbial Residues and Amino Sugars in Loess Soil after Six Years of Different Inorganic Nitrogen Enrichment Scenarios

Amino sugars are key microbial biomarkers for determining the contribution of microbial residues in soil organic matter (SOM). However, it remains largely unclear as to what extent inorganic nitrogen (N) fertilization can lead to the significant degradation of SOM in alkaline agricultural soils. A six-year field experiment was conducted from 2013 to 2018 to evaluate the effects of chronic N enrichment on microbial residues, amino sugars, and soil biochemical properties under four nitrogen (urea, 46% N) fertilization scenarios: 0 (no-N, control), 75 (low-N), 225 (medium-N), and 375 (high-N) kg N ha−1. The results showed that chronic N enrichment stimulated microbial residues and amino sugar accumulation over time. The medium-N treatment increased the concentration of muramic acid (15.77%), glucosamine (13.55%), galactosamine (18.84%), bacterial residues (16.88%), fungal residues (11.31%), and total microbial residues (12.57%) compared to the control in 2018; however, these concentrations were comparable to the high-N treatment concentrations. The ratio of glucosamine to galactosamine and of glucosamine to muramic acid decreased over time due to a larger increase in bacterial residues as compared to fungal residues. Microbial biomass, soil organic carbon, and aboveground plant biomass positively correlated with microbial residues and amino sugar components. Chronic N enrichment improved the soil biochemical properties and aboveground plant biomass, which stimulated microbial residues and amino sugar accumulation over time.