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Microorganisms in wastewater treatment plants (WWTPs) are essential for water purification to protect public and environmental health. However, the diversity of microorganisms and the factors that control it are poorly understood. Using a systematic global-sampling effort, we analysed the 16S ribosomal RNA gene sequences from ~1,200 activated sludge samples taken from 269 WWTPs in 23 countries on 6 continents. Our analyses revealed that the global activated sludge bacterial communities contain ~1 billion bacterial phylotypes with a Poisson lognormal diversity distribution. Despite this high diversity, activated sludge has a small, global core bacterial community (n = 28 operational taxonomic units) that is strongly linked to activated sludge performance. Meta-analyses with global datasets associate the activated sludge microbiomes most closely to freshwater populations. In contrast to macroorganism diversity, activated sludge bacterial communities show no latitudinal gradient. Furthermore, their spatial turnover is scale-dependent and appears to be largely driven by stochastic processes (dispersal and drift), although deterministic factors (temperature and organic input) are also important. Our findings enhance our mechanistic understanding of the global diversity and biogeography of activated sludge bacterial communities within a theoretical ecology framework and have important implications for microbial ecology and wastewater treatment processes.

Simple Summary: China is a major goose-raising country, and the geese industry plays a significant role in animal husbandry. Goose growth performance (body weight) is a critical topic. This study used 16S rRNA sequencing to comprehensively analyze the cecal flora of healthy 70-day-old Yangzhou geese with varying weights but identical feeding methods to investigate the correlation between their intestinal microorganisms and body weight. Correlation analysis of production performance indicators between cecal microflora and body weight revealed a significant positive correlation between birth weight and Deferribacterota at the phylum level. At the genus level, leg and chest muscle weights exhibited significant positive correlations with Prevotellace-ae_Ga6A1_group, suggesting its critical role in promoting the growth and development of goose leg and chest muscles. These findings offer a crucial theoretical foundation for studying gastrointestinal microorganisms and provide insights into the development and formulation of poultry probiotics. China is a major goose-raising country, and the geese industry plays a significant role in animal husbandry. Therefore, goose growth performance (body weight) is a critical topic. Goose gut microbiota influences weight gain by regulating its energy metabolism and digestion. Additionally, the impact of cecal microbial community structure on goose growth and development, energy metabolism, and immunity has been examined. However, most studies have used different additives or feeds as variables. Improving the understanding of the dynamic changes in gut microbial communities in geese of different body weights during their growth and development and their correlation with the host's body weight is necessary. In this study, the cecal microbiota of healthy Yangzhou geese with large (L) and small (S) body weights, all at the same age (70 days old) and under the same feeding conditions, were sequenced using 16S rRNA. The sequencing results were annotated using QIIME2 (classify-sklearn algorithm) software, and the linkET package was used to explore the correlation between intestinal microorganisms and the body weight of the Yangzhou goose (Spearman). At the phylum level, the Firmicutes/Bacteroidetes ratio in the large body weight group was approximately 20% higher than that in the small body weight group, with Bacteroidetes and Firmicutes exhibiting a highly significant negative correlation. At the genus level, Bacteroides constituted the most abundant microbial group in both groups, although the Prevotellaceae_Ga6A1_group exhibited a higher abundance in the large than the small weight group. Spearman correlation analysis and the linkET package were used to analyze the correlation between cecal microflora and production performance indicators that showed significant differences between the two groups and showed that birth weight was significantly positively correlated with Deferribacterota at the phylum level. At the genus level, leg and chest muscle weights exhibited significant positive correlations with Prevotellace-ae_Ga6A1_group, suggesting its critical role in promoting the growth and development of goose leg and chest muscles. A significant negative correlation was observed between [Ruminococ-cus]_torque and Prevotellaceae_Ga6A1_group. These findings offer a crucial theoretical foundation for the study of gastrointestinal microorganisms and provide insights into the development and formulation of poultry probiotics. [ABSTRACT FROM AUTHOR]

The intricate interplay between water resources, land resources, energy systems, and carbon emissions has emerged as a prominent discourse in academic research. Nonetheless, there remains a dearth of comprehensive research dedicated to fostering environmentally friendly and low-carbon development through systematic integration and coordination efforts. This study aimed to fill this gap by integrating the coupling mechanism of the Water-Land-Energy-Carbon (WLEC) system, thereby constructing an evaluation index framework that assesses coordinated developments in Northwest China's WLEC system. It scrutinizes the security levels within the Water-Land-Energy (WLE) subsystem while conducting quantitative analyses on the degrees of coupling coordination within the WLEC systems, alongside their associated hindering factors. The preliminary findings were as follows: Firstly, the safety development within the WLE system demonstrates a positive trend across Northwest China, with notable advancements primarily observed in the Qinghai and Gansu provinces. In 2021, all five Northwestern provinces exhibited moderate levels of safe development, except for the Qinghai province, which transitioned from moderate to robust. Secondly, the coupling coordination degree of the WLEC system across the five provinces has consistently illustrated an upward trajectory over the years. However, as of 2021, the system remains in a state characterized by marginal disorder. Notably, the Qinghai and Gansu provinces have shown particularly encouraging upward trends, with the Shaanxi province also making notable progress. Conversely, Xinjiang has declined since 2017 due to negative interactions between the subsystems of water, soil, energy, and carbon emissions. Thirdly, spatial variations exist in the distribution patterns between the provinces regarding the influence of obstructing factors on indicators related to coupled coordinated development, such as per capita arable land area, per capita energy consumption, per capita carbon emissions, per capita construction land area, and the proportion of groundwater water in the total amount of water supply, which demonstrated an increasing trend. These findings carry significant practical implications for actively and steadily promoting carbon peaking and carbon neutrality in Northwest China. [ABSTRACT FROM AUTHOR]

Clarifying the appropriate application rates of N, P, and K fertilizers and the physiological mechanisms of wheat under water-saving recharge irrigation in the North China Plain would provide a theoretical basis for formulating reasonable fertilization plans for high-yield and high-efficiency wheat production. We established four treatments with different amounts of nitrogen (N), phosphorus (P2O5), and potassium (K2O) application: 0,0, and 0 kg • hm2(F0), 180, 75, and 60 kg • hm-2(F2), 225, 120, and 105 kg • hm-2(F2), and 270, 165, and 150 kg • hm2(F3). During the jointing and anthesis stages of wheat, the relative water content of each treatment in the 0-40 cm soil layer was replenished to 70%, to investigate the differences in wheat flag leaf photosynthetic characteristics, distribution of 13C assimilates, grain starch accumulation, and fertilizer utilization. The results showed that the relative chlorophyll content of flag leaves, photosynthetic and chlorophyll fluorescence parameters, 13C assimilate allocation in each organ, enzyme activities involved in starch synthesis, and starch accumulation in the F, treatment were significantly higher than that in F0 treatment, which was an important physiological basis for the 20.9% increase in grain yield. The above parameters and yield in the F2 and F3 treatments showed no significant increase compared to F (treatment, while fertilizer productivity and agronomic efficiency of N, P, and K decreased by 17.5%-58.4% and 12.7%-50.7%, respectively. Therefore, F (could promote flag leaf photosynthetic assimilate production and grain starch accumulation under water-saving supplementary irrigation conditions, resulting in higher grain yield and fertilizer utilization efficiency. [ABSTRACT FROM AUTHOR]