Responses of soil microbial communities to manure and biochar in wheat cultivation of a rice-wheat rotation agroecosystem in East China

Soil contamination in agroecosystems remains a global environmental problem. Biochar has been suggested as an organic amendment to alleviate soil pollution, sequester carbon(C), and improve soil fertility. However, information on how bacterial and fungal communities in acidic bulk and rhizosphere soils respond to swine manure and its biochar is still lacking. In this study, biochar and swine manure were applied at two rates of 1.5 and 3 t ha-1in a rice-wheat rotation field to assess how soil characteristics, especially p H and chemical element availability, correlate to compositional variations of bacteria and fungi in bulk and rhizosphere soils. Our results showed that high rates of biochar and manure promoted the bacterial richness in bulk and rhizosphere soils by increasing soil pH and reducing soil arsenic(As) and copper(Cu) availability. Compared with soil As and Cu availability, soil p H had opposite effects on beta diversity of both the bacterial and fungal communities. Specifically, biochar and swine manure applications stimulated the bacterial classes Gemmatimonadetes, Deltaproteobacteria, and Gammaproteobacteria by increasing soil pH and decreasing soil available chemical elements. Opposite trends were observed in fungal communities responding to biochar and manure. For example, biochar restrained the fungal class Eurotiomycetes by decreasing soil As and Cu availability, but manure inhibited Leotiomycetes mainly because of an increase in soil pH and a decrease in soil dissolved organic C. These suggest that both bacterial and fungal communities respond significantly to biochar and manure amendments in both bulk and rhizosphere soils, possibly because of their sensitive adaptation to variations in soil environmental factors, such as pH level and chemical element availability.

Contrasting patterns of bacterial communities in the rearing water and gut of Penaeus vannamei in response to exogenous glucose addition

Supplementing exogenous carbon sources is a practical approach to improving shrimp health by manipulating the microbial communities of aquaculture systems. However, little is known about the microbiological processes and mechanisms of these systems. Here, the effects of glucose addition on shrimp growth performance and bacterial communities of the rearing water and the shrimp gut were investigated to address this knowledge gap. The results showed that glucose addition significantly improved the growth and survival of shrimp. Although the α-diversity indices of both bacterioplankton communities and gut microbiota were significantly decreased by adding glucose, both bacterial communities exhibited divergent response patterns to glucose addition. Glucose addition induced a dispersive bacterioplankton community but a more stable gut bacterial community. Bacterial taxa belonging to Ruegeria were significantly enriched by glucose in the guts, especially the operational taxonomic unit 2575 (OTU2575), which showed the highest relative importance to the survival rate and individual weight of shrimp, with the values of 43.8 and 40.6%, respectively. In addition, glucose addition increased the complexity of interspecies interactions within gut bacterial communities and the network nodes from Rhodobacteraceae accounted for higher proportions and linked more with the nodes from other taxa in the glucose addition group than that in control. These findings suggest that glucose addition may provide a more stable gut microbiota for shrimp by increasing the abundance of certain bacterial taxa, such as Ruegeria.

Septic cardiomyopathy:characteristics,evaluation,and mechanism

Sepsis is a common clinical disease;if there is no early active treatment,it is likely to develop into multiple organ dysfunction syndrome and even cause death.Septic cardiomyopathy is a complication of sepsis-related cardiovascular failure,characterized by reversible left ventricular dilatation and decreased ventricular systolic and/or diastolic function.At present,echocardiography and biomarkers are often used to screen septic cardiomyopathy in clinics.Although there is still a lack of clear diagnostic criteria for septic cardiomyopathy,according to existing studies,the pathogenesis of several septic cardiomyopathy has been clarified,such as immune response caused by infection and mitochondrial dysfunction.This review summarizes the characteristics,pathophysiology,and diagnosis of septic cardiomyopathy and focuses on the mechanisms of infection immunity and mitochondrial dysfunction.