Sewage sludge-derived nutrients and biostimulants stimulate rice leaf photosynthesis and root metabolism to enhance carbohydrate, nitrogen and antioxidants accumulation.

The production of high quality liquid nitrogen fertilizer with both nutrient comprehensive and biostimulant properties by alkaline thermal hydrolysis of sewage sludge has shown great potential in agricultural production. However, little is known about the effects of sewage sludge-derived nutrients, and biostimulants (SS-NB) on leaf photosynthesis and root growth in rice. Phenotypic, metabolic and microbial analyses were used to reveal the mechanism of SS-NB on rice. Compared to NF treatment, phenotypic parameters (fresh/dry weight, soluble sugar, amino acid, protein) were increased by SS-NB in rice. SS-NB can enhance the photosynthesis of rice leaves by improving the photoconversion efficiency, chlorophyll content, ATP synthase activity, Rubisco and NADPH production. Meanwhile, SS-NB also increased antioxidant capacity (SOD, POD, CAT and proline) in rice leaf and root tissues. Metabolomics revealed that SS-NB application increased the expression levels of metabolites in root and leaf tissues, including carbohydrate, nitrogen and sulfur metabolism, amino acid metabolism, antioxidants, and phytohormone. Most importantly, the regulation of metabolites in rice root tissues is more sensitive than in leaf tissues, especially to the higher levels of antioxidants and phytohormones (IAA and GA) in rice root tissues. Furthermore, SS-NB increased the abundance of photosynthetic autotrophic, organic acids-degrading and denitrifying functional bacteria in rice roots and recruited plant growth-promoting bacteria (Azospirillum and norank_f_JG30-KF-CM45), while the NF treatment group resulted in an imbalance of the microbial community, leading to the dominance of pathogenic bacteria. The results showed that SS-NB had great application potential in crop growth and stress resistance improvement.

Double Advantages of Nutrients and Biostimulants Derived from Sewage Sludge by Alkaline Thermal Hydrolysis Process for Agricultural Use: Quality Promotion of Soil and Crop.

Low-carbon alkaline thermal hydrolysis of sewage sludge for the production of high-quality plant-growth-promoting nutrients and biostimulants is a growing concern for sludge resource utilization in agriculture. Thus, this study aims to investigate functional characteristics and soil biochemical effects of sewage sludge-derived nutrients and biostimulants (SS-NB). The content of heavy metals in SS-NB decreased by 47.39-100%, and an increase in soil protease, invertase, and soil nutrient utilization rates are observed in SS-NB groups. SS-NB substituted for chemical fertilizer increased the diversity and evenness of microbial community and reduced the abundance of the soil-borne bacterial genus Arthrobacter. The dominant community of SS-NB100 group is mainly enriched in Microvirga, Ensifer, Novosphingobium, Bosea and Ellin6055, which are principally beneficial symbiotic bacteria of plants and participated in C and N cycles. Moreover, SS-NB reduced the accumulation of Ktedonobacteria and Nitrosospira, which are involved in the production of CO2 and N2O, and also enhanced the coordination of soil microorganisms with enzyme activities and nutrient utilization rate. In conclusion, the results suggest that SS-NB exerts a positive effect on reducing greenhouse gas emissions and preventing soil-borne diseases, and can further enhance collaboration with soil enzyme activity and soil nutrient utilization by stimulating soil microorganisms.

Soybean continuous cropping affects yield by changing soil chemical properties and microbial community richness.

In agroecosystems, different cropping patterns cause changes in soil physicochemical properties and thus in microbial communities, which in turn affect crop yields. In this study, the yields of soybean continuous cropping for 5 years (C5), 10 years (C10), and 20 years (C20) and of soybean-corn rotational cropping (R) treatments were determined, and samples of the tillage layer soil were collected. High-throughput sequencing technology was used to analyze the diversity and composition of the soil bacterial and fungal communities. The factors influencing microbial communities, along with the effects of these communities and those of soil chemical indexes on yield, were further evaluated. The results showed that the community richness index of bacteria was higher in C20 than in R and that of fungi was highest in C5. The differences in the bacterial and fungal communities diversity indexes were not significant among the different continuous cropping treatments, respectively. The soil microbial community composition of all continuous cropping treatments differed significantly from R. The dominant bacterial phylum was Actinobacteriota and the dominant fungal phylum was Ascomycota. The relative abundance of Fusarium did not differ significantly among the continuous cropping treatments, while that of the plant pathogen fungi Lectera sp., Plectosphaerella sp., and Volutella sp. increased with continuous cropping years. Soil pH, SOM, N, and TP had significant effects on both bacterial and fungal communities, and TK and C/N had highly significant effects on fungal communities. The yield of C5 was significantly lower than that of R, and the differences in yield between C10, C20, and R were not significant. TN, TP, and pH had significant effects on yield, and fungal community abundance had a greater negative effect on yield than bacterial community abundance.

Characteristics of Biohydrogen Production and Performance of Hydrogen-Producing Acetogen by Increasing Normal Molasses Wastewater Proportion in Anaerobic Baffled Reactor.

The biohydrogen production efficiency and performance of hydrogen-producing acetogen in a four-compartment anaerobic baffled reactor (ABR) were studied by gradually increasing the influent normal molasses wastewater (NMWW) proportion. When the influent NMWW proportion increased to 55%, ABR could develop microbial community with methanogenic function in 63 days and reach a stable operation. When the influent NMWW proportion increased to 80% and reached a stable state, ethanol fermentation was established from butyric acid fermentation in the first three compartments, whereas butyric acid fermentation in the fourth compartment was strengthened. The average biohydrogen production yield and biohydrogen production capacity by COD removal increased to as high as 12.85 L/day and 360.22 L/kg COD when the influent NMWW proportion increased from 55% to 80%, respectively. Although the biogas yield and the specific biogas production rate reached 61.54 L/day and 232 L/kg MLVSS·day, the biohydrogen production yield and specific biohydrogen production rate were only 12.85 L/day and 48 L/kg MLVSS·day, which results in hydrogen consumption by homoacetogenesis and methanogenesis.

Isolation and recombinant analysis of variants of porcine epidemic diarrhea virus strains from Beijing, China.

Porcine epidemic diarrhea virus (PEDV) is a highly infectious virus infecting pigs with high morbidity, especially for newborn piglets. Several PEDV strains were isolated from the intestinal tracts of diarrheic piglets from the Beijing area, China. Sequencing of the whole-genome of the PEDV isolates (GenBank numbers MG546687-MG546690) yielded sequences of 28033-28038 nt. The phylogenetic tree revealed that these strains from the Beijing area belonged to group II, while the vaccine strain, CV777, belonged to group I. We also determined the genetic correlation between these strains and CV777 strain. However, it showed that these strains in the Beijing area had unique mutations. The sequence identity of PEDV strains showed that these strains are most similar to these strains LZW, CH/JX-1/2013, USAIllinois972013, USAKansas1252014, CH/GDZQ/2014, SHQPYM2013, AJ1102, CHZMDZY11, KoreaK14JB01, and CHYJ130330, respectively. The possible recombination events indicate that PEDV in this studies were possibly recombinant strain formed by parent strains USAIllinois972013, KoreaK14JB01, CHYJ130330, and CHZMDZY11. These PEDV strains has been genetic recombination and mutations. The variant strains characterized in this study help to the evolutionary analysis of PEDV.

Bacillus daqingensis sp. nov., a halophilic, alkaliphilic bacterium isolated from saline-sodic soil in Daqing, China.

An alkaliphilic, moderately halophilic, bacterium, designated strain X10-1(T), was isolated from saline-alkaline soil in Daqing, Heilongjiang Province, China. Strain X10-1(T) was determined to be a Gram-positive aerobe with rod-shaped cells. The isolate was catalase-positive, oxidase-negative, non-motile, and capable of growth at salinities of 0-16% (w/v) NaCl (optimum, 3%). The pH range for growth was 7.5-11.0 (optimum, pH 10.0). The genomic DNA G+C content was 47.7 mol%. Its major isoprenoid quinone was MK-7 and its cellular fatty acid profile mainly consisted of anteiso-C15:0, anteiso-C17:0, iso-C15:0, C16:0, and iso-C16:0. The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylglycerol. Phylogenetic analysis based on 16S rRNA gene sequences showed that X10-1(T) is a member of the genus Bacillus, being most closely related to B. saliphilus DSM15402(T) (97.8% similarity) and B. agaradhaerens DSM 8721(T) (96.2%). DNA-DNA relatedness to the type strains of these species was less than 40%. On the basis of the phylogenetic, physiological, and biochemical data, strain X10-1(T) represents a novel species of the genus Bacillus, for which the name Bacillus daqingensis sp. nov. is proposed. The type strain is X10-1(T) (=NBRC 109404(T) = CGMCC 1.12295(T)).