Quorum sensing (QS) plays an important role in the growth, nodulation, and nitrogen fixation of rhizobia. In this study, we show that water-soluble humic materials (WSHM) repress the expression of the QS related genes , and in This decreased the production of -acetyl homoserine lactones (AHL) and exopolysaccharides (EPS), and ultimately increased cell density. We also identified a novel regulator, SMc03890 (renamed QsrR), which binds directly to the promoter.
View Article and Find Full Text PDFFour paddy soils were collected in Ningxiang County, Hunan province. These used with different long-term fertilization regimes, including a control without fertilizer (CK), chemical fertilization with nitrogen, phosphate, and kalium (NPK), straw fertilization combined with NPK (ST), and manure fertilization combinedwith NPK (OM). Phospholipid fatty acid (PLFA) technology and Microresp method were used to study the effect of long-term fertilization on soil microorganism abundance, community structure, and activity.
View Article and Find Full Text PDFAmmonium nitrogen (NH-N) at high concentrations is toxic to plants. In order to explore the NH-N tolerance of () and its ability of nitrogen (N) and phosphorus (P) uptake, this study used a nutrient solution with three NH-N levels (70, 210, 420 mg·L) to incubate for 21 d. The characteristics of plant physiology and N and P uptake of were measured.
View Article and Find Full Text PDFDyslipidemia in patients with hypercholesterolemia has been recently linked to increased human cathelicidin LL-37 (LL-37) serum concentration. We tested a hypothesis that upregulated expression of LL-37 gene in peripheral blood leucocytes is involved in dyslipidemia in patients with hypercholesteremia. Patients with hypercholesterolemia were used in the study.
View Article and Find Full Text PDFFertilizer and water management are two key factors for rice growth. A better understanding of the carbon (C) cycling in paddy soil requires investigation into the input characteristics and distribution dynamics of photosynthesized carbon in rice-soil system. We grew rice (Zhongzao 39) in PVC pots and used the C-CO continuous labeling method to quantify the allocation of photosynthesized carbon in rice-soil system under two regimes(Drying-rewetting .
View Article and Find Full Text PDFTo study the effects of long-term mining activities on the agricultural soil quality of Mengnuo town in Yunnan province, China, the heavy metal and soil enzyme activities of soil samples from 47 sites were examined. The results showed that long-term mining processes led to point source heavy metal pollution and Pb, Cd, Zn and As were the primary metal pollutants. Polyphenoloxidase was found the most sensitive soil enzyme activity and significantly correlated with almost all the metals (P < 0.
View Article and Find Full Text PDFThe lignite biodegradation procedure to produce water-soluble humic materials (WSHM) with a Penicillium stain was established by previous studies in our laboratory. This study researched the effects of WSHM on the growth of Bradyrhizobium liaoningense CCBAU05525 and its nodulation on soybean. Results showed that WSHM enhanced the cell density of CCBAU05525 in culture, and increased the nodule number, nodule fresh weight and nitrogenase activity of the inoculated soybean plants.
View Article and Find Full Text PDFAntonie Van Leeuwenhoek
July 2015
A Gram-negative, non-motive, aerobic and non-spore-forming strain 16-28-2(T) isolated from freshwater sediment of Taihu Lake was characterized by using a polyphasic approach. The optimum growth conditions were found to be as follows: 28 °C, pH 6.5 and 0-0.
View Article and Find Full Text PDFTo investigate the temporal variation of the sediment prokaryote communities and their relation with the rapid increase of algae population in Taihu, a shallow eutrophic freshwater Lake, water and surface sediments were sampled from seven sites in different stages of algal bloom. The physicochemical characterization revealed positive correlations among the nutrient (N, P) parameters in the water and sediments, as well as TN/TP ratio 30.79 in average in water and 0.
View Article and Find Full Text PDFCutaneous vasculitis, interstitial pneumonia with crazy-paving appearance on high-resolution computed tomography, and repeated positive perinuclear anti-neutrophil cytoplasmic antibodies (pANCA) are rarely found together in patients with inflammatory bowel disease in the existing literature. We report the case of a Chinese patient previously diagnosed with cutaneous vasculitis and interstitial pneumonia, who presented with acute pain and mass in his right lower quadrant a couple of years later. The terminal ileum biopsy and postoperative pathology confirmed Crohn's disease (CD).
View Article and Find Full Text PDFPhotosynthesized carbon is an important part in C cycling of "atmosphere-plant-soil" and is the source of soil organic carbon (SOC), but its mineralization and transformation dynamics in paddy soils remains still unclear. Therefore, a batch incubation experiment was conducted to investigate the mineralization and transformation of rice photosynthesized carbon in paddy soils after rice harvest. The results showed that the mineralization rate of native SOC ranged from 4.
View Article and Find Full Text PDFThe effects of a variety of environmental factors on lipid accumulation of Chlorella minutissima UTEX 2341 under low-nutrition conditions were investigated. The growth of UTEX 2341 reached the exponential phase on the 1st day in low-nutrition medium. And the highest biomass productivity of 3.
View Article and Find Full Text PDFJ Gen Appl Microbiol
November 2013
A Gram-negative, rod-shaped, aerobic, non-motile, bacterium (YG-17(T)) was isolated from eutrophic Taihu lake sediment. Colonies grown on YG agar plates were circular, convex, and yellow-colored. On the basis of 16S rRNA gene sequence similarity, strain YG-17(T) was shown to be closely related to Novosphingobium aromaticivorum (97.
View Article and Find Full Text PDFButane-oxidizing bacteria in soil sample sites from Puguang gas field in Sichuan province and Jianghan oil field in Hubei province were isolated and 16S rRNA gene sequence and phylogenetic analysis were applied. The differences of number and phylogenetic position and population diversity of hydrocarbon-oxidizing bacteria in different environment were investigated. The results show that 25 strains of butane-oxidizing bacteria were isolated.
View Article and Find Full Text PDFIn this study, three bacterial communities were obtained from 12 Leonardite samples with the aim of identifying a clean, effective, and economic technique for the dissolution of Leonardite, a type of low-grade coal, in the production of humic acid (HA). The biodegradation ability and characteristics of the degraded products of the most effective bacterial community (MCSL-2), which degraded 50% of the Leonardite within 21 days, were further investigated. Analyses of elemental composition, (13)C NMR, and Fourier transform infrared revealed that the contents of C, O, and aliphatic carbon were similar in biodegraded humic acid (bHA) and chemically (alkali) extracted humic acid (cHA).
View Article and Find Full Text PDFBioresour Technol
October 2011
High production cost is a major obstacle to the extensive use of microalgae biodiesel. To cut the cost and achieve higher biomass productivity, Chlorella minutissima UTEX2341 was cultured under photoheterotrophic conditions. With the carbon, nitrogen and phosphorus concentration of 26.
View Article and Find Full Text PDFEffects of phosphorus of low concentrations on the growth and the phosphorus removal efficiency of Scenedesmus obliquus were investigated in this study. Results showed that Scenedesmus obliquus achieved a phosphorus removal efficiency of 100% within 22 h when the initial algal cell concentration was 1 x 10(5) /mL and the initial phosphorus concentration was 0.02-0.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
September 2010
A Gram-negative, yellow-pigmented bacterium, designated strain R2A-16(T), was isolated from sediment of Rupa Lake in Nepal and analysed using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain R2A-16(T) is affiliated to the genus Cloacibacterium of the family Flavobacteriaceae; 16S rRNA gene sequence similarity between strain R2A-16(T) and Cloacibacterium normanense CCUG 46293(T) was 98.07 %.
View Article and Find Full Text PDFA novel intracellular bioflocculant (named MBF-W6) produced by Chryseobacterium daeguense W6 cultured in low nutrition medium was investigated in this study. The effects of carbon source, nitrogen source, C/N ratio, initial pH, inoculum size, culture temperature and shaking speed on MBF-W6 production were studied. Chemical analysis showed that the purified MBF-W6 was mainly composed of 32.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
June 2010
A Gram-stain-positive, rod-shaped, endospore-forming, halophilic, alkalitolerant bacterium, designated halo-1(T), was isolated from sediment of Xiarinaoer soda lake, located in the Inner Mongolia Autonomous Region of China. Strain halo-1(T) grew in the presence of 9-30 % (w/v) NaCl (optimum 19 %) and at pH 5-10 (optimum pH 9). The cell-wall peptidoglycan contained meso-diaminopimelic acid and the major respiratory isoprenoid quinone was MK-7.
View Article and Find Full Text PDFBiomass wastewater contains plenty of cellulose, hemicellulose, starch, saccharide, organic acid and protein. It has high COD value and leads to environment pollution and resource waste. Biomass wastewater was treated in this investigate using a biological aerated filter (BAF) on laboratory scale, and the effect of treatment in different hydraulic retention time (HRT) had been studied.
View Article and Find Full Text PDFIn this study, the feasibility of bioflocculant extraction from backwashing sludge to reduce its production costs was investigated. Results showed that ultrasound and base treatment could significantly enhance bioflocculant extraction efficiency, however, flocculating activity was affected. It was observed that bioflocculants extracted from sludge of pH 11.
View Article and Find Full Text PDFThe removal kinetic characteristic and mechanism of cadmium by growing Rhodobacter sphaeroides were investigated. The removal data were fitted to the second-order equation, with a correlation coefficient, R2=0.9790-0.
View Article and Find Full Text PDF