ABSTRACT
Decomposing cyanobacterial bloom-induced black blooms been seen as an issue in the management of freshwater ecosystems, but its effect on sulfate-reducing bacteria (SRB) in shallow freshwater lakes is not clear. The objective of this study is to present an in-depth investigation of black bloom effects on the activities and composition of SRB, as well as the interactions between SRB and other bacteria. Water and surface sediments samples were collected from a shallow freshwater lake during black and non-black blooms. Sulfate reduction rates (SRRs) in the water column were determined from the linear regression of sulfate depletion with time. Quantitative real-time polymerase chain reactions (qPCRs), targeting the dsrA gene and Illumina sequencing of 16S rDNA, were used to estimate the SRB population and SRB community structures, respectively. Our data indicate that although a higher abundance of SRB was responsible for the higher SRR in the bottom water (34.09⯱â¯2.37â¯nmolâ¯mL-1 day-1) than in the surface water (14.57⯱â¯2.91â¯nmolâ¯mL-1 day-1) during black blooms, cell-specific sulfate reduction rates (csSRRs) in the distinct water layers were not significantly different (Pâ¯=â¯0.95), with the value of approximately 0.017â¯fmol cell-1 day-1. Additionally, Desulfomicrobium and Desulfovibrio were the two main genera of SRB in the water column during black bloom season, while Desulfobulbus, Desulfobacca and Desulfatiglans genera were identified in the sediments of both the black and non-black blooms in genera pools. Each SRB genus preferentially associated with bacteria for specific functions in the bacterial co-occurrence network, regardless of whether black booms occurred or not. These results extend our knowledge on the importance of SRB during black blooms and the adaptation of SRB to environmental changes in freshwater lakes.
Subject(s)
Cyanobacteria , Lakes , Ecosystem , Eutrophication , Lakes/chemistry , SulfatesABSTRACT
Previous studies of the dynamics of sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB) have focused on deep stratified lakes. The objective of this study is to present an in-depth investigation of the structure and dynamics of sulfur bacteria (including SRB and SOB) in the water column of shallow freshwater lakes. A cyanobacterial bloom biomass (CBB)-amended mesocosm experiment was conducted in this study, in which water was taken from a shallow eutrophic lake with sulfate levels near 40 mg L-1. Illumina sequencing was used to investigate SRB and SOB species involved in CBB decomposition and the effects of the increases in sulfate input on the water column microbial community structure. The accumulation of dissolved sulfide (∑H2S) produced by SRB during CBB decomposition stimulated the growth of SOB, and ∑H2S was then oxidized back to sulfate by SOB in the water column. Chlorobaculum sequences (the main SOB species in the study) were significantly influenced by increases in sulfate input, with relative abundance increasing approximately four-fold in treatments amended with 40 mg L-1 sulfate (referred to as 40S) when compared to the treatment without additional sulfate addition (referred to as CU). Additionally, an increase in SOB number was observed from day 26-37, concurrent with the decrease in SRB number, indicating the succession of sulfur bacteria. These findings suggest that biological sulfur oxidation and succession of sulfur bacteria occur in the water column during CBB decomposition in shallow freshwater ecosystems, and the increases in sulfate input stimulate microbial sulfur oxidation.
Subject(s)
Cyanobacteria/growth & development , Lakes/microbiology , Biomass , Chlorobi , Ecosystem , Oxidation-Reduction , Sulfates , Sulfides , Sulfur/chemistryABSTRACT
A Gram-stain-negative, rod-shaped bacterium, strain F01T, was isolated from leaves of Tamarix chinensis Lour. The isolate grew optimally at 30 °C, at pH 7.0 and with 5.0â% (w/v) NaCl, and showed a high tolerance to manganese, lead, nickel, ferrous ions and copper ions. The major fatty acids were C18â:â1ω7c and C16â:â0, and the predominant respiratory quinone was Q-9. Polar lipids were dominated by diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, unidentified aminoglycolipids and phospholipids. The DNA G+C content was 65.8â%. Based on multilocus phylogenetic analysis, strain F01T belonged to the genus Salinicola, with highest 16S rRNA gene sequence similarity to Salinicola peritrichatus CGMCC 1.12381T (97.7â%). The level of DNA-DNA hybridization between strain F01T and closely related Salinicola strains was well below 70â%. According to the phenotypic, genetic and chemotaxonomic data, strain F01T is considered to represent a novel species in the genus Salinicola, for which the name Salinicola tamaricis sp. nov. is proposed. The type strain is F01T (=CCTCC AB 2015304T=KCTC 42855T).
Subject(s)
Halomonadaceae/classification , Phylogeny , Salt-Tolerant Plants/microbiology , Tamaricaceae/microbiology , Bacterial Typing Techniques , Base Composition , China , DNA, Bacterial/genetics , Fatty Acids/chemistry , Halomonadaceae/genetics , Halomonadaceae/isolation & purification , Metals , Nucleic Acid Hybridization , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/chemistryABSTRACT
BACKGROUND: High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is a promising approach for lymphomas. This study aimed to evaluate the effect of ifosfamide, cisplatin or carboplatin, and etoposide (ICE)-based regimen as a mobilization regimen on relapsed, refractory, or high-risk aggressive lymphoma. METHODS: From June 2001 to May 2013, patients with lymphomas who mobilized by ICE-based regimen for ASCT were analyzed in this retrospective study. The results of the autologous peripheral blood stem cells collection, toxicity, engraftment after ICE-based mobilization regimen were analyzed in this study. Furthermore, risk factors for overall survival (OS) and progression free survival (PFS) were evaluated by univariate analysis. RESULTS: The stem cells were mobilized using ICE-based regimen plus rituximab or ICE-based regimen alone in 12 patients and 54 patients, respectively. The results of stem cell mobilization were excellent. Ninety-seven percentages of the patients had the stem cell collection of at least 2.0 × 10 6 CD34 + cells/kg and 68% had at least 5 × 10 6 CD34 + cells/kg. Fifty-eight percentage of the patients experienced Grade 4 neutropenia, 20% developed febrile neutropenia, and only 12% had Grade 4 thrombocytopenia. At a median follow-up of 63.8 months, the 5-year PFS and OS were 64.4% and 75.3%, respectively. CONCLUSION: ICE is a powerful regimen for stem cell mobilization in patients with lymphomas.
Subject(s)
Antineoplastic Agents/therapeutic use , Carboplatin/therapeutic use , Cisplatin/therapeutic use , Etoposide/therapeutic use , Hematopoietic Stem Cell Mobilization/methods , Ifosfamide/therapeutic use , Lymphoma/drug therapy , Stem Cell Transplantation/methods , Adolescent , Adult , Child , Female , Humans , Male , Middle Aged , Retrospective Studies , Transplantation, Autologous , Young AdultABSTRACT
OBJECTIVE: To explore the association of cardiovascular disease (CVD) risk factors and its impact on the 10-year prevalence of carotid atherosclerosis. METHODS: Two surveys for CVD risk factors were carried out in a population consisting of 1323 subjects in Beijing in both 1992 and 2002 and a direct measurement of carotid arteries with B-mode ultrasound imaging were performed in 2002. Intima-media thickness (IMT) and plaque of carotid arteries were regarded as the indicators of carotid atherosclerosis and main CVD risk factors were treated as the impact factors. RESULTS: (1) 10-year prevalence of carotid atherosclerosis continually increased with elevated baseline risk factors levels. Age, smoking, hypertension and hypercholesterolemia were found to be independently associated with carotid atherosclerosis. (2) 10-year prevalence of carotid atherosclerosis increased with the elevated number of risk factors clustering in individuals. (3) The prevalence of IMT and plaque were 67.1% and 42.6% in subjects with CVD risk factors in both 1992 and 2002 surveys with Odds Ratios being 1.7 and 3.1 times as those without risk factors. CONCLUSION: Traditional CVD risk factors exert impact on CVD and carotid atherosclerosis with different degrees and carotid atherosclerosis can be regarded as an early evaluation indicator for risk of atherosclerotic diseases.
Subject(s)
Cardiovascular Diseases/epidemiology , Carotid Artery Diseases/epidemiology , Aged , Cardiovascular Diseases/diagnostic imaging , Carotid Arteries/diagnostic imaging , Carotid Artery Diseases/diagnostic imaging , China/epidemiology , Female , Humans , Hypercholesterolemia/epidemiology , Hypertension/epidemiology , Male , Middle Aged , Prevalence , Prospective Studies , Risk Factors , Smoking/epidemiology , UltrasonographyABSTRACT
OBJECTIVE: To investigate the quality of life of Chinese malignant patients who treated with the high dose chemoradiotherapy combined with autologous stem cell transplantation (ASCT). METHODS: The data of 89 patients who answer the EORTC QLQ-C30 Chinese version 3.0 after finished ASCT and disease free were analyzed using SPSS 10.0. RESULTS: The score of global health status and functional assessment were near or over 80, more than 80 percent of patient had good or very good global health status or function, the patients who were experiencing moderate or severe financial dysfunction, fatigue, dyspnea, sleeping disturbance and diarrhea were in 72.5% (65/89), 50.6% (45/89), 42.7% (38/89), 33.7% (30/89) and 32.5% (29/89) respectively. The score of dyspnea in female patients was significant higher than male patients (P = 0.024). The score of global health status (P = 0.000), physical function (P = 0.000), role function (P = 0.031) and social function (P = 0.029) became higher significantly with time from transplantation and the score of fatigue became lower (P = 0.020). The Hodgkin's lymphoma patients had higher score significantly in nausea & vomiting (P = 0.002) and dyspnea (P = 0.006) than NHL. The age at transplantation and evaluation took none effect on the score. CONCLUSION: Most patient have good global health status and function after autologous stem cell transplantation, they are more suffered from financial dysfunction, fatigue, dyspnea, sleeping disturbance and diarrhea. Females have more dyspnea symptoms, the quality of life of patient will improve gradually with the time from transplantation, the Hodgkin's lymphoma patients have more symptoms than non-Hodgkin's lymphoma patients, we do not find any effect of age at transplantation and assessment on the quality of life.
Subject(s)
Hematopoietic Stem Cell Transplantation , Quality of Life , Adolescent , Adult , Child , Child, Preschool , Female , Follow-Up Studies , Humans , Male , Middle Aged , Postoperative Period , Surveys and Questionnaires , Transplantation, Autologous , Young AdultABSTRACT
BACKGROUND AND AIMS: The relative importance of pre- and post-germination determinants for recruitment of natural plant communities is rarely explored. An annual plant community on moving sandy land was chosen for a case study. Answers to the following questions were sought: (a) Does recruitment of new individuals within the community of annual plants differ in time and space? (b) Is there spatial concordance between seed deposition, seedling emergence, survival and recruitment? (c) What are the direct and indirect effects of pre- and post-germination determinants on plant recruitment. METHODS: An integrative approach combining investigation of natural recruitment processes with regression, correlation and path analyses was adopted. Data on seed deposition and seedling recruitment were collected by monitoring the number of seeds deposited in the top 5 cm of the soil and the numbers of seedlings emerged and recruited from all annual plants at sites to a range of distances from the existing shrub Artemisia halodendron (Asteraceae) in eight compass directions for two consecutive growing seasons. KEY RESULTS: Community-level recruitment was strongly affected by inter-annual rainfall variation and was highly site- and density-dependent. Low recruitment rate in this system was due to low emergence rate and low post-emergence survival rate. Of the pre- and post-germination determinants studied, it was the number of seedlings which emerged and the post-emergence survival rate that had the greatest direct effects on recruitment, with a combination of both variables explaining the majority of the variance (97 %) in recruitment. CONCLUSIONS: This study suggests that post-germination determinants (emergence and survival) rather than pre-germination determinants (seed deposition) substantially determined the final pattern of recruitment. Although the density of seeds deposited did not have a significant direct effect on recruitment, it contributed to observed variation in recruitment indirectly through density-dependent emergence of seedlings.
Subject(s)
Germination , Analysis of Variance , Artemisia , Environment , Regression Analysis , Seasons , Seeds , Soil , Time Factors , WindABSTRACT
BACKGROUND AND AIMS: Artemisia halodendron is a native sub-shrub that occurs mainly in moving and semi-fixed sandy lands in Inner Mongolia, China. Information on the spatial patterns of wind-dispersed seed deposition and seedling recruitment of A. halodendron inhabiting moving sandy lands is very limited. The aim of this study was to examine wind-dispersed seed deposition patterns and post-dispersal recruitment of A. halodendron seedlings. * METHODS: The spatial patterns of wind-dispersed seed deposition and seedling recruitment of A. halodendron were examined by investigating the numbers of deposited seeds, emerged and surviving seedlings using sampling points at a range of distances from the parent plant in eight compass directions for two consecutive growing seasons. * KEY RESULTS: Wind-dispersed seed deposition showed considerable variation between directions and years. Wind transported A. halodendron seeds only a few meters away from the parent plant in all eight directions. Seedling emergence and establishment also showed between-direction and between-year variability, but the spatial pattern of seedling distribution differed from that of seed deposition. Only a very small fraction (<1 %) of the deposited seeds emerged in the field and survived for long enough to be included in our seedling censuses at the end of the growing season. * CONCLUSIONS: The spatial variation in wind speed and frequency strongly affects the pattern of seed deposition, although the variation in seed deposition does not determine the spatial pattern of seedling recruitment. Seeds of A. halodendron are not dispersed very well by wind. The low probability of recruitment success for A. halodendron seedlings suggests that this species does not rely on seedling recruitment for its persistence and maintenance of population.