Background: Systemic lupus erythematosus, characterized by persistent inflammation, is a complex autoimmune disorder with no known cure. Immunosuppressants used in treatment put patients at a higher risk of infections. New knowledge of disease modulators, such as symbiotic bacteria, can enable fine-tuning of parts of the immune system, rather than suppressing it altogether.
View Article and Find Full Text PDFBackground: Rotavirus vaccines have poor efficacy in infants from low- and middle-income countries. Gut microbiota is thought to influence the immune response to oral vaccines. Thus, we developed a gnotobiotic (Gn) pig model of enteric dysbiosis to study the effects of human gut microbiota (HGM) on immune responses to rotavirus vaccination, and the effects of rotavirus challenge on the HGM by colonizing Gn pigs with healthy HGM (HHGM) or unhealthy HGM (UHGM).
View Article and Find Full Text PDFBackground: Clostridium difficile is the most common known cause of antibiotic-associated diarrhea. Upon the disturbance of gut microbiota by antibiotics, C. difficile establishes growth and releases toxins A and B, which cause tissue damage in the host.
View Article and Find Full Text PDFThe nitritation-anammox process has been a promising nitrogen removal technology towards sustainable wastewater treatment, but its application in treating domestic wastewater with relatively low ammonium concentrations (mainstream) remains a great challenge. In this study, an innovative lab-scale upflow membrane-aerated biofilm reactor (UMABR) was employed to treat a synthetic wastewater containing 70 mg N L(-1) ammonium. With a DO level at 0.
View Article and Find Full Text PDFCyclohexane and some of its derivatives have been a major concern because of their significant adverse human health effects and widespread occurrence in the environment. The 2014 West Virginia chemical spill has raised public attention to (4-methylcyclohexyl)methanol (4-MCHM), one cyclohexane derivative, which is widely used in coal processing but largely ignored. In particular, the environmental fate of its primary components, cis- and trans-4-MCHM, remains largely unexplored.
View Article and Find Full Text PDFCrude (4-methylcyclohexyl)methanol (MCHM) caused extensive contamination of drinking water, wastewater, and the environment during the 2014 West Virginia Chemical Spill. However, information related to the environmental degradation of cis- and trans-4-MCHM, the main components of the crude 4-MCHM mixture, remains largely unknown. This study is among the first to investigate the degradation kinetics and transformation of 4-MCHM isomers in activated sludge.
View Article and Find Full Text PDFSystemic lupus erythematosus (SLE) is a multi-system autoimmune disease. Despite years of study, the etiology of SLE is still unclear. Both genetic and environmental factors have been implicated in the disease mechanisms.
View Article and Find Full Text PDFPlasmacytoid dendritic cells (pDCs) are professional type I IFN producers believed to promote lupus. However, questions exist about whether they function at the same level throughout the course of lupus disease. We analyzed high-purity pDCs sorted from lupus mice.
View Article and Find Full Text PDFThe symbiotic relationship between the mammalian host and gut microbes has fascinated many researchers in recent years. Use of germ-free animals has contributed to our understanding of how commensal microbes affect the host. Immunodeficiency animals lacking specific components of the mammalian immune system, on the other hand, enable studying of the reciprocal function-how the host controls which microbes to allow for symbiosis.
View Article and Find Full Text PDFLead (Pb) is a prominent toxic metal in natural and engineered systems. Current knowledge on Pb toxicity to the activated sludge has been limited to short-term (≤24 h) toxicity. The effect of extended Pb exposure on process performance, bacterial viability, and community compositions remains unknown.
View Article and Find Full Text PDFWe generated a neonatal pig model with human infant gut microbiota (HGM) to study the effect of a probiotic on the composition of the transplanted microbiota following rotavirus vaccination and challenge. All the HGM-transplanted pigs received two doses of an oral attenuated rotavirus vaccine. The gut microbiota of vaccinated pigs were investigated for effects of Lactobacillus rhamnosus GG (LGG) supplement and homotypic virulent human rotavirus (HRV) challenge.
View Article and Find Full Text PDFGut microbiota has been recognized as an important environmental factor in health, as well as in metabolic and immunological diseases, in which perturbation of the host gut microbiota is often observed in the diseased state. However, little is known on the role of gut microbiota in systemic lupus erythematosus. We investigated the effects of host genetics, sex, age, and dietary intervention on the gut microbiome in a murine lupus model.
View Article and Find Full Text PDFBioresour Technol
November 2014
Microbial fuel cells (MFCs) employ microorganisms to recover electric energy from organic matter. However, fundamental knowledge of electrochemically active bacteria is still required to maximize MFCs power output for practical applications. This review presents microbiological and electrochemical techniques to help researchers choose the appropriate methods for the MFCs study.
View Article and Find Full Text PDFIt has long been recognized that the mammalian gut microbiota has a role in the development and activation of the host immune system. Much less is known on how host immunity regulates the gut microbiota. Here we investigated the role of adaptive immunity on the mouse distal gut microbial composition by sequencing 16 S rRNA genes from microbiota of immunodeficient Rag1(-/-) mice, versus wild-type mice, under the same housing environment.
View Article and Find Full Text PDFUnderstanding the microbial community structure and genetic potential of anode biofilms is key to improve extracellular electron transfers in microbial fuel cells. We investigated effect of substrate and temporal dynamics of anodic biofilm communities using phylogenetic and metagenomic approaches in parallel with electrochemical characterizations. The startup non-steady state anodic bacterial structures were compared for a simple substrate, acetate, and for a complex substrate, landfill leachate, using a single-chamber air-cathode microbial fuel cell.
View Article and Find Full Text PDFNew high-throughput technologies continue to emerge for studying complex microbial communities. In particular, massively parallel pyrosequencing enables very high numbers of sequences, providing a more complete view of community structures and a more accurate inference of the functions than has been possible just a few years ago. In parallel, quantitative real-time PCR (QPCR) allows quantitative monitoring of specific community members over time, space, or different environmental conditions.
View Article and Find Full Text PDFThe influences of fluorescence labeling on PCR amplification and T-RFLP analysis were examined by the analyses of a soil bacterial and archaeal community using both clone library and T-RFLP methods. The PCR amplification and microbial community structure patterns were compared among the primers labeled with and without fluorescent groups. PCR amplification was negatively affected by the labeling groups of the primers, which may be caused by the increment of primer molecular weight.
View Article and Find Full Text PDFRecent studies showed that the chlorinated solvents trichloroethene (TCE), 1,1,1-trichloroethane (TCA), and chloroform (CF) were reductively dehalogenated in a H(2)-based membrane biofilm reactor (MBfR) under denitrifying conditions. Here, we describe a detailed phylogenetic characterization of MBfR biofilm communities having distinctly different metabolic functions with respect to electron-acceptor reduction. Using massively parallel pyrosequencing of the V6 region of the 16S rRNA gene, we detected 312, 592, and 639 operational taxonomic units (OTU) in biofilms of three MBfRs that reduced nitrate; nitrate and TCE; or nitrate, sulfate, and all three chlorinated solvents.
View Article and Find Full Text PDFActivated sludge acclimated to biodegrade phenol was allowed to attach on and in light porous ceramic carriers and to function as a biofilm in a photolytic circulating-bed bioreactor (PCBBR). Phenol degradation in the PCBBR was investigated following three protocols: photolysis with ultraviolet light alone (P), biodegradation alone (B), and the two mechanisms operating simultaneously (P/B). Phenol was degraded at approximately equal rates by B and P/B, each of which was much faster than the rate by P.
View Article and Find Full Text PDFThe low yield of methane in anaerobic digestion systems represents a loss of energy that can be captured as renewable energy when the input sludge is pre-treated to make it more bioavailable. We investigated Focused-Pulsed (FP) pre-treatment, which make complex biological solids more bioavailable by exposing them to rapid pulses of a very strong electric field. We investigated how the microbial ecology in full-scale anaerobic digesters was altered when the digesters' methane production rate was significantly increased by FP pre-treatment.
View Article and Find Full Text PDFWe compared the microbial community structures that developed in the biofilm anode of two microbial electrolysis cells fed with ethanol, a fermentable substrate-one where methanogenesis was allowed and another in which it was completely inhibited with 2-bromoethane sulfonate. We observed a three-way syntrophy among ethanol fermenters, acetate-oxidizing anode-respiring bacteria (ARB), and a H2 scavenger. When methanogenesis was allowed, H2-oxidizing methanogens were the H2 scavengers, but when methanogenesis was inhibited, homo-acetogens became a channel for electron flow from H2 to current through acetate.
View Article and Find Full Text PDFWe developed the first model for predicting community structure in mixed-culture fermentative biohydrogen production using electron flows and NADH2 balances. A key assumption of the model is that H2 is produced only via the pyruvate decarboxylation-ferredoxin-hydrogenase pathway, which is commonly the case for fermentation by Clostridium and Ethanoligenens species. We experimentally tested the model using clone libraries to gauge community structures with mixed cultures in which we did not pre-select for specific bacterial groups, such as spore-formers.
View Article and Find Full Text PDFRecent evidence suggests that the microbial community in the human intestine may play an important role in the pathogenesis of obesity. We examined 184,094 sequences of microbial 16S rRNA genes from PCR amplicons by using the 454 pyrosequencing technology to compare the microbial community structures of 9 individuals, 3 in each of the categories of normal weight, morbidly obese, and post-gastric-bypass surgery. Phylogenetic analysis demonstrated that although the Bacteria in the human intestinal community were highly diverse, they fell mainly into 6 bacterial divisions that had distinct differences in the 3 study groups.
View Article and Find Full Text PDFThe sulfate-methane transition zone (SMTZ) is a widespread feature of continental margins, representing a diffusion-controlled interface where there is enhanced microbial activity. SMTZ microbial activity is commonly associated with the anaerobic oxidation of methane (AOM), which is carried out by syntrophic associations between sulfate-reducing bacteria and methane-oxidizing archaea. While our understanding of the microorganisms catalyzing AOM has advanced, the diversity and ecological role of the greater microbial assemblage associated with the SMTZ have not been well characterized.
View Article and Find Full Text PDFWe tested at full-scale the innovative Focused Pulsed (FP) technology for pre-treating waste sludge in order to improve methane gas production and biosolids reduction in sludge digestion, but without incurring problems of odors, toxicity, and high costs for chemical or energy consumption. FP pre-treatment of a mixture of primary and secondary sludge increased the soluble COD by 160% and DOC 120% over the control. FP pre-treatment of 63% of the input waste sludge increased biogas production by over 40% and reduced biosolids requiring disposal by 30% when compared to the plant baseline.
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