Techniques for Investigating the Role of Anaerobic Bacteria in Estuarine Sediments

2009 ◽  
pp. 107-107-12
Author(s):  
RJ Parkes ◽  
MJ Bryder ◽  
RH Madden ◽  
NJ Poole
Keyword(s):  
Anaerobic Bacteria ◽  
Estuarine Sediments

scholarly journals Nitrous Oxide Formation in the Colne Estuary, England: the Central Role of Nitrite

2002 ◽  
Vol 68 (3) ◽  
pp. 1240-1249 ◽  
Author(s):  
Liang F. Dong ◽  
David B. Nedwell ◽  
Graham J. C. Underwood ◽  
Daniel C. O. Thornton ◽  
Iman Rusmana
Keyword(s):  
Nitrous Oxide ◽  
Anaerobic Bacteria ◽  
Critical Factor ◽  
Estuarine Sediments ◽  
Overlying Water ◽  
High Nutrient ◽  
Nitrous Oxide Production ◽  
Colne Estuary ◽  
Nitrate And Nitrite

ABSTRACT Nitrate and nitrite concentrations in the water and nitrous oxide and nitrite fluxes across the sediment-water interface were measured monthly in the River Colne estuary, England, from December 1996 to March 1998. Water column concentrations of N2O in the Colne were supersaturated with respect to air, indicating that the estuary was a source of N2O for the atmosphere. At the freshwater end of the estuary, nitrous oxide effluxes from the sediment were closely correlated with the nitrite concentrations in the overlying water and with the nitrite influx into the sediment. Increases in N2O production from sediments were about 10 times greater with the addition of nitrite than with the addition of nitrate. Rates of denitrification were stimulated to a larger extent by enhanced nitrite than by nitrate concentrations. At 550 μM nitrite or nitrate (the highest concentration used), the rates of denitrification were 600 μmol N · m−2 · h−1 with nitrite but only 180 μmol N · m−2 · h−1 with nitrate. The ratios of rates of nitrous oxide production and denitrification (N2O/N2 × 100) were significantly higher with the addition of nitrite (7 to 13% of denitrification) than with nitrate (2 to 4% of denitrification). The results suggested that in addition to anaerobic bacteria, which possess the complete denitrification pathway for N2 formation in the estuarine sediments, there may be two other groups of bacteria: nitrite denitrifiers, which reduce nitrite to N2 via N2O, and obligate nitrite-denitrifying bacteria, which reduce nitrite to N2O as the end product. Consideration of free-energy changes during N2O formation led to the conclusion that N2O formation using nitrite as the electron acceptor is favored in the Colne estuary and may be a critical factor regulating the formation of N2O in high-nutrient-load estuaries.

Role of filter media in an anaerobic fixed-bed reactor

1995 ◽  
Vol 31 (9) ◽  
pp. 137-144 ◽  
Author(s):  
T. Miyahara ◽  
M. Takano ◽  
T. Noike
Keyword(s):  
Anaerobic Bacteria ◽  
Fixed Bed ◽  
Methanogenic Bacteria ◽  
The Other ◽  
Fixed Bed Reactor ◽  
Filter Media ◽  
Fixed Bed Reactors ◽  
Attached Bacteria ◽  
The Relationship

The relationship between the filter media and the behaviour of anaerobic bacteria was studied using anaerobic fixed-bed reactors. At an HRT of 48 hours, the number of suspended acidogenic bacteria was higher than those attached to the filter media. On the other hand, the number of attached methanogenic bacteria was more than ten times as higher than that of suspended ones. The numbers of suspended and deposited acidogenic and methanogenic bacteria in the reactor operated at an HRT of 3 hours were almost the same as those in the reactor operated at an HRT of 48 hours. Accumulation of attached bacteria was promoted by decreasing the HRT of the reactor. The number of acidogenic bacteria in the reactor packed sparsely with the filter media was higher than that in the closely packed reactor. The number of methanogenic bacteria in the sparsely packed reactor was lower than that in the closely packed reactor.

Study of the role of Chlamydia, Mycoplasma, Ureaplasma and other microaerophilic and aerobic bacteria in uterine infections of mares with reproductive disorders

2003 ◽  
Vol 51 (1) ◽  
pp. 45-52 ◽  
Author(s):  
László Szeredi ◽  
M. Tenk ◽  
I. Schiller ◽  
Keyword(s):  
Pathogenic Bacteria ◽  
Anaerobic Bacteria ◽  
Aerobic Bacteria ◽  
Relative Importance ◽  
Reproductive Disorders ◽  
Taylorella Equigenitalis

In six healthy mares and 24 mares showing reproductive disorders swab samples were taken from the fossa clitoridis to isolate Taylorella equigenitalis, and from the uterus to isolate mycoplasmas, ureaplasmas and other aerobic bacteria. Swab samples were also taken from the uterus for Chlamydiaantigen ELISA and ChlamydiaPCR studies. The uterus of 27 mares was examined cytologically, and biopsy samples were taken from the endometrium for histological examinations and for immunohistochemical examinations aimed at the detection of chlamydiae. T. equigenitalis, mycoplasmas, ureaplasmas and chlamydiae could not be detected from any of the mares examined. Aerobic facultative pathogenic bacteria were isolated from mares with endometritis in four cases. In 18 out of 22 mares with endometritis (82%) no infective agents could be demonstrated. Further studies are needed to elucidate the relative importance of non-infectious causes of endometritis and of anaerobic bacteria often detectable in the uterus in the aetiology of the reproductive disorders observed.

Intestinal Lesions Containing Coronavirus-like Particles in Neonatal Necrotizing Enterocolitis: An Ultrastructural Analysis

PEDIATRICS ◽  
1984 ◽  
Vol 73 (2) ◽  
pp. 218-224
Author(s):  
S. Rousset ◽  
O. Moscovici ◽  
P. Lebon ◽  
J. P. Barbet ◽  
P. Helardot ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Necrotizing Enterocolitis ◽  
Intestinal Mucosa ◽  
Light And Electron Microscopy ◽  
Anaerobic Bacteria ◽  
Intestinal Lesions ◽  
Maternity Hospitals ◽  
Neonatal Necrotizing Enterocolitis

Since the outbreaks of neonatal necrotizing enterocolitis occurring in maternity hospitals of Paris and suburbs in 1979-1980, it has been possible to examine by light and electron microscopy gut specimens from ten newborns with this illness. Coronavirus-like particles, enclosed in intracytoplasmic vesicles of damaged epithelial cells of the intestinal mucosa, were observed in the small intestine, appendix, and colon. The ultrastructural study, supported by bacteriologic findings, suggests the role of coronavirus-like particles in the appearance of the lesions. Secondary proliferation of mainly anaerobic bacteria, probably responsible for pneumatosis, may aggravate the disease.

The role of Akkermansia muciniphila in obesity, diabetes and atherosclerosis

2021 ◽  
Vol 70 (10) ◽  
Author(s):  
Alka Hasani ◽  
Saba Ebrahimzadeh ◽  
Fatemeh Hemmati ◽  
Aytak Khabbaz ◽  
Akbar Hasani ◽  
...  
Keyword(s):  
Type Species ◽  
Anaerobic Bacteria ◽  
Regulatory System ◽  
Content Type ◽  
Akkermansia Muciniphila ◽  
Link Type ◽  
Animal Trials ◽  
Obesity And Diabetes ◽  
Underlying Mechanisms

Alteration in the composition of the gut microbiota can lead to a number of chronic clinical diseases. Akkermansia muciniphila is an anaerobic bacteria constituting 3–5% of the gut microbial community in healthy adults. This bacterium is responsible for degenerating mucin in the gut; its scarcity leads to diverse clinical disorders. In this review, we focus on the role of A. muciniphila in diabetes, obesity and atherosclerosis, as well as the use of this bacterium as a next-generation probiotic. In regard to obesity and diabetes, human and animal trials have shown that A. muciniphila controls the essential regulatory system of glucose and energy metabolism. However, the underlying mechanisms by which A. muciniphila alleviates the complications of obesity, diabetes and atherosclerosis are unclear. At the same time, its abundance suggests improved metabolic disorders, such as metabolic endotoxemia, adiposity insulin resistance and glucose tolerance. The role of A. muciniphila is implicated in declining aortic lesions and atherosclerosis. Well-characterized virulence factors, antigens and cell wall extracts of A. muciniphila may act as effector molecules in these diseases. These molecules may provide novel mechanisms and strategies by which this bacterium could be used as a probiotic for the treatment of obesity, diabetes and atherosclerosis.

scholarly journals The Role of Matrix Metalloproteinases in Periodontal Disease

2020 ◽  
Vol 17 (14) ◽  
pp. 4923 ◽  
Author(s):  
Vittorio Checchi ◽  
Tatjana Maravic ◽  
Pierantonio Bellini ◽  
Luigi Generali ◽  
Ugo Consolo ◽  
...  
Keyword(s):  
Matrix Metalloproteinases ◽  
Periodontal Disease ◽  
Anaerobic Bacteria ◽  
Therapeutic Strategies ◽  
Oral Diseases ◽  
Tissue Destruction ◽  
Proinflammatory Mediators ◽  
Disease Therapy ◽  
Important Pathway

This review provides a detailed description of matrix metalloproteinases (MMPs), focusing on those that are known to have critical roles in bone and periodontal disease. Periodontal disease is an inflammatory process initiated by anaerobic bacteria, which promote the host immune response in the form of a complex network of molecular pathways involving proinflammatory mediators such as cytokines, growth factors, and MMPs. MMPs are a family of 23 endopeptidases, collectively capable of degrading virtually all extracellular matrix (ECM) components. This study critically discusses the available research concerning the involvement of the MMPs in periodontal disease development and progression and presents possible therapeutic strategies. MMPs participate in morphogenesis, physiological tissue turnover, and pathological tissue destruction. Alterations in the regulation of MMP activity are implicated in the manifestation of oral diseases, and MMPs comprise the most important pathway in tissue destruction associated with periodontal disease. MMPs can be considered a risk factor for periodontal disease, and measurements of MMP levels may be useful markers for early detection of periodontitis and as a tool to assess prognostic follow-ups. Detection and inhibition of MMPs could, therefore, be useful in periodontal disease prevention or be an essential part of periodontal disease therapy, which, considering the huge incidence of the disease, may greatly improve oral health globally.

Role of anaerobic bacteria in subdural empyema

1975 ◽  
Vol 58 (1) ◽  
pp. 99-104 ◽  
Author(s):  
Thomas T. Yoshikawa ◽  
Anthony W. Chow ◽  
Lucien B. Guze
Keyword(s):  
Anaerobic Bacteria ◽  
Subdural Empyema
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