-
Microbiology Spectrum Aug 2016Aerobic Gram-positive and Gram-negative bacteria can be important pathogens in the immunocompromised host. These bacteria can be found in many environments, as part of... (Review)
Review
Aerobic Gram-positive and Gram-negative bacteria can be important pathogens in the immunocompromised host. These bacteria can be found in many environments, as part of the normal microbiota of the human host and animals, in soil and water, on plants, on fomites in the hospital, and on hospital equipment. This review provides information from relevant studies about what are the most common aerobic bacteria associated with patients who have cancer and/or are being treated for it, or who have other diseases which lead to immunodeficiencies, such as HIV, multiple myeloma, aplastic anemia, chronic diseases, and aging. A discussion of the appropriate laboratory tests needed for diagnosis of aerobic infections and information about antibiotics and susceptibility testing are also included.
Topics: Bacteria, Aerobic; Bacterial Infections; Bacteriological Techniques; Disease Susceptibility; Humans; Immunocompromised Host
PubMed: 27726805
DOI: 10.1128/microbiolspec.DMIH2-0027-2016 -
Current Opinion in Biotechnology Apr 2016Several aerobic bacteria possess unique catabolic pathways enabling them to degrade persistent organic pollutants (POPs), including polychlorinated... (Review)
Review
Several aerobic bacteria possess unique catabolic pathways enabling them to degrade persistent organic pollutants (POPs), including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polybrominated diphenylethers (PBDEs), and polychlorinated biphenyls (PCBs). The catabolic activity of aerobic bacteria employed for removal of POPs in the environment may be modulated by several biotic (i.e. fungi, plants, algae, earthworms, and other bacteria) and abiotic (i.e. zero-valent iron, advanced oxidation, and electricity) agents. This review describes the basic biochemistry of the aerobic bacterial catabolism of selected POPs and discusses how biotic and abiotic agents enhance or inhibit the process. Solutions allowing biotic and abiotic agents to exert physical and chemical assistance to aerobic bacterial catabolism of POPs are also discussed.
Topics: Bacteria, Aerobic; Environmental Pollutants; Humans
PubMed: 26851837
DOI: 10.1016/j.copbio.2015.12.016 -
FEMS Microbiology Letters Nov 2009Methanol is an atmospheric compound that is primarily released from plant polymers and impacts ozone formation. The global methanol emission rate from terrestrial... (Review)
Review
Methanol is an atmospheric compound that is primarily released from plant polymers and impacts ozone formation. The global methanol emission rate from terrestrial ecosystems is of the same order of magnitude (4.9 x 10(12) mol year(-1)) as that of methane (10 x 10(12) mol year(-1)). The major proportion of the annual plant-released methanol does not enter the atmosphere, but may be reoxidized by biological methanol oxidation, which is catalyzed by methanol-oxidizing prokaryotes. Fifty-six aerobic methanol-oxidizing species have been isolated from soils. These methylotrophs belong to the Alpha-, Beta-, and Gammaproteobacteria, Verrucomicrobia, Firmicutes, and Actinobacteria. Their ecological niches are determined by oxygen and methanol concentration, temperature, pH, the capability to utilize nitrate as an electron acceptor, and the spectrum of nitrogen sources and utilizable multicarbon substrates. Recently discovered interactions with eukaryotes indicate that their ecological niches may not solely be defined by physicochemical parameters. Nonetheless, there are still gaps in knowledge; based on global methanol budgets, methanol oxidation in soil is important, but has not been addressed adequately by biogeochemical studies. Ratios of above-ground and soil-internal methanol oxidation are not known. The contribution to methanol-oxidation by aerobic and anaerobic methylotrophs in situ also needs further research.
Topics: Bacteria, Aerobic; Biodiversity; Ecosystem; Methane; Oxidation-Reduction; Soil Microbiology
PubMed: 19583792
DOI: 10.1111/j.1574-6968.2009.01681.x -
Microbiology and Molecular Biology... Jun 1998The moderately halophilic heterotrophic aerobic bacteria form a diverse group of microorganisms. The property of halophilism is widespread within the bacterial domain.... (Review)
Review
The moderately halophilic heterotrophic aerobic bacteria form a diverse group of microorganisms. The property of halophilism is widespread within the bacterial domain. Bacterial halophiles are abundant in environments such as salt lakes, saline soils, and salted food products. Most species keep their intracellular ionic concentrations at low levels while synthesizing or accumulating organic solutes to provide osmotic equilibrium of the cytoplasm with the surrounding medium. Complex mechanisms of adjustment of the intracellular environments and the properties of the cytoplasmic membrane enable rapid adaptation to changes in the salt concentration of the environment. Approaches to the study of genetic processes have recently been developed for several moderate halophiles, opening the way toward an understanding of haloadaptation at the molecular level. The new information obtained is also expected to contribute to the development of novel biotechnological uses for these organisms.
Topics: Adaptation, Biological; Bacteria, Aerobic; Biodegradation, Environmental; Ecology; Sodium Chloride; Soil Microbiology; Water Microbiology
PubMed: 9618450
DOI: 10.1128/MMBR.62.2.504-544.1998 -
Applied Microbiology and Biotechnology Apr 2005In recent years, the research on aerobic granulation has been intensive. So far, almost all aerobic granules can form only in sequencing batch reactors (SBR), while the... (Review)
Review
In recent years, the research on aerobic granulation has been intensive. So far, almost all aerobic granules can form only in sequencing batch reactors (SBR), while the reason is not yet understood. This paper attempts to review the factors involved in aerobic granulation in SBR, including substrate composition, organic loading rate, hydrodynamic shear force, feast-famine regime, feeding strategy, dissolved oxygen, reactor configuration, solids retention time, cycle time, settling time and exchange ratio. The major selection pressures responsible for aerobic granulation are identified as the settling time and exchange ratio. A concept of the minimal settling velocity of bioparticles is proposed; and it is quantitatively demonstrated that the effects of settling time and exchange ratio on aerobic granulation in SBR can be interpreted and unified on the basis of this concept very well. It appears that the formation and characteristics of aerobic granules can be manipulated through properly adjusting either the settling time or the exchange ratio in SBR. Consequently, theoretical and experimental evidence point to the fact that aerobic granulation is a selection pressure-driven cell-to-cell immobilization process.
Topics: Bacteria, Aerobic; Bacterial Adhesion; Bioreactors; Cell Aggregation; Waste Disposal, Fluid; Water Purification
PubMed: 15800730
DOI: 10.1007/s00253-004-1820-2 -
Nature Reviews. Microbiology Feb 2007Numerous studies indicate that carbon monoxide (CO) participates in a broader range of processes than any other single molecule, ranging from subcellular to planetary... (Review)
Review
Numerous studies indicate that carbon monoxide (CO) participates in a broader range of processes than any other single molecule, ranging from subcellular to planetary scales. Despite its toxicity to many organisms, a diverse group of bacteria that span multiple phylogenetic lineages metabolize CO. These bacteria are globally distributed and include pathogens, plant symbionts and biogeochemically important lineages in soils and the oceans. New molecular and isolation techniques, as well as genome sequencing, have greatly expanded our knowledge of the diversity of CO oxidizers. Here, we present a newly emerging picture of the distribution, diversity and ecology of aerobic CO-oxidizing bacteria.
Topics: Animals; Bacteria, Aerobic; Carbon Monoxide; Ecosystem; Environmental Microbiology; Oxidation-Reduction; Phylogeny; Plant Roots; RNA, Ribosomal, 16S
PubMed: 17224920
DOI: 10.1038/nrmicro1595 -
Antonie Van Leeuwenhoek Apr 1990Reports of the simultaneous use of oxygen and denitrification by different species of bacteria have become more common over the past few years. Research with some... (Review)
Review
Reports of the simultaneous use of oxygen and denitrification by different species of bacteria have become more common over the past few years. Research with some strains (e.g. Thiosphaera pantotropha) has indicated that there might be a link between this 'aerobic denitrification' and a form of nitrification which requires rather than generates energy and is therefore known as heterotrophic nitrification. This paper reviews recent research into heterotrophic nitrification and aerobic denitrification, and presents a preliminary model which, if verified, will provide at least a partial explanation for the simultaneous occurrence of nitrification and denitrification in some bacteria.
Topics: Aerobiosis; Bacteria; Bacteria, Aerobic; Bacterial Proteins; Kinetics; Models, Biological; Nitrates; Nitrites; Oxygen Consumption
PubMed: 2181927
DOI: 10.1007/BF00403948 -
Nature Communications Jul 2020Sparse microbial populations persist from seafloor to basement in the slowly accumulating oxic sediment of the oligotrophic South Pacific Gyre (SPG). The physiological...
Sparse microbial populations persist from seafloor to basement in the slowly accumulating oxic sediment of the oligotrophic South Pacific Gyre (SPG). The physiological status of these communities, including their substrate metabolism, is previously unconstrained. Here we show that diverse aerobic members of communities in SPG sediments (4.3‒101.5 Ma) are capable of readily incorporating carbon and nitrogen substrates and dividing. Most of the 6986 individual cells analyzed with nanometer-scale secondary ion mass spectrometry (NanoSIMS) actively incorporated isotope-labeled substrates. Many cells responded rapidly to incubation conditions, increasing total numbers by 4 orders of magnitude and taking up labeled carbon and nitrogen within 68 days after incubation. The response was generally faster (on average, 3.09 times) for nitrogen incorporation than for carbon incorporation. In contrast, anaerobic microbes were only minimally revived from this oxic sediment. Our results suggest that microbial communities widely distributed in organic-poor abyssal sediment consist mainly of aerobes that retain their metabolic potential under extremely low-energy conditions for up to 101.5 Ma.
Topics: Bacteria, Aerobic; Carbon Isotopes; Fossils; Geologic Sediments; Microbiota; Nitrogen Isotopes; Radiometric Dating; Spectrometry, Mass, Secondary Ion
PubMed: 32724059
DOI: 10.1038/s41467-020-17330-1 -
Antonie Van Leeuwenhoek 1995Toxic aromatic pollutants, concentrated in industrial wastes and contaminated sites, can potentially be eliminated by low cost bioremediation systems. Most commonly, the... (Review)
Review
Toxic aromatic pollutants, concentrated in industrial wastes and contaminated sites, can potentially be eliminated by low cost bioremediation systems. Most commonly, the goal of these treatment systems is directed at providing optimum environmental conditions for the mineralization of the pollutants by naturally occurring microflora. Electrophilic aromatic pollutants with multiple chloro, nitro and azo groups have proven to be persistent to biodegradation by aerobic bacteria. These compounds are readily reduced by anaerobic consortia to lower chlorinated aromatics or aromatic amines but are not mineralized further. The reduction increases the susceptibility of the aromatic molecule for oxygenolytic attack. Sequencing anaerobic and and aerobic biotreatment steps provide enhanced mineralization of many electrophilic aromatic pollutants. The combined activity of anaerobic and aerobic bacteria can also be obtained in a single treatment step if the bacteria are immobilized in particulate matrices (e.g. biofilm, soil aggregate, etc.). Due to the rapid uptake of oxygen by aerobes and facultative bacteria compared to the slow diffusion of oxygen, oxygen penetration into active biofilms seldom exceeds several hundred micrometers. The anaerobic microniches established inside the biofilms can be applied to the reduction of electron withdrawing functional groups in order to prepare recalcitrant aromatic compounds for further mineralization in the aerobic outer layer of the biofilm. Aside from mineralization, polyhydroxylated and chlorinated phenols as well as nitroaromatics and aromatic amines are susceptible to polymerization in aerobic environments. Consequently an alternative approach for bioremediation systems can be directed towards incorporating these aromatic pollutants into detoxified humic-like substances. The activation of aromatic pollutants for polymerization can potentially be encouraged by an anaerobic pretreatment step prior to oxidation. Anaerobic bacteria can modify aromatic pollutants by demethylating methoxy groups and reducing nitro groups. The resulting phenols and aromatic amines are readily polymerized in a subsequent aerobic step.
Topics: Bacteria, Aerobic; Bacteria, Anaerobic; Biodegradation, Environmental; Hydrocarbons; Industrial Waste
PubMed: 7741529
DOI: 10.1007/BF00872195 -
Clinical Therapeutics 1987Encapsulation affects the virulence and survival of anaerobic bacteria and their protection from phagocytosis. More encapsulated Bacteroides strains and anaerobic and... (Review)
Review
Encapsulation affects the virulence and survival of anaerobic bacteria and their protection from phagocytosis. More encapsulated Bacteroides strains and anaerobic and facultative gram-positive cocci are isolated from patients with clinical infections than from healthy people. The pathogenicity of Bacteroides, Fusobacterium, Clostridium, and cocci isolates was demonstrated by their ability to induce subcutaneous abscesses in mice. Encapsulated Bacteroides, Fusobacterium, and cocci isolates generally induced abscesses, whereas nonencapsulated organisms did not. When strains that had fewer than 1% encapsulated organisms were inoculated with other viable or nonviable encapsulated bacteria, many survived in the abscesses and became heavily encapsulated. These strains were then able to induce abscesses when injected alone. Encapsulated Bacteroides species and anaerobic cocci induced bacteremia and translocation and increased the mortality in infected animals more often than did nonencapsulated forms of the same strain. In studies of selective antimicrobial therapy and quantitative cultures of abscesses, it was determined that possession of a capsule generally made Bacteroides species more important in mixed infections than their aerobic counterparts. In vivo synergy was seen between encapsulated Bacteroides species and all tested aerobic bacteria and most anaerobic and facultative gram-positive cocci as well as between most of these cocci and Pseudomonas aeruginosa or Staphylococcus aureus. It is concluded that encapsulated anaerobic bacteria have an important pathogenic role in polymicrobial infections.
Topics: Animals; Bacteria, Aerobic; Bacteria, Anaerobic; Bacterial Infections; Child; Humans; Mice; Sepsis; Virulence
PubMed: 3319170
DOI: No ID Found