Principal Investigator:KATORI Hiroto,鹿取 広人, Project Period (FY):1992 - 1993, Research Category:Grant-in-Aid for General Scientific Research (A), Research Field:Psychology
Investigations were performed on the structural features responsible for kinetic thermal stability of a thermostable carboxypeptidase from the thermoacidophilic archaebacterium Sulfolobus solfataricus which had been purified previously and identified as a zinc metalloprotease [Colombo, DAuria, Fusi, Zecca, Raia and Tortora (1992) Eur. J. Biochem. 206, 349-357]. Removal of Zn2+ by dialysis led to reversible activity loss, which was promptly restored by addition of 80 microM ZnCl2 to the assay mixture. For the first-order irreversible thermal inactivation the metal-depleted enzyme showed an activation energy value of 205.6 kJ.mol-1, which is considerably lower than that of the holoenzyme (494.4 kJ.mol-1). The values of activation free energies, enthalpies and entropies also dropped with metal removal. Thermal inactivation of the apoenzyme was very quick at 80 degrees C, whereas the holoenzyme was stable at the same temperature. These findings suggest a major stabilizing role for the bivalent ...
1CAA: X-ray crystal structures of the oxidized and reduced forms of the rubredoxin from the marine hyperthermophilic archaebacterium Pyrococcus furiosus.
Biology Assignment Help, Heliozoans - protozoan, Heliozoans - Protozoan Heliozoans are spherical protozoan that occur in the sea or in still bodies of fresh water. They are mainly located in the bottom debris. Fine needle like pseudopodia radiate from the surface of the body. These are known a
Marine microorganisms and their extracellular enzymes (ECEs) play an important role in the remineralization of organic material by hydrolyzing high-molecular-weight substrates to sizes sufficiently small to be transported through cell membrane, yet the diversity of the enzyme-producing bacteria and the types of ECEs involved in the degradation process are largely unknown. In this work, we investigated the diversity of cultivable bacteria and their ECEs and the potential activities of aminopeptidase in the water column at eight different depths of the New Britain Trench. There was a great diversity of cultivable bacteria and ECEs, and depth appears an important driver of the diversity. The 16S rRNA sequence analysis revealed that the cultivable bacteria were affiliated mostly with the phyla Proteobacteria and Actinobacteria, and the predominant genera were Pseudoalteromonas (62.7%) and Halomonas (17.3%). Moreover, 70.7% of the isolates were found to produce hydrolytic zone on casein and gelatin plates,
A group of organisms of small size has been discovered which can be cultivated in indefinite series. The organisms form a well-defined group and have both relatively large and small forms. The smaller forms appear to be as small as vaccinia virus and from them the larger forms readily develop. Occurrence The organisms have been obtained from all samples of raw sewage so far examined from four London districts during the summer. They have not been detected in London tap-water, or faecal material from man, pig, rabbit, or rat. ...
Unit 1: How do living things stay alive?. In this unit students are introduced to some of the challenges to an organism in sustaining life. Students examine the cell as the structural and functional unit of life, from the single celled to the multicellular organism, and the requirements for sustaining cellular processes in terms of inputs and outputs. They analyse types of adaptations that enhance the organisms survival in a particular environment and consider the role homeostatic mechanisms play in maintaining the internal environment. Students investigate how a diverse group of organisms form a living interconnected community that is adapted to, and utilises, the abiotic resources of its habitat. The role of a keystone species in maintaining the structure of an ecosystem is explored. Students consider how the planets biodiversity is classified and the factors that affect the growth of a population. Area of study 1. How do organisms function?. Outcome 1 On completion of this unit the student ...
Immunoglobulins are made by white blood cells known as B cells (B lymphocytes). Any disease that harms the development or function of B cells will, therefore, affect the production of immunoglobulin antibodies. T cells, another type of white blood cell, may also be involved in immunodeficiency disorders. About 70 percent of immunoglobulin deficiencies involve B lymphocytes and 20-30 percent involve T lymphocytes. Another 10 percent may involve both B and T lymphocytes. Many of the infections that occur in children with immunoglobulin deficiency syndromes are caused by bacterial organisms or microbes. Certain of these invasive organisms form capsules when they enter the body, a mechanism used to confuse the immune system. In a healthy body with an adequately functioning immune system, immunoglobulin antibodies bind to the capsule and overcome the bacterias defenses. Streptococci, meningococci, and Haemophilus influenzae , organisms that cause diseases such as otitis media , sinusitis , pneumonia ...
modified with decent to adapt to their environment another statement at 100% conflict with any number of statements by leading evolutionists. Evolution has no direction, no purpose, no plan it is the product of random mutation at the genetic level giving rise to totally unplanned changes in the organisms form and function. The environment then is either hostile to or supportive of those changes and the organism is either as a species more reproductively successful or it is made extinct. In no sense does the organism adapt to the environment in fact the environment adapts it either to continued life or to death, as a species ...
With these matters in mind, what I wish to convey is that stem cells can obey various inputs in the terrestrial cogniscium. It is unclear precisely what the hierarchy of sources is, but we may imagine that up near the top of the local group is the Sun, the Earth, and the moon (as a force if not a cogniscium of its own). The Sun certainly comprises a cogniscium since it is intimately connected to every life form on Earth both by history and by actively existing transports. Thus, the organisms of Earth probably have the capacity to experience actually prophetic awareness and, where possible, understanding - related to opportunities, threats, and questions raised by changes in the broadest local scales of inputs. In other words, organisms form the distributed mind of a being whose basic character we are in no position to even begin to model - and, to make matters more complex, we are each, and in groups, instances of this being as well as participants. This means that our actions, thoughts, ...
With these matters in mind, what I wish to convey is that stem cells can obey various inputs in the terrestrial cogniscium. It is unclear precisely what the hierarchy of sources is, but we may imagine that up near the top of the local group is the Sun, the Earth, and the moon (as a force if not a cogniscium of its own). The Sun certainly comprises a cogniscium since it is intimately connected to every life form on Earth both by history and by actively existing transports. Thus, the organisms of Earth probably have the capacity to experience actually prophetic awareness and, where possible, understanding - related to opportunities, threats, and questions raised by changes in the broadest local scales of inputs. In other words, organisms form the distributed mind of a being whose basic character we are in no position to even begin to model - and, to make matters more complex, we are each, and in groups, instances of this being as well as participants. This means that our actions, thoughts, ...
Anthrax is a disease that is no stranger to the human race. It can be traced back to Biblical times and is the oldest known disease of animals. Moses mentions it in Exodus and so do Homer, Ovid, Pliny, and Virgil in their writings. Obviously, this disease has been around. It has many names, such as woolsorters disease, splenic fever, charbon in French, Milzbrand in German, and malignant pustule. Anthrax was the first infectious disease that a vaccine was found to be effective against by Louis Pasteur in 1881. The studies of Anthrax in the 18th century are the foundation for the science of bacteriology and immunology. Anthrax is an infectious disease caused by the organism Bacillus anthracis. In certain conditions, this organism forms virulent spores that are highly resistant and contaminate soil or other materials for years. Anthrax is most common in grass grazing animals such as cows and sheep but all animals can t get Anthrax. It can be passed on to a person who handles wool, hides, or carcass ...
...Blacksburg Va. Dec. 4 2006 -- From gemstones to transistors crysta...One ongoing question is how organisms form these mineralized structure...In the December 4-8 2006 online Early Edition of the Proceedings of ...,Scientists,uncover,speedometer,for,crystal,growth,controlled,by,biomolecule,properties,biological,biology news articles,biology news today,latest biology news,current biology news,biology newsletters
Leaving aside the troublesome adjective, what is the modernism that the Altenburg meeting is meant to move beyond - or to use Pigliuccis preferred term, extend1? Between about 1920 and 1940, researchers such as the American Sewall Wright and the Englishmen Ronald Fisher and J. B. S. Haldane took Charles Darwins ideas about natural selection and Gregor Mendels insights into how traits pass from parents to offspring - which many biologists of the time believed antithetical - and fused them into a mathematical description of the genetic makeup of populations and how it changes. That fusion was the modern synthesis. It treats an organisms form, or phenotype, as a readout of its hereditary information, or genotype. Change is explained as one version of a gene being replaced by another. Natural selection acts by changing the frequency of genes in the next generation according to the fitness of phenotypes in this one. In this world view, the gene is a black box, its relationship to phenotype is a ...
Archaea exist in a broad range of habitats, and as a major part of global ecosystems,[14] may represent about 20% of microbial cells in the oceans.[159] The first-discovered archaeans were extremophiles.[112] Indeed, some archaea survive high temperatures, often above 100 °C (212 °F), as found in geysers, black smokers, and oil wells. Other common habitats include very cold habitats and highly saline, acidic, or alkaline water. However, archaea include mesophiles that grow in mild conditions, in swamps and marshland, sewage, the oceans, the intestinal tract of animals, and soils.[14]. Extremophile archaea are members of four main physiological groups. These are the halophiles, thermophiles, alkaliphiles, and acidophiles.[160] These groups are not comprehensive or phylum-specific, nor are they mutually exclusive, since some archaea belong to several groups. Nonetheless, they are a useful starting point for classification.. Halophiles, including the genus Halobacterium, live in extremely saline ...
Archaea are nowadays known as the third domain of life. Before 1970 archaea were thought to belong to the domain bacteria, since archaeal cells have similar sizes as bacterial cells and like bacteria possess neither a nucleus nor cell organelles. In the 1970s Carl Woese sequenced ribosomal RNAs of prokaryotic organisms and discovered two different types of rRNA sequences. Because of this discovery Woese proposed that the prokaryotic domain has to be subdivided into two separate domains, namely Bacteria and Archaea. Since then more and more data accumulated which show that Archaea indeed belong to a separate domain. Initially people thought that archaea are freaks living only at sites with extreme living conditions like f.i. hot geysers in Yellowstone National Park and Black Smokers at the bottom of the ocean. But nowadays it is known that archaea also constitute a big part of the biomass in normal environments. Asgard archaea: Close relatives to the first eukaryotic cell? ...
Emerging virus discovery through meta-transcriptomics: a novel virus impacting Rainbow Trout (Oncorhynchus mykiss) farming in Chile.
Archaea exist in a broad range of habitats, and as a major part of global ecosystems,[15] may represent about 20% of microbial cells in the oceans.[161] The first-discovered archaeans were extremophiles.[114] Indeed, some archaea survive high temperatures, often above 100 °C (212 °F), as found in geysers, black smokers, and oil wells. Other common habitats include very cold habitats and highly saline, acidic, or alkaline water. However, archaea include mesophiles that grow in mild conditions, in swamps and marshland, sewage, the oceans, the intestinal tract of animals, and soils.[15]. Extremophile archaea are members of four main physiological groups. These are the halophiles, thermophiles, alkaliphiles, and acidophiles.[162] These groups are not comprehensive or phylum-specific, nor are they mutually exclusive, since some archaea belong to several groups. Nonetheless, they are a useful starting point for classification.. Halophiles, including the genus Halobacterium, live in extremely saline ...
Over the last decades, the study of extremophiles has providing ground breaking discoveries that challenge the paradigms of modern biology and make us rethink intriguing questions such as what is life?, what are the limits of life?, and what are the fundamental features of life?. These findings and possibilities have made the study of life in extreme environments one of the most exciting areas of research in recent decades. However, despite the latest advances we are just in the beginning of exploring and characterizing the world of extremophiles. This special issue discusses several aspects of these fascinating organisms, exploring their habitats, biodiversity, ecology, evolution, genetics, biochemistry, and biotechnological applications in a collection of exciting reviews and original articles written by leading experts and research groups in the field. [...]
Our division studies the Biology of Archaea as well as bacterial symbioses with a focus on ecological, physiological and evolutionary aspects to shed light on the diversity and fundamental distinctions between these two prokaryotic groups. In particular we are interested in: - The ecological distribution of archaea from terrestrial, aquatic and hot environments - The phylogeny of archaea - The metabolism and genomes of ammonia oxidizing thaumarchaeota - virus-defense (CRISPR-) systems of hyperthermophilic archaea - physiology and biotechnological application of methanogenic archaea - bacterium-nematode symbioses ...
Our division studies the Biology of Archaea as well as bacterial symbioses with a focus on ecological, physiological and evolutionary aspects to shed light on the diversity and fundamental distinctions between these two prokaryotic groups. In particular we are interested in: - The ecological distribution of archaea from terrestrial, aquatic and hot environments - The phylogeny of archaea - The metabolism and genomes of ammonia oxidizing thaumarchaeota - virus-defense (CRISPR-) systems of hyperthermophilic archaea - physiology and biotechnological application of methanogenic archaea - bacterium-nematode symbioses ...
Previous work has explored the use of bacteria as biosensors to report information from their environments. However, these efforts have typically used electrochemical or optical properties of well-characterized strains in response to defined targets that are generally metabolized. In contrast, this study built on previous analyses of the relationships between bacterial communities and their environments (8, 30) to show that, with appropriate training data and analytical models, natural bacterial communities can be used as biosensors for a diverse array of geochemical measurements, including many which are not directly metabolized. There is no need for prior knowledge of the relevant strains or pathways-these are identified as a product of the statistical models employed.. In this effort, we have focused on samples collected from within a single geographic area. Future efforts should prioritize the evaluation of biosensors trained in one environment against data collected from a similar ...
Domain Archaea is currently represented by one phylum (Euryarchaeota) and two superphyla (TACK and DPANN). However, gene surveys indicate the existence of a vast diversity of uncultivated archaea for which metabolic information is lacking. We sequenced DNA from complex sediment- and groundwater-associated microbial communities sampled prior to and during an acetate biostimulation field experiment to investigate the diversity and physiology of uncultivated subsurface archaea. We sampled 15 genomes that improve resolution of a new phylum within the TACK superphylum and 119 DPANN genomes that highlight a major subdivision within the archaeal domain that separates DPANN from TACK/Euryarchaeota lineages. Within the DPANN superphylum, which lacks any isolated representatives, we defined two new phyla using sequences from 100 newly sampled genomes. The first new phylum, for which we propose the name Woesearchaeota, was defined using 54 new sequences. We reconstructed a complete (finished) genome for an ...
Archaea is a single-celled micro-organism that lives underwater and in soil. A single individual or species is called an archaeon (sometimes spelled "archeon"). Archaea, like bacteria, are prokaryotes. They have no cell nucleus or any other organelles within their cells. In the past they were viewed as an unusual group of bacteria and named archaebacteria but since the Archaea have an independent evolutionary history and show many differences in their biochemistry from other forms of life, they are now classed into their own group. They have been found in a broad range of habitats, such as soils, lakes, oceans, and marshlands. Archaea are particularly numerous in the oceans, and the archaea in plankton may be one of the most abundant groups of organisms on the planet. These prokaryotes are now recognized as a major part of life on Earth and may play an important role in both the carbon cycle and nitrogen cycle. No clear examples of archaeal pathogens or parasites are known. ...
Beneficial changes in rumen bacterial community profile in sheep and dairy calves as a result of feeding the probiotic Bacillus amyloliquefaciens ...
View Notes - 22 from BIOL 4125 at LSU. PROKARYOTIC DIVERSITY BIOL 4125 SPRING 2009 LECTURE 22 Hyperthermophilic Archaea Part II The early overview of archaeal diversity was exemplified by a
Abstract: Fresh fruits and vegetables can harbor large and diverse populations of bacteria. However, most of the work on produce-associated bacteria has focused on a relatively small number of pathogenic bacteria and, as a result, we know far less about the overall diversity and composition of those bacterial communities found on produce and how the structure of these communities varies across produce types. Moreover, we lack a comprehensive view of the potential effects of differing farming practices on the bacterial communities to which consumers are exposed. We addressed these knowledge gaps by assessing bacterial community structure on conventional and organic analogs of eleven store-bought produce types using a culture-independent approach, 16 S rRNA gene pyrosequencing. Our results demonstrated that the fruits and vegetables harbored diverse bacterial communities, and the communities on each produce type were significantly distinct from one another. However, certain produce types (i.e., ...
Ti Archaea ket buklen ti domimio wenno pagarian dagiti agmaymaysa a selula a mikroorganismo. Dagitoy a mikrobio ket awananda ti pagtengngaan a selula wenno dagiti dadduma pay a mangbedbed a kulanit nga organulo iti kaunegan dagiti selula. Iti napalabas ti Archaea ket naiklase idi kadagiti bakteria a kas dagiti prokaryote (wenno Pagarian ti Monera) ken nanganan iti archaebakteria, ngem daytoy a pannakaidasig ket naikeddengen a duog.[5] Iti kinapudno, ti Archaea ket adda ti nawaya nga ebolusionario a pakasaritaan ken mangipakpakita kadagiti adu a paggigiddiatan kadagiti bukodda a biokimika manipud kadagiti sabali a porma ti biag, ken isu a tattan ket naidasigda a kas maysa a nailasin a dominio iti sistema ti tallo a dominio. Iti daytoy a sistema, ti maipapan ti pilohenetiko a naisangayan a sangsanga iti ebolusionario a tinaudan ket ti Archaea, Bakteria ken ti Eukaryota. Itan ket ti Archaea ket nabingbingay pay kadagiti uppat a mabigbigan a pilo; mabalin pay nga adu kadagiti pilo ti mabangon ...
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Life Science: Protists -eukaryotic micro-organisms whose cells have a nucleus. Text book summary notes with links to a related rap song, free mp3 download, & lyrics.
Bacteria help our bodies with digestion and produce needed vitamins. Bacteria also help us by destroying harmful organisms within our bodies.. There are more bacterial cells in your body than there are human cells.. Most bacteria reproduce using a process called binary fission. To do this, a single bacterium will grow to twice its normal size and then split into two daughter cells. The two new cells are exact copies of the original bacterium.. Bacteria are used to make cheese, milk, sourdough bread and yogurt.. 99% of all bacteria are helpful.. Dead or weakened bacteria and viruses are used for making helpful vaccines.. Scientists estimate that bacteria produce nearly half the oxygen found in the atmosphere.. Helpful bacteria are used to purify water at sewage treatment plants and to break down oil after oil spills.. One healthy bacterium, given the proper environment, could reproduce into a colony of more than 2 million in just seven hours.. There are more microbes on your body than there ...
Dr. Sayeed Ahmad D. I. Hom. (London). Bacteria are simple organisms that consist of one cell. They are among the smallest living things. Most bacteria measure from 0.3 to 2.0 microns in diameter and can be seen only through a microscope. (One micron equals 0.001 millimeter or 1/25,400 inch.) Scientists classify bacteria as prokaryotes.. Bacteria exist almost everywhere. There are thousands of kinds of bacteria, most of which are harmless to human beings. Large numbers of bacteria live in the human body but cause no harm. Some species cause diseases, but many others are helpful.. The importance of bacteria. Helpful bacteria. Certain kinds of bacteria live in the intestines of human beings and other animals. These bacteria help in digestion and in destroying harmful organisms. Intestinal bacteria also produce some vitamins needed by the body.. Bacteria in soil and water play a vital role in recycling carbon, nitrogen, sulfur, and other chemical elements used by living things. Many bacteria help ...
Many studies on bacterial community composition (BCC) do not distinguish between particle-associated (PA) and free-living (FL) bacteria or neglect the PA fraction by pre-filtration removing most particles. Although temporal and spatial gradients in environmental variables are known to shape BCC, it remains unclear how and to what extent PA and FL bacterial diversity responds to such environmental changes. To elucidate the BCC of both bacterial fractions related to different environmental settings, we studied surface samples of three Baltic Sea stations (marine, mesohaline and oligohaline) in two different seasons (summer and fall/winter). Amplicon sequencing of the 16S rRNA gene revealed significant differences in BCC of both bacterial fractions among stations and seasons, with a particularly high number of PA operational taxonomic units (OTUs at genus-level) at the marine station in both seasons.
What: Academic Seminar, Dr. Emma Allen Vercoe, Department of Molecular and Cellular Biology at the University of Guelph Topic: Understanding gut microbial community dynamics using an in vitro bioreactor model When: Monday, August 14, 10:30-11:30 a.m. Where: Robert B. Schultz Lecture Theatre
Since protozoa are eukaryotic organisms, they contain vacuoles, a cell membrane and all the other cellular machinery found in the cells of plants, fungi, animals and other eukaryotes. For example, protozoa use their cell membrane and vacuoles for food absorption and digestion. Their cell membranes assist in the engulfing of food and their vacuoles can give off useable nitrogen during digestion. Generally, protozoa feed on other organic matter, bacteria, fungi and other protozoans in some cases.. Protozoa are not a huge concern when it comes to human illnesses because they are usually harmless. With this being said however, protozoa are the cause of malaria and dysentery. Malaria is a disease transmitted by mosquitoes, but these infected mosquitoes carry a microorganism from the genus Plasmodium, in which five specific species are infectious. Protozoa are truly remarkable microorganisms. They are capable of reproducing by the process of fission, they can move in a variety of ways despite having ...
This bacterium can be airborne so if you are around someone with TB, then there is a good chance that you will get it as well. When you do, the bacterium enters and if you have a strong immune system, you may not notice the disease right away because your immune is fighting off the bacteria. when the bacteria cant take over, it starts to reproduce more of its kind and sooner or later, your immune system wont stand a chance against the bacteria. As this battle continues, bacteria reproduces its kind to make a large group.When the immune system cannot take anymore, the bacteria invades and since there are so many bacteria cells, it is like an explosion of disease in the body. The macrophage are phagocytic cells and if they cant kill the bacteria, then the bacteria will replicate by cell division until the macrophage bursts. The bacteria are then taken over by the macrophage and soon the bacteria is being eaten by macrophage in the bloodstreams. The bacteria spreads into the bloodstream but the ...
TY - JOUR. T1 - Optimization of conditions for culture of test bacteria used for direct bioautographic TLC detection. 2. Gram-negative test bacterium. T2 - Escherichia coli. AU - Nagy, Sándor. AU - Koszegi, Tamás. AU - Botz, Lajos. AU - Kocsis, Béla. PY - 2003/3/1. Y1 - 2003/3/1. N2 - Direct bioautography is a potent means of obtaining information about the antimicrobial activity of a compound separated from a complex mixture. In this process the developed TLC plate is dipped into a broth culture of a test bacterium and the bacterium will grow directly on the plate. Optimum experimental conditions must, however, be used for each test bacterium. The main purpose of this study was to find optimum culture conditions for a Gram-negative test bacterium, Escherichia coli (ATCC 25922) enabling us to establish a direct bioautographic method with the shortest possible performance time. Because the intracellular adenosine-5′-triphosphate (ATP) level is a direct and sensitive measure of bacterial ...
Collections of Clusters of Orthologous Genes (COGs) provide indispensable tools for comparative genomic analysis, evolutionary reconstruction and functional annotation of new genomes. Initially, COGs were made for all complete genomes of cellular life forms that were available at the time. However, with the accumulation of thousands of complete genomes, construction of a comprehensive COG set has become extremely computationally demanding and prone to error propagation, necessitating the switch to taxon-specific COG collections. Previously, we reported the collection of COGs for 41 genomes of Archaea (arCOGs). Here we present a major update of the arCOGs and describe evolutionary reconstructions to reveal general trends in the evolution of Archaea. The updated version of the arCOG database incorporates 91% of the pangenome of 120 archaea (251,032 protein-coding genes altogether) into 10,335 arCOGs. Using this new set of arCOGs, we performed maximum likelihood reconstruction of the genome content of
Although I am fully convinced of the truth of the views given in this volume, I by no means expect to convince experienced naturalists whose minds are stocked with a multitude of facts all viewed, during a long course of years, from a point of view directly opposite to mine. It is so easy to hide our ignorance under such expressions as "plan of creation," "unity of design," etc., and to think that we give an explanation when we only restate a fact. Any one whose disposition leads him to attach more weight to unexplained difficulties than to the explanation of a certain number of facts will certainly reject the theory. ...
ATCC offers a variety of extremophiles including archaea, halophiles, acidophiles, thermophiles, psychrophiles, and alkaliphiles.
ATCC offers a variety of extremophiles including archaea, halophiles, acidophiles, thermophiles, psychrophiles, and alkaliphiles.
Household biogas digesters are widely used to harvest energy in rural areas of developing countries. Understanding core prokaryotic communities, their co-occurrence patterns, and their relationships to environmental factors is important to manage these small-scale anaerobic digestion systems effectively. In this study, 43 household biogas digesters were collected across eight provinces in China. Prokaryotic communities were investigated using 454 pyrosequencing of 16S rRNA genes. Fourteen core genera and ten core OTUs were identified in household biogas digesters. They were mainly affiliated with the phylum Firmicutes, Synergistetes, Actinobacteria, Chloroflexi, and Spirochaetes. Core prokaryotic genera were mainly composed of Clostridium, Clostridium XI, Syntrophomonas, Cloacibacillus, Sedimentibacter, and Turicibacter. Prokaryotic communities in the 43 samples were clearly divided into two clusters. Cluster I was dominated by Clostridium, while Cluster II was dominated by members of Spirochaetes,
Introduction. Experiment 4 Title : The Determination of Microbial Numbers Objectives: * Practically every phase of microbiology requires method for measuring microbial numbers. * Study the theoretical relationship of one bacterial cell, or clump of cells. * Study the effect of dilution to the bacteria growth. * Determine the cell masses of a culture in order estimates the total cellular protoplasm per milliliter of culture. * To learn both quantitative plating methods which are spread plate and pour plate to measure the number of bacteria. * To understand the measurement for the number bacteria by performing plate and dilution count. Result and Observations: Part I: Spread Plate Unlabelled sample - Dilution factor 10-1 Sample A - Dilution factor 10-2 Sample B - Dilution factor 10-3 Sample C - Dilution factor 10-4 Observation: According to the observation, the result is showed that the colonies of E.coli cultures are too numerous to count via normal visible with density diminish from sample A to ...
Here are my 5 cents worth of opinion concerning the Postinggs from L.A. Maron ,CnsIqJ.MDz at gpu.utcc.utoronto.ca, lamoran at gpu.utcc.utoronto.ca (L.A. Moran): There are many characters (not only 16S rRNAs) which separate Archae- and Eubacteria (see Zillig et al., 1992, for a listing). With many molecular markers the Archaebacteria appear closer to the Eukaryotes (e.g.: ATPases, elongation factors, RNA polymerases). Not all of these molecular markers show the Archaebacteria as a monophyletic group, in some analyses they appear paraphyletic; however, the branch that separates the two archaebacterial groups is very short (as is the branch that connects the 16S rRNA of the Archaebacteria to the other 16SrRNAs). Based only on nucleotide data it will be difficult to discriminate between the para and monophyletic origin of the archaebacteria. Rivera and Lake report a higher order character (a deletion/insertion) that unites only some of the archaebacteria with the eukaryotes. I think that one of the ...
In nitritationammox reactors, several bacterial groups contribute to the overall nitrogen conversion. Knowing the activity of the main bacterial groups, especially of anaerobic ammonium-oxidising bacteria (AMX), is extremely helpful to understand the process and optimise its operation. Mass balances of dissolved compounds such as ammonium, nitrite and nitrate commonly allow the determination of bacterial activities in a nitritationammox process, but the activity of heterotrophic bacteria (HET) is usually neglected. However, even in wastewater with a low organic substrate content, heterotrophic denitrification can contribute substantially to nitrogen removal. The goal of this study was to critically evaluate the applicability of mass balances for the determination of the relevant bacterial activities in a nitritationammox process with high HET activity. We set up and solved mass balances of different degrees of complexity. Both linear equation systems, with catabolic reactions alone and with ...
One of the three domains of life (together with Bacteria and Eukaryotes). Their morphology is similar to bacteria but many cellular mechanisms are actually closer to eukaryotic than bacterial. They form a distinct clade in the phylogenetic analysis based on the 16S rRNA sequence. Archaea are at least as far from bacteria as from eukaryotes (there is a lot of discussion about exactly what the "tree of life" looks like) but they are often placed with bacteria into the common grouping called prokaryotes. Originally they were discovered in extreme environments and thus are still often thought of as extremophiles. Now archaea are known to be very common in nature, being a dominating group of microorganisms for example in oceans below the photic zone. --Katarzyna Zaremba 15:00, 27 February 2008 (CET) ...
Pterocystis heliozoan. Coloured scanning electron micrograph (SEM) of Pterocystis a freshwater protozoan. This single-celled organism has many projections, known as axopods, radiating from its cell body. The axopods are used to capture prey and for movement. In this species the axopods are funnel shaped. Magnification: x 3000 when printed at 10cm wide. Specimen collected from Vietnam courtesy of Mike Allen, Plymouth Marine Laboratory. - Stock Image C036/0565
This chapter provides a brief summary of a classification system for medically important bacteria, based on a traditional phenotypic approach. The primary focus is on organisms that are significant causes of disease in the tropics and subtropics.
Light microscopy of two heliozoa (white), with extended axopods radiating from their cell surface. Heliozoa are amoeba-like protozoa common in all aquatic environments. The axopods aid them in detecting and engulfing prey, which they do by phagocytosis. Filmed with Darkfield illumination. - Stock Video Clip K003/3275
So the subject of this lecture is RNase P in the other branch of life on Earth; the Archaea. The Archaea are a group of prokaryotic organisms that are really independent of the Bacteria, and if anything are more closely related geneologically to the eukaryotes (Eukarya) than to the Bacteria. In addition to being a distinct group, they are generally primative. In many ways, the molecular biology of the Archaea probably resembles those of the ancestors of the eukaryotes, and have proven to be very useful in sorting out the simpler roots of modern eukaryotic complexity.. ...