微生物学重要名词解释(英英).docx

U11Adaptive immunityrefers to antigen-specific immuneresponse. Theadaptive immune response is more complex than the innate. The antigen first must be processed and recognized. Once an antigen has been recognized, the adaptive immunesystem creates an army of immunecells specifically designed to attack that antigen.Immunoglobulins(抗体), also known as antibodies, are glycoprotein molecules produced by plasma cells (white blood cells). They act as a critical part of the immune response by specifically recognizing and binding to particular antigens, such as bacteria or viruses and aiding in their destruction.Antigen, any substance that causes your immune system to produce antibodies against it. Anantigenmay be a foreign substance from the environment, such as chemicals, bacteria, viruses, or pollen. Anantigenmay also be formed inside the body, as with bacterial toxins or tissue cells.Anepitope(表位), also known as antigenic determinant(抗原决定簇), is the part of an antigen that is recognized by the immune system, specifically by antibodies, B cells, or T cells. For example, theepitopeis the specific piece of the antigen that an antibody binds to.Haptens(半抗原)are small molecules that elicit(引出) an immune response only when attached to a large carrier such as a protein; the carrier may be one that also does not elicit an immune response by itself.Immune complex, sometimes called an antigen-antibodycomplex, is a molecule formed from the integral binding of an antibody to a soluble antigen. The bound antigen and antibody act as a unitary object, effectively an antigen of its own with a specific epitope.Innate host resistance(先天性宿主抵抗力), compare to adaptive immunityEndotoxin A toxin produced by certain bacteria and released upon destruction of the bacterial cell.Exotoxin a toxin released by a living bacterial cell into its surroundings.Pathogenicityrefers to the ability of an organism to cause disease (ie, harm the host). This ability represents a genetic component of the pathogen and the overt damage done to the host is a property of the host-pathogen interactions. Commensals(共栖) and opportunistic pathogens lack this inherent ability to cause disease.Toxoid(类毒素) bacterial toxin (usually an exotoxin) whose toxicity has been inactivated or suppressed either by chemical (formalin) or heat treatment, while other properties, typically immunogenicity, are maintained.U10Amensalism(偏害共栖), association between organisms of two different species in which one is inhibited(抑制) or destroyed and the other is unaffected.Commensalism(偏利共栖), in ecology, is a class of relationships between two organisms where one organism benefits from the other without affecting it.Compromised host, a patient with acquired or congenital(先天的) immunologic deficiency at increased risk for infectious disease complications.Cooperation, the action or process of working together to the same end.Mutualism(互利共栖), the way two organisms of different species exist in a relationship in which each individual benefits from the activity of the other. Similar interactions within a species are known as co-operation.Normal microbiota(正常微生物群), microorganisms that reside on the surface and deep layers of skin, in the saliva and oral mucosa(口腔黏液膜), in the conjunctiva(结膜), and in the gastrointestinal(胃肠的) tracts of every human being.Opportunistic pathogen/microorganism(条件致病微生物) organism that is capable of causing disease only when the hosts resistance is lowered, for example, by other diseases or drugs.Parasitism a form of living in which two organisms that are phylogenically different (unrelated) co-exist over a long period of time (usually for the lifetime of one of the individuals).Predation is a biological interaction where a predator (an organism that is hunting) feeds on its prey (the organism that is attacked).Symbiosis(from Greek together and living) is close and often long-term interaction between two different biological species.U9Domain(also superregnum, superkingdom, empire, or regio) is the highest taxonomic rank of organisms in the three-domainsystem of taxonomy designed by Carl Woese, an American microbiologist and biophysicist.Genus a taxonomic rank used in the biological classification of living and fossil organisms in biology. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature(命名), the genus name forms the first part of the binomial species name for each species within the genus.GC-content(or guanine-cytosinecontent) the percentage of nitrogenous bases on a DNA molecule that are either guanine or cytosine (from a possibility of four different ones, also including adenine and thymine).Polyphasic classification(多相分类) a consensus approach to bacterial systematics via more than one phase.Aspeciesis often defined as the largest group of organisms where two individuals are capable of reproducing fertile offspring (hybrids), typically using sexual reproduction.Strain(biology), variants of plants, viruses or bacteria; or an inbred(选种产生的) animal used for experimental purposes.Type strainis thestrain, which was used when the species was described for the first time and which was selected by the author as the type strain. Astraindesignation including superscript T (e.g. B78T) shows the thestrainis atype strain.Chlamydia a very small parasitic bacterium that, like a virus, requires the biochemical mechanisms of another cell in order to reproduce. Bacteria of this type cause various diseases including trachoma(沙眼), psittacosis(鹦鹉热), and nonspecific urethritis(尿道炎).The elementary body(EB原体) the nonreplicating infectious particle that is released when infected cells rupture(破裂).The reticulate body(RB网状体) anintracytoplasmic(胞质内)form, highly involved in the process of replication and growth of these bacteria.Chlamydiae exist as two stages: (1) infectious particles called elementary bodies and (2) intracytoplasmic, reproductive forms calledreticulate bodies.Mycoplasma is a genus of bacteria that lack a cell wall around their cell membrane. Without a cell wall, they are unaffected by many common antibiotics such as penicillin or other beta-lactam(内酰胺) antibiotics that target cell wall synthesis.Rickettsia(立克次氏体) a genus of nonmotile(不能动), Gram-negative, nonspore-forming, highly pleomorphic(可变形) bacteria that can present as cocci, rods, or thread-like.Cyanobacteria, also known as Cyanophyta, is a phylum of bacteria that obtain their energy through photosynthesis. The name cyanobacteria comes from the color of the bacteria. They are often called blue-green algae.Heterocyst(异生胞) differentiated cyanobacterial cell that carries out nitrogen fixation. The heterocystsfunction as the sites for nitrogen fixation under aerobic conditions. They are formed in response to a lack of fixed nitrogen (NH4 or NO3).Fruiting bodya multicellular structure on which spore-producing structures, such as basidia(担子体) or asci(子囊孢子), are born.Fruiting bodymay also refer to:Fruiting body(bacteria), the aggregation(聚合体) of myxobacterial(粘液性细菌) cells when nutrients are scarce.Myxobacteria(粘液性细菌) a group of bacteria that predominantly live in the soil and feed on insoluble organic substances. The myxobacteria have very large genomes, relative to other bacteria, e.g. 910 million nucleotides.Myxospore spore formed by myxobacteria.Actinobacteria(放线菌) a phylum of Gram-positive bacteria with high guanine and cytosine content in their DNA. The G+C content of Actinobacteria can be as high as 70%, though some may have a low G+C content. They can be terrestrial(地生) or aquatic(水生).Methanogens microorganisms that produce methane as a metabolic byproduct in anoxic conditions. They are classified as archaea, a domain distinct from bacteria.Haloarchaea a kind of the achaea, found in water saturated(饱和) or nearly saturated with salt.Pseudopeptidoglycan(假肽聚糖also known aspseudomurein) is a major cell wall component of some archaea that differs from bacterial peptidoglycan in chemical structure, but resembles eubacterial peptidoglycan in morphology, function, and physical structure.Hypha(plural hyphae, from Greek , huph, “web”) is a long, branching filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium(菌丝体).Mycelium the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed ofmyceliumare found in and on soil and many other substrates.Septate(有隔膜的) Hyphae with cross-walls.Sporagium a receptacle(容器) in which asexual spores are formed.Gametanium a specialized organ or cell in which gametes are formed in algae, ferns, and some other plants.Ascomycete(子囊菌) a fungus whose spores develop within asci. The ascomycetes include most molds, mildews, and yeasts, the fungal component of most lichens, and a few large forms such as morels and truffles.Ascospore(子囊孢子) a spore contained in an ascus or that was produced inside an ascus. This kind of spore is specific to fungi classified as ascomycetes (Ascomycota). Typically, a single ascus will contain eightascospores. The eight spores are produced by meiosis followed by a mitotic division.Basidiomycete(担子菌) a fungus whose spores develop in basidia. Basidiomycetes include the majority of familiar mushrooms and toadstools.Basidiospore(担孢子) spore produced by bysidium.Zygomycete(接合菌) A class of fungi that usually has a coenocyte(多核的) mycelium with chitinous cell walls.Zygospore the thick-walled resting cell of certain fungi and algae, arising from the fusion of two similar gametes.U8Cloning vector(克隆载体) a small piece of DNA, taken from a virus, a plasmid, or the cell of a higher organism, that can be stably maintained in an organism, and into which a foreign DNA fragment can be inserted forcloningpurposes.Expression vector(表达载体), otherwise known as an expressionconstruct, is usually a plasmid or virus designed for proteinexpressionin cells. Thevectoris used to introduce a specific gene into a target cell, and can commandeer the cells mechanism for protein synthesis to produce the protein encoded by the gene.Genetic engineering(GE) the modification(修改)of an organismsgenetic composition by artificial means, often involving the transfer of specific traits, orgenes, from one organism into a plant or animal of an entirely different species.Genomic library a collection of the total genomicDNA from a single organism. The DNA is stored in a population of identical(同一的) vectors, each containing a different insert of DNA.Polymerase chain reaction(PCR) a technology in molecular biology used to amplify(放大) a single copy or a few copies of a piece of DNA across several orders of magnitude(等度), generating thousands to millions of copies of a particular DNA sequence.Restriction enzymes, also known asrestriction endonucleases, areenzymesthat cut a DNA molecule at a particular place. They are essential tools for recombinant DNA technology. Theenzyme scans a DNA molecule, looking for a particular sequence, usually of four to six nucleotides.Recombinant DNA technology: A series of procedures that are used to join together (recombine)DNAsegments. Arecombinant DNA molecule is constructed from segments of two or more differentDNA molecules.Metagenomics(宏基因组学)is the study of genetic material recovered directly from environmental samples. The broad field may also be referred to as environmental genomics, ecogenomics or community genomics.U7Ames test a widely employed method that uses bacteria totest whether a given chemical can cause mutations in the DNA of thetest organism. More formally, it is a biological assay(鉴定) to assess the mutagenic potential of chemical compounds.Auxotroph(营养缺陷型)an organism that unable to synthesize a particular organic compound required for its growth.Conjugationis the transfer of genetic material betweencells by direct cell-to-cell contact or by a bridge-like connection between two cells.The Fertility/Ffactor(first namedFby one of its discoverers Esther Lederberg) allows genes to be transferred from one bacterium carrying thefactorto another bacterium lacking thefactorby conjugation. TheF factoris carried on theFepisome(因子副体), the first episome to be discovered.F-plasmid, orF-factor is a prototypical conjugativeplasmidwhich is an episome (aplasmidthat can integrate itself into the bacterial chromosome by homologous recombination) with a length of about 100 kb.A high-frequency recombination cell (Hfrcell) (also called anHfr strain) is a bacterium with a conjugative plasmid (often the F-factor) integrated(嵌合) into its genomic DNA. TheHfr strainwas first characterized by Luca Cavalli-Sforza.Prototroph(原养型) having the same metabolic capabilities and nutritional requirements as the wild type parent strain.Reverse mutation the reversion of amutantto the original phenotype(表现型). Contemporarydefinitionsforreverse mutationExpand. A mutationthat causes a gene to revert to its original wild or original type; also called backmutation.Specialized transduction(局限性转导)is the process by which a restricted set of bacterial genes is transferred to another bacterium. The genes that get transferred (donor给予体 genes) depend on where the phage genome is located on the chromosome.Transduction the process by which DNA is transferred from one bacterium to another by a virus. It also refers to the process whereby foreign DNA is introduced into another cell via a viral vector.Transformation the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material (exogenous DNA外源基因) from its surroundings and taken up through the cell membrane(s).Wild type(WT) a strain, gene, or characteristic that prevails(占上风) among individuals in natural conditions, as distinct from an atypical mutant type.U6Lithoautotroph a microbe which derives energy from reduced compounds of mineral origin. They may also be referred to as chemolithoautotrophs, a type of lithotrophs, reflecting their autotrophic metabolic pathways.Photoautotroph any organism that derives its energy for food synthesis from light and is capable of using carbon dioxide as its principal source of carbon. Chemoorganotroph an organism that depends on organic chemicals for its energy and carbon.Photoheterotrophs heterotrophic phototrophsthat is, they are organisms that use light for energy, but cannot use carbon dioxide as their sole carbon source.Aerobic respiration a type of respiration in which oxygen is taken in and carbon dioxide and water are produced; also, the use of oxygen in the breakdown of foodstuffs to create energy.Anaerobic respirationis a form ofrespirationusing electron acceptors other than oxygen. Although oxygen is not used as the final electron acceptor, the process still uses a respiratory electron transport chain; it isrespirationwithout oxygen. Denitrification/ Dissimilatory nitrate reduction(硝酸盐异化还原) the loss or removal of nitrogen or nitrogen compounds; specifically: reduction of nitrates or nitrites commonly by bacteria (as in soil) that usually results in the escape of nitrogen into the air.Fermentation(发酵)is a metabolic process that converts sugar to acids, gases or alcohol. It occurs in yeast and bacteria, and also in oxygen-starved muscle cells, as in the case of lactic acid(乳酸)fermentation.Nitrificationis the biological oxidation of ammonia or ammonium to nitrite followed by the oxidation of the nitrite to nitrate. The transformation of ammonia to nitrite is usually the rate limiting step ofnitrification. Nitrificationis an important step in the nitrogen cycle in soil.Nitrifying bacteria chemoautotrophic or chemolithotrophs depending on the genera (genus pl.) bacteria that grow by consuming inorganic nitrogen compounds.Respirationa catabolic(分解代谢的) process where the microorganisms convert biochemical energy from nutrients into Adenosine Tripohsphate(ATP).U5Acidophilesoracidophilicorganisms are those that thrive under highly acidic conditions (usually at pH 2.0 or below). These organisms can be found in different branches of the tree of life, including Archaea, Bacteria, and Eukaryotes.Aerobic organism or aerobe an organism that can survive and grow in an oxygenated environment.Alkaliphilesare microorganisms that grow optimally or very well at pH values above 9, often between 10 and 12, but cannot grow or grow slowly at the near-neutral pH value of 6.5.Anaerobic organism oranaerobe any organism that does not require oxygen for growth. It may react negatively or even die if oxygen is present.Batch cultureA technique used to grow microorganisms or cells. A limited supply of nutrients for growth is provided; when these are used up, or some other factor becomes limiting, theculturedeclines. Cells, or products that the organisms have made, can then be harvested from the culture.Biofilm(生物膜) any group of microorganisms in which cells stick to each other on a surface. These adherent cells are frequently embedded within a self-produced matrix of extracellular polymeric substance (EPS, 外细胞聚合物).Chemostat(from chemical environment is static, 恒化器) a bioreactor to which fresh medium is continuously added, while culture liquid containing left over nutrients, metabolic end products and microorganisms is continuously removed at the same rate to keep the culture volume constant.Colony-forming unit(CFU) a unit used to e