专业词汇

Glossary

actinomycetes A group of filamentous, funguslike bacteria.

active transport Nutrient transport method that requires carrier proteins in the membranes of the living cells and the expenditure of energy.

adenovirus Nonenveloped DNA virus; means of transmission is human-to-human via respiratory and ocular secretions.

aerobe A microorganism that lives and grows in the presence of free gaseous oxygen (O2).

aerobic respiration Respiration in which the final electron acceptor in the electron transport chain is oxygen (O2).

agar A polysaccharide found in seaweed and commonly used to prepare solid culture media.

AIDS Acquired immunodeficiency syndrome. The complex of signs and symptoms characteristic of the late phase of human immunodeficiency virus (HIV) infection.

algae Photosynthetic, plant-like organisms which generally lack the complex structure of plants; they may be single-celled or multicellular, and inhabit diverse habitats such as marine and freshwater environments, glaciers, and hot springs.

Ames test A method for detecting mutagenic and potentially carcinogenic agents based upon the genetic alteration of nutritionally defective bacteria. ammonification Phase of the nitrogen cycle in which ammonia is released from decomposing organic material.

anaerobe A microorganism that grows best, or exclusively, in the absence of oxygen. anaerobic respiration Respiration in which the final electron acceptor in the electron transport chain is an inorganic molecule containing sulfate, nitrate, nitrite, carbonate, etc.

antagonism Relationship in which microorganisms compete for survival in a common environment by taking actions that inhibit or destroy another organism. antibiotic A chemical substance from one microorganism that can inhibit or kill another microbe even in minute amounts.

archaea Prokaryotic single-celled organisms of primitive origin that have unusual anatomy, physiology and genetics, and live in harsh habitats; when capitalized (Archaea) the term refers to one of the three domains of living organisms as proposed by Woese.

arthrospore A fungal spore formed by the septation and fragmentation of hyphae. ascospore A spore formed within a saclike cell (ascus) of Ascomycota following nuclear fusion and meiosis.

ascus Special fungal sac in which haploid spores are created.

autoclave A sterilization chamber which allows the use of steam under pressure to sterilize materials. The most common temperature/pressure combination for an autoclave is 121℃and 15 psi.

autotroph A microorganism that requires only inorganic nutrients and whose sole source of carbon is carbon dioxide.

bacillus Bacterial cell shape that is cylindrical (longer than it is wide).

back-mutation A mutation which counteracts an earlier mutation, resulting in the restoration of the original DNA sequence.

bacteria Category of prokaryotes with peptidoglycan in their cell wails and a single, circular chromosome. This group of small cells is widely distributed in the earth’s habitats.

Bacteria (plural of bacterium) When capitalized can refer to one of the three domains of living organisms proposed by Woese, containing all non- archaea prokaryotes. bacterial chromosome A circular body in bacteria that contains the primary genetic material. Also called nucleoid.

bacteriophage A virus that specifically infects bacteria.

bacterium A tiny unicellular prokaryotic organism that usually reproduces by binary fission and usually has a peptidoglycan cell wall, has various shapes, and can be found in virtually any environment.

basidiospore A sexual spore that arises from a basidium. Found in basidiomycota fungi.

bdellovibrio A bacterium that preys on certain other bacteria. It bores a hole into a specific host and inserts itself between the protoplast and the cell wall. There it elongates before subdividing into several cells and devouring the host cell. capsule In bacteria, the loose, gel-like covering or slime made chiefly of simple polysaccharides. This layer is protective and can be associated with virulence. Chemoautotroph An organism that relies upon inorganic chemicals for its energy and carbon dioxide for its carbon. Also called a chemolithotroph. chemoheterotroph Microorganisms that derive their nutritional needs from organic compounds.

chemotaxis The tendency of organisms to move in response to a chemical gradient (toward an attractant or to avoid adverse stimuli).

chitin A polysaccharide similar to cellulose in chemical structure. This polymer makes up the horny substance of the exoskeletons of arthropods and certain fungi.

chromosome The tightly coiled bodies in cells that are the primary sites of genes. clone A colony of cells (or group of organisms) derived from a single cell (or single organism) by asexual reproduction. All units share identical characteristics. Also used as a verb to refer to the process of producing a genetically identical population of cells or genes.

colony A macroscopic cluster of cells appearing on a solid medium, each arising from the multiplication of a single cell.

commensalism An unequal relationship in which one species derives benefit without harming the other.

conjugation In bacteria, the contact between donor and recipient cells associated with the transfer of genetic material such as plasmids. Can involve special (sex) pili.

Also a form of sexual recombination in ciliated protozoans.

death phase End of the cell growth due to lack of nutrition, depletion of environment, and accumulation of wastes. Population of cells begins to die.

decomposition The breakdown of dead matter and wastes into simple compounds, that can be directed back into the natural cycle of living things.

diffusion The dispersal of molecules, ions, or microscopic particles propelled down a concentration gradient by spontaneous random motion to achieve a uniform distribution.

diploid Somatic cells having twice the basic chromosome number. One set in the pair is derived from the father, and the other from the mother.

direct, or total cell count 1. Counting total numbers of individual cells being viewed with magnification. 2. Counting isolated colonies of organisms growing on a plate of media as a way to determine population size.

endospore A small, dormant, resistant derivative of a bacterial cell that germinates under favorable growth conditions into a vegetative cell. The bacterial genera Bacillus and Clostridium are typical sporeformers.

eubacteria Term used for non-archaea prokaryotes, stands for "true bacteria" eucaryotie cell A cell that differs from a prokaryotic cell chiefly by having a nuclear membrane (a well-defined nucleus), membrane-bounded subcellular organelles, and mitotic cell division.

Eukarya One of the three domains (sometimes called superkingdoms) of living organisms, as proposed by Woese; contains all eukaryotic organisms. eutrophication The process whereby dissolved nutrients resulting from natural seasonal enrichment or industrial pollution of water cause overgrowth of algae and cyanobacteria to the detriment of fishand other large aquatic inhabitants. fermentation The extraction of energy through anaerobic degradation of substrates into simpler, reduced metabolites. In large industrial processes, fermentation can mean any use of microbial metabolism to manufacture organic chemicals or other products.

fimbria A short, numerous surface appendage on some bacteria that provides adhesion but not locomotion.

flagellum A structure that is used to propel the organism through a fluid environment. gene A site on a chromosome that provides information for a certain cell function. A specific segment of DNA that contains the necessary code to make a protein or RNA molecule.

generation time Time required for a complete fission cycle－from parent cell to two new daughter cells. Also called doubling time.

genome The complete set of chromosomes and genes in an organism.

genotype The genetic makeup of an organism. The genotype is ultimately responsible for an organism's phenotype, or expressed characteristics.

Gram stain A differential stain for bacteria useful in identification and taxonomy.

Gram-positive organisms appear purple from crystal violet- mordant retention, whereas gram-negative organisms appear red after loss of crystal violet and absorbance of the safranin counterstain.

growth curve A graphical representation of the change in population size over time.

This graph has four periods known as lag phase, exponential or log phase, stationary phase, and death phase.

growth factor An organic compound such as a vitamin or amino acid that must be provided in the diet to facilitate growth. An essential nutrient.

halophile A microbe whose growth is either stimulated by salt or requires a high concentration of salt for growth.

haploid Having a single set of unpaired chromosomes, such as occurs in gametes and certain microbes.

host Organism in which smaller organisms or viruses live, feed, and reproduce. human immunodeficiency virus (HIV) A retro virus that causes acquired immunodeficiency syndrome (AIDS).

intron The segments on split genes of eucaryotes that do not code for polypeptide.

They can have regulatory functions. See exon.

in vitro Literally means "in glass," signifying a process or reaction occurring in an artificial environment, as in a test tube or culture medium.

in vivo Literally means “in a living being,” signifying a process or reaction occurring in a living thing.

Koch’s postulates A procedure to establish the specific cause of disease. In all cases of infection: ( 1 ) The agent must be found; (2) inoculations of a pure culture must reproduce the same disease in animals; (3) the agent must again be present in the experimental animal: and (4) a pure culture must again be obtained.

lag phase The early phase of population growth during which no signs of growth occur.

L form L-phase variants; wall-less forms of some bacteria that are induced by drugs or chemicals. These forms can be involved in infections.

lipopolysaceharide A molecular complex of lipid and carbohydrate found in the bacterial cell wall. The lipopolysaccharide (LPS) of gram-negative bacteria is an endotoxin with generalized pathologic effects such as fever.

log phase Maximum rate of cell division during which growth is geometric in its rate of increase. Also called exponential growth phase.

meiosis The type of cell division necessary for producing gametes in diploid organisms. Two nuclear divisions in rapid succession produce four gametocytes, each containing a haploid number of chromosomes.

minimum inhibitory concentration (MIC) The smallest concentration of drug needed to visibly control microbial growth.

minimum temperature The lowest temperature at which an organism will grow. missense mutation A mutation in which a change in the DNA sequence results in a different amino acid being incorporated into a protein, with varying results. mitosis Somatic cell division that preserves the somatic chromosome number. mycelium The filamentous mass that makes up a mold. Composed of hyphae. mycorrhizae Various species of fungi adapted in an intimate, mutualistic relationship to plant roots.

nitrification Phase of the nitrogen cycle in which ammonium is oxidized.

nitrogen fixation A process occurring in certain bacteria in which atmospheric N2 gas is converted to a form (NH4) usable by plants.

nonsense mutation A mutation that changes an amino acid-producing codon into a

stop codon, leading to premature termination of a protein.

nucleus The central core of an atom, composed of protons and neutrons.

obligate Without alternative; restricted to a particular characteristic. Example: An obligate parasite survives and grows only in a host; an obligate aerobe must have oxygen to grow; an obligate anaerobe is destroyed by oxygen.

optimum temperature The temperature at which a species shows the most rapid growth rate.

parasite An organism that lives on or within another organism (the host), from which it obtains nutrients and enjoys protection. The parasite produces some degree of harm in the host.

passive transport Nutrient transport method that follows basic physical laws and does not require direct energy input from the cell.

pasteurization Heat treatment of perishable fluids such as milk, fruit juices, or wine to destroy heat-sensitive vegetative cells, followed by rapid chilling to inhibit growth of survivors and germination of spores. It prevents infection and spoilage. pathogen Any agent, usually a virus, bacterium, fungus, protozoan, or helminth, that causes disease.

phage A bacteriophage; a virus that specifically parasitizes bacteria.

phenotype The observable characteristics of an organism produced by the interaction between its genetic potential (genotype) and the environment. photoautotroph An organism that utilizes light for its energy and carbon dioxide chiefly for its carbon needs.

pill Small, stiff filamentous appendages in gram-negative bacteria that function in DNA exchange during bacterial conjugation.

plasmids Extrachromosomal genetic units characterized by several features. A plasmid is a double-stranded DNA that is smaller than and replicates independently of the cell chromosome; it bears genes that are not essential for cell growth; it can bear genes that code for adaptive traits; and it is transmissible to other bacteria.

polysaccharide A carbohydrate that can be hydrolyzed into a number of monosaccharides. Examples: cellulose, starch, glycogen.

prion A concocted word to denote “proteinaceous infectious agent”; a cytopathic protein associated with the slow-virus spongiform encephalopathies of humans and animals.

prophage A lysogenized bacteriophage; a phage that is latently incorporated into the host chromosome instead of undergoing viral replication and lysis.

protoplast A bacterial cell whose cell wall is completely lacking and that is vulnerable to osmotic lysis.

protozoa A group of single-celIed, eucaryotic organisms.

pseudohypha A chain of easily separated, spherical to sausage-shaped yeast cells partitioned by constrictions rather than by septa.

pure culture A container growing a single species of microbe whose identity is known.

retrovirus A group of RNA viruses (including HIV) that have the mechanisms for

converting their genorne into a double strand of DNA that can be inserted on a host’s chromosome.

reverse transeriptase The enzyme possessed by retrovimses that carries out the reversion of RNA to DNA a form of reverse transcription.

rhizobia Bacteria that live in plant roots and supply supplemental nitrogen that boosts plant growth.

rhizosphere The zone of soil, complete with microbial inhabitants, in the immediate vicinity of plant roots.

rickettsias Medically important family of bacteria, commonly carried by ticks, lice, and fleas. Significant cause of important emerging diseases.

root nodules Small growths on the roots of legume plants that arise from a symbiotic association between the plant tissues and bacteria (Rhizobia). This association allows fixation of nitrogen gas from the air into a usable nitrogen source for the plant.

silent mutation A mutation that, because of tire degeneracy of the genetic code, results in a nucleotide change in both the DNA and mRNA but not the resultant amino acid and thus, not the protein.

spore A differentiated, specialized cell form that can be used for dissemination, for adverse conditions, and/or for reproduction.Spores are usually unicellular and may develop into gametes or vegetative organisms.

stationary growth phase Survival mode in which cells either stop growing or grow very slowly.

sterilization Any process that completely removes or destroys all viable microorganisms, including viruses, from an object or habitat. Material so treated is sterile.

strict, or obligate anaerobe An organism which does not use oxygen gas in metabolism and cannot survive in oxygen’s presence.

symbiosis An intimate association between individuals from two species; used as a synonym for mutualism.

synergism The coordinated or correlated action by two or more drugs or microbes that results in a heightened response or greater activity.

temperate phage A bacteriophage that enters into a less virulent state by becoming incorporated into the host genome as a prophage instead of in the vegetative or lytic form that eventually destroys the cell.

template The strand in a double stranded DNA molecule which is used as a model to synthesize a complementary strand of DNA or RNA during replication or transcription.

thermal death point The lowest temperature that achieves sterilization in a given quantity of broth culture upon a 10-minute exposure. Examples: 55℃for Escherichia coli, 60℃for Mycobacterium tuberculosis, and 120℃for spores. thermal death time The least time required to kill all cells of a culture at a specified temperature.

thermophile A microorganism that thrives at a temperature of 50℃or higher.

transcription mRNA synthesis; the process by which a strand of RNA is produced against a DNA template.

transduction The transfer of genetic material from one bacterium to another by means of a bacteriophage vector.

transformation In microbial genetics, the transfer of genetic material contained in “naked” DNA fragments from a donor cell to a competent recipient cell. transposon A DNA segment with an insertion sequence at each end, enabling it to migrate to another plasmid, to the bacterial chromosome, or to a bacteriophage. vibrio A curved, rod-shaped bacterial cell.

virulence In infection, the relative capacity of a pathogen to invade and harm host cells.

zygospore A thick-walled sexual spore produced by the zygomycete fungi. It develops from the union of two hyphae, each bearing nuclei of opposite mating types.

人名

微生物学必记的拉丁文学名

细菌

假单胞菌属Pseudomonas

固氮菌属Azotobacter

根瘤菌属Rhizobium

慢生根瘤菌属Bradyrhizobium

醋杆菌属Acetobacter

螺菌属Spirillum

沙门氏菌属Salmonella

大肠杆菌Escherichia coli

欧文氏菌属Erwinia

沙雷氏菌属Serratia(又叫赛氏杆菌)

粘质沙雷氏菌Serratia marcescens(又叫粘质赛氏杆菌) 变形杆菌属Proteus

发酵单胞菌属Zymnomonas

拟杆菌属Bacteroides

弧菌属Vibrio

蛭弧菌属Bdellovibrio

韦荣氏球菌属Veillonella

脱硫弧菌属Desulfovibrio

立克次氏体属Rickettsia

衣原体属Chlamydia

支原体属Mycoplasma

密螺旋体属Treponema

球衣菌属Sphaerotilus

柄杆菌属Caulobacter

浮霉状菌属Planctomyces

贝日阿托菌属Beggiatoa

黏球菌属Myxococcus

着色菌属Chromatium

绿菌属Chlorobium

鱼腥蓝细菌属Anabaena

满江红鱼腥蓝细菌Anabaena azollae

念珠蓝细菌属Nostoc

螺旋蓝细菌属Spirulina

硫杆菌属Thiobacillus

土壤杆菌属Agrobacterium

亚硝化单胞菌属Nitrosomonas

硝酸杆菌属Nitrobacter

葡萄球菌属Staphylococcus

金黄色葡萄球菌属Staphylococcus aureus 八叠球菌属Sarcina

微球菌属Micrococcus

明串珠菌属Leuconostoc

消化球菌属Peptococcus

链球菌属Streptococcus

肺炎球菌Streptococus pneumoniae 奈氏球菌属Neisseria

乳杆菌属Lactobacillus

芽胞杆菌属Bacillus

苏云金芽胞杆菌Bacillus thuringiensis

枯草芽胞杆菌Bacillus subtilis

炭疽芽胞杆菌Bacillus anthracis

梭菌属Clostridium

丙酸杆菌属Propionibacterium

棒状细菌属Corynebacterium

双歧杆菌属Bifidobacterium

分枝杆菌属Mycobacterium

诺卡氏菌属Nocardia

链霉菌属Streptomyces

弗兰克氏菌属Frankia

小单胞菌属Micromonospora

高温放线菌属Thermoactinomyces

马杜拉放线菌属Actinomadura

古细菌

甲烷杆菌属Methanobacterium

甲烷球菌属Methanococcus

盐杆菌属Halobacter

盐球菌属Halococcus

热网菌属Pyrodictium

热原体属Themoplasma

真菌

裂殖酵母属Schizosaccharomyces

酵母属Saccharomyces

酿酒酵母Saccharomyces cerevisiae 汉逊酵母属Hansenula

红酵母Rhodotorula

假丝酵母属Candida

球拟酵母属Torulopsis

绵霉属Achlya

毛霉属Mucor

根霉属Rhizopus

葡枝根霉（黑根霉）Rhizopus stolonifer

脉胞菌属Neurospora

银耳属Tremella

伞菌属Agaricus

香菇属Lentinus

木耳属Auricularia

平菇Pleurotus ostreatus

曲霉属Aspergillus

青霉属Penicillium

藻类

小球藻属Chlorella

水绵属Spirogyra

羽纹硅藻属Pinnularia

舟形藻属Navicula

原生动物

眼虫属Euglena

变形虫属Amoeba

草履虫属Paramecium

疟原虫属Plasmodium

病毒

慢病毒属Lentivirus引起HIV

核型多角体病毒属Nucleopolyhedrovirus

烟草花叶病毒属Tobamovirus

T4噬菌体属T4-like viruses

马铃薯纺锤形块茎类病毒属Pospivioid

羊搔痒因子Scrapie agent