1. 미생물의 종류와 특성

2. Archaea (고세균) Archaea (archaeon)
3 domains : Bacteria, Archaea, Eukaryota
(Archaebacteria : outdated)
Similar to bacteria
Single celled
Procaryotic : circular chromosome
no nucleus, no membrane-bound organelles
Size & Shape : generally similar to bacteria
Ribosome : 70S
Asexual Reproduction :
binary fission, fragmentation, or budding
(no spore formation)
Energy source
autotrophic, phototrophic, heterotrophic
ammonia, metal ions, hydrogen gas

3. Archaea (archaeon) Similar to eucaryotes
Gene : intron (tRNA, rRNA), histone,
Transcription & translation
RNA polymerase not inhibited by rifampin
1st AA of proteins : methionine
Ribosome inhibited by anisomycin
(but not by kanamycin & chloramphenicol)
Unique
Cell membrane : ether-linked lipids
Cell wall : pseudopeptidoglycan

4. Archaea (archaeon) Broad range of habitats
Extremophiles : thermophilic, halophilic, …
(hot springs, salt lakes)
No clear examples of pathogens or parasites
Phyla
Crenarchaeota :
Euryarchaeota :
Korarchaeota Nanoarchaeota Thaumarchaeota

5. Phylogenetic Relationships among Bacteria, Archaea and Eukaryotae

6. Phylogenetic Relationships Among the Procaryotes

7. Bacteria Proteobacteria : Gram (-) Firmicutes : Low G+C Gram (+)
Actinobacteria : High G+C Gram (+)
Others

8. Phylum Proteobacteria
a major group (phylum) of gram-negative bacteria
1987 Carl Woese
"purple bacteria and their relatives"
Proteus : Greek god of the sea capable of assuming
many different shapes
include a wide variety of pathogens
Escherichia, Salmonella, Vibrio, Helicobacter, Yersinia
5 (6) Classes
Alphaproteobacteria
Betaproteobacteria
Gammaproteobacteria
Deltaproteobacteria
Epsilonpeoteobacteria
(Zetaproteobacteria)

9. Proteobacterial clades
Alphaproteobacteria
Brucella, Rickettsia, Rhizobium, Agrobacterium,
Caulobacter, Wolbachia, …
Betaproteobacteria
Bordetella, Neisseria, Burkholderia, Alcaligenes,
Nitrosomonas, Methylophus, Ralstonia, …
Gammaproteobacteria : the largest group
Escherichia, Shigella, Salmonella, Yersinia,
Legionella, Haemophilus, Vibrio, Pseudomonas, …
Deltaproteobacteria
Desulfovibrio, Geobacter, Bdellovibrio, …
Epsilonproteobacteria
Helicobacter, Campylobacter, Wolinella, …
Zetaproteobacteria
Mariprofundus ferrooxydans (from hydrothermal vent)

10. Phylum Firmicutes Firmicutes
. firmus, (L) strong + cutis, (L) skin (cell wall)
. Low G+C Gram (+)
Coccus or Bacillus
Many produce endospores
. Class
Bacilli
Clostridia
Mollicutes
Erysipelotrichi
Negativicutes
Thermolithobacteria

11. Firmicutes Class Bacilli Class Clostridia Class Mollicutes
Bacillus, Phaenibacillus, Staphylococcus, Listeria,
Lactobacillus, Pediococcus, Lactococcus, Leuconostoc,
Streptococcus, Enterococcus, …
Class Clostridia
Clostridium, Helicobacterium, Veillonella,
Epulopiscium, Desulfotomaculum, …
Class Mollicutes
No cell wall :
mollis, (L) "soft" or "pliable“ + cutis (L), skin
Mycoplasma, Ureaplasma, Spiroplasma, …

12. Phylum Actinobacteria
Actinobacteria (phylum, class)
. Actinomyces vs. Actinobacteria
hyphae, spore
. High G+C Gram-positive bacteria
The G+C content can be as high as 70%
. Abundant in soil ; geosmin
might be more abundant in freshwaters
. Antibiotics & other bioactive metabolites
. Streptomyces, Actinomyces, Nocardia, Arthrobacter,
Propionibacterium, Bifidobacterium, Cellulomonas
Corynebacterium, Mycobacterium, …

13. Fungi (진균) 진균 (Fungus – Fungi) . Eucaryotic microorganism
. 효모(yeast) : 단세포 (unicellular)
곰팡이(mold): 다세포, 균사상 (multicellular, filamentous)
* 이형성 진균 (dimorphic fungi)
. 광합성 못함 : 화학합성 종속영양(chemooheterotrophic)
대부분 부생성 (saprobes) : hydrolytic enzymes
식물 병원균 많음 (plant pathogens)
동물, 사람 병원균 : 약 150종
. 세포벽 : chitin, β-glucan 포함
. 무성 및 유성 생식 (Asexual & Sexual reproduction)

14. 곰팡이 (mold)

15. 곰팡이 (mold) 다세포 균사상 진균 (사상균) 균사(Hyphae) : tubular
multicellular, mycelial fungi
균사(Hyphae) : tubular
무격벽 균사 (nonseptate or coenocytic hyphae)
다핵세포(multinucleate, coenocytic cell)
유격 균사 (septate hyphae)
격벽(격막) vs 세포벽(막)
균사체(Mycelium) : widely branched
균총(Mycelial mat, colony) : mycelium + fruiting body
* 균핵(sclerotium, sclerotia) : 저항성 강함
영양체(vegetative body) : 균사 (hyphae)
자실체(fruiting body) : 포자(spore)와 그 지지체
* 버섯(mushroom) : 담자균류의 자실체

16. 곰팡이의 증식 진핵세포 : 무성증식, 유성생식, (준유성생식) 무성증식(Asexual reproduction)
무성(불완전)세대 (Asexual, Imperfect stage, Anamorph)
균사생장 : 균사의 정점생장 (apical growth)
무성포자 : 증식과 전파의 수단
포자형성기관 :
분생포자 (Conidiospore, conidium)
포자낭포자 (Sporangiospore)
균사가 직접 포자로 : Thallospores
분절포자 (Arthrospore)
후막포자 (Chlamydospore)
배아포자 (Blastospore)

17. 곰팡이의 무성포자(Asexual spores)

18. 유성생식 (sexual reproduction) : 유성포자 형성
유성(완전)세대 (sexual phase, perfect stage, telemorph)
배우자 (gamate), 접합자 (zygote) 형성
감수분열 (meiosis),
원형질 융합(plasmogamy), 핵 융합 (karyogamy)
Homothallic sexual reproduction
Heterothallic sexual reproduction
유성포자 :
접합포자(zygospore) : 접합균문(Zygomycota)
자낭포자(ascospore) : 자낭균문(Ascomycota)
담자포자(basidiospore) : 담자균류(Basidiomycota)

20. 불완전균류 (Fungi imperfecti, Deuteromycota)
Holomorph : 진균의 완전한 생활사
anamorph + telemorph
불완전균류 (Fungi imperfecti, Deuteromycota)
No sexual spore formation (No telemorph)
Ascomycetes (Basidiomycetes)
Parasexual reproduction : no spore formation
Chytridiomycota (병꼴균류문)
Zoospore (운동성 유주자)

21. 효모 (Yeast)
Yeast infection Saccharomyces cerevisiae

22. 효모 (yeast) 단세포 진균 (unicellular fungi) 대부분 구형 또는 타원형
주로 당(sugar)이 많은 곳에 서식
알코올 발효능력을 가진 것이 많음
무성증식과 유성생식(유성포자 형성)
무성증식 : 대부분 출아(budding)에 의해
출아흔(bud scar), 출아연결
가균사(위균사, pseudohyphae) - Candida
진균사(true mycelium) – Endomycopsis
유성생식 : 유성포자 형성
자낭포자 : Ascomycetes)
사출포자 : Basidiomycetes

23. 이형성 진균(fungal dimorphism)
Candida albicans, Penicillium marneffei
At room temperature : mycelial form (mold)
At 37℃ : unicellular form (yeast)
Several species are potential pathogens

24. 지의류 (Lichens)
공생 (Symbiotic)
곰팡이
광합성 생물 : 조류, 남세균

25. 조류 (Algae) Protista (원생생물) : Algae, Protozoa 광합성 (photosynthesis)
이산화탄소 동화, 산소 공급, 먹이(식물성 플랑크톤), 석유
* 만약에 조류가 없어진다면?
엽록소와 기타 색소 함유 ; 녹조류, 갈조류, 홍조류, …
Cell wall polysaccharide
대부분 수생 (aquatic)
녹조현상, 적조현상
* 조류 독소
단세포 (unicellular)
다세포 (multicellular) : colonial
filamentous
plantlike

26. Volvox Chlorella

27. Algae 녹조류 (Chlorophyta, Green algae) 갈조류 (Phaeophyta, Brown algae)
홍조류 (Rhodophyta, Red algae)
규조류 (Bacillariophyta, Diatoms)
와편모조류 (Dinoflagellata) : Red tide
난형점균류 (Oomycota) : water mold

28. 원생동물 (Protozoa) 진핵세포 (eucaryotic cell) : Protista 단세포 (unicellular)
대부분 세포벽 없음
대부분 운동성 있음 – 분류의 기준
아메바류, 섬모충류, 선모충류, 편모충류
피낭체 (Cyst) (Encystment, Excystment)
휴지기 상태에 형성하는 주머니 모양의 세포 구조
보호막 역할

29. Amoeba Tripanosoma gambiensis (African sleeping sickness) Trichomonas vaginalis Giardia lamblia (Gastroenteritis) Didiniium consuming Paramecium Paramecium in conjugation

30. Protozoa Archaezoa : Microspora Amoebozoa : Apicomplexa :
Trichomonas vaginalis, Giardia lamblia
Microspora
Amoebozoa :
Entamoeba histolytica, Acanthamoeba
Apicomplexa :
Plasmodium, Toxoplasma gondii
Cillophora (섬모충류)
Euglenozoa :
Euglena (phothosynthetic or heterotrophic)
Hemoflagellate :
Trypanosoma, Leishmania

31. Euglena

33. Virus Virus : organism at the edge of life Latin, poison
Adolf Mayer
Tobacco Mosaic Disease (TMD) : transferable
Dmitri Ivanovsky
TMD : Filtrable, Non-bacterial pathogen
Martinus Beijerinck
Causative agent for TMD : Virus
the agent multiplied only in cells that were dividing
contagium vivum fluidum : viruses are liquid in nature
1935 Wendell Stanley
Virus : particulate
Isolation of TMV : nucleoprotein
1935 Friedrich Loeffler, Paul Frosch
first animal virus : agent of foot-and-mouth disease

34. Virus Virus Non-cellular microorganism Submicroscopic size, filterable
Obligate parasite
a small infectious agent that replicates
only inside the living cells of other organisms
Host-specific
animal virus
plant virus
bacterial virus (bacteriophage, phage)
Virion
stable infective viral particle
fully capable of infecting other cells

35. Virus Virus particle (virion) Core : Genetic material, DNA or RNA
Enzymes for replication
Capsid : protein coat
Protomers - Capsomers : self-assembly
Helical (Spiral), Icosahedral, Complex
Envelope : lipids, enzymes
Non-enveloped (naked virus) : Nucleocapsid
Enveloped virus :
from host - nuclear or cell membrane (lipovirus)
attachment

36. Influenza virus
고병원성 vs 저병원성 : H (Hemagglutinin)
N (Nuraminidase)

37. Viral Replication Only inside the living cells
1. 부착, 흡착(Attachment, Adsorption)
2. 침투∙탈피 (Penetration & Uncoating)
3. 생합성(Biosynthesis)
4. 조립∙포장(Assembly & Packaging, Maturation, 성숙)
5. 방출(Release)

38. Viral Replication 1. 부착, 흡착(Attachment, Adsorption)
Host specificity (숙주 특이성)
virus : adsorption site (흡착부위)
host cell : receptor site (수용체) on surface
glycoprotein, O-antigen, surface protein
2. 침투 (Penetration or Entry)
Penetration (Injection, 주입)
phage, viral genome only
Endocytosis (내포작용)
capsid + 핵산 (Uncoating, 세포 내에서 탈피)
most animal viruses
Fusion : viral envelope + cell membrane

39. 동물바이러스의 세포내흡입과정

40. 3. 생합성(Biosynthesis) : genome, protein
Enzyme synthesis : enzymes for genome replication, …
Genome replication :
Proteins synthesis : protomers (capsomers)
Viral genome replication
. ds DNA
. ss DNA
. ds RNA
. (+) ss RNA with mRNA function
. (-) ss RNA
. (+) ss RNA with no mRNA function : reverse transcription
. Partially ds DNA : reverse transcription

41. 5. 방출(Release) 4. 조립∙포장(Assembly & Packaging) 자가조립 (self-assembly)
capsid
encapsidation
성숙 (maturation)
Eclipse period (소실기, 암흑기)
5. 방출(Release)
Non-enveloped vs Envelovped
방출량(burst size)
용균반점(plaque)

42. * 세포병변효과 (cytopathic effect, CPE) 바이러스에 감염된 숙주세포에 나타나는 형태와 구조의 변화 세포분열의 정지, 봉입체(inclusion body) 형성 세포질 융합 (syncytium formation), 접촉저지 현상 (contact inhibition)의 소멸 항원 변화 (antigenic change), interferon 생산

43. Lytic & Lysogenic cycle
Virus
virulent virus (병원성) : 용균성 생활환 (Lytic cycle)
temperate virus (잠재성) : 용균성 & 용원성 생활환 (Lysogenic cycle)
용균성 생활환(lytic cycle)
감염(infection)
용원성 생활환(lysogeny)
virus의 유전물질이 숙주세포 염색체의 일부로 존재
provirus(prophage)
lysogenic bacterium
면역(immunity)
유도(induction)
provirus가 숙주세포의 염색체에서 떨어져 나옴 ⇒ 용균성 생활환

44. Horizontal Gene Transfer (HGT)
형질변환(Phage conversion, Lysogenic conversion)
provirus의 유전자에 의해 숙주세포의 형질이 바뀌는 현상
Corynebacterium diphtheriae : 디프테리아 독소
Clostridium botulinum : botox
Horizontal Gene Transfer (HGT)

45. Viral Taxonomy Classification based on phenotypic characteristics
morphology, nucleic acid type, mode of replication,
host organisms, type of disease
ICTV system
The International Committee on Taxonomy of Viruses
International Union of Microbiological Societies
Based on :
types of nucleic acid
strandedness (ss, ds)
positive(sense) or negative(antisense) strand RNA
envelope
viral morphology and symmetry of capsid
mode of replication

46. ICTV system Phylum : Virus Order : -virales Family : viridae
Subfamily : -virinae
Genus : -virus
Species : [Disease] virus
* names of orders and families are italicized

47. ICTV system (7 orders + α)
Caudovirales : tailed dsDNA (group I) bacteriophages
Herpesvirales : large eukaryotic dsDNA viruses
Ligamenvirales : linear, dsDNA (group I) archaean viruses
Mononegavirales : nonsegmented (-) strand ssRNA (Group V)
plant and animal viruses
Nidovirales : (+) strand ssRNA (Group IV) viruses
with vertebrate hosts
Picornavirales : small (+) strand ssRNA viruses that infect
a variety of plant, insect and animal hosts
Tymovirales : monopartite (+) ssRNA viruses that infect plants
Virus families not assigned to an order 

48. Viral Taxonomy - Baltimore classification
Seven groups (I ~ VII)
Based on the method of mRNA synthesis
nucleic acid (DNA/RNA)
strandedness (ss/ds)
positive(sense) or negative(antisense) strand RNA
mode of replication ; reverse transcription, replication
I : dsDNA viruses : Adenoviruses, Herpes viruses, Poxviruses
II : ssDNA viruses : Parvoviruses
III : dsRNA viruses : Reoviruses
IV : (+) ssRNA viruses : Picornaviruses, Togaviruses
V : (−) ssRNA viruses : Orthomyxoviruses, Rhabdoviruses
VI : (+) ssRNA-RT viruses - replicate thru a DNA intermediate,
(reverse transcription involved) : Retroviruses
VII : dsDNA-RT viruses - replicate thru an ss RNA intermediate,
(reverse transcription involved) : Hepadnaviruses

49. Non-cellular particles
Viroid
single stranded RNA circle not encoding for any proteins
No capsid, No envelope
Replication : rolling circle mechanism, RNA polymerase
Infectious agent : plant diseases
Virusoid
single stranded RNA circle encoding for proteins
Need helper virus for infection
Human hepatitis D virus (helper virus : hepatitis B virus)

50. Non-cellular particles
Prion
Proteinaceous infectious particle : PrP (prion protein)
PrPc (normal), PrPsc (sc : scrapie) : differ in conformation
Degenerative disease of central nerve system
Creutzfeldt-Jacob disease (CJD)
Bovine spongiform encephalopathy (BSE, 광우병)
Fatal familial insomnia