University:
Brigham Young University
Course:
MMBIO 221 | General Microbiology
Academic year:

2023
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253

Pages:

29
Author:

3AstralArtisan

CHAPTER-I "BACTERIA"- Introduction (Discovery) → Antonie van Leeuwenhoek of Holland firest discovered bacteria in rain drop and tartark of teeth. →He described micro-oropinions are "streaks and threads" animacicules. →Linnaeus called them as" verems!" →Antonie dan Leeuwenhoek called as "Father of microbiology. → Christian G. Ehrenberg Ehrent first to coin the terem Babteria. → Louis parterne discovered" that bacteria were the cause of Some diseases. This facts coas come comed "Gerry theory of Disease". Genersace Charecteristics & Baderia Bacteria are the smallest & the simplest of all diving organitens → They are cosmopolitan in distribution że deur in every alere. They are basically unicentiare, but may be colonial or filamentous. Structurally they aree prokaryotte ceus cwith outer envelop enclosing protoplarm... ceee envelop includes outers most gliocalyx (simple layer on capsule), middle ces coale and inner cex membrane (foramma membrane). Except mycoplasma, cete wale y present in all composed of musein on peptidoglycan. →True nucreus and true chromosomes are absent. Instead, alingra naked Circular DNA 4 locmed located in the zone of Cytoplasm Called nucreoid or Genophore ore Incipient nucleus. → Some passess extranorean είπευιαπ episomes. DNA called flarmids ore → Genes of bacteria are not interrupted by introons. → Cytoplarm contain 70s reibosomes, mesosomes, and Storage granules Present but chondria membrane bound organees like foor fuastide, mito- ies etc. are absent, Golgi bodice Cyanobacteria. except thylakoidy in →Surface appendages like fiagelna (fore locomotion)," (for adhesion) or pirei fere (conjugation) are pretend Fimbriae Cap va coules ang absent. Nutrition may be photoautotrophic chemo auto trophie, saprotrophic and parasitic. They reproduce by binary Aission, bodding and sporulation. →Typice sexuere, neprocuction is missing in bacteria. In Steid genetic recombination occurss. Bacteria con exist even in the absence of oxygen and with standard temperature as low as 17°C anel as 80°C. Structure of Bacterial cere The structure of malterial ces can be dicassed under the headings: (4) Capsule and siisme layer. (B) Suckuce appendages cem wall. ( cele membrane (E) The Cytofolatm (F) The Genome Nociecare body (A) Capsule & filme layer ~~ The capsove, orcsime layer & known as glycocalyx ahose literae. Is sugar coat. → of & the outermost covering formed in most bacteria. It is a network of polysaccharides. when these ayer yin the form of loose Sheath then it is called ay Slime layer and cehen it is in the forem of thick and tough Sheath then it y called as capsule.. Function of capsule 9t protects bacteria and forems adefensin defensive mechanism. →gt acts as osmotic barrier, reserve food in adverse environ Mental Condition. It protects against attacks from balterio bacterine viruses. (8) Surface Appendages There are some external Structure of the cele, These ane called as Sorefare appendages and may be flagella, fimbriacon pili. (a) Flagella The most prominently obsercbed external structures protruding from the cere cwall Thay motifility ane responsible for balterial fertility Shelp to swim! In eigend. ← → A Flagellum has - a chip like filament, amotor complex and a hack tee that connects these two. firament →filament & 20 nm diameter and made up of many proto filaments. →fach proto filaments contecins thousand of filament flagellin suto enfts. (b) Fimbrae, Pili and spinae There are short, fine and hair Dike Surface Structure in bacterioc There are non-locomotive Structure. These arce dry sean under the electron microscope. Bach fimbza e ly made up of a protein called plein. timbra e help in attaching to substrates, help in foreminy biofilms heip in transfer of genetic materials, andinfeed case help in gliding motion. → sex pili are a type of fimbrae which are longer than the normal fimbrae. →ame once tus sex pilei ane fand and theire presence & geneticany determined. Pile help in foremation of Conjugation bridge. → Spine are rrigid haig appendages fanding some tome gram the bacteria. Each ping made adjust to environmental condition. epof spinin. They hat to (e) cell cocell in Bacteria) ty a rigid Structure present inner to capsule ore Prime layer. →ty made up of morrein or peptidoglycan. ✓ of gives shape and structure support to the cele. Plasma membrane) y a sq Seniperzniable, membrane present inser to the rell call and covering layer of cytoplasm, wonks as cater cove If y made up of lipid, frotein and a Smace amount of carbohode (E) cytoplary →ti viscous, granulare substance prosent between the could and membrane and noclear body body. → Conteins tribosomes, mesosom Chromatophore, extr CirevINY DNA, RNA and food reserved material in the forem of glycogen, lipid, and voletin granule. membronne bond eropneees like mitochondria, endoplasmic trettcomm, Golgiboortes and beastide are abrent. Mayane xos type. They are d Ribosome ? Tho touro tyres. (1) free rribesames Jury fixed ribosomes. → There are fared freely in the cytotram & fixed ribosome anelond attached to the case manbrane, of heeps in motein gonthesis. & toured which atie Some times the chain of ribosomes calveal poly ribosomes. Chronato phores They single membrane bound sac-like thylakoid which arve found Freely in the Cytoplasm. chormatophores ane the site forme photol Synthesis. Theyare only found in photo Synthetic bacteria. * mesoseme They ane fingerlike infolding on projection of cere membranes They Parreases the surface area for respiration. They Contain respiratory enzymes. mesosomes are present in goam possitive bacteria absent in goam negative baetenta- negative bacteria respiration acurs di goum negative from the inner surface cece Mambrane. directly (F) Nuclean body: →The Mocters yan incipient type aluch (acks organised →34 lacks nuclear membrane and nucleous which y alle caused nucreoid. DANA Ý cong, double-stroanded and with out histonep protein. Such DNA y also called narked DAIA OR Circculare DNA → Extra Circulare DNA or plarmids y found in the Cytoplatn echien is a short fragment of circular DNA. genetic infoternation -factor. about fer Heity- 31 cannies factor anel resistance Reproduction in bacteria Reproduction în bacteria on multiplication of cere no. in bacteria occurs mainly by vagetative reproduction, and neexual method. Their aneno sexual reproduction in balteria due to to lack off Sex onyons onyans on gamete formation. But genetic necombination occurs. Avegetative methods of Reproducim 16 Assion. by three methods - Buobling, fougmentation and Binaray (ⅰ) Audding :) Building occurs by formation of a protuberance called bus at one end of tod cere. Genome replication oceuss anda Copy of the genome enters into the bud. The buod then endariges and finally gets seperrated foxom parent organiitions cese to give rise to a new daughter independent beuterial cell. Fragmentation During unfavorable condition bacterial protopla endergoes compart mentalization gonidia. a minute Bach gonidium grocus to a new ofekomable condition. berly cou-el bacterian modery (1) Binary fission- →'s most common method of reponevetion in all balteria. →Before binary fission the cell constituent get doubted. → the entire event occuros in a proper sequence- first DNA replication, then partitioning and lastly chos were formation. As the call enlanges the daughter DNA stile attached to the get separated by a simple pinching off process. →forors wall isthes formal, fiest the transherede ployma membrane y laid down fellowed by the centripetee growth of the cere caccce alrich sprite the plasma membrane fito two harves NA Henk Asexual R Reproduction → some bacteria ane able to produce spores called as endo Spoores During the process, apart of the protoplast becomes emcentrated arround the genome ed →Ahard resistance coale y Sented around it. The rest of bacterial cell degenerated. →Each endospore y either Spherical, cylindrical on ellipsoidal in shap. → under fabovoable conditions, the enduspore germinates limiting water activating by limiting the cytoplasm and synthesizing metabolites and the due to swelling, brew buresting of coace rise to the new verge vegetative cell. sgiving * Stroucture of endosperma The endospore has a complex structure. لا Each endosperm y either spherical, Cylindrical en ellipascidae in shape. The outer layer y thin, desicoute and called followed by Sperre coat. exo porium. ity →anner to the Spore coat the contex contains Concentric ringe of was wall. Below the cortex, the core cell comete present surrounding cell membrane andofthe foro to plagm. → endospore contains especially dipicolinic acid (DPA) which in association with creciomion make the endospore heat resistance. Genetic recombination in bacterials →Genetic me combination in bacteria chanccterized by DANA Trans for focom one organism called domor to another organión as recipient. This process occurs in three main steps. wayl Trans-formation! Foans for of donor DNA to recipient bacteria via environment. of the only method of gene toans for that y mediated by bacterial choomasane." Transductim: Transfer of dmor DNA to recipient I bacterium by cel to cele contact. It'y maliated by plasmid. conjugation: Transter of donor DNA to recipient bustentom byan abnormal bucteriophage (Intermediate carrier) Transformation → It was firest discovered by F. Greiffith. → He Crodveted an experiment taking two stains of a bacteriom carreg Streptococcus pneumoniae or O Diplococcus pneumoniae. → out of too Strains-one way virulent, capsulated from Smooth Colonies (5) in colture. The Second & te a virulent, non pathogenic, non capsulated and forening Roug (R) in culture. He experimentiel on mice in the following steps! Step't: A virulent Stain (5) ane injected Sty due to the presenceof gene. to mice then the micey Leaf dief virulent Stein (5) → injected timice mice don't died. Avirulent stain (e) one injected to mice when the mice is lear lives it 'y due to A virulent stain (R) mice-Lives. posses that gene (") Heat killed virulent (s) y injected to mice ten the mice y lives it'y due to ty they avere died and cell ruptured leaving the DNA fragments in the surre meotiom. sunnonding Heat killed virulent (s) + living avirulent (R) injected to mice -mice Diving (iv) when head kiered vinulent & living a virulent (R) & injected to mice then the mice y dead, Osty due to some avirusent Stain convented to virulent fremsς have tockon tre gene Vincent from the fur Commented into vinulent forem due to The avireulent forms reight medium & become ne combination. genetie →It prooves the etic material. the DNA y a genetic gen the → si coas discovered by Ledenberg and Tatum Conjugation OCLUBS process of bya proces of Cellular conection between two Sexually differentiated bacterial cell of which one is a demore and the other y a recipient. The Cellular connection beteveen foro bacterial case thorough sex piexi forems ada conjugation tube or conjugation pilus. Then a segment of the donors genetic material y transferred to recipient cell which Corches may vades go recombination with the poncling segments of. the meripient genetic material. In contrast to transduction and froans formation, whersmace foagments of DNA Can be transferred, on conjugation a large fered. partion of DAYA y Chaenctemal OVA plasmid Donom (F) pilus Recipient (cen) onigingen dreare (Fcell) New denore (F'een) Transduction → It was discovered by Zinder and Leden & Speries. beng in Salmonera →on transduetton, virus that infeet bacteria move shoret pieces of chromosomae DNA from me bacterium to another. by accident". The viruses that inteet balteria are called bacteriophages. → The bacteriophages y complete in six steps suchas first attachmend then penetration, transcription, biosyntesis, maturation & lastly Lysis. →The bovirus attached to the surface of bacterial cen & teepinjects its DNA in to boulterior cell then transcri ption occurs te the host cell's DNA & degraded anf the cold's me faboltóry y directed.

Chapter 1: Bacteria

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