Study of Microorganisms

• Microbiology is the science that studies microorganisms, which are microscopic in size.
• Microorganisms are essential for the biosphere, enabling life's maintenance and causing benefits or harm to other living beings.
• The study of microorganisms encompasses the kingdom Monera (bacteria), kingdom Protoctista (protozoa and microscopic algae), kingdom Fungi (molds, mucous fungi, and yeasts), and viruses (acellular forms).
• Viruses are not microorganisms, viroids and prions are acellular forms.

Microorganism Cultivation

• Chemical composition is known with precision, each component is highly pure analytically and provides a specific contribution, used mostly for autotrophs.
• Natural or complex mediums are prepared from natural substances of animal or plant origin whose chemical composition is not strictly constant, examples include milk, serum, or corn macerate, used mostly for quimioheterotrofos.
• By their consistency mediums can be liquid, solid or semisolid.
• Liquid mediums do not contain a solidifying agent and do not allow colony isolation.
• Solid mediums include agar in concentrations of 1.5% to 2%.
• Semisolid mediums include agar at 0.3%.
• By their function, mediums can be enrichment, selective, or differential.
• Enrichment mediums, are liquid mediums, that favor the multiplication of a particular microorganism.
• Selective mediums, are solid mediums, that favor the multiplication of a particular microorganism.
• Differential mediums allow discrimination between different types of bacteria based on particular metabolic characteristics.

Microbiological Control

• Pasteurization eliminates non-sporulated microorganisms and reduces spoilage, using temperatures below 100°C.
• Sterilization destroys all forms of microbial life, pathogenic or not, and employs temperatures above 100°C.

Optical and Electronic Microscopy

• Optical microscopy allows the observation of microorganisms and other samples using a set of lenses that magnify the image between 1000 and 2000 times.
• Electron microscopy, invented in 1930 by E. Ruska and M. Knoll, allows magnifications of over one million times, enabling the observation of cellular organelles, bacteria, and even smaller objects like macromolecules.

Molecular Biology Techniques

• Molecular biology techniques are used to "manipulate biological molecules" such as DNA.
• Techniques are based on complementarity of bases and DNA replication.
• PCR (Polymerase Chain Reaction) amplifies a large number of copies from a DNA template using an enzymatic chain reaction in vitro.
• PCR is applicable in diagnostics, filiation, and forensic investigations.

Kingdom Monera: Bacteria

• Bacteria are prokaryotic organisms ranging in size from 0.1 to 50 micrometers.
• Bacteria can be autotrophs or heterotrophs, and aerobic, strict anaerobic, or facultative anaerobic.
• Bacteria are ancient, spread and numerous organisms in nature, found from polar zones and ocean ridges where the temperature reaches 350°C, to saline habitats and acidic waters.
• Microorganism can either be Acelulares or Celulares.
• The Celulares can be categorized by their organization as:
• Procariota.
• Bacteria.
• Eucariota.
• Algas
• Hodngos
• Protozoos

Morphology of bacteria

• Cocos are a spherical form, they have a minimum relation relation in surface volume, poor relation to the exterior
• Bacilos are an elongated cylinrdical form, they have a greater surface relation, nutrients are obtained more efficiently, and can live in poor conditions
• Espirilos y Vibrios are a helix form, of a small diameter, and pathogeneic through vectors.

Eubacteria and Other Bacterial Groups

• Eubacteria have acquired great adaptation and specialization to live in all types of environments, some are aerobes, others anaerobes.
• Facultative eubacteria live indistinctly in aerobic or anaerobic environments.
• Thermophilic eubacteria have adapted to live in very high temperature waters and are found in volcanic upwellings like ocean chimneys.
• This group includes most known bacteria, used in the food industry (alcoholic and lactic fermentations) or being pathogenic.
• Cyanobacteria, also called blue-green algae, exists as cells isolated as colonies, play an important role in the appearance of the oxidizing atmosphere.
• Prochlorophytes are bacteria with the appearance of chloroplasts and live as endosymbionts inside ascidians.
• Nitrifying bacteria synthesize organic molecules thanks to the oxidation of inorganic nitrogen compounds from soil or marine funds.
• Nitrogen-fixing bacteria capture atmospheric nitrogen for plants leguminous with which they live in symbiosis.
• Spirochetes are spirilla frequent in aquatic media, some are parasites.
• Lactic acid bacteria are anaerobes but tolerant to oxygen; cause lactic fermentation.
• Mycoplasmas lack a cell wall, are like small coques and are parasitic.

Archaebacteria

• Archaebacteria are prokaryotic cells, their membranes that do not have fatty acids and their cell walls lack peptidoglycans.
• Their lipids are arranged in rigid monolayers and most are anaerobic.
• Nutrition is autotrophic or heterotrophic.
• They live in diverse habitats: halophilic (salty waters), thermophilic (thermal waters rich in sulfur), and methanogenic (anaerobic environments and produce methane).

Morphology of Bacteria: Structures

• Capsule: An external layer in all pathogenic bacteria, viscous in nature, composed of glucose polymers, glycoproteins, acetylglucosamine, and uronic and glucuronic acids.
• Capsule functions include: regulating water, ions, and nutrient exchange; working as a water reservoir during desiccation; adhering to host tissues; hindering antibodies, bacteriophages, and phagocytic cells; and enabling colony formation.
• Cell Wall or Bacteria: A rigid envelope, 5 to 10 nanometers thick, characteristic of all types of bacteria with the exception of mycoplasmas. -Primarily formed by peptidoglycans. Evidenced by Gram staining (+/-). -Cell wall functions include: supporting the strong osmotic pressures that act on the bacteria regulating ion passage, and resisting antibiotic attacks.
• Plasma Membrane: Similar in structure and composition to eukaryotic cells. -Presents internal folds called mesosomes (=invaginations towards the inside of the cell) and an absence of cholesterol (both characteristics differ from eukaryotic cells). -Its functions include limiting and regulating the cellular cytoplasm and the passage of substances.
• Mesosomes: The mesosomes are internal folds of the plasma membrane that suppose a large increase in the surface. -They often carry out processes like cellular respiration and photosynthesis. -They support and maintain, in suspension, the bacterial chromosone. -They create DNA polymerase -> replication.
• Genetic Material: Formed by a single molecule of DNA double helix (=bicatenario), circular and not associated with histones. -Directs all the activity of the cell and stores the genetic information.
• Plasmid: Also circular DNA molecules, that bacteria often exchange. -They are used as cloning vectors in genetic engineering; They helps the bacteria to face poison, antibiotic, heavy metals, They help the bacterial cell to digest substances that are not usual
• Flagellum: Filamentous structures of locomotion found variable in number and consist of a basal body and a long filament. -Formed by protein fibers.
• Fimbrias or Pili: Tubular structures that are like anchors on top of the bacterial cell membrane (only Gram negative) -Fimbrias are what help a cell adhere to a surface -Pili are there to interchanging genetic information.
• Cytoplasm: The cytoplasm, (protoplasm) is the contents in the cell and is the membrane where its consistncy is a gel-like consistency of the same -Contains water, enzymes, various cell structures such as vesicles and includes ribosomes, chromosomes, and plasmids. -The cytoplasmic matrix defined for materials wether it exists as a bacteria.
  • The region that contain in eukaryotes.
  • Vesicles: accumulate masses of gaseous substances which are very numerous.
  • Nucleidos: The region that contain nucleid acid, (ADN)

Gram-positive and Gram-negative bacteria

• Gram-positive bacteria have a thick peptidoglycan layer.
• The murein layer associates with proteins, polysaccharides, and teichoic acids.
• Gram-negative bacteria also contain murein. -The layer is finer than in a previous method the external is a lipidic bilayes the majority is enzymatic -It is presented with a certain layer with protein of porinas. Murein (Peptidoglycan)
• Peptidoglycan formed from chains of N-acetyl glucosamine (NAG) molecules joined by glucosidic bonds with molecules of N-acetyl muramic acid (NAM). -The are bind with four amino acid chains wich are a part of inter catenation.

Bacterial Physiology

• Autotrophs use inorganic compounds to synthesize organic compounds, either photosynthetic or chemosynthetic.
• Photosynthetic autotrophs do not use water as an electron donor, produce no oxygen and use pigments that absorb near-infrared light -Chemosynthetic autotrophs use energy released from oxidizing inorganic compounds and transform CO₂ into hydrogenated compounds (anabolism).
• Heterotrophs use organic compounds to synthesize their own organic compounds.
• Saprophytes are free-living bacteria on dead organic matter.
• Many live in close relation to other organisms, being commensals, parasites, or symbionts.
• Regardless of the nutrition type, bacteria may or may not need atmospheric oxygen (aerobic or anaerobic bacteria).
• Some anaerobic bacteria find oxygen to be a poisonous gas (strict anaerobes).
• Others can use oxygen when present, but may live without it (facultative anaerobes).
• Bacteria gets energy from the enviroment.
• FOTOTROFAS - Get their energy from radiation.
• FOTOAUTÓTROFAS - Get luminescent energy without any inorganic objects. -FOTOORGANÓTROFAS - Get luminescent energy in requierment from various organic parts. -QUIMIOTROFAS - Get energy from chemical reaction. -QUIMIOAUTÓTROFAS - Capture of chemical energy from inorganic items. -QUIMIOORGANÓTROFAS - Capture chemical energy from organic organisms.
• Bacteria are mobile, they move by contractions and dilating their own, or using their flagellum. -They repsonse to stimulus like light and temp chemicals. -Bacteria can endure bad conditions by developing endospores.

Bacterial Reproduction

• Bacteria reproduce through binary fission, resulting in two identical cells.
• After DNA replication, guided by DNA polymerase in mesosomes, the cell wall grows to form a transverse septum. -A colony is a clone of bacteria.
• Bacteria are able to exchange genetic informaiton (Parsexual) and exchange DNA producing genetical variability. -Conjugation is when a bacterium, F+ transfers bacteria from pilito a bacteria without the plasmid (F-) and the F- becomes transformed and transfers the genetic informantion -Transformation is the bacteria that introduces itself with a fragment of a bacteria that is already lyse it self, The new bacteria get this fragment by transformation and gets resisitant to antibacterial items.

Transduction

• In transduction, genetic exchange requires a transmitting agent, a bacteriophage virus.
• The genetic material of the virus integrates into the donor bacterium's chromosome.
• The virus picks up some genes that it will transmit to the recipient bacteria.
• The three mechanisms imply genetic recombination of the material and gives and adds to the variability of some bacteria when live others species.

Viruses: Agents and Characteristics

• Viruses are microscopic and acellular parasitic agents that reproduce inside a host cell, causing damage in the process.
• Viruses infect any life form, from animals to plants and bacteria (bacteriophages).
• They are used as vectors in gene cloning for therapeutic or industrial ends.
• Also capable of intervening in the evolution of SVs, viruses are able to attach to various materials.
• The viral genetic material contains DNA or RNA (never coexist the time two) which can have has a fragmented genomce in a doulbe chain.
• They are also simle and infrom about coding for the proteins.
• All viruses have 3 groups: ESTUCTURALES, ENZIMÁTICAS, AGLUTINANTES
• Nucleocapsid is formed by combining the viruses of the capsule
• Envoltos presents is viruses

Viruses: Morphology and Reproduction Cycle

• The external covering of the capsids of virus in general in multiples
• Nucleocapsic is formed in the capside al that contians.

Virus reproduction

• Virus always parasitic its an obligation.
• Viruses create multiple production cells. -Some introcuce theme selvez directly in the cell membrane(litiico)
• Other dont directly destro the cell.
• After intergraded in cells, its replicated by a cycle (lisogénico) -When the bacterium is devided without causing new forms of virus
• Adsorption and penetration: Occurs when the capsid's proteins or the envelope recognize and bind the the host cell's membrane
• Synthesis of them genom and proteins a virica uses their mechanism cells.
• Maturation and assembly: Starts production of the new virions and the capsid is ready
• Liberation - After completion of one the virons they release the cl cells

Lysogentic cycle

• Se introce cell and start producing cells with out disturbing any thing new and making new viruses .
• In the state it is it is immune
• Agents that cause this is physical chemical or the ADN

Viroides and Prions

• Subviral particles are simpler and smaller acellular infectious agents compared to viruses.
• Viroides are infectious agents that are smaller and compotes of: -Made out from the mc of ARN
• The structure is one where they can do polymiraza. -Only attacked with in plantas/
• Prions are infectious items that attack neuronas.
• Son particles proteicas infecciosas and seem to provoce a transformaticaa en to protein in the nervous.
• Causes illinesses and are normally deadly