MICROBIAL NUTRITION OUTLINE

NUTRITION;

  • defn: process by which chemical substances (nutrients) are acquired from the environment and used in cellular activities

  • Essential Nutrients: elements or molecules that must be provided to an organism b/c they can’t be synthesized by the organism

    • For humans?

    • Fats-Omega 3 Fatty Acids

    • Amino acids- Tryptophan

    • Vitamins- ABD

    • Dietary minerals- Ca, Cu, Na, Fe

GROWTH FACTORS: ESSENTIAL ORGANIC NUTRIENTS

  • GROWTH FACTORS are organic compounds that must be provided as a nutrient

    • An organism cannot make it on its own

    • essential amino acids, vitamins, and nucleic Macronutrients

  • required in large quantities

  • cell structure/metabolism

  • ex, proteins, carbs

Micronutrients

  • Aka trace elements required in small amounts

  • protein structure, enzyme function

  • ex. manganese, zinc, nickel

Organic nutrients

contain carbon and hydrogen atoms

  • Inorganic nutrients- NO C-H

  • metals and their salts(magnesium, sulfate ferric nitrate)

Chemical analysis of cell contents: Water (70%), Organic material 29.1%, Inorganic (0.9)

CHONPS

Nutritional Types

  • Main determinants of nutritional type are:

    • Carbon source

    • Energy source

  • HETEROTROPH- must obtain carbon in an organic form made by other living organisms

  • AUTOTROPH- an organism that uses CO2, an inorganic gas as its carbon source

    • Not nutritionally dependent on other living things

HETEROTROPHS

  • 2 categories

  • Saprobes are free-living microorganisms that feed on organic detritus from dead organisms.

    • Opportunistic pathogen

    • Facultative parasite

  • Parasites- derive nutrients from hosts, often causing harm to their host in the process.

  • Pathogents

  • Some are obligate (have to be) parasites, while others can be facultative, meaning they can live independently but will parasitize when opportunities arise.

NUTRITIONAL TYPES

  • Many determinants of nutritional type are the energy source

  • Chemotroph- gains energy from chemical compounds

Phototrophs- gain energy through photosynthesis

Mode of nutrition

Energy source

Carbon source

Photoautotroph

Light

CO2

Chemoautotroph

Inorganic chems

CO2

Photoheterotroph

Light

Organic Chemicals

Chemoheterotroph

Org chems

Organic Chemicals

ACTIVE AND PASSIVE TRANSPORT

  • Active Transport requires energy because it goes against the concentration gradient. Requires energy + carrier proteins; gradient-independent. Active transport

  • Group TRANSLOCATION: transported molecule chemically altered to enable its passage across the membrane, ensuring efficient uptake into microbial cells.

  • Bulk transport- endocytosis and exocytosis involve the movement of large quantities of substances into or out of the cell by forming vesicles. This process allows cells to take in nutrients or expel waste. pinocytosis, phagocytosis

  • Passive Transport: does not require energy, substances exist in a gradient and move from areas of higher concentration forward to areas of lower concentration/

  • Diffusion- Net movement of molecules down their concentration gradient (Passive transport)(Spreading out)

  • Osmosis: diffusion of water

    • PLAYS A BIG ROLE IN the kidney

  • Facilitated diffusion: requires a carrier

  • Alcohol and caffeine trick you into thinking you're hydrated when you're really not, opening the channels so you don’t conserve water

Hypertonic

Hypotonic

Isotonic

More solute

Less solute

Same solute

Towards Lower Water

Towards higher water

equal

solutions move from hypo to hyper

group translocation

Endocytosis

  • bringing substances into the cell through a vesicle or phagosome

  • phagocytosis: ingests substances(like a solid) or cells

  • Pinocytosis: ingests liquids

ENVIRONMENTAL FACTORS THAT INFLUENCE MICROBES

  • Niche: the totality of adaptations organisms make to their habitat

  • Env. factors affect the function of metabolic enzymes

    • including:

    • temperature

    • oxygen reqs

    • pH

    • Osmotic and Barometric pressure

3 TEMP ADAPTATION GROUPS

  • PSYCHROPHILES- Optimum temps below 15 °C; capable of growth at 0 °C

  • MESOPHILES- Optimum temperatures between 20 C and 45 C; these organisms thrive in moderate temperature ranges, including many pathogens.

  • THERMOPHILES - Optimum temperatures above 45 °C; these organisms typically inhabit environments such as hot springs and compost heaps, demonstrating adaptations that allow them to withstand extreme heat.

TEMP AND DISEASE

  • The body isn’t evenly heated

  • extremities at 30-35 °C and scrotum at 32 °C

  • Cooler areas are much more prone to diseases such as

    • HANSEN’S DISEASE

    • SYPHILLIS

GAS REQUIREMENTS

  • Oxygen is not as wonderful as we think!

    • Oxygen radicals— antioxidants fight these

Very destructive molecule

  • There are enzymes to detoxify O2

CATEGORIES OF OXYGEN REQUIREMENT

  • Aerobe- utilizes oxygen and can detoxify it

  • Aerotolerant Anerobe- do not utilize oxygen but can survive and grow in its presence

  • Anaerobe- does not utilize oxygen

  • .Facultative Anaerobe - can grow with or without oxygen but prefers to utilize oxygen when available

  • Microaerophilic- requires only a small amount of oxygen

  • Obligate Aerobe - requires oxygen for growth and survival, relying on aerobic respiration for energy.

  • Obligate Anaerobe- lacks the enzymes to detoxify oxygen so cannot survive in an oxygen environemnt

ENVIRONEMNTAL FACTORS THATT INFLUENCE MICROBES

  • Majority of microorganisms grow at a pH between 6 and 8 aka Neutrophiles

  • Acidophiles- grow at extreme acid pH

  • Alkalineophiles- grow at extreme alkaline pH

OSMOTIC PRESSURE

  • Most microbes exist under hypotonic or isotonic conditions

  • Halophiles

  • require a high concentration of salt

  • Few organisms can live in such an extreme environment so halophiles are archaea.

  • Osmotolerant

  • do not require a high concentration of solute but can tolerate it when it occurs, allowing them to survive in environments with varying salt concentrations.

  • Barophiles- can survive under extreme pressure and will rupture if exposed to normal atmospheric pressure

ECOLOGICAL ASSOC. AMONG MICROORGS

  • SYMBIOTIC-Organisms live in close nutritional relationships, required by one or both members

    • Mutualism- Obligatory, dependent, both members benefit

      • ex. Cows and bacteria that produce cellulase, rhizobium, and legume plants

    • Commensalism- The commensal benefits one member; the other member is not harmed

      • Some of the bacteria in our stomach, and Mites on the skin

    • Parasitism- Parasite is dependent and benefits, host is harmed

    • Can change: Streptococcus pyogenes

      • Ringworm (fungus)

      • Hookworm

      • Cholera bacteria

      • Tuberculosis

  • NONSYMBIOTIC- Organisms are free-living, living relationship not required for survival

    • Synergism- when two or more things (like drugs, chemicals, or organisms) work together to produce a combined effect that is greater than the sum of their individual effects,

THE STUDY OF MICROBIAL GROWTH

  • Microbial growth occurs in 2 levels:

  • Cellular Level/ Size - Refers to an increase in the number of cells through processes such as binary fission.

  • Population Level/Size - Involves the increase in biomass and population density within a given environment.

  • Division of bacterial cells occurs mainly through Binary Fission (Transverse)

    • Parent cell enlarges

    • Duplicates its chromosomes

    • Forms a central transverse septum

    • Divides the cell into two daughter cells

    • Similar to what process in animal/plant cells?