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microbial ecology
study of microbes in their natural habitats
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Applied microbiology
study of practical uses of microbes in water and food processing, industrial production, and biotechnology
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Microbial ecology and applied microbiology overlap because
most natural habitats have been altered by human activities
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Eutrophication
- change dues to humans
- produce waste
- change things slightly so microbes have to alter/change with them
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Human intervention in natural settings has:
(4)
- changed the earth's warming and cooling cycles
- increased waste in soil
- polluted water
- altered some basic relationships between microbial, animal, and plant life
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Human Micro biome Projest used to
identify microbes living in the environment- land water air
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Environmental genomics has revealed (2)
- bacteria living in glaciers
- bacteria living deep under the seafloor
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metagenomics
the genes of all microbes in a habitat samples
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metagenomic process
- begins with an environmental sample: a gallon of sea water, or a gram of soil
- DNA is extracted from these samples
- fragments are cloned into a plasmid
- a library of DNA fragments is preserved and amplified
- once the nucleotide pieces are retrieved, they can be sequenced
- it can determine whether they match known sequences or are new to us
- DNA sequences can be cloned into expression vectors, which can then be screened for their functions or their products
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At microscopic level, soil is a
dynamic ecosystem
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Soil serves as
a dynamic role in biogeochemical cycles
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soil import what
important repository for organic detritus and dead terrestrial organisms
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Rock decomposition release
various size particles
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Porous structures of the soil creates
various size pockets or spaces that provide numerous microhabitats
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Some spaces in soil trap
moisture
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Some spaces in soil trap moisture and form
a liquid phase in which mineral ions and other nutrients are dissolved
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Other spaces in soil trap
are that will provide gasses to soil, microbes, plant, and animals
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Soil supports a great number of
bacteria, fungi, algae, protozoa, and viruses
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Rhizosphere
zone of soil surrounding the roots of plants
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Rhizosphere contains
bacteria, fungi, and protozoa
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Plants interact with soil microbes in a
synergistic fashion
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a rich microbial community grows in a
biofilm around root hairs, and other exposed surfaces
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Soil is a ____ for ______, ______, _______ ______
repository for agricultural, industrial, and domestic wastes
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Agricultural, industrial and domestic wastes examples
insecticides, herbicides, fungicide, manufacturing waste, household chemical
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Applied microbiologist work to
work to explore the disability of harnessing indigenous soil microbes to break down undesirable hydrocarbons and pesticides
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Deep subsurface microbiology
bacteria that metabolize petroleum to CO2 a million times slower than surface microbes
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microbes may be anywhere from ____ to ____ years old
100 to 100,000 years old
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Deep subsurface microbes exist solely in
biofilms on rock surfaces
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Deep surface microbes live in
nearly abiotic environments, and may provide clues to the origin of life
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water occupies nearly
3/4 of the earth surface
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Hydrologic cycle
- begins with surface water (lakes, ocean, and river) is exposed to the sun and evaporates
- plants lose moisture through transpiration
- aerobic organisms give off water through respiration
- airborne moisture accumulates in the atmosphere as clouds
- water is return to the earth through condensation or perception (rain and snow)
- clouds release rain and snow when particles of water become too large for a fine mist of clouds to support
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Nucleators
tiny particles that cause the formation of raindrops or snowflakes
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dust particles are thought to be
nucleator
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what causes most percipation
research has shown that bacteria are nucleator causing most precipitation
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Ocean exhibits extreme variation in
salinity, depth, temperature, hydrostatic pressure, and mixing
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Ocean supports
great abundance of bacteria and viruses
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Freshwater is site of
tremendous microbiological activity
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microbial distribution is asociated with
sunlight, temperature, oxygen levels, and nutrients availability
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Red tide produced by
toxin producing dinoflagellates
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red tide fish and human disease traced to
overgrowth of these algae in polluted water
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red tide algae produce
a potent muscle toxin that is a concentrated in shellfish through filtration feeding
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When humans eat clams, muscles, or oysters containing the toxin
they develop paralytic shellfish poisoning
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Eutrophication
addition of excess quantities of nutrients to aquatic ecosystems
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bloom
heavy surface growth of cyanobacteria and algae due to influx of nutrients and warm temperatures
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they heavy ____ of ____ shuts off oxygen supple to the lake below
mat of biomass
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What further depletes by aerobic heterotrophs that decomposes the organic matter
oxygen
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lack of oxygen disturbs the ecological balance causing
massive die off of higher organism
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Drinking water most comes from
river, aquifers, and springs
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In most cities, water must be
treated before it its supplied to consumers
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Sewage contains large amounts of
- solid waster
- dissolved organic matter
- toxic chemicals
- pose health risks
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Primary stage water treatments
separates out urge matter
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secondary stage of water treatment
reduces remaining matter and removes some toxic substances
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tertiary stage of water treatment
completes purification of the water
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membrane bioreactors
combinations of microbial communities and high efficiency membranes that are efficient at removing
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reclaimed sewage water used to
- water golf courses and parks rather than drinking
- may be gradually released into large bodies of water
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worldwide epidemics of ____ have killed thousands of people
cholera
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what is responsible for billion of cases of diarrheal diseases that kill 3 million children a year
lack of sanitary water
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in US, 1 million people develop
waterborne illness every year
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Good health is dependent on
clean, potable water
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Good water must be
free of pathogen, dissolved toxins, disagreeable turbidity, odor, color, taste
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Most prominent waterborne protozoa
Giardia and cryptosporidium
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Most prominent waterborne bacteria
camplylobacter, salmonella, shigella, vibrio, mycobacterium
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Most prominent waterborne viruses
hepatitis A, norwalk viruses
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Some microorganism can survive
in natural waters for long period of without human host
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water purity assays are focuses on detecting
fecal contamination
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high fecal levels can mean
the water contains pathogens and is unsafe to drink
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indicator bacteria
intestinal residents of birds and mammals readily identified using routine lab procedures
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cloakrooms and enteric streptococci indicate
high levels of fecal contamination
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Coliforms
- gram-negative,lactose-fermenting, gas producing bacteria
- Escherichia coli, enterobacter, and citrobacter
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EPA standards for water sanitation are based on
primarily on levels of coliforms
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coliforms enumeration
simple tests such as presence-absence broth detect coliform activity but do not quantify it
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Rapid test
isolate coliforms and provide quantities of coliform present
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What is a good way to determine if the water or its products have been exposed to feces
to test for E. coli
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Coliform used to
regulate food production and to trace the causes of food-borne outbreaks
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most probable number (MPN)
detects coliforms by a series of presumptive, confirmatory, and completed test
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Most probable number (MPN) is
set of numbers is applied to a statistical table that estimates the most likely or probable concentration of coliforms
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food is fermented or otherwise chemically changed by
addition of microbes or microbial products to alter or improve flavor, taste, texture
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microbes can _____ as ____
sere as food
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Detrimental: Microbes cause
- food poisoning or food-borne illness
- microbes spoil food
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CDC estimates that
several million people suffer each year from some form of food infection
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Outbreaks attributed to common pathogens have
doubles in the past 20 years
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Most common implicated viruses and protozoa
- Salmonella
- E. coli
- Vibrio
- Listeria
- Campylobacter
- hepatitis A virus
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What is major factor in the increase in out outbreaks
mass production and distribution of processed foods and raw veggies
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hazard Analysis and Critical Control Point (HACCP)
- new approach to regulating the food industry
- based on principles that are more systematic and scientific than previous random-sampling quality procedures
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HACCP projects are taking place in facilities that
process cheese, breakfast cereals, salad dressings, and bread
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Many reported food-poisoning outbreaks occur where
food contaminated food has been served to large groups if people
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Most cases of food poisoning probably occur in
the home and are not reported
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it will never be possible to avoid all types of food borne illness because of
the ubiquity of microbes in the air, water, food, and the human body
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food poisoning can be prevented by
proper food handling, preparation, and storage
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method of food poisoning prevention:
- preventing the incorporation of microbes into food
- removing or destroying microbes in food
- keeping microbes from multiplying (hot/cold temp)
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What is common way to destroy microbial contaminations or reduce the load of microorganims
heat
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Pasteurization
application of heat below 100C to destroy nonresistant bacteria and yeasts in liquids such as milk, wine, and fruit juices
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What can render microbes free or relatively free of microbes
cooking temperatures used to boil, roast, or fry foods
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Food storage
a good directive is to store foods at temperatures below 4C or above 60C
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refrigeration
reduces the growth rate mesophyllic bacteria by 10 times
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Some _______ microbes can continue to grow at a rate that causes food spoilage
psychrotrophic
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What types microbes can continue to grow in refrigerated foods
- Salmonella
- listeria monocytogenes
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Ultraviolet (UV) radiation
used to destroy microbes on the surfaces of foods or utensils
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Main class of chemical preservatives
- organic acids
- nitrogen salts
- sulfur compounds
- oxides
- salt
- sugar
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what was recently approved by the FDA to be sprayed on ready to eat meat products
bacteriophages- only infect bacteria
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bacteriophages specific for
Listeria
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Bacteriophages will act to
kill the bacteria that would not be otherwise killed because cold cuts and poultry are usually not cooked before consumption
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industrial microbiology
large scale commercial enterprise that uses microorganisms to manufacture consumable materials
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industrial microbiology bulk production of
organic compounds such as antibiotics, hormones, vitamins, acids, solvents, and enzymes
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Aim of industrial microbiology
produce chemicals that can be purified and packaged for sale or use in other commercial products
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Biofuels use
use cyanobacteria and algal species
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biofuels would replace
gasoline and jet fuel
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microorganisms produce major
pharmaceutical substances, food additive, and solvents
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Hyperthermophiles adapted for
high temperature detergent and enzyme production
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Psychrophiles used for
cold processing of reagents for molecular biology and medical test
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Halophiles effective for
processing of salted foods and dietary supplements
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healthcare products derived from microbial biosynthesis are
antibiotics, hormones, vitamins, and vaccines
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the first mass produced antimicrobial was
penicillin
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