Environmental Microbiology Applied Environmental Microbiology applied microbiology is

Environmental Microbiology

Applied & Environmental Microbiology applied microbiology is the interaction of the microbial world and the rest of the world – genetic variances – microbial effect on soil, water, our food microorganisms are present in most every aspect of our lives – microorganisms are critical to our survival on Earth to be a successful ecosystem on Earth, you’d best be nice to the microorganisms!

Microbial Ecology: relationship of microorganisms with each other and their environment ecosystem: interaction of living and non-living components – oceans, deserts, marshes, forests, tundra, lakes – microorganisms play a key role in ecosystem structure

Microbial Ecology: relationship of microorganisms with each other and their environment microenvironment: immediately surrounds a microorganism – relevant to survival and growth of the microorganism

Nutrient Acquisition within an Ecosystem 3 main levels exist in every ecosystem in regards to nutrient acquisition – producer – consumer – decomposer 1. primary producers: convert CO 2 to organic material

Nutrient Acquisition within an Ecosystem 2. consumers – heterotrophs – utilize organic material created by producers

Nutrient Acquisition within Ecosystem 3. decomposers – heterotrophs – digest leftovers of primary producers and consumers detritus ( fresh or partially decomposed organic matter) – bacteria and fungi are key players in the process of decomposition

Low Nutrient Environments: common in nature bacteria do best in biofilms if nutrition availability is low – biofilms are a polysaccharide encased community of microorganisms – microorganisms extract nutrients that are absorbed by water from air or nutrients that are adsorbed onto the biofilm

Microbial competition and antagonism most environments are suitable to many kinds of microorganisms only one or a few can actually occupy the environment at a given time

Competition and Antagonism: among microorganisms competition: – fierce competition for nutrients and water – the faster a microbe reproduces the larger the population – the larger population competes better critical, especially if the microorganisms competing utilize similar nutrients antagonism – bacteriocins: protein produced by bacteria that destroys similar strains “WINNER TAKES ALL AND IS KING/QUEEN OF THE MICROBIAL ECOSYSTEM”

Example of Competition stability of microbial community in human intestine is attributed to competition and antagonism amongst its members – compete nicely for nutrients – produce toxins to limit growth of new microbes

Environmental Change affect microbial population environmental fluctuations are common and resident microorganisms may respond by – producing enzymes to help adapt to changing environment additional or different enzymes may be necessary for survival – mutation – domination by other species (can’t compete any more)

Microbial Mat: thick, dense, organized biofilm generally found attached to a solid substrate or at airwater interfaces Microbial mat attached to rocks Microbial mat in stream bed

The Study of Microbial Ecology somewhat difficult to accomplish – less than 1% of environmental microorganisms can be successfully cultured in the lab

Microbial Habitat aquatic – marine: deep waters are usually stable and consistent shoreline habitat varies due to nutrient rich run-off

Microbial Habitat freshwater: algae – lakes stratification allows for the mixing of the water seasonally. Increases the presence of O 2 in the deeper H 2 O paramecium

Microbial Habitat moving water – rivers generally aerobic due to turbulence facilitating O 2 circulation river ostracod

Microbial Habitat terrestrial – microorganisms are critical to soil habitat composition of microbes is dependent on soil conditions wet soil: anaerobic conditions due to water filling the pore space in the soil, soil dries and microbes go produce endospores for survival Endospores

Mutualism with Eukaryotes mychorrhizae: fungus – assist plants in the uptake of phosphorous – mychorrizae gain nutrient from plant

Mutualism nitrogen fixers: fix nitrogen and make it available for the use by their partner plant – most common is Rhizobium, a microorganism found in many root nodules Rhizobium in root nodules

Nitrogen Cycle

Carbon cycle

Mutualism: microorganisms and the world microorganisms and herbivores – animal with a rumens (cow) or cecums (horse) need microorganisms to digest the plant food they ingest Bacillus in a cow rumen

Microorganisms in Sewage Treatment decreasing biochemical oxygen demand (BOD) decreases impact of sewage on the environment BOD is the amount of O 2 needed for microbial decomposition of the organic material in a sample Grit chamber Biological filter Clarifier

Microorganisms in Sewage Treatment if not treated the high BOD found in sewage could deplete the O 2 level in the receiving water in other words if raw sewage is deposited into a lake or stream without treatment, it would effectively suck the oxygen out of the water, leaving very little for the fish and other organisms

Microorganisms in Sewage Treatment sewage treatment is a controlled process that strives to eliminate the excess organic material, thus diminishing the BOD – most of the removal of organic matter is done by microorganisms bacterial filaments

Microorganisms and Water Treatment and Testing municipal water supplies are tested and treated for the removal of pathogenic microorganisms and chemicals – this is done with the use of chemicals

Microorganisms and Solid Waste Treatment the elimination of organic waste material can be enhanced by microorganisms – increase cost to separate organic material from inorganic (glass, metal, plastic) – composting: natural decomposition of organic solid materiel results in excellent fertilizer

Compost microorganisms are needed to breakdown the organic material

Bioremediation: use of microorganisms to eliminate or make harmless pollutants in an environment pollutants removed can include – organic solvents – toxic chemicals – hydrocarbons oil spill

Bioremediation introduces specific organisms to the polluted area – many toxic substances are man-made/new to the environment (xenobiotics) – no time for naturally occurring microbes to have evolved biochemical pathways for their degradation scientists are trying to develop new microbes for the degradation of environmental polluters Cleaning an oil spill

Bioremediation scientists are also making use of organisms already found in the environment – enhance their requirements for growth, such as nutrition or water availability Bacteria in an oil spill

Why Bioremediation? current methods of controlling some environmental polluters are incineration or storage in land fills, which result in – more pollution – health risks bioremediation is – inexpensive – publicly accepted – non-polluting (ideally) – in situ treatment (at the site)