Environmental Engineering Microorganisms

Common Bacteria in Water

Salmonella sp., Legionella sp., Escherichia coli, Vibrio cholera

Common viruses in water

Adenovirus, Noroviruses, Rotavirus

Common Protozoan

Cryptosporidium parvum, Giardia lamblia

Beach water quality issues

stormwater washes sewage from cities and towns to costal waters, 40% had 1 advisory or closure

Indicator Organisms for Recreational Water

fecal coliform, E. coli and Enterococci

what decomposes solid waste in landfills

fungi, anaerobic bacteria, methanogenic archaea

what gas does anaerobic degradation generate

methane

Microbial Contamination

major water quality and public health issue

Top 5 causative agents of pathogens

legionella, cyanobacterial toxins, campylobacter, cryptosporidium and pseudomonas

What do indicator organisms show

high presence of indicator organisms point to high probability of fecal pollution and thus suggest high probability of pathogens being present

Why use indicators over individual pathogens

pathogens are low number in water and isolating and enumerating individual pathogens is analytically challenging and costly

coliforms

any gram negative, non spore forming, facultative, anaerobic, rod shaped and ferments lactose with the production of gas

Shortcomings of indicators

do not correlate well with protozoans and viral pathogens, are prone to false positives due to inclusion of non fecal organisms from environment and not measuring pathogens directly and are not reliable for accurate quantitative risk assesment

First evidence of prokaryotic life

3.8 billion years

microscopic fossil of a bacterium

3.5 bya

first oxygen in atmosphere

2.3 bya

first algea

1.2 bya

Three domains of life

Eukarya, Archaea and Bacteria

Bacteria Examples

Rikketsia, chlamydia, mycoplasms

Cyanobacteria

responsible for oxygenation of Earth’s atmosphere

Archaea

similar to bacteria in shape and size, very different genetically, live in extreme environmental conditions, no known diseases caused by them

Protazoan

single cell Eukaryotes

Protazoa attributes

most have no cell walls, most use preformed organic matter instead of photosynthesis

Algae

plant like Eukaryotes capable of photosynthesis

prokaryote

bacteria and archaea

Viruses

neither prokaryote or eukaryote, cannot metabolize, can replicate only in a host cell

virus classification

DNA they carry (eg. ss RNA, ds DNA)

coccus

ball

bacillus

rod

sarcina

8 coccus

strepto

chain

catabolism

breakdown of large molecules

Anabolism

buildup/synthesis of large molecules from small precursors

Enzymes

increase the rate of reaction by decreasing activation energy

cells obtain energy in two ways

from solar power, from chemical reactions

chemoorganotrophy

oxidation or reduction of organic compounds (electron donor is organic)

chemolithotrophy

electron donor inorganic

anabolism

energy used for making new cells

Heterotrophs

organic

Autotrophs

inorganic

Anoxic

Nitrate is electron acceptor

How do microorganisms grow

binary fission

lag phase

microorganisms adjusting to new environment

Exponential Phase

Cells in balanced growth

Stationary Phase

growth rate declines, lack of food or substrate

Death Phase

Decline in cell numbers

Environmental Factors that affect growth

Temperature, Oxygen,Nutrients and pH