Transcript water microbiology

MIC 303
INDUSTRIAL AND
ENVIRONMENTAL
MICROBIOLOGY
CHAPTER 8-ENVIRONMENTAL
MICROBIOLOGY
INTRODUCTION
• Environmental microbiology applied the principles of
microbiology to the solution of environmental problems.
• Applications in environmental microbiology include:
1) Treatment of industrial and municipal wastewater.
2) Enhancement of the quality of drinking water.
3) Restoration of industrial, commercial, residential and
government sites contaminated with hazardous
materials.
4) Protection or restoration of rivers, lakes, estuaries and
coastal waters from environmental contaminants.
5) Prevention of the spread through water or air of
pathogens among humans and other species.
INTRODUCTION (CON’T)
•
•
Almost always are concerned with
mixed cultures and open, nonsterile
systems.
Success are depends on:
1) How individual microbes with
desired
characteristics
can
survive in competition with other
organisms.
2) How desired functions can be
maintained
in
complex
ecosystems.
3) How
the
survival
and
proliferation
of
undesired
microorganisms
can
be
prevented.
WATER
MICROBIOLOGY
Water Microbiology
Aquatic Microbiology (Freshwater): study of
microscopic microorganisms living in freshwater
system, river and ponds.
Marine Microbiology (Seawater): study
microscopic
microorganisms
living
sea/oceans.
of
in
AQUATIC
MICROBIOLOGY
Aquatic Microbiota
A typical lakes or ponds serves as an example to
represent the various zones and the kinds of
microbiota found in the freshwater.
Have characteristics zoonitic pattern/ stratification.
Four (4) zones:
 Littoral zone
 Limnetic zone
 Profundal zone
 Benthic Zone
Characteristics of the Aquatic zones
 Littoral zone:
• Along shore line.
• Large population of rooted vegetation and light
can penetrate.
• Zone can be determine by amount of light
penetration.
• Photosynthesis decreasing when increase depth of
zone.
• Greatest microbiology diversity, producers: Plant.
Characteristics of the Aquatic zones
(cont)
 Limnetic zone:
• Surface of open water along shore, light penetrates
throughout it.
• Producers: Algae and cyanobacteria – because of
light penetrationsupport the population of bacteria,
protozoa, fish and other aquatic life.
Characteristics of the Aquatic zones
(cont)
 Profundal zone:
• Middle zone, deeper water, under limnetic zone, has
low oxygen concentrations and less light.
• Populated by chemolitotrophy microorganisms
because of availability of nutrients in this zones.
• Producers:
Anaerobic
purple
and
green
photosynthetic bacteria (metabolize H2S to sulphate
and sulfur).
Characteristics of the Aquatic zones
(cont)
 Benthic zone:
• Bottom sediment, often no light and little O2.
• Composed of soft mud, mainly organic matter.
• Populated by heterotrophic microorganisms,
mainly anaerobic decomposer.
SRB: Desulfovibrio (reduce sulphate to H2S).
Methanogens (produce methane gas).
Clostridrium sp, particularly those causing
outbreaks of botulism in waterfowl.
Factor affecting type and no of m/o’s in
aquatic
 Oxygen availability.
• O2 solubility in water never exceed 0.007g/100g of fresh
water.
 Concentration of organic matter.
• High number of organic matter content encourage
bacteria decomposer, resulting in changes in liquid O2
supply in water.
 Depth of sunlight penetration.
• Effect type and quantity of photosynthesis.
 pH of water.
• Acidic pH encourage acidophilic microorganisms to grow.
• Alkaline pH: alkalophilic microorganisms.
 Temperature.
• Water from hot spring, encourage thermophilic bacteria
to grow.
MARINE
MICROBIOLOGY
Marine Microbiology
• Characteristics of seawater.
 High no of salt concentration – salt concentration very
constant, dissolve salt concentration vary from 33.37g/
kg of seawater.
 Salt concentration less in shallow water compared to
deeper water.
• Microflora of seawater.
 Halophiles – Bacteria, Algae, protozoa, Viruses.
 Planktons – Zooplanktons (animal origin), Phytoplankton
(plant origin)
Marine Microbiota
Marine Microbiota
• Populations of different strains vary at different depths
according to their adaptation to available sunlight.
• Phytoplankton in top 100 m (upper of ocean):
Photosynthetic cyanobacteria:
 They fix carbon dioxide to form organic matter
(released as dissolved organic matter) and used by
ocean’s heterotrophic bacteria.
• Prochlorococcus
• Synechococcus
 Fixes nitrogen and help replenish the nitrogen that is lost
as organisms sink to oceanic depths.
• Trichodesmium
Marine Microbiota
• Waste products of photosynthetic populations will
decomposed by:
• Pelagibacter ubique
• Archaea dominate below 100 m:
• Crenarchaeota, well adapt to cool temperatures
and low oxygen levels of oceanic depths. Carbon
sources derived from dissolved CO2.
• Bioluminescent (aka light emission) bacteria are
present.
 Have established symbiotic relationship with benthicdwelling fish.
 Fish use the glow of luminescence bacteria to attract
and capture prey in the darkness of ocean depths.
Bioluminescence
FMNH2
(Flavoprotein)
Luciferase
FMN + photon of light
METHODS OF WATER
PURIFICATION
Water Treatment
• Objectives:
1) To make it safe for drinking and all organisms
activities.
2) Free of disease-causing microbes, not
intended to produce sterile water.
The Treatment of Water
• Water Purification is a Three-Step Process:
 Sedimentation removes large objects and
particles through flocculation.
 Filtration removes microorganisms by passing
water through a layer of:
• Sand.
• Gravel.
• accumulated microbe biofilm.
 Chlorination involves adding chlorine gas to kill
remaining organisms.
Flocculation Process
• Turbid (cloudy) water is allowed to stand in a holding
reservoir to allow as much particulate suspended
matter as possible to settle out.
• Followed by flocculation process to remove colloidal
materials (e.g clay).
• A flocculant chemical {Aluminium potassium sulfate
(alum)} is added to form aggregations of fine
suspended particles called ‘floc’, which later slowly
settle out to the bottom.
• Most viruses and bacteria are removed by this way.
Filtration Process
• Filtration prosesses - water passed through beds
of 2- 4 ft of fine sand or a crushed anthracite
coal.
• Protozoan cysts and oocysts are removed by this
method.
• Water system of cities: Sand filtration were
supplement with activated charcoal (carbon) to
remove particulate matter and most dissolved
organic chemical pollutants.
• To date, Low pressure membrane filtration
systems (pore openings 0.2 µm) also used to
remove Giardia and Cryptosporidium.
Disinfection Process
• Filtered water is chlorinated (organic matter
neutralizes chlorine).
• Another methods is ozone treatment, used as
primary disinfectant treatment followed by
chlorination.
• Ozone is highly reactive form of oxygen that is
formed by electrical spark discharges and UV
light.
• Ozone for water treatment is generated
electrically at the site of treatment.
• Adv: leaves no taste or odor, has little residual
effect.
Municipal Water Purification Treatment