ENVIRONMENTAL MICROBIOLOGY SLIDES-B.pptx

Lecture notes

1. Microbiology Denis D. Yar Ph.D

2. ENVIRONMENTAL MICROBIOLOGY Environmental microbiology This is the study of the composition and physiology of microbial communities in the environment. The environment in this case means the soil, water, air, and sediments covering the planet and can also include the animals and plants that inhabit these areas.

3. Environmental microbiology also involves : Microbial interaction and interaction with macroorganisims . Population biology of microorganisms. Microbial communities genetic and evolutionary processes. Element cycles and biogeochemical processes. Microbial life in extreme and unusual environment

4. Microbial habitats: Microbes are found in just about every kind of habitat. Microbes are incredibly diverse thriving in environments from the very cold to the extremely hot. They are also tolerant of many other conditions such as limited water availability high salt content and low oxygen levels. Not every microbe can survive in all habitats. Types of microbial habitats: Terrestial (soil ) microbial habitats. Aquatic(water) microbial habitats. Microbial Habitats in Other Organisms. air microbial habitat.

5. Soil Microbial Habitats Only one percent of microbes that live in soil have been identified. These organisms take part in the formation of soil and are essential components of their ecosystems. Bacteria and fungi that live in soil feed mostly on organic matter such as other plants and animals. These microbes are very sensitive to their local environment. Factors such as the levels of carbon dioxide and oxygen the pH moisture and temperature all affect the growth of microbes in the soil.

6. Water Microbial Habitat Microbes live in both fresh and salt water. These organisms include microscopic plants and animals as well as bacteria fungi and viruses. As with other microbes the ones that live in water are adapted to the specific conditions of their environment. Habitats range from ocean water with an extremely high salt content to freshwater lakes or rivers

7. Microbial Habitats in Other Organisms. Microbes also live on other organisms. As with the ones found on people these microbes can be harmful or beneficial to the host. Example: Bacteria grow in nodules on the roots of pea and bean plants. These microbes convert nitrogen from the air into a form that the plants can use. In many ways animals and plants have evolved as habitats for the millions of microbes that call them home.

8. WATER AS MICROBIAL HABITAT Water is essential to life, but many people do not have access to clean and safe drinking water and many die of waterborne bacterial infections.

9. Microbiological Water Analysis The most important bacterial gastrointestinal diseases transmitted through water are cholera, salmonellosis and shigellosis. These diseases are mainly transmitted through water (and food) contaminated with feaces of patients. Drinking water can be contaminated with these pathogenic bacteria, and this is an issue of great concern. However, the presence of pathogenic bacteria in water is sporadic and erratic, levels are low, and the isolation and culture of these bacteria is not straight-forward. For these reasons, routine water microbiological analysis does not include the detection of pathogenic bacteria. However, safe water demands that water is free from pathogenic bacteria.

10. Coliforms Coliforms are a broad class of bacteria found in our environment, including the feaces of man and other warm-blooded animals The presence of coliform bacteria in drinking water may indicate a possible presence of harmful, disease-causing organisms. They are defined as rod-shaped Gram-negative non-spore forming and motile or non-motile bacteria which can ferment lactose with the production of acid and gas when incubated at 35–37°C. Coliforms can be found in the aquatic environment, in soil and on vegetation; While coliforms themselves are not normally causes of serious illness, they are easy to culture, and their presence is used to indicate that other pathogenic organisms of feacal origin may be present.

11. A good bacterial indicator of fecal pollution should fulfill the following criteria: (1) exist in high numbers in the human intestine and feaces (2) not be pathogenic to humans (3) easily, reliably and cheaply detectable in environmental waters. (4) does not multiply outside the enteric environment (5) in environmental waters, the indicator should exist in greater numbers than eventual pathogenic bacteria

12. Bacteria Disease/ infection Symptoms Aeromonas Enteritis Very thin, blood- and mucus-containing diarrhea Campylobacter jejuni Campilobacteriose Flue, diarrhea, head- and stomachaches, fever, cramps and nausea Escherichia coli Urinary tract infections, neonatal meningitis, intestinal disease Watery diarrhea, headaches, fever, homiletic uremia, kidney damage Plesiomonas shigelloides Plesiomonas -infection Nausea, stomachaches and watery diarrhea, sometimes fevers, headaches and vomiting Typhus Typhoid fever Fevers   Salmonella Salmonellosis Sickness, intestinal cramps, vomiting, diarrhea and sometimes light fevers Streptococcus (Gastro) intestinal disease Stomach aches, diarrhea and fevers, sometimes vomiting Vibrio Cholera Heavy diarrhea Bacteria Found In Surface Water

13. Microorganisms Disease Symptoms Amoeba Amoebic dysentery Severe diarrhea, headache, abdominal pain, chills, fever; if not treated can cause liver abscess, bowel perforation and death Cryptosporidium parvum Cryptosporidiosis Feeling of sickness, watery diarrhea, vomiting, lack of appetite Giardia Giardiasis Diarrhea, abdominal cramps, flatulence, belching, fatigue Toxoplasm gondii Toxoplasmosis Flu, swelling of lymph glands With pregnant women subtle abortion and brain infections Protozoa Found in Surface Water

14. Viral Sources of Waterborne Disease Hepatitis A: inflammation and necrosis of liver Norwalk-type virus: acute gastroenteritis Rotaviruses: acute gastroenteritis, especially in children Enteroviruses: many types affect intestines and upper respiratory tract Reoviruses: infects intestines and upper respiratory tract

15. Soil Microorganisms And Their Functions BACTERIA They are decomposers, eating dead plant material and organisms' waste. Do you know what soil smells like?

16. Well actinomycetes, a unique type of bacteria, cause that smell, and it is a good sign of healthy soil. Actually, people have been smelling soil for many, many years as a way to judge if the land is good for planting [ Nitrogen-fixing bacteria form symbiotic associations with the roots of legumes like clover and lupine, and trees such as alder and locust.

17. FUNGI Fungi are organisms. They are not plants, nor are they animals. They group themselves into strings called hyphae. The hyphae then form groups called mycelium. They are helpful but could also be harmful to soil organisms. Fungi are helpful because they have the ability to break down nutrients that other organisms cannot.

18. Fungi can attach themselves to plant roots. This is a good relationship called mycorriza . The fungi help the plant by giving it those needed nutrients, and the fungi get food from the plant, the same food that plants give to humans. On the other hand, fungi can get food by being parasites, attaching themselves to plants or other organisms, but for selfish reasons.