Ecology Lecture Notes

Difference between Oligotrophic and Eutrophic Lakes


characteristics of lake ecosystem

Oligotrophic vs Eutrophic Lakes
Similarities and Difference between Oligotrophic vs Eutrophic Lakes / Ponds

Lake Ecosystem is an example for a lentic ecosystem. An aquatic ecosystem with stationary or relatively still water is called lentic ecosystem. Based on the trophic state* and productivity, the lake ecosystem is divided into three categories.

(1). Oligotrophic lakes

(2). Eutrophic lakes

(3). Mesotrophic lakes

(1). Oligotrophic lake: a lake with low productivity, low nutrients and clear water with drinking water quality.

(2). Eutrophic lake: a lake with high productivity, high nutrients and with dark water. The water is usually not good for drinking purpose.

(3). Mesotrophic lake: a lake with intermediate nutrient level and productivity.

This post describes the similarities and differences between an Oligotrophic Lake Ecosystem and a Eutrophic Lake Ecosystem as a comparison table.

Similarities between Oligotrophic and Eutrophic Lakes / Ponds

Ø  Both are aquatic ecosystems.

Ø  Both are natural ecosystems.

Ø  Both contain biological and abiological components.

Ø  Water in both ecosystems is rich in oxygen.

Ø  Both are lentic ecosystems.

Ø  Both ecosystems show thermal stratification.

Difference between Oligotrophic and Eutrophic Lakes/Ponds

Continue reading

Biotechnology Lecture Notes

Batch Fermentation vs Continuous Fermentation Process: Similarities and Differences – A Comparison Table


Difference continuous and batch fermentation

Batch Fermentation vs Continuous Fermentation Process
(Similarities and difference between Batch Fermentation and Continuous Fermentation Process)

Batch Fermentation and Continuous Fermentation are the two commonly adopted Industrial Fermentation methods for the scale production of microbial biomass or metabolites.

Batch Fermentation: Here the fermenter is first filled with the raw material (carbon source). Then the microbes are added and allowed to ferment the raw material under optimum pH and aeration. The products remain in the fermenter until the completion of fermentation. After fermentation, the products are extracted and the fermenter is cleaned and sterilized before next round. Thus here the fermentation is done as separate batches.

Continuous Fermentation: Here the exponential growth rate of the microbes is maintained in the fermenter for prolonged periods of time in by the addition of fresh media are regular intervals. The metabolite or the product of fermentation is extracted for the overflow from the fermenter. Thus unlike batch fermentation, in continuous fermentation, the fermentation process never stops in between and it continues to run for a long period of time with the addition of nutrients and harvesting the metabolites at regular intervals.

The present post describes the Similarities and Differences between Batch Fermentation and Continuous Fermentation Process as a Comparison Table.

Similarities between Batch Culture and Continuous Culture Fermentation Methods

Ø  Both are industrial fermentation methods for the large scale production.

Ø  Both methods can be used for the production of microbial biomass or products.

Ø  Both run under controlled environmental conditions

Ø  The mechanical components of fermenter is almost similar in both types

Difference between Batch Fermentation and Continuous Fermentation Process

Continue reading

Biotechnology Lecture Notes

Industrial Fermentation Process (Batch, Fed-batch and Continuous Fermentation)


types of fermentation process

Fermentation Technology
(Types of Industrial Fermentation Processes)

Fermentation: An art from the past, a skill for the future…
Brain McNeil

What is fermentation?

Ø  Fermentation is a metabolic process which converts carbohydrates to alcohols, organic acids or gases by the activity of enzymes of microbial origin.

Ø   Microbes involved in fermentation process: Bacteria and Fungi.

Ø  The process of anaerobic respiration in the muscle cells of animals during exercise which produce lactic acid is also a type of fermentation.

Ø  The technique of fermentation was very ancient in origin.

Ø  Egyptians and Sumerians had the knowledge of the technique of converting starchy grains to alcoholics.

Ø  For a microbiologist, the word ‘fermentation’ means many processes such as:

$   A method of mass cultivation of microbes under aerobic or anaerobic conditions.

$   Any biological process occurs in the absence of oxygen.

$   Spoilage of food by microbial activity.

$   Production of alcoholic beverages, organic acids, antibiotics or biopolymers

$   Partial oxidation of carbohydrates

What is industrial fermentation?

Ø  The intentional use of fermentation technology for the large scale production of microbial biomass or metabolites is called industrial fermentation.

Continue reading

Human Physiology Lecture Notes

Artery vs Vein: Similarities and Differences (A Comparison Table)


difference between artery and vein

Arteries vs Veins
Similarities and Differences between Arteries and Veins

The circulatory system in an organism ensures the transport of oxygen, nutrients, carbon dioxide and hormone throughout the body. The blood circulatory system in an animal is facilitated by the heart (the blood pumping organ) and blood vessels (closed pipelines which carry out the circulation of blood throughout the body). There are three types of blood vessels in our body. They are:

(1).    Arteries
(2).    Veins
(3).    Capillaries

(1). Artery: They are blood vessels which originated from the heart and carry blood away from the heart. Arteries usually carry oxygenated blood except for pulmonary and umbilical arteries that carries deoxygenated blood.

(2). Vein: They are blood vessels which carry blood to the heart from various organs of the body. Veins usually carry deoxygenated blood except for pulmonary and umbilical vein that carries oxygenated blood.

(3). Capillaries: They are minutes blood vessels of one cell layer thickness and they facilitate the exchange of oxygen, carbon dioxide, nutrients and hormones in the blood to individuals cells of different organs. Arteries and veins are interconnected through capillaries and thus the blood circulation forms a closed system in majority of animals.

The current post describes the similarities and differences between Arteries and Veins with a comparison table.

Similarities between Arteries and Veins

Ø  Both are blood vessels.

Ø  Both transport blood.

Ø  Blood transport is unidirectional in both arteries and vein.

Ø  Arteries and veins composed of layers of cells.

Ø  Both arteries and veins composed of three layers of cells namely Tunica externa (external layer), tunica media (middle layer) and tunica interna (internal layer).

Ø  Both arteries and veins are covered by muscular tissues which assist in the contraction or expansion of blood vessels.

Ø  Both undergo vasoconstriction and vasodilation to adjust the blood pressure according to the action of hormones and neurotransmitters.

Ø  Both arteries and veins show anastomosis.

Difference between Arteries and Veins

Continue reading

Lecture notes in Microbiology

MCQ on History of Microbiology (MCQ 05) with Answer Key


mcq on history of microbiology

MICROBIOLOGY MCQ-05
(Biology / Life Sciences MCQ: Multiple Choice Questions in Microbiology)

MCQ on Scientists & Discoveries in Microbiology Part 2
(Sample/Model/Practice Questions for NEET, AIPMT, M.Sc. and Medical Entrance Examination)


1. Who discovered Mycobacterium tuberculosis?

a.       Koch
b.      Jenner
c.       Pasteur
d.      Virchow

2. Mycobacterium lepree was discovered by:

a.       Pasteur
b.      Jenner
c.       Koch
d.      Hansen

3. Antibodies were discovered by:

a.       Edelman
b.      Porter
c.       Edelman and Porter
d.      Edelman and Hess

4. Streptococcus pneumonia was discovered by:

a.       Pasteur
b.      Jenner
c.       Koch
d.      Hansen

5. Who discovered Bacillus anthacis?

a.       Koch
b.      Pasteur
c.       Jenner
d.      Hansen

Continue reading