Cosmarium

Class: chlorophceae

Order: Zygnematales

Family: Desmidiaceae

Genus: Cosmarium

Cosmarium is a uni-cellular fresh water desmids occurring in ponds, rich in organic decaying matter, along with other free-floating algae. Usually it occurs in abundance in mucilaginous masses along the wall of reservoirs and water tanks especially in winter'

The cell posses a distinct median constriction called sinus. This divides them in to two distinct halves called semi- cells. Which remains join together by a connecting zone called isthmus. Each semi-cell maybe circular, elliptical or oval in shape. The cells posses a three layered transversely segmented walls with vertical poles arranged in a definite pattern. A single nucleus is found in the isthmus region. There is one or more chloroplast in each semi-cell with one or two pyrenoid.

Reproduction takes place by asexual reproduction (cell division) and isogamous sexual reproduction. Sexual reproduction results formation of zygospore.

Read more »

Posted in: Microbiology

Anabaena

Kingdom: Bacteria

Division: Cyanophyta

Class: Cyanophyceae

Order: Nostocales

Family: Nostocaceae

Genus: Anabaena

Anabaena is the filamentous form found occurring either in the single filament or as free-floating colonies or in a delicate means the stratum in permanent or semi- permanent form. Some spices of anabaena are endophytic and have within roots of circus and aquatic pteriodophyte azolla. The Trico are the same thickness through out, sometimes slightly alternated at the typical ends. They are straight cercinated or irregularly contorted concurringly with a hyaline watery sheet.

The cells are usually spherical or barrel shaped .they are typically cyanophyceae with a cell wall made up of peptidoglycogen enclosing the protoplasm. The protoplasm differentiated in outer and central colorless

The centroplasm has an incipient nuclei and the chromoplasm has phycocyrin , phcoerithrin, along with the chlorophyll on photosynthetic lamellae . The protoplasm of vegetative cells are usually filled with numerous psedovacuoles. The heterocyst’s in the filament are inter-colonial and are in a same shape as vegetative cells.

Thick walled resting cells called akinetes are found adjacent to the heterocysts.

Reproduction takes place by means of homogonium and akinetes.

Read more »

Posted in: Microbiology

Basic Structure of an Amino Acid

Basic Structure

All amino acids found in proteins have this basic structure, differing only in the structure of the R-group or the side chain.

The simplest, and smallest, amino acid found in proteins is glycine for which the R-group is hydrogen (H).

L-isomer
In proteins, only the L-isomer is found normally.

As you travel onward (from the carbonyl carbon to the amino group), the R group of L-amino acids will be on the left as shown in the molecular graphic on the right

Essential amino acids

Humans can produce 10 of the 20 amino acids. The others must be supplied in the food. Failure to obtain enough of even 1 of the 10 essential amino acids, those that we cannot make, results in degradation of the body's proteins—muscle and so forth—to obtain the one amino acid that is needed. Unlike fat and starch, the human body does not store excess amino acids for later use—the amino acids must be in the food every day.

The 10 amino acids that we can produce are alanine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine and tyrosine. Tyrosine is produced from phenylalanine, so if the diet is deficient in phenylalanine, tyrosine will be required as well. The essential amino acids are argentine (required for the young, but not for adults), histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. These amino acids are required in the diet. Plants, of course, must be able to make all the amino acids. Humans, on the other hand, do not have all the enzymes required for the biosynthesis of all of the amino acids.

Read more »

Posted in: Biotechnology

Scenedesmus

Scenedesmus is a widely distributed green algae found freely in stagnant water. It appears in pure culture in aquarium and in jar containing standing uncharged water in the laboratory.

It is colonial form with a number of cells in the coenobium (colony) being multiplies of two usually 4-8 cells. The cell are ellipsoidal or fusiform in shape and arranged in single or double series with long axis, parallel to one another so as to form a flat or curve plain. The two end cells of the coenobium may differ from the shape of the others and often teeth or spines or gelatinous bristles, which are projections of the mucilaginous cell envelope .each cell is un-nucleated and contain a single longitudinal laminate chloroplast with one pyrenoid.

Reproduction is by the formation of 2, 4,8,16 or 32 autospores by each cell in the colony. They remain laterally united to another to form a coenobium which is liberated by rupturing of the parent cell wall.

Read more »

Posted in: Microbiology

Spirulina

Spirulina is a planktonic blue green algae found growing in fresh water bodies, sewages etc. it consists of a unicellular trichrome’ which is helically or spirally twisted and hence the name Spirulina.

Each cell is typically cyanophyceae and is bounded by the cell wall enclosing the protoplasm and is differentiated in to outer pigmented chromoplasm consisting of the pigment phycocyanin and chlorophyll which give the green colour to the algae . The inner centroplasm consists of the incipient nucleus.

Reserved food materials such as cyanophytin starch, cyanophytin granules (protein) and oil globules are present in the cytoplasm

Reproduction occurs by cell division or fragmentation of the filaments.

ECONOMIC IMPORTANCE
Spirulina is excellent source of protein .vitamins and minerals, hence can be consumed as s food supplement (single cell protein) .it is also used as an animal feed due to its nutritional value.

Read more »

Posted in: Microbiology

Chlorella

Chlorella is a green algae generally found to occur as a plankton in fresh water bodies and damp walls, rocks etc. The thallus is unicellular some times growing small groups and colonies.

Each cell is small cylindrical or ellipsoidal in shape. The cell is surrounded by 3 layered cell wall. The wall shows the presence of sporopollinin. Each cell posses a single large cup shaped chloroplast which is parietal in position. The cells are unicellular. The nucleus lies in the chloroplast cup, other cell organelles like mitochondrion, ribosome etc are present.

Asexual reproduction takes place by the formation of non-motile autospores. Two to sixteen autospores are produced and they are liberated by the rupture of the parental cell wall.

Read more »

Posted in: Microbiology

Spirogyra

Spirogyra commonly called “pond silk” occurs in extensive muscles in living bright green free floating algae on the surface of stagnant ponds’ slowly running streams and fresh water streams. The thallus or plant body consists of long slender thread like un-branched filaments which are slimy to touch due to mucilage on there outer wall .

A cell enlarged

Each filament is composed of a single raw of similar cylindrical cells. Each cell consists of a cell wall made up of cellulose and protein in definite within the cell wall is a parietal layer of protoplasm enclosing a large central vacuoles. In the protoplasm is embedded 1-14 chloroplast.

Each chloroplast is in the form of a constitutes a green spiral band with toothed edges hence the name spirogyra. The chloroplast has large pyrenoids in them. There is a large single nucleus one or two nucleoli and it is suspended in the middle of the cell by cytoplasmic strands

Lateral conjugation

Reproduction occurs asexually by fragmentation of the filaments and during unfavorable conditions by the formation of walled resting spores. Sexual reproduction is by conjugation. Turning of two morphologically identical cells but physiologically dissimilar gametes.

scalariform conjugation

Read more »

Posted in: Microbiology