PHYTOCHEMICAL SCREENING

PHYTOCHEMICAL SCREENING

Phytochemical screening - is a process of tracing plant constituents. For example you want to found out if a certain plant contains alkaloids (a plant constituent) then, you will be performing a phytochemical screening procedures for alkaloids (in this case mayer's and Wagner's test). There are general plant constituents that can be performed with a standard test. And these are screening for: Alkaloids, Saponin, Glycosides, Flavonoids, Tannins, Phenols, Anthocyanins and Carbohydrates.

REAGENT

Mayer's reagent- is an alkaloidal precipitating reagent used for the detection of alkaloids in natural products. Mayer’s reagent is freshly prepared by dissolving a mixture of mercuric chloride (1.36 g) and of potassium iodide (5.00 g) in water (100.0 ml). Most alkaloids are precipitated from neutral or slightly acidic solution by Mayer’s reagent (potassiomercuric iodide solution) to give a cream coloured precipitate.

Wagner's reagent- An aqueous solution of iodine and potassium iodide; used for microchemical analysis of alkaloids. Also known as Wagner's solution. Wagner's reagent is used to test for alkaloids. To prepare Wagner's reagent; Dissolve 2g of iodine and 6g of KI in 100ml of water.

INDICATOR

Alkaloids- are also sources of antimicrobial agents.

Flavanoids- are phytochemicals that could act as an antimicrobial agent.

Saponins- May serve sa anti-feedants, and to protect the plan against microbes and fungi.

Carbohydrates- Are most abundant class of organic compounds found in living organism. It is also for protection of bacterial cells as bacterial cell wall polysacharides, made up of meurin.

Anthocyanin- is used as a determinant in the pH and pOH of acids and bases.

Tannins- Which are mainly used in tanning or darkening the color of fabrics.

Phenols- are phytochemicals that could act as an antimicrobial agent.

Glycosides- are antidiarrheal and inhibit release of autocoids and prostaglandins.

PLANTS WITH PHYTOCHEMICAL SCREENING

What is blackberry?

Blackberry is a sprawling shrub growing up to 3 meter in height. The stems and leaves bear thorns, although some thorn free cultivars exist. The dark green compound leaves consist of 3 or 5 leaflets. The flowers resemble small roses and are white or light pink coloured. During late summer and autumn the typical blackberries are formed, which purplish-black coloured.

Parts used

Blackberry leaves, bark and root can be used to make tea. The blackberries (fruits) are also eaten and used in fruit juice and jams.

Phytochemicals

These are typical phytochemicals found in blackberry: blackberry leaves contain tannins, gallotannins, dimeric ellagitannins and flavonoids. blackberries (fruits) are exceptionally rich in phytochemicals mainly, flavonoids, anthocyanins, cyanidin, ellagic acid.

Benefits of blackberry

Blackberry leaves are traditionally used for the treatment of burns and scald. Tea from blackberry (leaves, root and bark) is astringent and used against intestinal disorders such as diarrhoea and dysentery. Chewing of fresh blackberry leaves helps to heal bleeding gums and inflammation of the mouth and troat. 
The anthocyanins in blackberries are responsible for the potential anti-carcinogenic properties. The chemopreventive effects of fresh blackberries is caused by their antioxidant properties. Flavonoids strengthen the blood vessels and capillaries.

Other facts

Blackberry is native to Europe (mainly Mediterranean region) and is cultivated in many countries with moderate climate. There exist various cultivars which produce larger berries. From the blackberry juice a very nice red wine can be produced.

Other names

Bramble, brymbyl, bumble-kite, brameberry, brambleberry.

Bacteria

BACTERIA

Constitute a large domain of prokaryotic microorganism. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep portions of Earth's crust. Bacteria also live in symbiotic and parasitic relationships with plants and animals.

DIFFERENT KINDS OF BACTERIA

Coccus

Cocci are round, spherical-shaped bacteria. They can occur as a single bacterium or be arranged in a pair, chain or cluster of bacteria depending on which type of coccus it is. 

Bacillus

Bacilli are rod-shaped bacteria that look like cylinders, arranged singly or in chains. Escherichia coli is a rod-shaped bacteria that normally lives in your intestinal tract without causing disease.

Vibrio

Vibrios are one of three types of bacteria with a spiral-like shape. Vibrios are comma-shaped bacteria that look like a curved rod. They typically live in aquatic environments. Vibrio cholera moves in a darting motion by a single flagellum, a whip like structure.

Spirillum

Spirilla are another subgroup of bacteria with a more rigid spiral shape. 

Spirochete

Spirochetes are long, thin and flexible corkscrew-shaped bacteria. They typically move in a distinctive rotating manner that allows them to be mobile in mucus-lined tissue or where it is viscous.

DESCRIBE THAT EACH TYPE OF BACTERIA CAUSE

Coccus- These bacteria cause many different types of common diseases. Among the more common cocci are Staphylococcus aureus, which appears as a cluster of cocci. Staph aureus can often be found in the nose and on the skin without causing disease, but it is also responsible for causing conditions such as boils, pneumonia, meningitis and toxic shock syndrome. Streptococcus pyogenes occurs as a chain of cocci and causes diseases that originate in the throat or skin, including strep throat and scarlet fever. Neisseria meningitidis occurs in pairs of cocci. This bacteria causes bacterial meningitis, an inflammation of the brain and spinal cord, after entering the body through the nose or throat.

Bacillus- A few strains of E. coli do cause disease that's spread typically by eating or drinking contaminated food or water; a typical symptom is diarrhea. Corynebacterium diphtheriae, another rod-shaped bacterium, infects the respiratory tract and causes diphtheria. Diphtheria causes a thick coating on the back of the nose and throat, making it difficult to swallow or breathe, followed by swelling of the neck and potentially death. Bacillus anthracis is the bacteria that cause anthrax. This rod-shaped bacterium grows in long chains and can infect you through broken skin, ingestion or inhalation.

Vibrio- bacteria that causes cholera. Cholera is an intestinal infection that causes severe diarrhea and dehydration, typically transmitted by drinking contaminated water. It is a very serious disease that can lead to death if not treated promptly.

Spirillum- Causes diarrhea. Campylobacter jejuni is typically acquired in places where sanitation is poor or by eating raw or undercooked poultry. Helicobacter pylori is a similar-shaped bacteria found in your stomach. While some people infected with Helicobacter pylori have no symptoms, it is a common cause of stomach inflammation and ulcers.

Spirochete- Two well-known spirochetes that cause disease in humans are Treponema pallidum and Borrelia burgdorferi. Treponema pallidum causes the sexually transmitted disease syphilis. Infection typically begins as a single sore at the site of infection. Additional lesions or rashes can develop elsewhere on the body if left untreated. Borrelia burgdorferi is transmitted through the bite of an infected tick and causes Lyme disease. Infection with Borrelia burgdorferi causes a typical "bull's-eye" rash. If left untreated, it can affect your heart and nervous system and cause arthritis.

DIFFERENCE BETWEEN GRAM-POSITIVE AND GRAM NEGATIVE BACTERIA

GRAM POSITIVE-  Bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain (safranin or fuchsine) and appearing red or pink. Gram-positive organisms are able to retain the crystal violet stain because of the high amount of peptidoglycan in the cell wall. Gram-positive cell walls typically lack the outer membrane found in Gram-negative bacteria.

GRAM NEGATIVE- Bacteria are a class of bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation, making positive identification possible. The thin peptidoglycan layer of their cell wall is sandwiched between an inner cell membrane and a bacterial outer membrane. In Gram staining, the outer lipid-based membrane of gram-negative bacteria is removed by an alcohol solution. The alcohol also decolorizes the then exposed peptidoglycan layer by dissolving away the previously applied crystal violet. A counterstain (safranin or fuchsine) is then added which recolorizes the bacteria red or pink.

WHAT I LEARNED

* I learned the different kinds of bacteria.

* I learned the disease each type of bacteria cause

* I learned the difference between gram positive and gram negative bacteria.

WHAT I DID

* I search through the internet for information about bacteria and learned much more about it.

I CAN APPLY MY LEARNING TO

* I can apply my learning to research proposal that are needed to be done.