Fungi Eukaryotic Heterotrophic Organisms Biology Essay


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Fungi are eukaryotic, heterotrophic organism (they consume organic forms of carbon for energy) that lack motility (the ability to move by self-generated propulsion). Fungi are monophyletic group, also called the Eumycota ("true fungi" or eumycetes) that is phylogenetically distinct from the morphologically similar slime molds (myxomycetes) and water molds (oomycetes). They are divided into three basic shapes which are unicellular yeasts, filamentous hyphea (molds) and sporangia (mushrooms).

Fungi sexual and asexual reproduction is commonly via spores, often produced on specialized structures or in fruiting bodies. Some species have lost the ability to form reproductive structure and propagate solely by vegetative growth. Besides, fungi are typically aerobic and may be single-celled species or multicellular. Yeasts are single-celled fungi. Most of yeast form asci, which comprise up to eight haploid ascospores in sexual reproduction. These ascospores may liquefy with adjoining nuclei and multiply through vegetative division or, as with certain yeast, fuse with other ascospores. Molds grow as networks of filaments while sporangia grow as macroscopic organisms with fruiting bodies. Molds reproduce by means of spores, which are easily dispersed and often survive in conditions that would kill the active cells.

Some fungi have their benefits in our life. It is because they can perform an essential role in all ecosystems in decomposing organic matter and are indispensible in nutrient cycling and exchange. However, fungi also have negative effects to human. They can cause serious disease to human which some of the disease may lead to death. One of the pathogenic fungi that cause diseases in human is Candida sp. In this study, selected Malaysian plants will be screened to determine potential plants that possess the ability to disrupt the growth of Candida sp.

2.2 Candida

Candida is a genus of yeast that has more than 20 species and the most common species is Candida albicans. Nowadays, Candida albicans is thought to be the major fungal pathogen of humans. Several Candida infections are very serious problem, especially to people whose immune defense mechanisms have been weakened. Moreover, C. albicans can enter the bloodstream by direct penetration from the epithelium after tissue damage, or by dissemination from biofilms formed on medical devices introduces into patient`s organism, e.g. catheters, dental implants, endoprostheses, artificial joints or central nervous system shunts (Chandra et al., Mavor et al., 2005). Thus it easily cause infections like vaginal yeast infections, thrush (infection of tissues of the oral cavity) and diaper rash.

Vaginal yeast infection is an infection which involves a type of fungus. It is also known as vaginal candidiasis, genital candidiasis or vulvovaginal candidiasis. Umeh and Umeakanne (2010) elaborate that the vagina infection is characterized by vulvar pruritus, dysuria, dyspareunia, irritation, and soreness of the vulva; and is sometimes accompanied by erythematous and curdlike vaginal non foul smelling dis-charge. People can realize the vagina infection by looking at the symptoms of that infection such as itching and irritation in the vagina, a burning sensation, especially during intercourse or while urinating, redness and swelling of the vulva, vaginal pain and soreness and thick, white, odor-free vaginal discharge with a cottage cheese appearance. A change in the vaginal environment can cause the yeast to grow excessively, resulting in thrush (vaginal candidiasis).

However, for superficial yeast infection which is thrush may involve the tongue, inner cheek and inner lip region. Although many people think that thrush may affect baby, but it does not means toddlers, children and adult will not affect by thrush. Actually, thrush will affect people without consider the ages.

Different with vagina infection and thrush, diaper rash is a common infection especially happen to children below than two years or people who are incontinent or paralyzed. This infection usually occurs on the skin under a diaper. Thus, this infection can be consider as compulsory to children who are always use diaper in the early age like below than two years. However, baby at nine until twelve month will easily to get this infection because in this time baby is still sitting most of the time besides they eating solid foods which can lead the acidity of the bowel movements make changes.

2.3 Antifungal (PLEASE REWRITE THIS 2.3). You should have the name of antifungal drugs and how it kills the fungi. Describe antifungal from plant found by previous study. Has it been commercialized?

Antifungal drugs are used to treat infections caused by a fungus which is unicellular form of life. It survives by occupying and alive off other living things. Athlete`s foot, jock itch, yeast infection and ringworm are the common fungal infections. People can get these drugs at the counter without a doctor`s prescription. There are two types of antifungal drugs which are systemic antifungal drugs and topical antifungal drugs.

Systemic antifungals are often reserved for the treatment of onychomycosis, tineacapitis, superficial and systemic candidiasis, and prophylaxis and treatment of invasive fungal infections while topical antifungal agents are generally used for the treatment of superficial fungal infections unless the infection is widespread, involves an extensive area, or is resistant to initial therapy (Alexandra, William and Boni, 2007). In other word, for the infection caused by fungus can be treats by systemic antifungal drugs that taken the medicines by mouth or injections and topical antifungal drugs that applied medicines to the skin like cream or antifungal powder.

The examples of systemic antifungal drugs that had been commercialized are capsofungin (Cancidas), flucytosine, fluconazole (Diflucan), itraconazole (Sporanox), ketoconazole (Nizoral), and miconazole (Monistat I.V.). These antifungal drugs are presence in many forms like in tablet, capsule, liquid, and injectable forms. However, there have some side effects of using these antifungal drugs. For instant, if using fluconazole there will expose to the side effects such as swelling, swallowing problems, sudden drop in blood pressure and abdominal pain. Compare to fluconazole, ketonazole will give effects of loss of appetite, vomiting, yellow skin or eyes, unusual fatigue and dark urine. Thus, it shows that different antifungal drugs give different side effects.

Besides, clotrimazole, econazole, miconazole and terbinafine are the examples of topical antifungal drugs. These antifungals drugs have some side effects when people use it such as irritation, itching and redness. For clotrimazole, it is used as a cream, spray, powder or solution to treat fungal infection of a vagina and infections of the skin. By using clotrimazole, it will carry out some side effects such as mild burning, rash, itchiness, pain and allergic reaction. However, people should take some guidelines as a precaution to avoid the side effects become more serious. Thus, people should tell the doctor if they have allergic to the antifungal drugs which are given.

However, both fungi and humans are eukaryotes. It means that both of the species are stand at same molecular level. Thus, it becomes more challenging part for scientist in order to find the drugs that only target to fungi without affecting human cells.

Most of the commercial antifungal drugs have side-effects and one of them is life-threating if the drugs is not handling or used properly. Thus, the need to search for new antifungal that have less side effects and safe to people.

Describe antifungal from plant found by previous study. Has it been commercialized?

2.4 Medical plants

Millions of dollars are needed in order to develop the medical plants into therapeutics drug besides it take several years to get the result. This process has very high risk because the results not always show the successful result. Nevertheless, some scientists will go ahead and do research and run the experiment of plants. It is because of many reasons and one of the reasons is there have high chemical diversity of natural products as compared to the synthetics and the potential of these natural products is unknown. Besides, most scientists believe, an advance and modern technology in this field nowadays can help them very much in run the experiment especially.

Malaysia, with her rich source of medical plants from the tropical forest haven taken steps to increase the scientific knowledge of the plants and make it useful to people. Philip et al., (2009) states that in Peninsular Malaysia, 1,200 species of higher plants and 2,000 species in Sabah and Sarawak are reported to have medicinal value and have been used for generations in various traditional health care systems. Products derived from plants may potentially control microbial growth in diverse situations and the specific case of disease treatment, numerous studies have aim to describe the chemical composition of these plant antimicrobials and the mechanism involved in microbial growth inhibition, either separately or associated with conventional antimicrobials (Junior A and NCC, 2010, p. 402).

In this study, seven plants will be screen to determine either it have antifungal compound or not. They are White Mussaenda  philippica (Pokok Janda Kaya Putih), Erythrinaglauca (Bunga Dedap), Lagerstroemialoudonii (Bungur), Hymenocallislittoralis (Bakung), CostusSpicatus (Pokok Lipstik), Heliconiarostrata (Sepit Udang) and Piper Botol (Sireh Melayu).

2.4.1 White Mussaenda  philippica (Pokok Janda Kaya Putih)

Figure 2.1 :White Mussaenda philippica (Pokok Janda Kaya Putih)

Mussaenda is a genus of plants in the family Rubiaceae which has common name as Tropical Dogname or Virgin Tree. It is a tropical shrub or sub-shrubreaching10 feet tall even it is qualified as a single specimen of 5 feet on ground or less than 3 feet in containers. This flower is unique because it has small tubular five-petalled corolla in orangey-yellow and five greatly enlarged sepals. This plant can be grown as decorative in parks and public gardens or along roadsides and highways. This plant become more attractive to butterflies, bees, hummingbirds and insect pollinators as a nectar plant due to its beauty of flower. In native Philippines, they believe that this plant can be used to against snake bikes and cure dysentery. Brown (1950) found that the roots and leaves in decoction can be used for certain affectins of chest and lungs. He also elaborate that the root is employed in cases of jaundice as are also the white, full-grown sepals.

2.4.2 Erythrinaglauca (Bunga Dedap)

Figure 2.2 :Erythrinaglauca (Bunga Dedap)

Erythrinaglaucahas or Erythrinafusca which come from the family of Fabaceae. The common name of this plant is coral bean or cape kaffirboom. E. fusca has the broadest spreading of any Erythrina species. This plant grows on coasts and along rivers in tropical Asia, Oceania, the Mascarene Islands, Madagascar, Africa, and the Neotropics. It has three different sizes which are 6-9 m, 9-12 m, and also over 12 m while the colors of this plant are coral or apricot, and red-orange. Full sun exposure is needed for the growth. Similar to other species in the genus Erythrina, E. fusca contains toxic alkaloids which have been exploited for medicinal value but are poisonous if it is taking in large amounts. The common alkaloid is Erythraline, which is named for the genus. The new buds and leaves can be eaten as a vegetable.

2.4.3 Lagerstroemialoudonii(Bungur)

Figure 2.3 : Lagerstroemialoudonii (Bungur)

Lagerstroemia is a genus of around 50 species of deciduous and evergreen trees and shrubs native to the Indian subcontinent, southeast Asia, northern Australia and parts of Oceania.It is a member of the Lythraceae family, which is also known as the Loosestrife family. However, the origins of this plant are Malaysia and Australia. During the flowering season, this plant is a beautiful sight to behold. All its leaves shed, giving way to mouve-pink flowers which covers the entire crown. It flowers yearly during month of February and March.


2.4.4 Hymenocallislittoralis(Bakung)

Figure 2.4 :Hymenocallislittoralis (Bakung)

Hymenocallislittoralis is a plant species of the genus Hymenocallis, with large white flowers.Besides, it is also a bulbous perennial herb. Hymenocallislittoralis is an active evergreen species from Mexico and Guatemala which grows with its roots in the water during the warm growing season and makes a good garden subject in that season. However, during cold winter, it needs some protection to make sure it can grow as usual. This flower has long narrow reflexed petals behind a central cup with the height is from 60-70 cm (36 inches), the diameter is 7-10 cm (3-4 inches) and develops the bulb when a neck is reaches 4-5 cm in diameter (up to 2 inches). Besides, this plant has large and white flower, and smell like vanilla scented.


2.4.5 CostusSpicatus (Pokoklipstik)

Figure 2.5 :CostusSpicatus (PokokLipstik)

The CostusSpicatus is a plant indigenous to tropical regions. It grows mainly in moist areas, yet can thrive in the sun so long as there is plenty of water. The CostusSpicatuscan grow as high as seven feet, leaves about a foot long and four inches wide. This plant produce a short cylindrical red cone with red-orange flowers emerging one at a time, long lasting and used as a cut flower. The petals resemble the leafy ginger one might see in a restaurant. Since the plant makes a sugary nectar, thus the ant will be attract to it.


2.4.6 Heliconiarostrata (SepitUdang)

Figure 2.6 :Heliconiarostrata(SepitUdang)

Heliconiarostrata or common name Lobster claw is an herbaceous perennial native to the north western region of South America. The size of this plant is about 6-8 feet tall and has spectacular bright red bracts with yellow tips. Rostrata in plant name means "beaked", which refer to the bracts` resemblance to a parrot`s beak. The foliage of Heliconiarostrata is much like that of a banana. The unique of this plant make it always used as a specimen for tropical gardens. The mature plant normally starts to flower in the summer. This plant is better placing it at sheltered area because strong winds can shred the leaves pretty bad.


2.5 Extraction

Extraction is a process in which two phase come into contact with the objective of transferring a solute or particle from one phase to the other. For the separation of biological products, the phases are most commonly immiscible liquids and the solute is in soluble form. Extraction can be divided into two types which are liquid-liquid extraction and solid-liquid extraction. However, in this project, solid-liquid extraction will be used.

2.5.1 Solid-liquid extraction

WHY YOU DESCRIBE LEACHING?? ARE WE DOING LEACHING?? Leaching is one of many solid-liquid extraction processes that carried out the chemical, mineral and related industries. The significant of leaching is the removal of a soluble material from an insoluble, permeable solid phase. Solid or liquid for soluble fraction may exist mechanically in the pore structure of the insoluble material or chemically combined with that material. This soluble material is removed through dissolution in a dissolving solvent. For instant of leaching are the extraction of tea and coffee, extraction sugar from sugar beets, and oil from oil bearing seeds.

Physical and chemical phenomena are the major factors that affect the rate of leaching. There have some steps of leaching which start from the solvent diffuses into the solid phase. Then, the diffused solvent dissolves the solutes which is transfer the solute to the liquid phase. The process of leaching always followed by solvent recovery such as filtration, which involve mass transfer operation.

2.5.2 Solvent of extraction

According to Rydberg, et al., (2005), the term solvent extraction refers to the distribution of a solute between two immiscible liquid phases in contact with each other such as a two phase distribution of a solute. Solvent extraction is a common form of chemical extraction using organic solvent as the extractant. It is commonly used with liquids, but can also be employed for gases and solids. A solution is homogeneous mixture when it is mixing well while a solvent is a liquid substance capable of dissolving other substances and the solvent does not change its state in forming a solution.

In daily life, the common solvent that be used by humans is water. However, organics solvents which are organic (carbon containing) chemicals are other most commonly used as solvents. There are some characteristics of solvents which have a low boiling point and evaporate easily or can be removed by distillation, leaving the dissolved substance behind. Some people confuse between solutes and solvents. In order to make it clear explanation, solvents are usually present in the big amount and it can also be used to extract soluble compounds from a mixture compared to solutes. Besides, solvents are usually in clear and colorless liquids. WHAT IS THE COMMON SOLVENT USED TO EXTRACT ANTIFUNGAL COMPOUND? ELABORATE ON THAT.

2.6 Antifungal Extraction

Based on the other previous researchers, they found that there are many methods in extraction which are steam distillation, expression, solvent extraction, maceration and enfleurage. In this study, solvent extraction of agitation is used. In order to get the better result, pre-treatment process should be done carefully in all methods that be applied.

2.7 Optimization of Extraction

The conditions to extract antifungal compounds will be optimized to reduce the cost of operations and time spends. In order to get the high yield of antifungal compounds, the extraction parameter such as temperature, time and agitation speed are be manipulated. Furthermore, to get the best result, each parameter should be apply in three different levels which is low, middle and high.

2.7.1 Temperature

Temperature is one of the manipulative parameter that needs to control and alter selectivity. Raised up temperatures are sometimes used in order to keep the viscosity in low condition and thereby minimizing mass-transfer resistance. It is proportional to the compound recovery. Thus, if the temperature increases so the compound recovery will also be increase.

2.7.2 Time

There is an inverse relationship between the time required for efficient extraction and size of the sample particles (Kotze & Eloff, 2002). Extraction times differ depending on the amount of the sample used. Often 10 min are sufficient for extracting1 to 3 g samples, which is exemplified by the extraction of organic pollutants (Lopez-Avila etal., 1994), but even 3 min have been demonstrated to give full recovery for pesticides from solids and sediments (Onuska & Terry, 1993).

2.7.3 Agitation Speed

2.8 Screening for Antifungal Compounds

2.8.1 Candida albicans

Candida albicans occurs naturally as a commensal of mucous membranes and in the digestive tract of humans and animals. At least 70 % of Candida strains isolated from sites of infections have been identified as C. albicans, and it has been reported as pathogenic in all forms of candidiasis (Arora, 2004). C. albicans can also be isolated from sources contaminated by human or animal excreta (Ellis, 1994).

2.8.2 Candida glabrata

Candida glabrata is found on body surfaces and is often isolated as an incidental finding from the skin, urine, and faeces. It is an opportunistic agent in systemic and superficial infections, especially in immunocompromised hosts, and it has been isolated from patients with septicaemia, pulmonary infections, endocarditis and pyelonephritis (Edwards, 1995; Ellis, 1994).

2.8.3 Candida parapsilosis

Candida parapsilosis is a species that involved in 15 to 30 percent of Candida infections. Furthermore, the increase in C. parapsilosis is affecting concern in hospitals, especially in Europe. It is due to the growing number of fungemia and tissue infections in immune-weakened people and it shows a high natural resistance to antimicrobial drugs. Besides, C. parapsilosis may cause fungal infections of the nail beds and systemic disease, especially endocarditis which is inflammation of the inside lining of the heart chambers and heart valves.

2.8.4 Candida tropicalis

Candida tropicalis has been identified as the most prevalent pathogenic yeast species of the Candida-non-albicans group (Kothavade et al., 2010 ). He also says that Candida albicans has been the major species responsible for causing candidiasis in immunocompromised and immunocompetent patients. However, infections (candidiasis) due to C. tropicalis have increased dramatically on a global scale thus proclaiming this organism to be emerging pathogenic yeast. The reasons for this organism's dominance and its resistance to fluconazole have been difficult to elucidate. In addition, the mechanism of this organism's pathogenicity and the consequent immune response remain to be clarified.

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