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| Thanks Sean that would be great an as a heads up so there isn't any overlap I can do the signal transduction pathways portion and maybe look over everything and se eif any more definitions need to be entered. - Amanda | Thanks Sean that would be great an as a heads up so there isn't any overlap I can do the signal transduction pathways portion and maybe look over everything and se eif any more definitions need to be entered. - Amanda | ||
| - | ==References Used (indicate name) | + | OKAY since everyone is working on something and its all divided, im going to add to "Fungal Decomposition/ Recycling" and "species type" since those two section dont have enough writings .-ranad |
| + | ==References Used (indicate name) | ||
| Sean/Jordan 1) May, G. S., & Adams, T. H. (1997). The importance of fungi to man. Genome research, 7(11), 1041-1044. | Sean/Jordan 1) May, G. S., & Adams, T. H. (1997). The importance of fungi to man. Genome research, 7(11), 1041-1044. | ||
Revision as of 20:03, 21 March 2013
Ecological contributions of fungi (biochemistry).
Fungus is a group of unicellular, multicellular, or syncytial spore-producing organisms feeding on organic matter, including moulds, yeast, mushrooms, and toadstools.[1] Fungi are widely known for their culinary uses, however fungi have a significant ecological impact; fungi impact ecology in both beneficial and harmful ways. Ecological studies have found that in healthy forest soils, 90% of the total living organisms consist of fungi. The remaining 10% are made up of organisms such as nematodes, algae, rotifiers, protozoa, springtails, mites and worms [2]. In addition, fungi are used in the agriculture, medicine, research, and biotechnology sectors.[3]
Fungi may contribute substantially to soil microbial biomass as well as to the genetic diversity among soil microorganisms. [4] Fungi can utilize carbohydrates like L-arabinose, D-xylose and cellobiose aerobically and some soil yeasts are also found to assimilate intermediates of lignin degradation as well. [4] It has also been shown that fungi can enhance plant growth as well. They do this by expanding the plant's roots and thus making it easier for both the plant and fungi to get nutrients.
Contents |
History
Fungi are found everywhere in the natural environment and they play fundamental roles in the biosphere. Several biochemical processes controlled by fungi are thus; the recycling of nutrient, plant nutrient acquisition, decomposition of dead biomass, release of gases to the environment. Fungi can respond to processes altered by global change such as soil temperature and moisture, availability of nutrient and atmospheric chemistry.
Decomposition is a vital ecological process driven by fungi. Without decomposition, the world would be filled with piles of dead biomass or dead organic matter. For decomposition to fully take effect, fungi secretes chemical that digests dead organic matter, following the initial decomposition process by detritus. Fungi are saprophytes. Saprophytes together with detritus are essential in the recycling and fragmentation processes of decomposition.(http://science.jrank.org/pages/1967/Decomposition.html)
- Contribution of fungi to leaf litter decomposition
contribution of fungi in the decomposition of leaf litter results in the generation of inorganic compounds, fine-particulate organic matter and decomposer biomass.(REFERENCE: Hieber, M., & Gessner, M. O. (2002). Contribution of stream detrivores, fungi, and bacteria to leaf breakdown based on biomass estimates. Ecology, 83(4), 1026-1038.). In ecosystem, decomposition of leaf litters in stream or rivers depends on the activity of invertebrates and microorganism. Fungi and some bacterial mediates the conversion of leaf litters to microbial biomass, the prevalence of fungi in microbial decomposer assemblages has been found in aquatic environment. (REFERENCE:Pascoal, C., & Cássio, F. (2004). Contribution of fungi and bacteria to leaf litter decomposition in a polluted river. Applied and Environmental Microbiology, 70(9), 5266-5273). Not only do fungi contribute to decomposition of leaf litter, they increase the food value of leaves in the aquatic environment. Hyphomycetes fungi which are mostly aquatic have been recognized as playing a major task in microbial decomposition of leaf litter in stream or rivers.(REFERENCE:Pascoal, C., & Cássio, F. (2004). Contribution of fungi and bacteria to leaf litter decomposition in a polluted river. Applied and Environmental Microbiology, 70(9), 5266-5273). When leaf litters fall in aquatic environment, they are colonized and conditioned by fungi by spreading mycelium over the leaf surface and thereby penetrating the leaf. Extracellular enzymes are released to degrade the leaf constituent such as cellulose, hemicelluloses and pectin, thereby making the leaf material more suitable food source for invertebrates in aquatic environment. (REFERENCE:Pascoal, C., & Cássio, F. (2004). Contribution of fungi and bacteria to leaf litter decomposition in a polluted river. Applied and Environmental Microbiology, 70(9), 5266-5273).
- Contribution of fungi to soil organic matter/plant residue
Species Types
Many fungal species contribute ecologically, although the most common relationship between a fungi and plants can be seen as Mycorrhiza. A mycorrhiza is a symbiotic relationship in which a fungus can associate with the roots of a vascular plant. In a mycorrhizal association, the fungus has the ability to colonize the host plant's roots. This process generally occurs intracellularly as in arbuscular mycorrhizal fungi (AMF or AM), but may also occur extracellularly as in ectomycorrhizal fungi. The relationship between these fungi and their plant host's is extremely important in maintaining soil growth and soil chemistry. ( REFERENCE: Habte, M. "Mycorrhizal Fungi and Plant Nutrition." Journal of Plant Nutrition 18.10 (1995): 2191-198.)
Processes
Lichens & Pedogenesis
Lichens are organisms made up of both fungi and a photosynthetic partner in which they form a symbiotic relationship. This has actually become one of the most successful ways of nutrient uptake for a fungi. It is because of lichens you have healthy forests and plants all over the planet and importantly creates a habitable soil for photosynthetic organisms to thrive in. Soil formation or Pedogenesis is one of the most important impacts that fungi have contributed for organisms in many environments. Most lichens are usually grown under rocks and slabs where they act as grazers and degrade the rock into soil.
Fungal Decomposition/ Recycling
Decomposition is a general term used to describe the interrelated processes by which organic matter is broken down to CO2 and humus with a simultaneous release of nutrients. (http://lawr.ucdavis.edu/classes/ssc219/biogeo/decomp.htm) The amount of organic matter decomposed depends on two factors: climate and temperature However, because these two factors often determine one another the rate of decompostion (Mt) = M0 e-kt (http://nre509.wikidot.com/lecture-5:decomposition-constant-k)
M is the mass of litter at a certain time;
M0 is the initial mass of litter;
e is the base of the natural logarithm;
k is the decomposition constant; and
t is the amount of time passed since the initial measurement
Leaf decomposition is commonly observed throughout many ecosystems, of which fungi can be classified the secondary contributor next to detritivorous invertebrates (shredders). Experimental results show that samples of alder (Alnus glutinosa) and willow (Salix fragilis) leaves placed in a stream during peak leaf fall, and retrieved periodically to determine leaf mass remaining and the biomass of leaf-associated organisms indicated that shredders accounted for approximately 51% of leaf mass loss, while fungi contributed approximately 18%, and bacteria approximately 7%. (REFERENCE IS: Hieber, Mäggi, and Mark O. Gessner)
Nutrient Uptake
Mark working on this
Biochemical By-Products
The arbuscular mycorrhizal fungi(AM) discussed above have many biochemical by-products observed through soil and root analysis of host plants/organisms. Glomalin is a common glycoprotein produced on the hyphae and spores of AM fungi, which has been shown to carry specific Glomalin-related soil proteins or GRSPs. These GRSPs are very common to organic soil matter and have been proven to aid in carbon sequestration, which is the process where carbon dioxide (CO2) or other forms of carbon are stored for long-term periods. This process of storing carbon species for long periods of time has been shown to slow the release of atmospheric and marine greenhouse gases produced naturally. (REFERENCE: Purin, Sonia; Rillig, Matthias C. (20 June 2007). "The arbuscular mycorrhizal fungal protein glomalin: Limitations, progress, and a new hypothesis for its function". Pedobiologia 51 (2): 123–130.) This process of carbon sequestration carried out by the AM fungi, more specifically the GRSPs have been theorized to have a primary productivity relationship with its ecosystem and has also been shown to aid directly in the ecosystems ability to remain healthy and produce viable soil.
Reference
Group Discussion
chat here
so when is everyone starting this ?
Jordan and I are starting our part today (March 18th). If everyone submits their parts I will look it over the night before and correct the formatting so it all looks the same.
ALSO, just put the reference in brackets like "Blah blah blah - (ah CLASSY writing sean) (Hieber, Mäggi, and Mark O. Gessner. 2002. CONTRIBUTION OF STREAM DETRIVORES, FUNGI, AND BACTERIA TO LEAF BREAKDOWN BASED ON BIOMASS ESTIMATES. Ecology 83:1026–1038.)" and i will add them to the reference page at the end so it has the correct reference format and anchor links
its due march 22, so friday
so i just re-read the outline and it actually has a few headings we "should" be using, you guys think what we have is good or should we add the ones we are missing/ change the titles to these ones? anyways maybe someone could get started on some of the ones not added yet or even just adding to ones to perfect them
"You must include the follow sections on your Wiki (some may be combined if needed):
Definitions Introduction Describe species types involved Describe processes involved Describe history References"
Hey guys sorry for the lack of input had a million things going on. I see there is one heading that hasn't been started yet I have no problem working on that one. If anything else needs to be completed maybe we could post a list and everyone can figure out what they can help with? Looking really good so far! -Amanda
Yeah i think if there were some heading and then everyone takes one and talk fully about it that will be perfect
unless you guys just want to talk about whatever and then we can put them all in order and make it look better? what does everyone think ?
I've got some stuff sort of put together on phosphorus uptake by AM fungi although I'm not exactly sure which heading that goes under, just the processes one? Also was anyone else going to do that? Just not too sure on who is doing what here. - Mark
Christine just posted a message saying to have it done by 4pm friday. I'm pretty sure they can see the time we edit it so please refrain from editing it after 4 or else we might lose marks. Who knows they might even lock us out from editing right at 4 anyways. If everyone can have their part entered by 2 on Friday I can go through it and adjust the formatting and make sure the reference links work, tags are correct, etc. Thanks - Sean
Sounds good @Sean
Thanks Sean that would be great an as a heads up so there isn't any overlap I can do the signal transduction pathways portion and maybe look over everything and se eif any more definitions need to be entered. - Amanda
OKAY since everyone is working on something and its all divided, im going to add to "Fungal Decomposition/ Recycling" and "species type" since those two section dont have enough writings .-ranad ==References Used (indicate name) Sean/Jordan 1) May, G. S., & Adams, T. H. (1997). The importance of fungi to man. Genome research, 7(11), 1041-1044.
Sean/Jordan 2) The importance and ecology of yeasts in soil Soil Biology and Biochemistry (January 2011), 43 (1), pg. 1-8 Alfred Botha
Norbert 3) Hieber, Mäggi, and Mark O. Gessner. 2002. CONTRIBUTION OF STREAM DETRIVORES, FUNGI, AND BACTERIA TO LEAF BREAKDOWN BASED ON BIOMASS ESTIMATES. Ecology 83:1026–1038.
Norbert 4) Habte, M. "Mycorrhizal Fungi and Plant Nutrition." Journal of Plant Nutrition 18.10 (1995): 2191-198.
Norbert 5) Purin, Sonia; Rillig, Matthias C. (20 June 2007). "The arbuscular mycorrhizal fungal protein glomalin: Limitations, progress, and a new hypothesis for its function". Pedobiologia 51 (2): 123–130.
Mark 6) Li, H., Smith, S. E., Holloway, R. E., & Smith, F. (2006). Arbuscular Mycorrhizal Fungi Contribute to Phosphorus Uptake by Wheat Grown in a Phosphorus-Fixing Soil Even in the Absence of Positive Growth Responses. New Phytologist, (3), 536. doi:10.2307/4131237
Mark 7) Vladimir, K., & Marcel, B. (n.d). Symbiotic phosphate transport in arbuscular mycorrhizas. Trends In Plant Science, 1022-29. doi:10.1016/j.tplants.2004.12.003
Jugraj 8) Oksanen I., I (2006). "Ecological and biotechnological aspects of lichens". Applied Microbiology and Biotechnology
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