Metagenomics is the study of metagenomes. Metagenome is the genetic material taken directly from the environmental samples not from only one organism. The samples are of variety of organisms or individual which either have symbiotic relationship with each other or the genetic samples collected at the crime scene. This is an emerging field and can also be referred as ecogenomics, environmental genomics or community genomics. In this field, the analysis of the DNA is done in an organism.
Metagenomics also gives information about many organisms whose genome has not yet been sequenced and it cannot be sequenced with common DNA sequencing methods. These organisms cannot be cultured. The study of this field has also revealed such species of bacteria and viruses which were not found before.
It is the goal of National Institute of Health to sequence the genome of the microbes living in human body. Only 1% of the microbial population f human body has been sequenced so far. Other microbes have still to be sequenced.
There are many techniques which are used for the metagenomic processes. There are chances that new methods will also develop as this field will develop further. Following are the basic steps involved in metagenomic processes.
- The project or process of Metagenomics starts with the collection of sample of the particular environment for example soil, human mouth or seawater.
- The sample of DNA is extracted from the microbes present in the environment.
- The genetic information obtained from the DNA molecule is used to reveal important properties of the community of microbes.
- In the study of sequence based metagenomics, the whole genetic sequence is observed along with the four nucleotide bases such as A, T, C and G. these are the nucleotide bases found in the DNA molecule present in the sample.
- The function based metagenomics, screening of the extracted genes take place to reveal different functions of the genes. For example antibiotic or vitamin production is observed.
- Scientists have already new antibiotics using the techniques of function based metagenomics.
Applications of metagenomics:-
Metagenomics can be applied in different areas of science.
There are a lot of microorganisms present on the plants and also around them. They play an important role in the growth of plants by providing essential nutrients. Bacteria present in the soil not only increase the soil fertility but also convert the atmospheric nitrogen into ammonia. Some microbes decompose the dead animals and plants and other convert the elements like iron and manganese to the nutrients which can easily be used by plants as nutrients.
Suppressive soil is a phenomenon in which the harmful and beneficial microbes live at one place and they do not affect the health of the plants. If the soil is sterilized by killing the harmful bacteria, the health of the plants will be affected and they will die eventually because harmful microbes may penetrate in the soil and cause death of the plants. Scientists have observed that suppressive soil microbes provide protection to the plants and if they are removed, the plants become susceptible to infections. The suppressing soil microbes' community is beneficial in agriculture. Scientists believe that there is not only specie of microbes which make the soil suppressed but there are various species which are involved in this process. The science of metagenomics enables the scientists to explore that how the microbial species are beneficial for plants. It will help them to produce more healthy crops.
Human beings are always surrounded with microbes. Microbes not only reside around the humans but they also live in the human body. According to estimation, there are tenfold of microbes in the human body than the total number of human cells. Microbes living in the body contain genes more than the human genes. metagenomics enables the scientists to develop such tools and guidelines in human and animal nutrition and also the drug discovery. It also make possible to study dangerous diseases like cancer and certain immune disorders.
Microbes are the essential part of the human body as they by living in intestines help in the digestion of food an produce certain vitamins and amino acids. Some microbes stay in the stomach and control the pH and acid level of the stomach. Metagenomics provides opportunities to study both beneficial and harmful microbes. It can also be helpful in identifying other compounds released or produced by the microbes which are beneficial for the animal and human health.
Microbes living in the environment are helpful in many ways. They decompose dead materials and are the source of cleaning the environment from pollutants. There are some microbes which use methane gas which seeps through the landfills and some are related with the wastewater treatments. Microbes are also the source of cleaning the ground water by eliminating gasoline leaked from the petroleum pipes. The analysis of metagenomics enables to identify the particular species of microbes concerned with the water treatment purposes.
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