A tremendous research is going on in the field of genomics. Genomics is helping the world to understand the surroundings in a more better way.The first organism genome to be sequenced was Saccharomyces cerevisiae (baker's yeast). Then the sequencing of the human genome opened new horizons into the study of the genomes and made the world realize that there is more and more to explore in the field of biology. The recent applications of knowing the human genome information are many but best one of all is the curing of the diseases in human beings. Now when researchers were thinking about how genomics can be used in studying and improving the environment , then came the field of Metagenomics.The word meta-genome itself tells that it is a large sample of genomes.This means that it is the sample collected from the environment or the ecosystem directly. While the traditional genomics deals with the sequencing of the cultured samples , it was found that there were some of the organisms and particularly the microorganisms for which the culturing and thus the sequencing was not possible. Thus came the field of metagenomics that helped in understanding the uncultured environmental samples such as soils from different places and areas etc. There are different steps while carrying out the metagenomic analysis.These steps have been discussed wonderfully in the metagenomics page in the .These steps can be read from this page.But the motive of this article is to discuss how metagenomics is helpful in sustaining and improving the environment.Following are some of the ways by which we can say that metagenomics is helpful in improving the environment. Synergic Relationship of Micro-organisms with Ecosystem There are many micro-organisms that live in a symbiotic relationship with their hosts and thus it is difficult to culture them as they live in the environments which are tough to first of all be find and then to be cultured.Thus , the first application of the metagenomics is to extract those micro-organisms from their environments and thus help in sequencing the genome of those micro-organisms and making the world understand the symbiotic relationship of these micro-organisms with the ecosystem.The example of this type of study is the study on Cenarchaeum symbiosum How do micro-organisms interact?? This study is important and is worth studying because all the environmental aspects are linked to it as , it only tells us and makes us know that how the micro-organisms interact with each other and thus accomplish all these environmental processes so accurately.Mutant analysis can be done for this and also this mutant analysis study has revealed that there is much more to know than has been already known.The example of this kind of study is the study on Rhizobium Tropici. Waste water treatment and other environmental studies The metagenomics has other applications apart from understanding the ecosystem of the micro-organisms.One of these can be advanced wastewater treatment example phosphorus removal from wastewater. The second application can be the study of the microbiology of biological phosphorus removal in activated sludge systems. Soil Analysis Transcriptomic analysis with the help of metagenomics is another type of work that is being done in the field of environmental studies and betterment.One of these examples is the study of Effect of Tannic Acid on the Transcriptome of the Soil Bacterium Pseudomonas protegens Pf-5.