That can help the environment are called decomposers. They are nature's recyclers. They return basic chemicals to the environment for living things to reuse.
Bacteria play a very crucial role of silently getting the nature rid of the dead matter through the decomposition of dead organic matter by the micobes. Bacteria use them as a source of nutrients, and in turn help in recycling the organic compounds trapped in the dead matter. They do not have proper nucleus within the cell but the genetic material is attached to the cell membrane in an irregular form. They are found everywhere like top of the mountains, rivers, on land and in ice. Bacteria have the property of living in extreme weathers like extreme cold and extreme heat. This plasmid can be introduced into a bacterium by way of the process called transformation. Then, because bacteria divide rapidly, they can be used as factories to copy DNA fragments in large quantities. A plasmid is a small, circular, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA. Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes. Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance. Plasmids have a wide range of lengths, from roughly one thousand DNA base pairs to hundreds of thousands of base pairs They are most commonly found in bacteria as small, circular, double-stranded DNA molecules; however, plasmids are sometimes present in archaea and eukaryotic organisms. In nature, plasmids often carry genes that may benefit the survival of the organism, for example antibiotic resistance. In order for the plasmids to replicate independently within a cell, they must possess a stretch of DNA that can act as an origin of replication. The self-replicating unit, in this case the plasmid, is called a replicon. #1. Bacteria are the unicellular organisms and cannot be seen with naked eye. There is no particular method of cell division, they simply divide by binary fission in which cell divides into two daughter cells. They do not have proper nucleus within the cell but the genetic material is attached to the cell membrane in an irregular form. They are found everywhere like top of the mountains, rivers, on land and in ice. Bacteria have the property of living in extreme weathers like extreme cold and extreme heat. Mounting evidence indicates that these proteins have important roles in cellular functions such as DNA segregation, cell polarity and sporulation. Other uniquely bacterial proteins, the MIN proteins, assist in division-site placement and also seem to form cytoskeletal structures. Since the advent of microbiology, cell shape has been an important criterion in the description and classification of bacterial species. This is reflected in taxonomy — Streptococcus species are named for their spherical or seed-shaped (coccus) cells, bacilli for their rod shape and spirochaetes for their spiral shape. Conjugation is the direct transfer of DNA from one bacterial cell to another bacterial cell. The transferred DNA is a plasmid, a circle of DNA that is distinct from the main bacterial chromosome. The F plasmid is similar to a virus or a transposon in its ability to move independently of the main chromosome. The transfer of the plasmid take advantage of the complementary nature of double stranded DNA Bacterial DNA – a circular chromosome plus plasmids. The DNA of most bacteria is contained in a single circular molecule, called the bacterial chromosome. The chromosome, along with several proteins and RNA molecules, forms an irregularly shaped structure called the nucleoid. This sits in the cytoplasm of the bacterial cell. In addition to the chromosome, bacteria often contain plasmids – small circular DNA molecules. Bacteria can pick up new plasmids from other bacterial cells (during conjugation) or from the environment Some bacteria that can help the environment are called decomposers. They are nature's recyclers! They return basic chemicals to the environment for living things to reuse! For example, the leaves of many trees die in the Autumn and drop to the ground. 
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what is the role of bacterial cell in nature