Bacteria certainly outnumber all other microbes in the soil. Without bacteria, the soil cannot use organic materials to provide nutrients for plant growth. However, many different types of bacteria are harmful to both plants and humans.A very large group, proteobacteria includes many bacteria that also affect humans, such as Vibro cholarae, the root cause of cholera.eneficial bacteria can be fixed into the soil to help reduce harmful bacteria.
Plant pathogenic bacteria cause many serious diseases of plants throughout the world (Vidhyasekaran 2002; Figure 2), but fewer than fungi or viruses, and they cause relatively less damage and economic cost (Kennedy and Alcorn 1980). Plant associated bacteria may be beneficial or detrimental. All plant surfaces have microbes on them (termed epiphytes), and some microbes live inside plants (termed endophytes). Some are residents and some are transient. Bacteria are among the microbes that successively colonize plants as they mature Bacteria are an important part of the soil. They are able to capture some nu-. trients that plants cannot. When living things die, bacteria play a very important role as. decomposers, bacteria and fungi feeding on and breaking down plant and animal matter. Microorganisms may be unicellular or single-celled, any living thing that has only one cell, the smallest unit of life. Some microor-ganisms are multicellular, having more than one cell. Microorganisms require food, air, water, ways to dispose of waste and an environment in which they can live. How soil microorganisms directly or indirectly affect plant growth and health determines if they are considered. beneficial, harmful, or insignificant to plants. Microbes that harm plants are plant pathogens since the harm that they. cause is considered disease. On the other hand, beneficial microorganisms can either enhance plant growth, suppress. plant diseases, or both. The purpose of this article is to help make better sense of the different types of beneficial. effects and some of the beneficial microorganisms responsible for producing these effects. Bacteria certainly outnumber all other microbes in the soil. Without bacteria, the soil cannot use organic materials to provide nutrients for plant growth. However, many different types of bacteria are harmful to both plants and humans. Beneficial bacteria can be fixed into the soil to help reduce harmful bacteria. In most instances of bacterium-based disease, the recommended action is to avoid planting the specific species of plant affected for several seasons in the affected area. Microorganisms are classified into four major groups. These groups are bacteria, fungi, protozoa and some algae. Viruses are also microscopic. They, however, reproduce only inside the cells of the host organism, which may be a bacterium, plant or animal. Disease— causing Microorganisms in Plants. Several microorganisms cause diseases in plants like wheat, rice, potato, sugarcane, orange, apple and others. The diseases reduce the yield of crops. They can be controlled by the use of certain chemicals which kill the microbes. Types of Harmful Bacteria. Gardeners refer to beneficial soil bacteria as probiotics. Harmful bacteria are called proteobacteria. A very large group, proteobacteria includes many bacteria that also affect humans, such as Vibro cholarae, the root cause of cholera. Beneficial bacteria can be fixed into the soil to help reduce harmful bacteria. In most instances of bacterium-based disease, the recommended action is to avoid planting the specific species of plant affected for several seasons in the affected area. Article Summary: Bacteria is the most useful microorganism in the environment and beneficial for human beings. But it also has some harmful effects on human body.... The planet earth is full of bacteria and they play an important role in the different functions whether they are related to humans, animals or plants. In this disease paralysis can occur and it can be fatal if one millionth of a bacterium is ingested through mouth. To kill harmful bacteria, antibiotics are used. Some precautionary measures should also be taken so that they do not cause infections in the body, like washing hands before meal will kill the bacteria. Micro-organisms. Micro-organisms Micro-organisms (or microbes) are literally microscopic organisms, which can only be seen properly with the aid of a microscope. These include bacteria, microscopic fungi (moulds) and protoctists. 
http://www.apsnet.org/edcenter/intropp/PathogenGroups/Pages/Bacteria.aspx http://www.uen.org/core/science/sciber/TRB6/downloads/05literacy.pdf http://www.bioworksinc.com/products/shared/beneficial-soil-microorganisms.pdf http://www.gardenguides.com/124669-harmful-bacteria-soil.html http://www.excellup.com/ClassEight/scienceight/microorganismeight.aspx http://www.gardenguides.com/124669-harmful-bacteria-soil.html http://www.biotecharticles.com/Biology-Article/Beneficial-and-Harmful-Bacteria-312.html https://www.le.ac.uk/se/centres/sci/selfstudy/eco7.htm
harmful effects of microorganisms to plants