ARS | Publication request: BACTERIAL DIVERSITY IN AGROECOSYSTEMS

Submitted to: Agriculture Ecosystems and the Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 1, 1997
Publication Date: N/A

Interpretive Summary: Single-celled organisms have been on the earth 2 to 3 billion years longer than any other life. Bacteria are one of the most diverse life forms on earth and may consist of more than one million species. Only a fraction of these species has been identified, and even fewer are being studied or are in culture collections. The vastness of bacterial diversity is a concept that is overwhelming to the human mind, and our knowledge of the genetic diversity within the bacterial genome is limited. Bacterial diversity will influence nutrient cycling and decomposition, soil structure and biological interactions. The identification of obvious bacterial functions is attainable, but it is more difficult to further dissect species function and relationships. We addressed the issues critical to understanding diversity of bacteria in a soil system. The challenge ahead is to identify the level of bacterial diversity, species composition and distribution to maintain resiliency and withstand stress. The importance of soil bacterial diversity and its role in ecosystems needs to be realized to increase food productivity and enhance the quality of life for all.

Technical Abstract: All life forms rely on bacterial processes for their survival. Bacterial diversity is greater than the diversity of any other group of organisms. Bacteria are responsible for diverse metabolic functions that affect soil and plant health. Nutrient cycling, organic matter formation and decomposition, soil structure formation, and plant growth promotion are among the beneficial functions that bacteria perform, while deleterious effects include plant disease promotion. Since bacterial functioning is critical to soil and plant health, the objective of this manuscript was to explore bacterial diversity in agroecosystems. Microbial research has generally involved studying bacteria that are culturable; however, since it is estimated that only a small portion of all bacteria are culturable, a vast portion of soil bacterial communities remains unstudied. With molecular techniques, more information can be obtained about those bacteria that are contributing to ecosystem functioning and are viable, but not culturable. Enhancing our knowledge of soil bacterial functioning and diversity will aid in the development of sustainable agroecosystems.