Abstract

TAPIA-TORRES, Yunuen  and  GARCIA-OLIVA, Felipe. Phosphorus availability is a product of soil bacterial activity in oligotrophic ecosystems: A critical review. Terra Latinoam [online]. 2013, vol.31, n.3, pp.231-242. ISSN 2395-8030.

Phosphorus (P) is an essential element for life; thus, understanding the mechanisms associated with soil P availability is primordial. There are several processes of P dynamics that are not clearly understood, mainly in oligotrophic ecosystems. In the present review, current literature on the P availability process is analyzed, emphasizing the role of bacteria in the soil. Orthophosphate is the form in which available P is found, but due to its high reactivity and demand by the biota it rapidly diminishes in the soil solution. For this reason, it is necessary that the biota acquire P from other chemical forms. Among these, organic forms represent the main source for P through biochemical mineralization, which is mainly accomplished by the soil bacterial community. Among the organophosphorus compounds, phosphate esters are easier to mineralize due to the low energy demand for production of enzymes involved in this process. However, mineralization of organic phosphonate represents an alternative source of available P, although it has been considered that this chemical form was not available due to its molecular complexity. In general, a successful strategy for P acquisition in limited ecosystems depends on the presence of the genetic machinery capable of synthesizing different enzymes which mineralize organic compounds with different energy demands (phosphohydrolases, phosphonatases and C-Plyases), as the presence of specific membrane transporters and the availability of C as an energy source. More integrated studies are needed to elucidate the movement of P in ecosystems and how it can be controlled and carried out by soil bacteria.

Keywords : phosphatase; phosphonatase; ester; fertility; phosphonates.