Epibenthic Microbial Mats behavior as Phosphorus Sinks or Sources in relation to biological and physicochemical conditions

PERILLO, V.L; LA COLLA N.S; PAN, J.; SERRA A.V; BOTTÉ S.E; CUADRADO D

JOURNAL OF ENVIRONMENTAL MANAGEMENT

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2022

0301-4797

Microbial mats are complex microecosystems that have shown promise as possiblegreen filters to remediate polluted sea water. This usage would possibly requirechanging the natural conditions under which these microbial mats prosper in order tomaximize their contact with the water. Thus, it is necessary to evaluate the adaptationof the mats to different environmental conditions, while monitoring their short-termefficiency at nutrient removal. To that aim, we incubated epibenthic microbial mats,taken from a tidal flat in the Bahía Blanca Estuary, under different flooding conditions(periodically exposed to the air or continuously flooded), with and without the additionof a high phosphorus concentration ( 5 mg PO 4 3- L -1 ), and with and without thepresence of penicillin. This last condition was added to understand the influence ofpenicillin-sensitive microbes on cyanobacteria and diatom communities and theirimportance for P remediation. The presence of high P concentrations as well as thecontinual flooding of the mats resulted in the decrease of the dominantColeofasciculus ( Microcoleus ) chthonoplastes population, giving rise to thedominance of Arthrospira sp. or Oscillatoria sp., depending on the presence orabsence of the antibiotic, respectively. Water P removal was highly efficient ( 60-87 %)when the mats were treated with the high-P water. However, microbial mat behaviorchanged from P sink to source when mats where in the presence of sea water with noP addition, suggesting that mats can both function as P sinks or sources, depending onthe condition of the water they come in contact with.