Microbiological observations in the anoxic basin Golfo Dulce, Costa Rica

 

Authors
Kuever, Jan; Wawer, Cathrin; Lillebaek, Rolf
Format
Article
Status
publishedVersion
Description

Our basic microbiological studies of the water column and the sediment of Golfo Dulce, Costa Rica, were focused on aerobic and denitrifying sulfur-oxidizing bacteria and anaerobic sulfate-reducing bacteria. We observed no increasing numbers of total bacterial counts within the water column. Although no oxygen was present hydrogen sulfide was only detectable close to the sediment. The highest numbers of solfate-reducing bacteria measured by Most-Probable-Number counts were found in or close to the sediment. In the anoxic bottom water sulfide-oxidizing bacteria typically containing large sulfur globules were observed microscopically. They were identified as free-swimming Thiovulum and Thiospira species. At one station large vacuolated forms of the filamentous colourless sulfur bacterium Beggiatoa were noted. Together with these sulfur containing bacteria there were long free swimming rods showing no sulfur inclusions of unknown character. The microscopic observations showed good correlation with Most-Probable-Number-counts and molecular biological techniques for sulfate-reducing bacteria.
Se estudio microbiológicamente la columna de agua y el sedimento del Golfo Dulce, Costa Rica, concentrándose en las bacterias aeróbicas y desnitrificadoras oxidantes de azufre y anaeróbicas reductoras de sulfuro. No se observó cambios en el conteo bacteriano total dentro de la columna. A pesar de la ausencia de oxígeno solo se detectó el sulfuro de hidrógeno cerca del sedimento. Los conteos más altos de bacterias reductoras de sulfuros por el metodo de numero más probable estaban dentro o cerca del sedimento. Microscópicamente se observó, en el agua anóxica del fondo, bacterias oxidantes de sulfuro, que típicamente contienen grandes esférulas de azufre. Se les identificó como Thiovulum y Thiospira nadadoras. En una estación se vieron grandes formas vacuoladas de la incolora bacteria filamentosa sulfurosa Beggiatoa. Junto a estas bacterias sulfurosas había largos bastones nadadoress in inclusiones sulfurosas visibles, de caracter desconocido. Las observaciones al microscopio mostraron buenas correlaciones con los conteos de Numero Más Probable y con técnicas de biología molecular para bacterias reductoras de azufre.

Publication Year
2017
Language
eng
Topic
Microbial diversity
16S rRNA probes
Thiovulum
Thiospira
Beggiatoa
sulfate reduction
sulfide oxidation
Fuente
Portal de Revistas UCR
Get full text
https://revistas.ucr.ac.cr/index.php/rbt/article/view/29405
Derechos
openAccess
Licencia