Mercedes Martín-Cereceda

Dynamics of protozoan and metazoan communities in a full scale wastewater treatment plant by rotating biological contactors

Performance of a full-scale wastewater treatment plant by rotating biological contactors (RBC) system was monitored during a year by physico-chemical and microbial characterisation. Six points along wastewater treatment were selected in the plant: three points along the water line (influent, sedimentation tank and effluent) and three points along RBC system (RBC1, RBC2 and RBC3). Although a large seasonal change in the values of physico-chemical parameters was observed, operation of the plant was optimal during all year (90% of removal in BOD5 and SS influent content). Microbial characterisation was approached by determining the structure and dynamics of protozoan and metazoan communities. Protozoa were the most abundant in all stages in the plant, heterotrophic flagellates being the most representative group in the water line and ciliates in the RBC system. The same seasonal preference was only observed for heterotrophic flagellates in the water line and green flagellates in the RBC system, both groups having highest abundances in summer and spring, respectively. Identification of ciliated protozoa populations rendered 58 species of ciliates in the plant. Most of these species are typical of aerobic wastewater treatment systems except three of them, which are cited for the first time in this type of ecosystems: Chaenea stricta, Holosticha mancoidea and Oxytricha lanceolata. Along the water line 34 species were identified, and half of them only appeared occasionally (once in all the study), while along the RBC system biofilms 55 species were observed, and the majority appeared permanently in this system. Our results indicate that the type of habitat, rather than the physico-chemical water parameters, was the primary factor in determining the different distribution of protozoan and metazoan communities in the plant. In RBC biofilms, the structure of ciliate protozoa community was found to be quite sensitive to changes in physico-chemical parameters, mainly to organic loading (BOD5) variations.

Beyond the “Code”: A Guide to the Description and Documentation of Biodiversity in Ciliated Protists (Alveolata, Ciliophora)

Recent advances in molecular technology have revolutionized research on all aspects of the biology of organisms, including ciliates, and created unprecedented opportunities for pursuing a more integrative approach to investigations of biodiversity. However, this goal is complicated by large gaps and inconsistencies that still exist in the foundation of basic information about biodiversity of ciliates. The present paper reviews issues relating to the taxonomy of ciliates and presents specific recommendations for best practice in the observation and documentation of their biodiversity. This effort stems from a workshop that explored ways to implement six Grand Challenges proposed by the International Research Coordination Network for Biodiversity of Ciliates (IRCN‐BC). As part of its commitment to strengthening the knowledge base that supports research on biodiversity of ciliates, the IRCN‐BC proposes to populate The Ciliate Guide, an online database, with biodiversity‐related data and metadata to create a resource that will facilitate accurate taxonomic identifications and promote sharing of data.

Ciliate communities of rotating biological contactor biofilms: a multivariate approach.

Physical-chemical monitoring and characterization of ciliate communities from a full-scale rotating biological system (RBC) have been carried out for a year. RBC system operated efficiently in removing the organic matter, as the decrease of the BOD5 loading along the successive RBC units revealed. 55 species of ciliated protozoa were identified in the RBC biofilms. Differences in abundance, occurrence and type of species were found along the different units of the RBC system; the last RBC held a more stable and diverse ciliate community. The complexity of interspecific relationships among the ciliates has been outlined using multivariate methods (Cluster and Correspondence analysis). Correlation between ciliate species and physical-chemical conditions were obtained by regression analysis. Results show that 12 species of ciliates were related to an optimal efficiency in organic matter removal, Litonotus crystallinus being the most sensitive species. The presence and abundance of Litonotus crystallinus and Acineria uncinata was associated with a decrease in the organic factor. Metopus es was the only species related to a decrease in process efficiency due to its association with an increase in organic factor. The results provide statistical evidence of the use of certain ciliate species as reliable bioindicators in full-scale RBC wastewater treatment plants.

Occurrence of Acineria uncinata in activated sludge plants: morphology and relationship with physico-chemical plant parameters

Summary Acineria uncinata is a common species in the protozoan communities of the activated sludge plants from Madrid Community (Spain). It appears on the floc surface as a small lanceolate ciliate with a characteristic overlapping at the anterior area of the cell. The infraciliature of this species, investigated by silver impregnation and scanning electron microscopy, is composed of seven kineties with different arrangement at both sides of the cell, and a dorsal kinetal segment. The abundance of A. uncinata has been related with the physico-chemical and operational parameters. Correlation analysis showed that A. uncinata can be considered as an indicator of deficient sludge settlement conditions

Description of Opisthonecta Matiensis N. Sp. (Protozoa, Ciliophora), A New Peritrich Ciliate From Wastewater

ABSTRACT. Opisthonecta matiensis n. sp. was isolated from the inlet water of a wastewater treatment plant near Madrid. Spain, and studied in vivo, with silver methods, and using electronic and indirect immunofluorescence microscopy. This new species shows an amphora‐like cell shape and has a size of 45‐73 μm (x̄ 58.2) × 25‐40 μm (x̄ 31.3). the oral infraciliature is formed by one haplokinety, three polykineties, and a short row of kinetosomes (epistomial membrane). the aboral infraciliature is made up of the trochal band and the scopula. From the trochal band arise three fibrillar systems: oral fibers, aboral fibers, and oblique fibers. the myoneme system is composed of a delicate peristomial ring, longitudinal branched fibers that reach the trochal band and of radial fibers extending from the scopula to the trochal band. the silverline system consists of an average of 147 lines. This new species is separated from other known forms by its smaller size, the presence of one single vacuole, and its higher number of silverlines.

Influencia de la temperatura sobre la asimetría de pilancones en ambiente granítico. Aplicación de un modelo de regresión lineal

Las pilas representan un tipo de forma presente en casi todos los ambientes climaticos. El trabajo estudia el papel de los ciclos termicos como un agente importante del modelado y asimetria que presentan las paredes de las pilas en un clima Mediterra- neo templado - frio. El estudio se ha realizado en el macizo granitico de la Pedriza de Manzanares, zona protegida de gran valor ambiental, incluida en el Parque Nacional de la Sierra de Guadarrama (Madrid, Espana). El analisis de la variabilidad termica mediante modelos de regresion perio- dica multiple, pone de manifiesto la influencia de los ciclos diario y anual en funcion de las orientaciones norte y sur de las paredes de las pilas. Un modelo matematico de regresion lineal muestra como la variabilidad termica diaria influye en la alteracion de las paredes de las pilas, generando superficies planas o de concavidad mas o menos pronunciada. El trabajo tambien establece relaciones entre el grado de alteracion de las diferentes partes de las pilas, con la presencia de liquenes y dureza relativa de la roca. Los resultados avalan la hipotesis de relacion causal entre la variabilidad termica y alteracion de las paredes de las pilas segun su orientacion norte o sur.