Characterization of a sulfide-oxidizing biofilm developed in a packed-column reactor Authors Isabel Ferrera Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain Olga Sánchez Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain Jordi Mas Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain Keywords: sulfide oxidation, biofilms, microbial diversity, 16S rRNA gene Abstract The potential of microbial mats to develop sulfide-oxidizing biofims was explored. A bioreactor specially designed for the treatment of sulfide-containing effluents was inoculated with a microbial-mat sample, and a complex microbial biofilm with sulfide-oxidation activity developed. The microbial composition of the biofilm was studied by pigment, microscopy, and 16S rRNA gene analyses. Purple sulfur bacteria and diatoms were observed by microscopy, chlorophyll a and bacteriochlorophyll a were detected in the pigment analysis, and high genetic diversity was found in the 16S rRNA gene library. Specialized anaerobic sulfur oxidizers (i.e., phototrophic purple and green sulfur bacteria) dominated the library. Aerobic phototrophs (diatoms) also developed and the oxygen produced allowed the growth of aerobic sulfide oxidizers, such as Thiomicrospira-like spp. Cyanobacteria, which are significant organisms in natural microbial mats, did not develop in the reactor but unexpected uncultured members from the Epsilonproteobacteria developed profusely. Moreover, a variety of more minor organisms, such as members of the Cytophaga-Flavobacterium-Bacteroides (CFB) and purple non-sulfur bacteria (Roseospirillum sp.), were also present. The results showed that a complex community with high genetic and metabolic diversity, including many uncultured organisms, can develop in a laboratory-scale reactor. [Int Microbiol 2007; 10(1):29-37] Author Biographies Isabel Ferrera, Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain Olga Sánchez, Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain Jordi Mas, Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain Downloads PDF Published 2010-01-27 Issue Vol. 10 No. 1 (2007) Section Research Articles License Submission of a manuscript to International Microbiology implies: that the work described has not been published before, including publication in the World Wide Web (except in the form of an Abstract or as part of a published lecture, review, or thesis); that it is not under consideration for publication elsewhere; that all the coauthors have agreed to its publication. The corresponding author signs for and accepts responsability for releasing this material and will act on behalf of any and all coauthors regarding the editorial review and publication process.If an article is accepted for publication in International Microbiology, the authors (or other copyright holder) must transfer to the journal the right–not exclusive–to reproduce and distribute the article including reprints, translations, photographic reproductions, microform, electronic form (offline, online) or any other reproductions of similar nature. Nevertheless, all article in International Microbiology will be available on the Internet to any reader at no cost. The journal allows users to freely download, copy, print, distribute, search, and link to the full text of any article, provided the authorship and source of the published article is cited. The copyright owner's consent does not include copying for new works, or resale. In these cases, the specific written permission of International Microbiology must first be obtained.Authors are requested to create a link to the published article on the journal's website. The link must be accompanied by the following text: "The original publication is available on LINK at <http://www.im.microbios.org>. Please use the appropiate URL for the article in LINK. Articles disseminated via LINK are indexed, abstracted, and referenced by many abstracting and information services, bibliographic networks, subscription agencies, library networks, and consortia.
