title: Chlamydomonas pitschmannii Ettl, a little known species from thermoacidic environments.
abstract: Three Chlamydomonas strains were isolated from the soils of a hot spring located in the Campi Flegrei Caldera (Naples, Italy). Ecophysiological, morpho-cytological and molecular features were used to characterize these isolates and to compare them with chlamydomonax acidophila strains from algal culture collections. The strains were collected from three points of the volcanic site, differing in their physico-chemical conditions. Among the examined Chlamydomonas strains, only the isolates from Campi Flegrei could grow optimally at pH values < or =3.0. These isolates also showed a high tolerance to desiccation and high temperatures, not evidenced by the other Chlamydomonas strains included in the study. 18S rDNA phylogeny indicates that the isolates from Campi Flegrei are closely related to Chlamydomonas pitschmannii and two strains isolated in Canada and Europe, that have been designated as Chlamydomonas acidophila. A Chlamydomonas acidophila strain isolated from the type locality in Japan is less closely related according to its molecular phylogeny, and can also be discerned by light and electron microscopy. Moreover, vegetative cells and sporangia of Chlamydomonas acidophila from Japan showed a median trilaminar structure not observed in the other strains. Our results show that Chlamydomonas pitschmannii could represent a hitherto unknown extremophilic Chlamydomonas species.
authors.affiliation: Dipartimento di Biologia Vegetale dell'Università di Napoli Federico II, Via Foria 223, 80139 Napoli, Italy. anpollio@unina.it
authors.forename: Antonino
authors.initials: A
authors.lastname: Pollio
authors.forename: Paola
authors.initials: P
authors.lastname: Cennamo
authors.forename: Claudia
authors.initials: C
authors.lastname: Ciniglia
authors.forename: Mario
authors.initials: M
authors.lastname: De Stefano
authors.forename: Gabriele
authors.initials: G
authors.lastname: Pinto
authors.forename: Volker A R
authors.initials: VA
authors.lastname: Huss
mesh_terms: D000818:Animals; D002170:Canada; D002455:Cell Division; D002696:Chlamydomonas / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D018153:Czech Republic; D004777:Environment; D056890:Eukaryota / Q000469:parasitology; D005718:Gametogenesis; D045482:Hot Springs / Q000469:parasitology; D006863:Hydrogen-Ion Concentration; D007558:Italy; D007564:Japan; D008969:Molecular Sequence Data; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012987:Soil / Q000469:parasitology; D014617:Vacuoles / Q000648:ultrastructure
chemical_list: D012337:RNA, Ribosomal, 18S; D012987:Soil