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Background Beginning in the last century, coral reefs have suffered the consequences of anthropogenic activities, including oil contamination. Chemical remediation methods, such as dispersants, can cause substantial harm to corals and reduce their resilience to stressors. To evaluate the impacts of oil contamination and find potential alternative solutions to chemical dispersants, we conducted a mesocosm experiment with the fire coral Millepora alcicornis, which is sensitive to environmental changes. We exposed M. alcicornis to a realistic oil-spill scenario in which we applied an innovative multi-domain bioremediator consortium (bacteria, filamentous fungi, and yeast) and a chemical dispersant (Corexit® 9500, one of the most widely used dispersants), to assess the effects on host health and host-associated microbial communities. Results The selected multi-domain microbial consortium helped to mitigate the impacts of the oil, substantially degrading the polycyclic aromatic and n-alkane fractions and maintaining the physiological integrity of the corals. Exposure to Corexit 9500 negatively impacted the host physiology and altered the coral-associated microbial community. After exposure, the abundances of certain bacterial genera such as Rugeria and Roseovarius increased, as previously reported in stressed or diseased corals. We also identified several bioindicators of Corexit 9500 in the microbiome. The impact of Corexit 9500 on the coral health and microbial community was far greater than oil alone, killing corals after only 4 days of exposure in the flow-through system. In the treatments with Corexit 9500, the action of the bioremediator consortium could not be observed directly because of the extreme toxicity of the dispersant to M. alcicornis and its associated microbiome. Conclusions Our results emphasize the importance of investigating the host-associated microbiome in order to detect and mitigate the effects of oil contamination on corals and the potential role of microbial mitigation and bioindicators as conservation tools. Chemical dispersants were far more damaging to corals and their associated microbiome than oil, and should not be used close to coral reefs. This study can aid in decision-making to minimize the negative effects of oil and dispersants on coral reefs.

Abbreviations: ITS, internal transcribed spacer; LSU, large subunit.The GenBank/EMBL/DDBJ accession numbers for the sequences of the D1/D2 domain and ITS region of the LSU rRNA gene of strain BI118T are KC169793 and FJ828959, respectively.One supplementary figure is available with the online version of this paper.

Two novel yeast species were isolated during three independent studies of yeasts associated with natural substrates in Brazil and Taiwan. Analysis of the sequences of the D1/D2 domains of the large subunit rRNA gene showed that these novel species belong to the Wickerhamiella clade. The first was isolated from freshwater and a leaf of sugar cane (Saccharum officinarum) in Brazil and from leaves of Wedelia biflora in Taiwan. Described here as Wickerhamiella slavikovae sp. nov., it differs by 56 nucleotide substitutions and 19 gaps in the D1/D2 region of the large subunit rRNA gene from Candida sorbophila, the least divergent species. The second species, named Wickerhamiella goesii sp. nov., was isolated from leaves and the rhizosphere of sugar cane collected in Rio de Janeiro, Brazil. The species differs by 54 nucleotide substitutions and nine gaps in the D1/D2 domains from Candida drosophilae, its least divergent relative. The type strains are Wickerhamiella slavikovae sp. nov. IMUFRJ 52096 T (5CBS 12417 T 5DBVPG 8032 T ) and Wickerhamiella goesii sp. nov. IMUFRJ 52102 T (5CBS 12419 T 5DBVPG 8034 T ).The clade Wickerhamiella consists, at the time of writing, of 26 species that include five species with a sexual state and 21 that may eventually be found to form ascospores (Lachance & Kurtzman, 2011;Barbosa et al., 2012;Badotti et al., 2013). Most of these species are highly specialized nutritionally and ecologically, and some of them have a strong association with floricolous insects and plant materials (Lachance & Kurtzman, 2011;Barbosa et al., 2012). In the course of three independent studies of yeasts associated with natural substrates in Brazil and Taiwan, four unidentified yeast strains were found to have almost identical sequences in the D1/D2 domains of the large subunit rRNA gene. The least divergent known sequence was that of Candida sorbophila. Another four unidentified isolates were recovered from leaves and the rhizosphere of sugar cane (Saccharum officinarum) in Rio de Janeiro, Brazil. These isolates, also in the Wickerhamiella clade, exhibited sequence affinity with Candida drosophilae. In this study, we propose the description of these eight strains as representatives of two novel species, Wickerhamiella slavikovae sp. nov. and Wickerhamiella goesii sp. nov., respectively.Strain UFMG-LD2.04 was isolated from a freshwater sample collected from the Lake de Dentro situated in Ecological State Park of Cantão, state of Tocantins, Brazil, in July 2008. The water sample was filtered on sterile nitrocellulose membranes of 0.45 mm pore size and 47 mm diameter using a Nalgene filtering device. The membrane was placed on the surface of YM agar (0.3 % yeast extract; 0.3 % malt extract; 0.5 % peptone; 1 % glucose; 2 % agar; The GenBank/EMBL/DDBJ accession numbers for the large subunit rRNA gene D1/D2 domain sequences of Wickerhamiella slavikovae IMUFRJ 52096 T and Wickerhamiella goesii IMUFRJ 52102 T are FJ463264 and JN790617, respectively.

BackgroundIndependent surveys across the globe led to the proposal of a new basidiomycetous yeast genus within the Bulleromyces clade of the Tremellales, Bandoniozyma gen. nov., with seven new species.Methodology/Principal FindingsThe species were characterized by multiple methods, including the analysis of D1/D2 and ITS nucleotide sequences, and morphological and physiological/biochemical traits. Most species can ferment glucose, which is an unusual trait among basidiomycetous yeasts.Conclusions/SignificanceIn this study we propose the new yeast genus Bandoniozyma, with seven species Bandoniozyma noutii sp. nov. (type species of genus; CBS 8364T  =  DBVPG 4489T), Bandoniozyma aquatica sp. nov. (UFMG-DH4.20T  =  CBS 12527T  =  ATCC MYA-4876T), Bandoniozyma complexa sp. nov. (CBS 11570T  =  ATCC MYA-4603T  =  MA28aT), Bandoniozyma fermentans sp. nov. (CBS 12399T  =  NU7M71T  =  BCRC 23267T), Bandoniozyma glucofermentans sp. nov. (CBS 10381T  =  NRRL Y-48076T  =  ATCC MYA-4760T  =  BG 02-7-15-015A-1-1T), Bandoniozyma tunnelae sp. nov. (CBS 8024T  =  DBVPG 7000T), and Bandoniozyma visegradensis sp. nov. (CBS 12505T  =  NRRL Y-48783T  =  NCAIM Y.01952T).