Tremella saccharicola f.a., sp. nov., a novel tremellaceous yeast species isolated from tropical regions.

Ten strains representing a single anamorphic novel yeast species were isolated from the external surface (DMKU-SP23 and DMKU-SP40) and tissue (DMKU-SE89, DMKU-SE99, DMKU-SE100 and DMKU-SE147) of sugarcane leaves in Thailand, and phylloplane (IMUFRJR 52034) and rhizoplane (IMUFRJ 52036 and 52037) of sugarcane and associated soil (IMUFRJ 52035) in Brazil. These strains showed zero to two nucleotide substitutions in the sequences of the D1/D2 region of the LSU rRNA gene and zero to three nucleotide substitutions in the internal transcribed spacer (ITS) region. Tremella globispora was the most closely related species, but with 1.7-2.1 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, and 5.3-6.0 % nucleotide substitutions in the ITS region. Phylogenetic analysis based on the concatenated sequences of the ITS and the D1/D2 regions showed that these 10 strains represented a single species belonging to the genus Tremella (class Tremellomycetes, subphylum Agaricomycotina) that was distinct from related species. They therefore represented a novel species of the genus Tremella although the formation of basidia and basidiocarp were not observed. The name Tremella saccharicola f.a., sp. nov. is proposed. The type strain is DMKU-SP23T (=NBRC 109698T=BCC 61186T).

Occultifur plantarum f.a., sp. nov., a novel cystobasidiomycetous yeast species.

Nine strains representing a single anamorphic novel yeast species in dispersed tropical and subtropical habitats were isolated from sugarcane leaf tissue (DMKU-SE24, DMKU-SE45T, DMKU-SE129 and DMKU-SE134) and corn leaf tissue (DMKU-CE36) in Thailand, phylloplane and rhizoplane of sugarcane in Brazil (IMUFRJ 52018 and IMUFRJ 52019), bromeliad leaf tissue in Brazil (IMUFRJ 51954) and plant leaf in Japan (IPM31-24). These strains showed identical or only 1 nt substitution in the sequences of the D1/D2 region of the LSU rRNA gene and 0-5 nt substitutions in the internal transcribed spacer (ITS) region. Phylogenetic analysis based on the combined sequences of the ITS and the D1/D2 regions showed that the eight of these strains represented a single species in the genus Occultifur that was distinct from related species. Occultifur kilbournensis was the most closely related species, but with 0.9-1.2 % nucleotide substitutions in the D1/D2 region of the LSU rRNA gene, and 2.4-2.6 % nucleotide substitutions in the ITS region. They are therefore considered to represent a novel species of the genus Occultifur although the formation of basidia was not observed. The name Occultifur plantarum f.a., sp. nov. is proposed. The type strain is DMKU-SE45T (=CBS 14554T=TBRC 6561T).

Occultifur tropicalis f.a., sp. nov., a novel cystobasidiomycetous yeast species isolated from tropical regions.

Five strains representing a single novel anamorphic yeast species were isolated from sugar cane. Two strains were from tissue (DMKU-SE38, DMKU-SE59(T)) and two from the external surface (DMKU-SP385, DMKU-SP403) of leaves collected in Thailand and the fifth (IMUFRJ 52020) from the rhizoplane of sugar cane in an organically cultivated field in Brazil. On the basis of sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, they were classified as representing a single species of the genus Occultifur. The sequences of the D1/D2 region of the LSU rRNA genes and the ITS regions of the five strains were either identical or differed from each other by only one nucleotide substitution. The novel species was related most closely to Occultifur brasiliensis f.a. CBS 12687(T) but with 0.7-1.0% nucleotide substitutions (4-6 nt) in the D1/D2 region of the LSU rRNA gene and 2.5-2.7% nucleotide substitutions (14-15 nt) in the ITS region. The name Occultifur tropicalis f.a., sp. nov. is proposed. The type strain is DMKU-SE59(T) ( =BCC 61184(T) =NBRC 109696(T) =CBS 13389 (T)).

Wickerhamiella slavikovae sp. nov. and Wickerhamiella goesii sp. nov., two yeast species isolated from natural substrates.

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) (= CBS 12417(T) = DBVPG 8032(T)) and Wickerhamiella goesii sp. nov. IMUFRJ 52102(T) (= CBS 12419(T) = DBVPG 8034(T)).

Kazachstania bromeliacearum sp. nov., a yeast species from water tanks of bromeliads.

Cultures of a novel nutritionally specialized, fermentative yeast species were isolated from 34 water tanks of five bromeliad species, two mangrove sediment samples and one swamp water sample in Rio de Janeiro, Brazil. Sequence analysis of the D1/D2 domains of the large subunit of the rRNA gene showed that the novel species belongs to the genus Kazachstania. The novel species differs from Kazachstania martiniae by 11 substitutions and 2 gaps in the sequence of the domains D1/D2 of the LSU rRNA gene. The name Kazachstania bromeliacearum sp. nov. is proposed for the novel species. The type strain is IMUFRJ 51496T (=CBS 7996T=DBVPG 6864T=UFMG BR-174T).

Candida middelhoveniana sp. nov., a new yeast species found on the rhizoplane of organically cultivated sugarcane.

A novel yeast species within the Metschnikowiaceae is described based on a strain from the sugarcane (Saccharum sp.) rhizoplane of an organically managed farm in Rio de Janeiro, Brazil. The D1/D2 domain of the large subunit ribosomal RNA gene sequence analysis showed that the closest related species were Candida tsuchiyae with 86.2% and Candida thailandica with 86.7% of sequence identity. All three are anamorphs in the Clavispora opuntiae clade. The name Candida middelhoveniana sp. nov. is proposed to accommodate this highly divergent organism with the type strain Instituto de Microbiologia, Universidade Federal do Rio de Janeiro (IMUFRJ) 51965(T) (=Centraalbureau voor Schimmelcultures (CBS) 12306(T), Universidade Federal de Minas Gerais (UFMG)-70(T), DBVPG 8031(T)) and the GenBank/EMBL/DDBJ accession number for the D1/D2 domain LSU rDNA sequence is FN428871. The Mycobank deposit number is MB 519801.

Pseudomonas fluorescens dynamics in the soil surface to subsurface transect.

Microbial displacement in the soil is an important process for bioremediation and dispersal of wastewater pathogens. We evaluated cell movement in surface and subsurface red-yellow podzolic soil driven by advection and microbial motility and also survival of a microbial population at high pressure as is prevalent in deep soil layers. Pseudomonas fluorescens Br 12, resistant to rifampycin and kanamycin, was used as a model organism traceable in non-sterile soil. Our results showed that more than 40% of the P. fluorescens population survived under high pressure, and that microbial motility was not a major factor for its displacement in the soil. Cells were adsorbed in similar amounts to surface and subsurface soils, but more viable cells were present in the leachate of surface than in subsurface soils. The nature of this unexpected cell binding to the subsurface soil was studied by EPR, Mossbauer, NMR, and infrared techniques, suggesting iron had a weak interaction with microbes in soil. P. fluorescens movement in soil resulted mainly from convection forces rather than microbial motility. The transport of this bacterium along the transept toward groundwater encountered restricted viability, although it survived under high pressure conditions simulating those in deep soil layers.

A preliminary note on yeasts associated with fecal pellets of rodents and marsupials of atlantic forest fragments in Rio de Janeiro, Brazil

Yeasts had men counts of above 10 (6) CFU/gin the fecal pellets of small mammals from tropical forest fragments. Most of the 55 species isolated werefermentative ascomycetes, with the most frequent being Debaryomyces hansenii, Pichia membranifaciens and Issatchenkia orientalis, whereas Rhodotorula mucilaginosa was the most frequent yeast of basidiomycetous affinity

Restriction analysis of the ITS region for characterization of the Debaryomyces species.

The internal transcribed spacer (ITS) region of rDNA was used for taxonomic inferences in ascomycetous yeasts. The Debaryomyces species had a 640-690 ITS size. The analyzed Candida species can be differentiated by its distinct ITS size. The enzymatic digestion of the ITS region show large homogeneity in Debaryomyces, with polymorphism for only two enzymes. The ITS size and the enzymatic restriction method were used in Brazilian isolates, detecting some Debaryomyces misidentifications in cultures previously identified by conventional methods.

Starvation-induced stress resistance development in a genetically modified pseudomonas fluorescens strain

The response of a genetically modified Pseudomonas flurescens to nutrient starvation and starvation-induced stress cross-protection were investigated. Strain BR12 was starved for carbon, nitrogen, phosphorus and sulphur individually and for all nutrients in defined mineral media and exposed for 6 h to chemical (ethanol 20 percentage), oxidative (H2O220µM), osmotic (NaCl3M), cold shock (0 degree) and heat shock (47 degree C) stresses at different incubationtimes. Response to starvation and stress cross-protection development were evaluated by viable bacteria counts. There was a significant increase in resistance of late phase cultures grown in rich medium to stress, except for ethanol, in all starvation situations. Multiple nutrient starved cultures were more resistant to stress than individual nutrient starved ones. This strain inoculated in oligotrophic stream water microcosms also showed the starvation-induced stress protection mechanism but it presented a higher resistance to ethanol than cultures starved in mineral media. the acquisition of nonspecific resistance to stress can favour the persistance of Genetically Modified Microorganisms (GMMos) in apparently unfavourable.

Ascomycetous yeasts from tropical intertidal dark mud of southeast Brazilian estuaries.

Four different intertidal estuarine sediments had distinct yeast communities. One-hundred-ninety-three yeast isolates were classified in 47 species, with 34 of these in the genus Candida. Candida tropicalis was the only ascomycetous species isolated from all four sites. Other opportunistic pathogens including Candida glabrata, Candida guilliermondii, Candida parapsilosis and Candida krusei were present, especially at the more polluted sites. Pichia species were also frequent isolates with Pichia membranaefaciens, and its anamorph, Candida valida, and other phenotypically similar low assimilation profile species the most frequent. Kluyveromyces aestuarii was prevalent at the only site with well established mangrove vegetation, but not present at the other sites. The sediment yeast communities were distinct from each other, but more similar to each other than to the yeast communities of other ecosystems in the same geographic region.

Yeasts associated with flowers and fruits from a semi-arid region of northeasthern Brazil

As espécies de leveduras associadas a flores e frutos do cajueiro (Anacardium occodentale); cajazeiro (Spondia lutea); umbuzeiro (Spondia sp).; e mangueira (Mangifera indica) da regiäo nordeste do Brasil, foram determinadas no campo e no mercado. A metodologia usada para remoçäo das leveduras da superfície dos frutos, utilizando a agitaçäo e homogeinizaçäo em liquidificador, foi eficaz para a desagregaçäo das células nesses substratos. Os frutos maduros foram dissecados assepticamente para permitir a separaçäo entre as células presentes na superfície e as situadas no interior dos frutos. Para o isolamento das leveduras foram usados os meios de cultura: Glicose-Extrato de Levedura-peptona e meio básico sem vitaminas, ajustados àpH 3.7 e adicionados de cloranfenicol. As comunidades de leveduras presentes nas flores e nos frutos foram denominadas pelas leveduras pretas e anamorfos de basidiomicetos, especialmente da espécie Cryptococcus laurentii, que no entanto sofrem uma sucessäo à medida que os frutos amadurecem passando a predominar as espécies de ascomicetos e seus anamorfos. A espécie Metschnikowia pulcherrima foi frequentemente isolada em flores de caju nas abelhas associadas a esse substrato. Uma espécie fenotipicamente semelhante à Candida entomaea foi prevalente em frutos de cajá coletados no campo. Nos frutos maduros foram prevalentes as espécies fermentativas de ascomicetos como Issatchenkia orientalis e kloeckera javanica que utilizam poucos substratos. As amostragens efetuadas durante os diferentes estágios de floraçäo e frutificaçäo, o tratamento vigoroso no isolamento e a utilizaçäo de meios de cultura diferentes permitiram a determinaçäo eficiente da composiçäo das comunidades de leveduras associadas às plantas

Influence of pesticides on counts of Bacillus, heterotrophic bacteria, and fungi in subtropical Brazilian soil microcosms

O crescimento de 200 estirpes de Bacillus, isoladas de solos arenosos, argiloso e orgânico do Rio de Janeiro, foi inibido nas concentraçöes de 10 ppm de Kelthane e 100 ppm de Folidol, testadas com culturas puras. O gênero Bacillus representou uma parcela majoritária da populaçäo de bactérias heterotróficas nesses solos. O efeito dos pesticidas nas contagens microbianas em microcosmos e extrato de solo foi reduzido. Após as primeiras horas de exposiçäo as contagens foram reduzidas em concentraçöes de 100 e 500 ppm, voltando a valores estáveis durante 2 a 4 semanas de experimento. As populaçöes microbianas mistas no solo säo menos afetadas pelos pesticidas que os microorganismos em cultura pura

Leveduras de leite humano coletado na cidade do Rio de Janeiro, Brasil / Years from human milk collected in Rio de Janeiro, Brazil

Leveduras foram detectadas em leite em 50 de 158 doadores. As contagens de leveduras foram menores do que 10/ml em 90 por cento das amostras e acima de 1000/ml em somente 0.4 por cento. As espécies predominantes foram Candida parapsilosis, Candida guilhermondii, Candida famata, Candida sorbophila, Rhodotorula minuta, Candida albicans, Candida sphaerica, e Pichia ohmeri.