RESUMEN
Fungi possess a range of light receptors to regulate metabolism and differentiation. To study the effect of light on Lentinula edodes (the shiitake mushroom), mycelial cultures were exposed to blue, green, and red fluorescent lights and light-emitting diodes, as well as green laser light. Biomass production, morphology, and pigment production were evaluated. Exposure to green light at intervals of 1 min/d at 0.4 W/m(2) stimulated biomass production by 50-100 %, depending on the light source. Light intensities in excess of 1.8 W/m(2) or illumination longer than 30 min/d did not affect biomass production. Carotenoid production and morphology remained unaltered during increased biomass production. These observations provide a cornerstone to the study of photoreception by this important fungus.
Asunto(s)
Micelio/crecimiento & desarrollo , Micelio/efectos de la radiación , Hongos Shiitake/crecimiento & desarrollo , Hongos Shiitake/efectos de la radiación , Biomasa , Color , Fluorescencia , Hifa/crecimiento & desarrollo , Hifa/efectos de la radiación , LuzRESUMEN
The purpose of this study was to characterize precipitates formed in anaerobic, H2S-producing cultures of two Tissierella isolates and Desulfosporosinus strain DB. The cultures were grown in Cu-containing media as part of a larger study of Cu resistance in anaerobic sulfidogens. The Tissierella strains produced H2S from peptone. Desulfosporosinus formed H2S from peptone or through dissimilatory sulfate reduction with lactate. Tissierella cultures precipitated iron phosphate, vivianite, but no crystalline phases or Cu sulfides were detected. Multiple Cu sulfides, including chalcopyrite and covellite, were detected in Desulfosporosinus cultures but vivianite was not formed. Ion microprobe spectra and electron microscopic examination showed major variation in the elemental composition and morphological differences depending on incubation conditions. Extended incubation time for at least 1-2 months increased the crystallinity of the precipitates. The results highlight biogeochemical differences in sulfide and phosphate precipitates between the two major groups of Firmicutes although they may share the same habitat including the human intestinal tract.
Asunto(s)
Cobre/química , Bacilos Grampositivos Formadores de Endosporas/metabolismo , Sulfuro de Hidrógeno/química , Intestinos/microbiología , Peptococcaceae/metabolismo , Aguas Residuales/microbiología , Anaerobiosis , Técnicas de Tipificación Bacteriana , Precipitación Química , Heces/microbiología , Bacilos Grampositivos Formadores de Endosporas/aislamiento & purificación , Humanos , Sulfuro de Hidrógeno/metabolismo , Minería , Peptococcaceae/aislamiento & purificación , ARN Ribosómico 16S/genéticaRESUMEN
The paper searches for new solutions for the development of highbush blueberry orchards (Vaccinium corymbosum L. (1753)) in Western Siberia. All species of the genus Vaccinium display special symbiotic mycorrhizal associations with root systems-ericoid mycorrhiza, which essentially enhances the formation of adventitious and lateral roots. For the first time, we obtained pure cultures of micromycetes associated with the roots of wild species of the family Ericaceae in the Tomsk region, Russia. With regard to the data of molecular genetic analysis of the ITS region sequence, we selected the BR2-1 isolate based on its morphophysiological traits, which was assigned to the genus Leptodophora. Representatives of this genus typically enter into symbiotic relationships with heathers to form ericoid mycorrhizae. We studied the effect of strain BR2-1 on the development of microclones of the highbush blueberry var. Nord blue during their in vitro adaptation and showed its beneficial effect on growth and shoot formation in young plants. Experiments performed using submerged and solid-state methods showed that the most optimal method for commercial production of BR2-1 is cultivation on grain sterilized by boiling, followed by spore washing.
RESUMEN
The goal of this work was to study the diversity of microorganisms inhabiting a deep subsurface aquifer system in order to understand their functional roles and interspecies relations formed in the course of buried organic matter degradation. A microbial community of a deep subsurface thermal aquifer in the Tomsk Region, Western Siberia was monitored over the course of 5 years via a 2.7 km deep borehole 3P, drilled down to a Palaeozoic basement. The borehole water discharges with a temperature of ca. 50°C. Its chemical composition varies, but it steadily contains acetate, propionate, and traces of hydrocarbons and gives rise to microbial mats along the surface flow. Community analysis by PCR-DGGE 16S rRNA genes profiling, repeatedly performed within 5 years, revealed several dominating phylotypes consistently found in the borehole water, and highly variable diversity of prokaryotes, brought to the surface with the borehole outflow. The major planktonic components of the microbial community were Desulfovirgula thermocuniculi and Methanothermobacter spp. The composition of the minor part of the community was unstable, and molecular analysis did not reveal any regularity in its variations, except some predominance of uncultured Firmicutes. Batch cultures with complex organic substrates inoculated with water samples were set in order to enrich prokaryotes from the variable part of the community. PCR-DGGE analysis of these enrichments yielded uncultured Firmicutes, Chloroflexi, and Ignavibacteriae. A continuous-flow microaerophilic enrichment culture with a water sample amended with acetate contained Hydrogenophilus thermoluteolus, which was previously detected in the microbial mat developing at the outflow of the borehole. Cultivation results allowed us to assume that variable components of the 3P well community are hydrolytic organotrophs, degrading buried biopolymers, while the constant planktonic components of the community degrade dissolved fermentation products to methane and CO2, possibly via interspecies hydrogen transfer. Occasional washout of minor community components capable of oxygen respiration leads to the development of microbial mats at the outflow of the borehole where residual dissolved fermentation products are aerobically oxidized. Long-term community analysis with the combination of molecular and cultivation techniques allowed us to characterize stable and variable parts of the community and propose their environmental roles.
RESUMEN
The sulfidogenic bacterium Desulfovibrio sp. TomC was isolated from acidic waste at the abandoned gold ore mining site in the Martaiga gold ore belt, Western Siberia. This bacterium, being the first reported acid-tolerant gram-negative sulfate-reducer of the order Deltaproteobacteria, is able to grow at pH as low as 2.5 and is resistant to high concentrations of metals. The draft 5.3 Mb genome sequence of Desulfovibrio sp. TomC has been established and provides the genetic basis for application of this microorganism in bioreactors and other bioremediation schemes for the treatment of metal-containing wastewater.