72 research outputs found
Production of scopularide A in submerged culture with Scopulariopsis brevicaulis
Background: Marine organisms produce many novel compounds with useful biological activity, but are currently underexploited. Considerable research has been invested in the study of compounds from marine bacteria, and several groups have now recognised that marine fungi also produce an interesting range of compounds. During product discovery, these compounds are often produced only in non-agitated culture conditions, which are unfortunately not well suited for scaling up. A marine isolate of Scopulariopsis brevicaulis, strain LF580, produces the cyclodepsipeptide scopularide A, which has previously only been produced in non-agitated cultivation.
Results: Scopulariopsis brevicaulis LF580 produced scopularide A when grown in batch and fed-batch submerged cultures. Scopularide A was extracted primarily from the biomass, with approximately 7% being extractable from the culture supernatant. By increasing the biomass density of the cultivations, we were able to increase the volumetric production of the cultures, but it was important to avoid nitrogen limitation. Specific production also increased with increasing biomass density, leading to improvements in volumetric production up to 29-fold, compared with previous, non-agitated cultivations. Cell densities up to 36 g L-1 were achieved in 1 to 10 L bioreactors. Production of scopularide A was optimised in complex medium, but was also possible in a completely defined medium.
Conclusions: Scopularide A production has been transferred from a non-agitated to a stirred tank bioreactor environment with an approximately 6-fold increase in specific and 29-fold increase in volumetric production. Production of scopularide A in stirred tank bioreactors demonstrates that marine fungal compounds can be suitable for scalable production, even with the native production organism
High throughput, small scale methods to characterise the growth of marine fungi
Various marine fungi have been shown to produce interesting, bioactive compounds, but scaling up the production of these compounds can be challenging, particularly because little is generally known about how the producing organisms grow. Here we assessed the suitability of using 100-well BioScreen plates or 96-well plates incubated in a robot hotel to cultivate eight filamentous marine fungi, six sporulating and two non-sporulating, to obtain data on growth and substrate (glucose, xylose, galactose or glycerol) utilisation in a high throughput manner. All eight fungi grew in both cultivation systems, but growth was more variable and with more noise in the data in the Cytomat plate hotel than in the BioScreen. Specific growth rates between 0.01 (no added substrate) and 0.07 h-1 were measured for strains growing in the BioScreen and between 0.01 and 0.27 h-1 for strains in the plate hotel. Three strains, Dendryphiella salina LF304, Penicillium chrysogenum KF657 and Penicillium pinophilum LF458, consistently had higher specific growth rates on glucose and xylose in the plate hotel than in the BioScreen, but otherwise results were similar in the two systems. However, because of the noise in data from the plate hotel, the data obtained from it could only be used to distinguish between substrates which did or did not support growth, whereas data from BioScreen also provided information on substrate preference. Glucose was the preferred substrate for all strains, followed by xylose and galactose. Five strains also grew on glycerol. Therefore it was important to minimise the amount of glycerol introduced with the inoculum to avoid misinterpreting the results for growth on poor substrates. We concluded that both systems could provide physiological data with filamentous fungi, provided sufficient replicates are included in the measurements
Satelliittihavaintojen hyödyntÀminen ilmanlaadun seurannassa
TÀssÀ selvityksessÀ kartoitetaan ensimmÀistÀ kertaa satelliittimittausten hyödyntÀmistÀ ilmanlaadun seurannassa Suomessa. Satelliittien ehdottomana vahvuutena on ilmanlaatumuuttujien alueellisen jakauman kuvaaminen sekÀ ilmansaasteiden kulkeutumisen seuranta, joita tÀssÀ työssÀ on demonstroitu kÀyttÀmÀllÀ alailmakehÀn typpidioksidi (NO2}-havaintoja TROPOspheric Monitoring Instrument (TROPOMI) ja Ozone Monitoring Instrument (OMI) satelliitti-instrumenteista. TROPOMI laukaistiin EU:n Copernicus-ohjelman rahoittamassa Sentinel-5P satelliitissa vuonna 2017, ja se on tÀllÀ hetkellÀ paikalliselta erotuskyvyltÀÀn tarkin ilmanlaadun kannalta oleellisia kaasuja havainnoiva satelliittimittalaite. Suomalais-hollantilainen OMI-instrumentti NASAn Aura-satelliitissa on puolestaan tuottanut maailmanlaajuisia havaintoja jo lÀhes 15 vuoden ajan.
TÀmÀn työn tulokset nÀyttÀvÀt, ettÀ satelliittien avulla voidaan tarkastella typpidioksidin alueellista jakaumaa Suomessa sekÀ lÀhialueilla aina kaupunkitasolle asti. Esimerkiksi pÀÀkaupunkiseudun keskimÀÀrÀisissÀ pitoisuuksissa voidaan erottaa alueellisia vaihteluita ja nÀhdÀ selvÀ ero viikonpÀivien ja viikonloppujen vÀlillÀ. OMI-instrumentin havainnoista puolestaan nÀhdÀÀn, ettÀ alailmakehÀn NO2-pitoisuudet ovat keskimÀÀrin laskeneet koko maassa vuodesta 2005 vuoteen 2018.
KeskeisimpiÀ kysymyksiÀ satelliittidatan hyödyntÀmisessÀ ilmanlaadun seurannassa on se, kuinka hyvin satelliittihavainnot vastaavat in situ -mittauksista nÀhtyjÀ vaihteluita. Vertailu TROPOMI-havaintojen ja pintamittausten vÀlillÀ nÀyttÀÀ, ettÀ vaikka kaupungin sisÀllÀ yksittÀisten asemien kohdalla yhteensopivuus voi vaihdella asemittain, korrelaatio on hyvÀ kun vastaavuutta tarkastellaan yhdistÀmÀllÀ kunkin kaupungin keskustan pintahavainnot. Tulos on samansuuntainen sekÀ Suomessa ettÀ myös muualla Euroopassa
Higher sleep spindle activity is associated with fewer false memories in adolescent girls
Background: Sleep facilitates the extraction of semantic regularities amongst newly encoded memories, which may also lead to increased false memories. We investigated sleep stage proportions and sleep spindles in the recollection of adolescents' false memories, and their potential sex-specific differences. Methods: 196 adolescents (mean age 16.9 y; SD = 0.1, 61% girls) underwent the Deese, Roediger & McDermott (DRM) false memory procedure and overnight polysomnography, with free recall the following morning. Sleep was scored manually into stages 1, 2, 3 and REM. Stage 2 sleep spindle frequency, density, and peak amplitude were used as measures of spindle activity for slow (10-13 Hz) and fast (13-16 Hz) ranges. Results: In girls, a lower number of critical lures was associated with higher spindle frequency (p Conclusions: In adolescent girls, higher spindle activity was associated with fewer critical lures being falsely recalled in the DRM paradigm. Unlike studies using adult participants, we did not observe any association between slow-wave sleep and false memory recollection.Peer reviewe
Dataset from a mesocosm experiment on brownification in the Baltic Sea
Refers to Brownification affects phytoplankton community composition but not primary productivity in eutrophic coastal waters: A mesocosm experiment in the Baltic Sea Science of The Total Environment, Volume 841, 1 October 2022, Pages 156510 Kristian Spilling, Eero Asmala, Noora Haavisto, Lumi Haraguchi, Kaisa Kraft, Anne-Mari Lehto, Aleksandra M. Lewandowska, Joanna Norkko, Jonna Piiparinen, Jukka SeppĂ€lĂ€, Mari Vanharanta, Anu Vehmaa, Pasi Ylöstalo, Timo TamminenClimate change is projected to cause brownification of some coastal seas due to increased runoff of terrestrially derived organic matter. We carried out a mesocosm experiment over 15 days to test the effect of this on the planktonic ecosystem. The experiment was set up in 2.2 m3 plastic bags moored outside the TvĂ€rminne Zoological Station at the SW coast of Finland. We used four treatments, each with three replicates: control (Contr) without any manipulation; addition of a commercially available organic carbon additive called HuminFeed (Hum; 2 mg Lâ1); addition of inorganic nutrients (Nutr; 5.7 ”M NH4 and 0.65”M PO4); and a final treatment of combined Nutr and Hum (Nutr+Hum) additions. Water samples were taken daily, and measured variables included water transparency, organic and inorganic nutrient pools, chlorophyll a (Chla), primary and bacterial production and particle counts by flow cytometry.Peer reviewe
Validation of TROPOMI Surface UV Radiation Product
The TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor (S5P) satellite was launched
on 13 October 2017 to provide the atmospheric composition for atmosphere and climate research. The S5P is a sun-synchronous polar-orbiting satellite providing global daily coverage. The TROPOMI swath is 2600 km wide, and the ground resolution for most data products is 7.2x3.5 km2 (5.6x3.5 km2 since 6 August 2019) at nadir. The Finnish Meteorological Institute (FMI) is responsible for the development and processing of the TROPOMI Surface Ultraviolet (UV) Radiation Product which includes 36 UV parameters in total. Ground-based data from 25 sites located in arctic, subarctic, temperate, equatorial and antarctic areas were used for validation of TROPOMI overpass irradiance at 305, 310, 324 and 380 nm, overpass erythemally weighted dose rate / UV index and erythemally weighted daily dose for the period from 1 January 2018 to 31 August 2019. The validation
results showed that for most sites 60â80% of TROPOMI data was within ±20% from ground-based data for snow
free surface conditions. The median relative differences to ground-based measurements of TROPOMI snow free surface daily doses were within ±10% and ±5% at two thirds and at half of the sites, respectively. At several sites more than 90% of clear sky TROPOMI data were within ±20% from ground-based measurements. Generally median relative differences between TROPOMI data and ground-based measurements were a little biased towards negative values, but at high latitudes where nonhomogeneous topography and albedo/snow conditions occurred, the negative bias was exceptionally high, from -30% to -65%. Positive biases of 10â15% were also found for mountainous sites due to challenging topography. The TROPOMI Surface UV Radiation Product includes quality flags to detect increased uncertainties in the data due to heterogeneous surface albedo and rough terrain which can be used to filter the data retrieved under challenging conditions
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