scholarly journals Redefining the Subsurface Biosphere: Characterization of Fungi Isolated From Energy-Limited Marine Deep Subsurface Sediment

2021 ◽  
Vol 2 ◽  
Author(s):  
Brandi Kiel Reese ◽  
Morgan S. Sobol ◽  
Marshall Wayne Bowles ◽  
Kai-Uwe Hinrichs
Keyword(s):  
Organic Carbon ◽  
Growth Parameters ◽  
Carbon Sources ◽  
South Pacific ◽  
Physical Growth ◽  
Energy Budgets ◽  
Deep Subsurface ◽  
Fungal Populations ◽  
South Pacific Gyre

The characterization of metabolically active fungal isolates within the deep marine subsurface will alter current ecosystem models and living biomass estimates that are limited to bacterial and archaeal populations. Although marine fungi have been studied for over fifty years, a detailed description of fungal populations within the deep subsurface is lacking. Fungi possess metabolic pathways capable of utilizing previously considered non-bioavailable energy reserves. Therefore, metabolically active fungi would occupy a unique niche within subsurface ecosystems, with the potential to provide an organic carbon source for heterotrophic prokaryotic populations from the transformation of non-bioavailable energy into substrates, as well as from the fungal necromass itself. These organic carbon sources are not currently being considered in subsurface energy budgets. Sediments from South Pacific Gyre subsurface, one of the most energy-limited environments on Earth, were collected during the Integrated Ocean Drilling Program Expedition 329. Anoxic and oxic sediment slurry enrichments using fresh sediment were used to isolate multiple fungal strains in media types that varied in organic carbon substrates and concentration. Metabolically active and dormant fungal populations were also determined from nucleic acids extracted from in situ cryopreserved South Pacific Gyre sediments. For further characterization of physical growth parameters, two isolates were chosen based on their representation of the whole South Pacific Gyre fungal community. Results from this study show that fungi have adapted to be metabolically active and key community members in South Pacific Gyre sediments and potentially within global biogeochemical cycles.

scholarly journals Evaluation of autotrophic and mixotrophic regimen Chlorella pyrenoidosa cells in various wastes water for its biochemical composition and biomass production

2014 ◽  
Author(s):  
Nisha Phour Dhull ◽  
Raman Soni ◽  
Deepak Kumar Rahi ◽  
Sanjeev Kumar Soni
Keyword(s):  
Organic Carbon ◽  
Biomass Production ◽  
Large Scale ◽  
Growth Parameters ◽  
Carbon Sources ◽  
Cost Effective ◽  
Chlorella Pyrenoidosa ◽  
Defined Medium ◽  
Dairy Wastewater ◽  
Treated Wastewater

The present study investigates the possibility of integrating an existing industrial large scale biomass production with the treatment of waste water in which a mixture of organic and inorganic rich pollutants was used as a medium. This study suggests that the replacement of a defined medium with a complete mixotrophic medium gives a significant statistical difference in terms of growth parameters i.e. biomass production and specific growth rate. The green microalga C. pyrenoidosa was cultivated under different mixotrophic conditions for evaluation of biomass production. Inorganic defined fog’s medium supplemented, with raw dairy wastewater led to 1.37g/L biomass production in comparison to 1.2g/L obtained with pure glucose revealing 14.16% increase. The study also involves the supplementation of raw dairy wastewater as an organic carbon source in an inorganic medium comprising municipal treated water and reverse osmosis (RO) treated wastewater and attained 2.4g/L and 1.6g/L of biomass respectively, as compared to 0.3g/L and 0.16g/L obtained in the wastewaters alone revealing 700% and 900% increase respectively. Mixotrophic regimen cells as analyzed by a 2D Fourier transform infrared (FTIR) spectroscopy for its biochemical content revealed that fog’s blended raw dairy waste (RDW) regimen cells had maximum Carbohydrate/Amide ratio. The study suggests that the mixotrophic regimen C. pyrenoidosa cells can show appropriate growth in a mixture of waste waters and the same comes out to be a cost effective and feasible alternative commercial medium for biomass production without requiring any expensive organic carbon sources in the culture medium.

scholarly journals Evaluation of autotrophic and mixotrophic regimen Chlorella pyrenoidosa cells in various wastes water for its biochemical composition and biomass production

2014 ◽  
Author(s):  
Nisha Phour Dhull ◽  
Raman Soni ◽  
Deepak Kumar Rahi ◽  
Sanjeev Kumar Soni
Keyword(s):  
Organic Carbon ◽  
Biomass Production ◽  
Large Scale ◽  
Growth Parameters ◽  
Carbon Sources ◽  
Cost Effective ◽  
Chlorella Pyrenoidosa ◽  
Defined Medium ◽  
Dairy Wastewater ◽  
Treated Wastewater

The present study investigates the possibility of integrating an existing industrial large scale biomass production with the treatment of waste water in which a mixture of organic and inorganic rich pollutants was used as a medium. This study suggests that the replacement of a defined medium with a complete mixotrophic medium gives a significant statistical difference in terms of growth parameters i.e. biomass production and specific growth rate. The green microalga C. pyrenoidosa was cultivated under different mixotrophic conditions for evaluation of biomass production. Inorganic defined fog’s medium supplemented, with raw dairy wastewater led to 1.37g/L biomass production in comparison to 1.2g/L obtained with pure glucose revealing 14.16% increase. The study also involves the supplementation of raw dairy wastewater as an organic carbon source in an inorganic medium comprising municipal treated water and reverse osmosis (RO) treated wastewater and attained 2.4g/L and 1.6g/L of biomass respectively, as compared to 0.3g/L and 0.16g/L obtained in the wastewaters alone revealing 700% and 900% increase respectively. Mixotrophic regimen cells as analyzed by a 2D Fourier transform infrared (FTIR) spectroscopy for its biochemical content revealed that fog’s blended raw dairy waste (RDW) regimen cells had maximum Carbohydrate/Amide ratio. The study suggests that the mixotrophic regimen C. pyrenoidosa cells can show appropriate growth in a mixture of waste waters and the same comes out to be a cost effective and feasible alternative commercial medium for biomass production without requiring any expensive organic carbon sources in the culture medium.

scholarly journals In-depth characterization of diazotroph activity across the western tropical South Pacific hotspot of N<sub>2</sub> fixation (OUTPACE cruise)

2018 ◽  
Vol 15 (13) ◽  
pp. 4215-4232 ◽  
Author(s):  
Sophie Bonnet ◽  
Mathieu Caffin ◽  
Hugo Berthelot ◽  
Olivier Grosso ◽  
Mar Benavides ◽  
...  
Keyword(s):  
N2 Fixation ◽  
Secondary Ion Mass Spectrometry ◽  
Seawater Temperature ◽  
Nifh Gene ◽  
World Ocean ◽  
South Pacific ◽  
Isotopic Analyses ◽  
South Pacific Gyre

Abstract. Here we report N2 fixation rates from a ∼ 4000 km transect in the western and central tropical South Pacific, a particularly undersampled region in the world ocean. Water samples were collected in the euphotic layer along a west to east transect from 160∘ E to 160∘ W that covered contrasting trophic regimes, from oligotrophy in the Melanesian archipelago (MA) waters to ultra-oligotrophy in the South Pacific Gyre (GY) waters. N2 fixation was detected at all 17 sampled stations with an average depth-integrated rate of 631 ± 286 µmolNm-2d-1 (range 196–1153 µmolNm-2d-1) in MA waters and of 85 ± 79 µmolNm-2d-1 (range 18–172 µmolNm-2d-1) in GY waters. Two cyanobacteria, the larger colonial filamentous Trichodesmium and the smaller UCYN-B, dominated the enumerated diazotroph community (> 80 %) and gene expression of the nifH gene (cDNA > 105 nifH copies L−1) in MA waters. Single-cell isotopic analyses performed by nanoscale secondary ion mass spectrometry (nanoSIMS) at selected stations revealed that Trichodesmium was always the major contributor to N2 fixation in MA waters, accounting for 47.1–83.8 % of bulk N2 fixation. The most plausible environmental factors explaining such exceptionally high rates of N2 fixation in MA waters are discussed in detail, emphasizing the role of macro- and micro-nutrient (e.g., iron) availability, seawater temperature and currents.

scholarly journals Gross community production and metabolic balance in the South Pacific Gyre, using a non intrusive bio-optical method

2008 ◽  
Vol 5 (2) ◽  
pp. 463-474 ◽  
Author(s):  
H. Claustre ◽  
Y. Huot ◽  
I. Obernosterer ◽  
B. Gentili ◽  
D. Tailliez ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Optical Method ◽  
Carbon Fixation ◽  
South Pacific ◽  
The South ◽  
Euphotic Layer ◽  
Deep Layers ◽  
South Pacific Gyre ◽  
Community Production

Abstract. The very clear waters of the South Pacific Gyre likely constitute an end-member of oligotrophic conditions which remain essentially unknown with respect to its impact on carbon fixation and exportation. We describe a non-intrusive bio-optical method to quantify the various terms of a production budget (Gross community production, community losses, net community production) in this area. This method is based on the analysis of the diel cycle in Particulate Organic Carbon (POC), derived from high frequency measurements of the particle attenuation coefficient cp. We report very high integrated rates of Gross Community Production within the euphotic layer (average of 846±484 mg C m−2 d−1 for 17 stations) that are far above any rates determined using incubation techniques for such areas. Furthermore we show that the daily production of POC is essentially balanced by the losses so that the system cannot be considered as net heterotrophic. Our results thus agree well with geochemical methods, but not with incubation studies based on oxygen methods. We stress to the important role of deep layers, below the euphotic layer, in contributing to carbon fixation when incident irradiance at the ocean surface is high (absence of cloud coverage). These deep layers, not considered up to know, might fuel part of the heterotrophic processes in the upper layer, including through dissolved organic carbon. We further demonstrate that, in these extremely clear and stratified waters, integrated gross community production is proportional to the POC content and surface irradiance via an efficiency index ψ GCP*, the water column cross section for Gross Community Production. We finally discuss our results in the context of the role of oligotrophic gyre in the global carbon budget and of the possibility of using optical proxies from space for the development of growth community rather than primary production global models.

scholarly journals In depth characterization of diazotroph activity across the Western Tropical South Pacific hot spot of N<sub>2</sub> fixation

2018 ◽  
Author(s):  
Sophie Bonnet ◽  
Mathieu Caffin ◽  
Hugo Berthelot ◽  
Olivier Grosso ◽  
Mar Benavides ◽  
...  
Keyword(s):  
N2 Fixation ◽  
Secondary Ion Mass Spectrometry ◽  
Hot Spot ◽  
Average Rate ◽  
South Pacific ◽  
Isotopic Analyses ◽  
Nitrogenase Genes ◽  
South Pacific Gyre ◽  
Secondary Ion

Abstract. Here we report quantification of N2 fixation rates over a ~ 4000 km transect in the western and central tropical South Pacific. Water samples were collected along a west to east transect from 160° E to 160° W, covering contrasting trophic regimes, from oligotrophy in the Melanesian archipelagoes (MA) waters to ultra-oligotrophy in the South Pacific Gyre (GY) waters. N2 fixation was detected at all 17 sampled stations with an average rate of 631 ± 286 µmol N m−2 d−1 (range 196–1153 µmol N m−2 d−1) in MA waters and of 85 ± 79 µmol N m−2 d−1 (range 18–172 µmol N m−2 d−1) in GY waters. Exceptionally high rates of N2 fixation in MA waters were favored by availability of both iron and phosphate and the observed warm sea surface temperatures (> 28 °C). Trichodesmium and UCYN-B cyanobacteria dominated the diazotroph community (> 80 %) and gene expression of nitrogenase genes (cDNA > 105 nifH copies L−1) in MA waters, and single-cell isotopic analyses performed by nanoscale secondary ion mass spectrometry at selected stations reveal that Trichodesmium was always the major contributor to N2 fixation in MA waters, accounting for 47.1 to 83.8 % of bulk N2 fixation.

scholarly journals Gross community production and metabolic balance in the South Pacific Gyre, using a non intrusive bio-optical method

2007 ◽  
Vol 4 (5) ◽  
pp. 3089-3121 ◽  
Author(s):  
H. Claustre ◽  
Y. Huot ◽  
I. Obernosterer ◽  
B. Gentili ◽  
D. Tailliez ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Optical Method ◽  
Carbon Fixation ◽  
South Pacific ◽  
The South ◽  
Euphotic Layer ◽  
Deep Layers ◽  
South Pacific Gyre ◽  
Community Production

Abstract. The very clear waters of the South Pacific Gyre likely constitute an end-member of oligotrophic conditions which remain essentially unknown with respect to its impact on carbon fixation and exportation. We describe a non-intrusive bio-optical method to quantify the various terms of a production budget (Gross Community Production, community losses, net community production) in this area. This method is based on the analysis of the diel cycle in Particulate Organic Carbon (POC), derived from high frequency measurements of the particle attenuation coefficient cp. We report very high integrated rates of Gross Community Production within the euphotic layer (average of 846±484 mg C m−2 d−1 for 17 stations) that are far above any rates determined using incubation techniques for such areas. Furthermore we show that the daily production of POC is essentially balanced by the losses so that the system cannot be considered as net heterotoph. Our results thus agree well with geochemical methods, but not with incubation studies based on oxygen methods. We stress to the important role of deep layers, below the euphotic layer, in contributing to carbon fixation when incident irradiance at the ocean surface is high (absence of cloud coverage). These deep layers, not considered up to now, might fuel a part of the heterotrophic processes in the upper layer, in particular through dissolved organic carbon release. We further demonstrate that, in these extremely clear and stratified waters, integrated Gross Community Production is proportional to the POC content and surface irradiance via an efficiency index ψGCP*, the water column cross section for Gross Community Production. We finally discuss our results in the context of the role of oligotrophic gyre in global carbon budget and of the possibility of using optical proxy from space for the development of gross community rather than primary production global models.

Assimilation of various organic carbon sources by Haematococcus strains

2009 ◽  
Vol 57 (2) ◽  
pp. 231-237
Author(s):  
M. Zych ◽  
A. Stolarczyk ◽  
K. Maca ◽  
A. Banaś ◽  
K. Termińska-Pabis ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Organic Compounds ◽  
Present Experiment ◽  
Carbon Sources ◽  
Growth Conditions ◽  
Mixotrophic Growth ◽  
Naturally Occurring ◽  
Organic Carbon Sources ◽  
Secondary Carotenoids ◽  
Colour Changes

Differences in the assimilation of individual organic compounds (5 mM sugars and L-asparagine) under mixotrophic growth conditions were described for three naturally occurring Haematococcus strains.The effects of assimilation were measured by the growth intensity and size of algal cells, and the effect of colour changes in the cultures was observed. Some compounds caused the cell colouration to change from green to yellow, being the result of chlorophyll disappearance and the accumulation of yellow secondary carotenoids. In the present experiment none of the cultures turned red, thus excluding the intense accumulation of the commercially interesting carotenoid, astaxanthin.

scholarly journals Quantitative Characterization of Geotrichum candidum Growth in Milk

2021 ◽  
Vol 11 (10) ◽  
pp. 4619
Author(s):  
Petra Šipošová ◽  
Martina Koňuchová ◽  
Ľubomír Valík ◽  
Monika Trebichavská ◽  
Alžbeta Medveďová
Keyword(s):  
Growth Parameters ◽  
Mechanistic Model ◽  
Geotrichum Candidum ◽  
Activity Level ◽  
Effect Of Temperature ◽  
Operational Parameters ◽  
Quantitative Characterization ◽  
Essential Knowledge ◽  
Cardinal Temperatures

The study of microbial growth in relation to food environments provides essential knowledge for food quality control. With respect to its significance in the dairy industry, the growth of Geotrichum candidum isolate J in milk without and with 1% NaCl was investigated under isothermal conditions ranging from 6 to 37 °C. The mechanistic model by Baranyi and Roberts was used to fit the fungal counts over time and to estimate the growth parameters of the isolate. The effect of temperature on the growth of G. candidum in milk was modelled with the cardinal models, and the cardinal temperatures were calculated as Tmin = −3.8–0.0 °C, Topt = 28.0–34.6 °C, and Tmax = 35.2–37.2 °C. The growth of G. candidum J was slightly faster in milk with 1% NaCl and in temperature regions under 21 °C. However, in a temperature range that was close to the optimum, its growth was slightly inhibited by the lowered water activity level. The present study provides useful cultivation data for understanding the behaviour of G. candidum in milk and can serve as an effective tool for assessing the risk of fungal spoilage, predicting the shelf life of dairy products, or assessing the optimal conditions for its growth in relation to the operational parameters in dairy practices.

scholarly journals Distribution of inorganic and organic nutrients in the South Pacific Ocean − evidence for long-term accumulation of organic matter in nitrogen-depleted waters

2008 ◽  
Vol 5 (2) ◽  
pp. 281-298 ◽  
Author(s):  
P. Raimbault ◽  
N. Garcia ◽  
F. Cerutti
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Dissolved Organic Matter ◽  
Dissolved Organic Carbon ◽  
Chlorophyll A ◽  
Organic Phosphorus ◽  
South Pacific ◽  
Nutrient Concentrations ◽  
The South ◽  
Photic Layer

Abstract. During the BIOSOPE cruise the RV Atalante was dedicated to study the biogeochemical properties in the South Pacific between the Marquesas Islands (141° W–8° S) and the Chilean upwelling (73° W–34° S). Over the 8000 km covered by the cruise, several different trophic situations were encountered, in particular strong oligotrophic conditions in the South Pacific Gyre (SPG, between 123° W and 101° W). In this isolated region, nitrate was undetectable between the surface and 160–180 m and only trace quantities (<20 nmoles l−1) of regenerated nitrogen (nitrite and ammonium) were detected, even in the subsurface maximum. Integrated nitrate over the photic layer, which reached 165 m, was close to zero. Despite this severe nitrogen-depletion, phosphate was always present in significant concentrations (≈0.1 μmoles l−1), while silicic acid was maintained at low but classical oceanic levels (≈1 μmoles l−1). In contrast, the Marquesas region (MAR) to the west and Chilean upwelling (UPW) to the east were characterized by high nutrient concentrations, one hundred to one thousand fold higher than in the SPG. The distribution of surface chlorophyll reflected the nitrate gradient, the lowest concentrations (0.023 nmoles l−1) being measured at the centre of the SPG, where integrated value throughout the photic layer was very low (≈ 10 mg m−2). However, due to the relatively high concentrations of chlorophyll-a encountered in the DCM (0.2 μg l−1), chlorophyll-a concentrations throughout the photic layer were less variable than nitrate concentrations (by a factor 2 to 5). In contrast to chlorophyll-a, integrated particulate organic matter (POM) remained more or less constant along the study area (500 mmoles m−2, 60 mmoles m−2 and 3.5 mmoles m−2 for particulate organic carbon, particulate organic nitrogen and particulate organic phosphorus, respectively), with the exception of the upwelling, where values were two fold higher. The residence time of particulate carbon in the surface water was only 4–5 days in the upwelling, but up to 30 days in the SPG, where light isotopic δ15N signal noted in the suspended POM suggests that N2-fixation provides a dominant supply of nitrogen to phytoplankton. The most striking feature was the large accumulation of dissolved organic matter (DOM) in the SPG compared to the surrounding waters, in particular dissolved organic carbon (DOC) where concentrations were at levels rarely measured in oceanic waters (>100 μmoles l−1). Due to this large pool of DOM in the SPG photic layer, integrated values followed a converse geographical pattern to that of inorganic nutrients with a large accumulation in the centre of the SPG. Whereas suspended particulate matter in the mixed layer had a C/N ratio largely conforming to the Redfield stochiometry (C/N≈6.6), marked deviations were observed in this excess DOM (C/N≈16 to 23). The marked geographical trend suggests that a net in situ source exists, mainly due to biological processes. Thus, in spite of strong nitrate-depletion leading to low chlorophyll biomass, the closed ecosystem of the SPG can accumulate large amounts of C-rich dissolved organic matter. The implications of this finding are examined, the conclusion being that, due to weak lateral advection, the biologically produced dissolved organic carbon can be accumulated and stored in the photic layer for very long periods. In spite of the lack of seasonal vertical mixing, a significant part of new production (up to 34%), which was mainly supported by dinitrogen fixation, can be exported to deep waters by turbulent diffusion in terms of DOC. The diffusive rate estimated in the SPG (134 μmolesC m−2 d−1), was quite equivalent to the particles flux measured by sediments traps.

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