scholarly journals Impact of organic carbon acquisition on growth and functional biomolecule production in diatoms

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Thomas Kiran Marella ◽  
Raya Bhattacharjya ◽  
Archana Tiwari
Keyword(s):  
Organic Carbon ◽  
Mass Culture ◽  
Carbon Sources ◽  
Eicosatetraenoic Acid ◽  
Freshwater Habitats ◽  
Current Mass ◽  
Bottle Neck ◽  
Phototrophic Growth ◽  
Unique Potential ◽  
Tubular Photobioreactors

AbstractDiatoms are unicellular photosynthetic protists which constitute one of the most successful microalgae contributing enormously to global primary productivity and nutrient cycles in marine and freshwater habitats. Though they possess the ability to biosynthesize high value compounds like eicosatetraenoic acid (EPA), fucoxanthin (Fx) and chrysolaminarin (Chrl) the major bottle neck in commercialization is their inability to attain high density growth. However, their unique potential of acquiring diverse carbon sources via varied mechanisms enables them to adapt and grow under phototrophic, mixotrophic as well as heterotrophic modes. Growth on organic carbon substrates promotes higher biomass, lipid, and carbohydrate productivity, which further triggers the yield of various biomolecules. Since, the current mass culture practices primarily employ open pond and tubular photobioreactors for phototrophic growth, they become cost intensive and economically non-viable. Therefore, in this review we attempt to explore and compare the mechanisms involved in organic carbon acquisition in diatoms and its implications on mixotrophic and heterotrophic growth and biomolecule production and validate how these strategies could pave a way for future exploration and establishment of sustainable diatom biorefineries for novel biomolecules.

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.

The vulnerability of Arctic shelf sediments to climate change

2015 ◽  
Vol 23 (4) ◽  
pp. 461-479 ◽  
Author(s):  
Robie W. Macdonald ◽  
Zou Zou A. Kuzyk ◽  
Sophia C. Johannessen
Keyword(s):  
Organic Carbon ◽  
Carbon Sources ◽  
The Arctic ◽  
Sedimentary Environments ◽  
Carbon Supply ◽  
Shelf Sediment ◽  
Wide Range ◽  
Metabolic Conditions ◽  
Shelf Sediments ◽  
Ocean Ecosystem

The sediments of the pan-Arctic shelves contribute an important component to the Arctic Ocean ecosystem by providing a habitat for biota (benthos), a repository for organic and inorganic non-conservative substances entering or produced within the ocean, a reactor and source of transformed substances back to the water column, and a mechanism of burial. Sediments interact with ice, ocean, and the surrounding land over a wide range of space and time scales. We discuss the vulnerability of shelf sediment to changes in (i) organic carbon sources, (ii) pathways of sediment and organic carbon supply, and (iii) physical and biogeochemical alteration (diagenesis). Sedimentary environments of the shelves and basins are likely to exhibit a wide variance in their response to global change because of their wide variation in sediment sources, processes, and metabolic conditions. In particular, the Chukchi and Barents shelves are dominated by inflowing waters from oceans to the south, whereas the interior shelves are more closely tied to terrigenous sources due to river inflow and coastal erosion.

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 Carbon Isotope Analysis of Land Snail Shells: Implications for Carbon Sources and Radiocarbon Dating

Radiocarbon ◽  
1983 ◽  
Vol 25 (3) ◽  
pp. 810-830 ◽  
Author(s):  
Glenn A Goodfriend ◽  
Darden G Hood
Keyword(s):  
Exchange Rate ◽  
Organic Carbon ◽  
Radiocarbon Dating ◽  
Activity Patterns ◽  
Isotope Analysis ◽  
Carbon Sources ◽  
Isotopic Fractionation ◽  
Land Snail ◽  
Land Snails ◽  
Shell Carbonate

13C and 14C analyses were performed on a series of modern Jamaican land snails in order to quantitatively determine the sources of shell carbon. A model of these carbon sources, the pathways by which carbon reaches the shell, and the fractionation processes involved are presented. The contribution of limestone to shell carbonate is variable but may comprise up to 33% of the shell. About 25–40% of shell carbonate is derived from plants and about 30–60% from atmospheric CO2. Variation among populations and species with respect to 13C and 14C is attributed to the effects of limestone incorporation, snail size (as it affects CO2 exchange rate), physiological characteristics (presence of urease, respiration rate), and activity patterns of the snails. A formula for correction for isotopic fractionation of 14C of shell carbonate, based on 13C measurements, is derived. Bicarbonate-aragonite fractionation is apparently very minimal. Shell organic carbon appears to be derived largely from plants but also to a lesser extent from inorganic hemolymph carbon. This introduces the possibility of a small age anomaly of shell organic 14C due to limestone incorporation.

Role of Organic Carbon Sources and Sulfate in Controlling Net Methylmercury Production in Riverbank Sediments of the South River, VA (USA)

2017 ◽  
Vol 35 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Krista M. A. Paulson ◽  
Carol J. Ptacek ◽  
David W. Blowes ◽  
W. Douglas Gould ◽  
Jing Ma ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Sources ◽  
The South ◽  
Organic Carbon Sources ◽  
Methylmercury Production

scholarly journals Modelling landscape controls on dissolved organic carbon sources and fluxes to streams

2014 ◽  
Vol 122 (2-3) ◽  
pp. 361-374 ◽  
Author(s):  
J. J. Dick ◽  
D. Tetzlaff ◽  
C. Birkel ◽  
C. Soulsby
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Carbon Sources ◽  
Organic Carbon Sources

Analysis of organic carbon sources in tropical seagrass fish: a case study of the east coast of Hainan Province

2019 ◽  
Vol 15 (8-9) ◽  
pp. 513-522 ◽  
Author(s):  
Jianguo Du ◽  
Zehao Chen ◽  
Meiling Xie ◽  
Mingru Chen ◽  
Xinqing Zheng ◽  
...  
Keyword(s):  
Organic Carbon ◽  
East Coast ◽  
Carbon Sources ◽  
Hainan Province ◽  
Organic Carbon Sources

scholarly journals Effect of corn cobs as external carbon sources on nitrogen removal in constructed wetlands treating micro-polluted river water

2019 ◽  
Vol 79 (9) ◽  
pp. 1639-1647 ◽  
Author(s):  
Lu-ji Yu ◽  
Tao Chen ◽  
Yanhong Xu
Keyword(s):  
Organic Carbon ◽  
River Water ◽  
Constructed Wetlands ◽  
Carbon Sources ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Flow Mode ◽  
Low Carbon ◽  
Polluted River ◽  
Corn Cobs

Abstract Micro-polluted river water is characterized as having limited biodegradability, low carbon to nitrogen ratio and little organic carbon supply, all of which makes it hard to further purify. Two bench scale constructed wetlands (CWs) with a horizontal subsurface flow mode were set up in the laboratory to evaluate their feasibility and efficiency on denitrification with and without corn cobs as external carbon sources. Micro-polluted river water was used as feed solution. The CW without corn cobs substrates possessed a good performance in removing chemical oxygen demand (COD, <40 mg/L) and ammonia nitrogen (NH3-N, <0.65 mg/L), but less efficiency in removing total nitrogen (TN) and nitrate nitrogen (NO3-N). In marked contrast, the CW with 1% (w/w) corn cobs substrates as external carbon sources achieved a significant improvement in the removal efficiency of TN (increased from 34.2% to 71.9%) and NO3-N (increased from 19% to 71.9%). The incorporation of corn cobs substrates did not cause any obvious increase in the concentrations of COD and NH3-N in the effluent. This improvement in the denitrification efficiency was owing to the released organic carbon from corn cobs substrates, which facilitated the growth of abundant microbes on the surface and pores of the substrate. The open area of the used corn chips is larger than that of the pristine ones, and corn cobs can continue to provide a carbon fiber source for denitrification.

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