scholarly journals Australian Strains of Botryococcus braunii Examined for Potential Hydrocarbon and Carotenoid Pigment Production and the Effect of Brackish Water

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6644
Author(s):  
Kim Jye Lee-Chang ◽  
Elisabeth Albinsson ◽  
Lesley Clementson ◽  
Andrew T. Revill ◽  
Ian Jameson ◽  
...  

The green alga Botryococcus braunii produces abundant hydrocarbons, in the form of drop-in biodiesel, which promoted interest in the species as a renewable fuel. However, despite the observation of dense populations in the wild, Botryococcus grows very slowly in culture, severely limiting its potential for development as a bioresource. Undertaking a biodiscovery program, we found new strains of Botryococcus in locations ranging from tropical to temperate Australia and from both fresh and brackish waters. As part of the ecophysiological characterisation of this new biodiversity, lipid and pigment compositions were studied for six new strains from six different locations. The strains were inoculated in either freshwater or brackish (salinity of 4)-based medium and maintained over 150 days. The growth of cultures was studied continuously, while lipid and pigment composition were analysed at final harvest on day 150. No significant differences in growth rate between fresh and brackish media were observed. Some strains were more tolerable of brackish conditions than others with a link between salinity tolerance and original location. The use of lower salinity (4 ppt) had a minimal effect on lipid composition, with only two of the six strains showing a different hydrocarbon profile in comparison to the other strains; pigment composition showed only minor variations for fresh and brackish water cultures, although the concentrations varied significantly with the freshwater cultures containing higher pigment concentrations.

Author(s):  
P. Tongiorgi ◽  
E. Fregni ◽  
M. Balsamo

During 1996–1997 a systematic sampling programme was carried out in brackish coastal lakes and lagoons and in the delta of the River Po. In six of the nine collecting locations, 12 species of Gastrotricha were identified. One species, Chaetonotus ichthydioides, is new to science; another three species, the chaetonotidans Heterolepidoderma foliatum and the macrodasyidans Dendrodasys ponticus and Turbanella cf. pontica, and one macrodasyidan genus, Paradasys (P. subterraneus), were found in Italy for the first time. The unusual morphology of some of the species identified shows that Gastrotricha colonized brackish waters from both marine and freshwater habitats.


2020 ◽  
Vol 44 ◽  
Author(s):  
Carlos Donato da Silva Souza ◽  
Geronimo Ferreira da Silva ◽  
Sirleide Maria de Menezes ◽  
José Edson Florentino de Morais ◽  
José Amilton Santos Júnior ◽  
...  

ABSTRACT Cultivation using brackish waters can result in nutritional and metabolic imbalances in several plant species, consequently reducing the production of dry matter (DM) and accumulation of toxic ions (Na+ and/or Cl-) in plants. We evaluated the DM production, and nutrient and inorganic solute (Na+ and Cl-) content in green onion plants (cv. Todo Ano Evergreen - Nebuka) under different levels of nutrient solution salinity in combination with circulation frequencies of this solution. Two experiments were conducted in a hydroponic system, using a completely randomized design, in a 6 × 2 factorial scheme, with five replicates: six levels of nutrient solution salinity (1.5, 3.0, 4.5, 6.0, 7.5, and 9.0 dS m-1) and two solution circulation frequencies (twice and thrice a day). In Experiment I, the evapotranspired depth was replaced using brackish water that was used to prepare each of the salinity levels (used exclusively), whereas in Experiment II, brackish water was used only to prepare each of the salinity levels and public water was used (electrical conductivity [ECw] = 0.12 dS m-1) for replacement in all treatments. The increase in the nutrient solution salinity reduced the production of DM and accumulation of nutrients; the reductions were more pronounced when brackish waters were used exclusively (Experiment I). However, the circulation of solutions thrice a day resulted in the harmful effects of the salinity effect. Replacing the evapotranspirated blade with water supply (Experiment II) mitigated the deleterious effects of salinity. Moreover, three circulations of the nutrient solution daily resulted in lower accumulation of inorganic Na+ and Cl- solutes and increased accumulation of nutrients N, P, K+, Ca2+, Mg2+, and S in the culture.


Parasitology ◽  
1971 ◽  
Vol 63 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Eli Chernin ◽  
Carol Bower

In the laboratory, transmission of Schistosoma mansoni to and from Biomphalaria glabrata can occur in artificial sea water at or below a concentration of 12-5%. Miracidia can also emerge and infect snails in 25 % sea water, but this concentration is inimical to the survival of the snails or their eggs. The parasite thus appears to be better adapted to brackish water than is the intermediate host. Epidemiological studies are needed to assess the limits imposed by brackish waters on the natural transmission of schistosomiasis.


1985 ◽  
Vol 63 (5) ◽  
pp. 920-927 ◽  
Author(s):  
J. Deschênes ◽  
J.-B. Sérodes

The amount of sodium in the aboveground part of the stalks of Scirpus americanus taken at the peak of biomass is a good indicator of the amount of salinity in the waters flooding the tidal marshes of an estuary. In fresh water, the Na concentrations remain below 10 000 and then increase sharply up to 20 000 – 30 000 mg/kg in brackish waters. Even though this plant can grow under brackish conditions, salinity has a considerable effect on the percentage of submersion it can withstand. Consequently, in the presence of saline water, the lower limit of the vegetation regresses towards the shore. In the case of fresh water, Scirpus americanus occupies the lower part of marshes up to an average of 75% of submersion, while in brackish water it extends to about 35% and then disappears when waters are more saline.


2013 ◽  
Vol 10 (1) ◽  
pp. 1041-1070 ◽  
Author(s):  
G. Mongelli ◽  
S. Monni ◽  
G. Oggiano ◽  
M. Paternoster ◽  
R. Sinisi

Abstract. In the Mediterranean area the demand of good quality water is often threatened by salinization, especially in coastal areas. The salinization is the result of concomitant processes due to both marine water intrusion and rock-water interaction, which in some cases are hardly distinguishable. In northwestern Sardinia, in the Nurra area, salinization due to marine water intrusion has been recently evidenced as consequence of bore hole exploitation. However, the geology of the Nurra records a long history from Paleozoic to Quaternary, resulting in relative structural complexity and in a wide variety of lithologies, including Triassic evaporites. To elucidate the origin of the saline component in the Nurra aquifer, may furnish a useful and more general model for the salinization processes in the Mediterranean area, where the occurrence of evaporitic rocks in coastal aquifers is a common feature. In addition, due to intensive human activities and recent climatic changes, the Nurra has become vulnerable to desertification and, similarly to other Mediterranean islands, surface-water resources can periodically suffer from drastic shortage. With this in mind we report new data, regarding brackish waters of Na-Cl type of the Nurra, including major ions and selected trace elements (B, Br, I and Sr) and isotopic data, including δ18O, δD in water, and δ34S and δ18O in dissolved sulphate. To better depict the origin of the salinity we also analyzed a set of Nurra Triassic evaporites for mineralogical and isotopic composition. The brackish waters have Cl contents up to 2025 mg L−1 and the ratios between dissolved ions and chlorine, with the exception of the Br/Cl ratio, are not those expected on the basis of a simple mixing between rain water and seawater. The δ18O and δD data indicate that most of the waters are within the Regional Meteoric Water Line and the Global Meteoric Water Line supporting the idea that they are meteoric in origin. A relevant consequence of the meteoric origin of the Nurra Na-Cl type water is that the Br/Cl ratio, extensively used to assess the origin of salinity in fresh water, should be used with care also in near coastal carbonate aquifers. Overall, and consistent with the geology and the lithological features of the study area, δ34S and δ18O in dissolved sulphate suggest that water-rock interaction is the responsible for the Nurra Na-Cl brackish water composition. Evaporites dissolution also explain the high chlorine contents since halite has been detected in the gypsum levels. Finally, the Nurra Na-Cl brackish water are undersaturated with respect to the more soluble salts involving, in a climate evolving toward semi-arid conditions, that the salinization process could dramatically intensify in the near future.


Author(s):  
Ru D. A. Smith ◽  
Andrew J. Ross

ABSTRACTClavate (club-shaped) structures rimming mid-Cretaceous Burmese amber from Myanmar, previously misdiagnosed as fungal sporocarps, are shown to be domichnia (crypts) of martesiine bivalves (Pholadidae: Martesiinae). They are similar in form to Teredolites clavatus Leymerie, 1842 and Gastrochaenolites lapidicus Kelly & Bromley, 1984; however, the former identification is preferable, given that they are martesiine crypts in amber as opposed to a lithic substrate. Cross-cutting relationships between the clavate features and inclusions in the amber demonstrate that the features post-date hardening of the resin. The fills of the crypts are variable, including sand grade sediment of very fine to coarse sand grainsize, and sparry calcite cements. In some cases, the articulated valves of the pholadid bivalve responsible are visible inside the borings. However, one remarkable specimen contains two pairs of articulated shells ‘floating’ in amber, not associated with crypts; an observation that suggests that the resin was still liquid or soft when the bivalves were trapped in the resin. One individual is associated with an irregular sediment-filled feature and shows shell breakage. Formation of a solid rim around a liquid central volume has been documented in subaqueous bodies of resin in modern swamp forests, and argues for a close proximity between the amber-producing trees and a brackish water habitat for the bivalves. The presence of pyrite as thin films and crystal groups within Burmese amber is further consistent with such a depositional environment. Comparison of the size of pholadid body fossils with growth rates of modern equivalents allows the duration of boring activities to be estimated and suggests that small fossil pholadids in Burmese amber became trapped and died within 1–2 weeks of having settled on the resin. Larger examples present within well-formed domichnia formed in hardened resin. Since ‘hardground’ describes early lithified sediment as a substrate and ‘woodground’ describes wood as a substrate, the term ‘amberground’ is used here to described borings in an amber substrate.


2015 ◽  
Vol 2 (1) ◽  
pp. 42-50
Author(s):  
Uwe Jueg ◽  
Michael L. Zettler

The knowledge about records of leeches (Hirudinea) in Baltic brackish waters of north-east Germany (Mecklenburg-West Pomerania) will be summarized. Observations were made from estuaries of rivers (Stepenitz and Warnow) and lagoons (Darss-Zingst, Stettin) as well in Baltic offshore waters (especially at the Adlergrund/Rønnebank). Altogether 33 taxa are established probably including a new Piscicola species. All species of Glossiphoniidae, Haemopidae and Erpobdellidae could live both in freshwater and oligohaline brackish water up to salinities of 2 psu, few of them even up to 3.6 psu. Only species of the family Piscicolidae are able to penetrate (or to find their optimum?) into mesohaline waters (here up to 13 psu). In the present study several first records for Germany were made in brackish waters (Piscicola kusznierzi, P. elishebae and P. wiktori). Further noteworthy observed species were shortly introduced (Glossiphonia paludosa, Placobdella costata, Italobdella epshteini, Haemopis elegans and Dina apathyi). 7 host fish species could be observed so far.


Author(s):  
D. H. N. Spence ◽  
E. D. Allen ◽  
J. Fraser

SynopsisCentred on Loch Druidibeg, macrophyte vegetation was surveyed in and around 30 lochs in northern South Uist. Alkalinity ranges from 0·014 to 2·33 m.-equiv −1, conductivity (25°C) from 100 to 33,900 μs cm−1, chlorinity from 0·66 m.-equiv −1 upwards. Lochs are classed broadly as non-calcareous (gneissic), calcareous (machair) and brackish. This is an example of a Hebridean range not found elsewhere in the British Isles. Fen vegetation is highly modified by grazing, whilst tall reedswamp and floating-leaved plants are scarce on the mainly exposed and rocky shores, factors which contribute to the predominance of Fucoids in brackish water, of the open Littorella-Lobelia association in non-calcareous water. The Potamogeton filiformis-Chara association is confined to sand in calcareous machair lochs. Deep freshwater vegetation is typified by Isoetes, Potamogeton perfoliatus and P. praelongus.The very wide ranges in alkalinity and conductivity are reflected in some unusual species' distributions. For example, in freshwater lochs (conductivity up to 660 μs cm−1) several species like Isoetes lacustris, confined elsewhere to oligotrophic water, also occur in South Uist at moderately high alkalinities (to 1·8 m. -equiv 1−1). Conductivity varies with chloride concentration in all but the calcareous (machair) lochs; brackish lochs range from 2500 μs cm −1), which floristically, apart from Fucus ceranoides, is fresh water, to Fucoid-dominated rocks, and Ruppia on silt, in conductivities up to 33,900 μs cm−1. Of other angiosperms, Potamogeton gramineus appears to tolerate conductivities of 22,000 μs cm −1. Causal distribution in general is discussed.


1977 ◽  
Vol 68 (1) ◽  
pp. 151-156
Author(s):  
R. W. EPP ◽  
P. W. WINSTON

The body fluid osmolarity of individual rotifers was measured at 12 external concentrations ranging from 32 to 957 m-osmol/1. Brachionus plicatilis is essentially an osmoconformer, since a change in the concentration of the medium results in a corresponding change in the concentration of the body fluids. Most animals were, however, slightly hyperosmotic throughout the range tested. The lowest body fluid osmolarity was 59 m-osmol/1 at an external concentration of 32 m-osmol/1. It appears that B. plicatilis is unable to tolerate the low concentrations that are frequently associated with acid water environments and this is responsible for the restriction of this species to alkaline and brackish waters.


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