Microbial lipid fermentation of Trichosporon cutaneum in high saline water

Fermentative production of microbial lipid requires high fresh water input. The utilization of high saline seawater or industrial wastewater is an important alternative to reduce the freshwater consumption. This study revealed that oleaginous yeast Trichosporon cutaneum was tolerant to a high salinity up to 130 g/L of NaCl after long-term adaptive evolution. Lipid fermentation of T. cutaneum in seawater achieved the lipid production of 31.7 g/L with approximately 36% greater than that in freshwater. The saline water containing phenol was also tested for lipid fermentation and 23.6 g/L of lipid was produced simultaneously with the complete biodegradation of phenol. An interesting phenomenon was also observed that the yeast cells spontaneously segregated onto the upper surface of the saline water. This study extended the lipid fermentation options with practical application potentials.

Coastal sea level changes in Africa from retracked Jason altimetry over 2002-2020

<p>Climate-related sea level changes in the world coastal zones result from the superposition of the global mean rise due to ocean warming and land ice melt, regional changes mostly caused by non-uniform ocean thermal expansion and salinity changes, and small-scale coastal processes (e.g., shelf currents, wind & waves changes, fresh water input from rivers, etc.). So far, satellite altimetry has provided global gridded sea level time series up to 10-15 km to the coast only, preventing estimation of sea level changes very close to the coast. In the context of the ESA Climate Change Initiative coastal sea level project, we have developed a complete reprocessing of high-resolution (20 Hz) Jason-1, 2 and 3 altimetry data along the world coastal zones using the ALES (Adaptative Leading Edge Subwaveform) retracker combined with the XTRACK system dedicated to improve geophysical corrections at the coast. Here we present coastal sea level trends over the period 2002-2020 along the whole African continent. Different coastal sea level trend behaviors are observed over the study period. We compare the computed coastal trends in Africa with results we previously obtained in other regions (Mediterranean Sea, Northeastern Europe, north Indian Sea, southeast Asia and Australia).</p>

Fluctuations of Lake Lisan (the Dead Sea) during the last glacial: Implications for paleoclimatic changes of the Levant.

<p> </p><p>Calcareous stromatolite crusts overgrowing beach gravels and stabilising piles of rocks were observed on shoreline terraces of Lake Lisan along the eastern coast of the Dead Sea. The stromatolite crusts are thick, massive and hard, with a dark-grey or white-grey finely-laminated structure, indicating that they are mostly calcareous organic build-up of cyanobacterial origin. Samples from these stromatolites have been analyzed using Stable Isotopes (δ13C & δ18O), AAS and XRD analysis. The samples range in altitude between -350 m and -19 m, representing the time interval of Lake Lisan (~ 80-19 ka BP) according to our U/Th dating. Since stromatolites grow in shallow water, they are very sensitive to minor shifts in rainfall and evaporation and therefore an excellent tool to track small changes in hydrology, in climate and in paleoenvironmental conditions of the lake basin.</p><p> </p><p>Oxygen and carbon isotopic compositions of these stromatolites show a linear covariant trend with a strong positive correlation (r = 0.8) and large ranges of 7.85 and 6.78‰, respectively. This trend is most typical of primary carbonates formed in closed lakes. Isotopes analyses show low negative values of stromatolites from the lake highest stands at -76 m to -19 m, reflecting fresh water conditions of the lake basin at the last interglacial-glacial boundary (80-76 ka BP). The lowest values were derived from stromatolites at -103 to -119 m associated with the transgression of the lake to these high stands between 55 and 33 ka BP. The heaviest values were derived from stromatolites at -137 to -160 m indicating a change to dry climatic conditions in the Eastern Mediterranean that caused a subsequent drop of the lake level during MIS 2 (31-19 ka BP).</p><p> </p><p>The Mg/Ca ratio and the XRD analysis of the stromatolites correlate also with transgression-regression phases of the lake. Dominance of calcite in stromatolites at -76 to 0 m and inferred low Mg/Ca ratios of the lake water (i.e. ~2) imply a high fresh water input of the lake during the   highest stands period. A high Mg/Ca ratio of the lake water of >7 inferred from low-level stromatolite at -350 m and the existence of aragonite as the sole mineral reflect low fresh water input and high evaporation rates that caused a lake level regression during H6, ~ 60 ka BP.</p><p> </p><p>Inferred low Mg/Ca ratios of stromatolites at -247 to -101 m and the existence of calcite as a main mineral phase indicate wet climatic conditions of the eastern Mediterranean and lake level transgression to higher than -137 during MIS 3. The appearance of more aragonite in stromatolites at -137 to -154 m and the inferred high Mg/Ca ratio of the lake water points to a return to dry climatic conditions that caused a regression of Lake Lisan between 32 to 22 ka BP (MIS 2). However, the change in the mineral composition to pure calcite at -160 m in addition to the inferred low Mg/Ca ratio correlates well with the transgression of the lake to this level by the end of the LGM.</p><p> </p><p> </p>

Numerical estimations of desalinated seawater modification using Laptev sea shelf seawater as the example

A new model for describing the behavior of the isotope (d18О, dD) parameters of desalinated seawater during freezing is proposed. The model was tested using the Laptev Sea shelf waters, which are actively desalinated by the Lena river input and modified by the freezing and ice removing. It is shown that taking into account the modification process leads to the correction of estimates of the fraction of fresh water input up to 20%. A criterion for determination of model availability is proposed.

Analisis variasi konsentrasi unsur hara nitrogen, fosfat dan silikat (N, P dan Si) di Perairan Teluk Meulaboh Aceh Barat

Penelitian analisis variasi konsentrasi unsur hara (N, P dan Si) di perairan Teluk Meulaboh dilaksanakan pada bulan Mei-Juli 2014 di perairan Teluk Meulaboh. Lokasi pengambilan sampel di setiap titik sampling pengamatan dilakukan secara purposing sampling yang dibagi atas 10 stasiun penelitian yang terdiri dari perairan sungai, muara sungai, perairan tengah teluk sampai ke perairan terluar dari teluk. Tujuan dari penelitian ini adalah untuk menganalisis variasi dari konsentrasi unsur hara (N, P dan Si) di perairan Teluk Meulaboh. Hasil yang diperoleh selama penelitian untuk nilai konsentrasi unsur hara (N, P dan Si) pada setiap stasiun pengamatan berturut-turut diantaranya adalah, amonia (stasiun A-E = 0,074-0,276 mg.L-1 dan stasiun F-J 0,045-0,199 mg.L-1 ) nitrit (stasiun A-E = 0,002-0,127 mg.L-1 dan stasiun F-J 0,001-0,021 mg.L-1 ), nitrat (stasiun A-E = 0,014-0,646 mg.L-1 dan stasiun F-J 0,020-0,193 mg.L-1 ), ortofosfat (stasiun A-E = 0,001-0,693 mg.L-1 dan stasiun F-J 0,001-0,013 mg.L-1 ), dan silikat (stasiun A-E = 0,604-4,520 mg.L-1 dan stasiun F-J 0,803-4,132 mg.L-1 ). Adapun variasi konsentrasi unsur hara (N, P dan Si) menunjukkan nilai semakin menurun ke arah perairan terluar dari teluk yang jauh dari pantai dan semakin tinggi ke arah perairan sungai yang dekat dengan daratan. Hal ini disebabkan karena adanya masukan air tawar dari daratan melalui sungai yang membawa unsur hara tinggi ke perairan teluk.The reaserch on variation analysis of the nutrients (N, P and Si) consentration in waters of Meulaboh Bay was conducted on Mei-July 2014 in Meulaboh Bay. Sampling Location on each observation sampling points as purposing sampling at 10 sites, wich consist of river, mouth river, bay waters, middle of bay to outer of bay. The purpose in this research was to analysis variation of the nutrients (N, P and Si) consentration in waters of Meulaboh Bay. The result in this research to nutrients (N, P and Si) consentration values at the observation sites consecutive among them were, ammonia (sites A-E = 0,074-0,276 mg.L-1 and sites F-J 0,045-0,199 mg.L-1 ) nitrite (sites A-E = 0,002-0,127 mg.L-1 dan sites F-J 0,001-0,021 mg.L-1 ), nitrate (sites A-E = 0,014-0,646 mg.L-1 dan sites F-J 0,020-0,193 mg.L-1 ), ortophosphate (sites A-E = 0,001-0,693 mg.L-1 dan sites F-J 0,001-0,013 mg.L-1), dan silicate (stasiun A-E = 0,604-4,520 mg.L-1 dan stasiun F-J 0,803-4,132 mg.L-1 ). As for variation of the nutrients (N, P and Si) consentration showed that the values deacreased toward the outer of Bay which far from coastal and increased toward the river waters wich near from tersterial land. This matter was caused presence fresh water input from teresterial land trough river that carried hight nutrients to the waters

Tide distortion and attenuation in an Amazonian tidal river

The present study seeks to evaluate tidal propagation in the Guamá-Capim river system, in the Amazonian region, considering hydrodynamic and geomorphological aspects. Available data sets on fluvial discharge and water level variations were considered, besides several methods of measuring the tides (currents, water levels and discharges) recorded at different stations and in different periods. The main point argued is that fluvial discharge is the key-factor in tidal distortion and tidal bore formation in the system investigated, whereas the low relief of the area would be the main factor contributing to landward tidal incursion. The results show an impressive upward tidal incursion of more than 200 km, including substantial distortion -increasing upstream -of the tidal wave, of which the ebb phase lasts up to 5 hours longer than the flood, including higher flood current velocities as far as 161 km upstream. Generally, only hyposynchronous tidal response was observed. Seasonally, the fluvial discharge varies about 10 times in the Guamá and 4 times in the Capim River. The increase of the fluvial discharge results in an increasing distortion of the tide, besides a weak increase of the attenuation. During high fluvial discharge periods in conjunction with equinoctial tides (e.g. March-April), a tidal bore occurs in the system, also increased by the generally low relief. Therefore, the conclusions include: low relief and the distortion related to high fluvial discharges are the main factors controlling tidal propagation along the system and tidal bore formation. Furthermore, the system could be classified as a tidal river, in which massive regional fresh water input results in virtually non-existent salinity throughout the Guamá-Capim system.