Extremophile enzyme optimization for low temperature and high salinity are fundamentally incompatible

Extremophiles ◽  
2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Luke Piszkin ◽  
Jeff Bowman
Keyword(s):  
Low Temperature ◽  
High Salinity ◽  
Enzyme Optimization

scholarly journals The Potential Roles of the G1LEA and G3LEA Proteins in Early Embryo Development and in Response to Low Temperature and High Salinity in Artemia sinica

PLoS ONE ◽  
2016 ◽  
Vol 11 (9) ◽  
pp. e0162272 ◽  
Author(s):  
Wei Zhao ◽  
Feng Yao ◽  
Mengchen Zhang ◽  
Ting Jing ◽  
Shuang Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Embryo Development ◽  
High Salinity ◽  
Early Embryo ◽  
Artemia Sinica ◽  
Early Embryo Development

scholarly journals Low Temperature Illitization through Illite-Dioctahedral Vermiculite Mixed Layers in a Tropical Saline Lake Rich in Hydrothermal Fluids (Sochagota Lake, Colombia)

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 523
Author(s):  
Gabriel Ricardo Cifuentes ◽  
Juan Jiménez-Millán ◽  
Claudia Patricia Quevedo ◽  
Fernando Nieto ◽  
Javier Cuadros ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Organic Matter ◽  
Low Temperature ◽  
High Salinity ◽  
Source Rocks ◽  
Temperate Climate ◽  
Lake Basin ◽  
X Ray ◽  
Saline Waters ◽  
Mixed Layers

In this investigation, we showed that high salinity promoted by hydrothermal inputs, reducing conditions of sediments with high content in organic matter, and the occurrence of an appropriate clay mineral precursor provide a suitable framework for low-temperature illitization processes. We studied the sedimentary illitization process that occurs in carbonaceous sediments from a lake with saline waters (Sochagota Lake, Colombia) located at a tropical latitude. Water isotopic composition suggests that high salinity was produced by hydrothermal contribution. Materials accumulated in the Sochagota Lake’s southern entrance are organic matter-poor sediments that contain detrital kaolinite and quartz. On the other hand, materials formed at the central segment and near the lake exit (north portion) are enriched in organic matter and characterized by the crystallization of Fe-sulfides. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and energy dispersive X-ray spectrometry (EDX) data allowed for the identification of illite and illite-dioctahedral vermiculite mixed layers (I-DV), which are absent in the southern sediments. High humidity and temperate climate caused the formation of small-sized metastable intermediates of I-DV particles by the weathering of the source rocks in the Sochagota Lake Basin. These particles were deposited in the low-energy lake environments (middle and north part). The interaction of these sediments enriched in organic matter with the saline waters of the lake enriched in hydrothermal K caused a reducing environment that favored Fe mobilization processes and its incorporation to I-DV mixed layers that acted as mineral precursor for fast low temperature illitization, revealing that in geothermal areas clays in lakes favor a hydrothermal K uptake.

Freeze-Thaw Cycle Impact on Volumetric and Low-Temperature Shear Behavior of High-Salinity Soils

2019 ◽  
Vol 33 (1) ◽  
pp. 06018002 ◽  
Author(s):  
Yu Zhang ◽  
Zhaohui Joey Yang ◽  
Jiankun Liu ◽  
Jianhong Fang
Keyword(s):  
Low Temperature ◽  
High Salinity ◽  
Shear Behavior ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Temperature Shear

Rheology of Brine-Based Fuzzy-Ball Drilling Fluids in Deepwater Drilling

2019 ◽  
Author(s):  
Zhaochuan Li ◽  
Lihui Zheng ◽  
Panfeng Wei ◽  
Xiaojuan Dai ◽  
Weian Huang
Keyword(s):  
Low Temperature ◽  
Yield Point ◽  
Apparent Viscosity ◽  
High Salinity ◽  
Flow Behavior ◽  
Plastic Viscosity ◽  
Rheological Parameters ◽  
Working Fluid ◽  
Drilling Fluids ◽  
Deepwater Drilling

Abstract In deepwater drilling, the rheology of traditional drilling fluid is uncontrollable since the fluid usually mixes with brine and encounters low temperature. A solution may be to use the newly designed brine-based fuzzy-ball drilling fluids (BFDFs) since these have a well-adapted rheology under high salinity and low temperature condition. This has the potential to make drilling safer and more efficient. In this experiment, the rheological properties of BFDFs under test conditions were characterized with a rheometer by varying salinity (2 to 20 mass%) and temperature (4 to 80 °C). The rheological parameters considered are apparent viscosity (AV), plastic viscosity (PV), yield point (YP), and θ6 reading. To characterize the magnitudes of changes of the rheological parameters and their low temperature dependence, their ratios at 4 and 25 °C, and 4 and 80 °C were calculated. The results showed that the apparent viscosity (AV), the plastic viscosity (PV), the yield point (YP), and θ6 reading of BFDFs increased slightly with the decrease of salinity and temperature. The ratios of rheological parameters at 4 and 25 °C were close to unity, while the ratios at 4 and 80 °C were about two. The flow behavior of BFDFs under high salinity and low temperature condition was stable. Therefore, brine could be used as the base fluid for BFDFs. Theoretically, the flow behavior of BFDFs under low temperature condition seems to follow the Herschel-Bulkley model. Practically, the tests indicated that the BFDFs possess a strong tolerance to sandstone cuttings and Cabentonite, an excellent inhibitive property to shaly cuttings, weak corrosive characteristics against N80 casing steel, excellent lubricity properties, and remarkable biodegradability. In summary, the empirical results showed that the newly designed fuzzy-ball working fluid can use brine instead of fresh water as based fluid and maintain remarkable properties under high salinity and low temperature condition. Properties of BFDFs could basically satisfy the requirement of deepwater drilling work.

Overwintering of sea trout (Salmo trutta) in freshwater: escaping salt and low temperature or an alternate life strategy?

2007 ◽  
Vol 64 (5) ◽  
pp. 793-802 ◽  
Author(s):  
Dennis S Thomsen ◽  
Anders Koed ◽  
Christian Nielsen ◽  
Steffen S Madsen
Keyword(s):  
Low Temperature ◽  
Water Temperature ◽  
Salmo Trutta ◽  
High Salinity ◽  
Life Strategy ◽  
Low Salinity ◽  
Sea Trout ◽  
Time Period ◽  
Coastal Sea ◽  
Brown Trout Salmo Trutta

Brown trout (Salmo trutta) show large phenotypic plasticity. Juveniles may reside in their native freshwater habitat until maturation or migrate into the ocean as 1- to 3-year-old smolts. Sea-going fish (sea trout) reside at sea for 2–3 years until migrating back to their native stream for reproduction. However, immature fish may leave the ocean during their first or second winter at sea and overwinter in freshwater. The question is why does this occur? We tested the hypothesis that hypo-osmoregulatory capacity is compromised by low temperature in two coastal sea trout populations, one representing high salinity and the other, low salinity. Immature sea-run trout were caught in lower parts of two rivers during winter and acclimated to laboratory conditions. Subgroups were challenged with high salinity or low water temperature or both, and their osmoregulatory performance was investigated. Low temperature compromised the hypo-osmoregulatory ability, as indicated by insufficient compensatory adjustments of ion-transport mechanisms. Tagging experiments revealed that descent of overwintering fish into the ocean occurred over a narrow time period coincident with increasing water temperature. We conclude that overwintering in freshwater is partly driven by compromised osmoregulatory physiology, but because not all fish in a population do so, the phenomenon may also reflect diverging life strategies.

scholarly journals A Novel Subfamily of Endo-β-1,4-Glucanases in Glycoside Hydrolase Family 10

2019 ◽  
Vol 85 (18) ◽  
Author(s):  
Fang Zhao ◽  
Hai-Yan Cao ◽  
Long-Sheng Zhao ◽  
Yi Zhang ◽  
Chun-Yang Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Substrate Specificity ◽  
Glycoside Hydrolase ◽  
Marine Bacterium ◽  
High Salinity ◽  
Binding Capacity ◽  
Glycoside Hydrolase Family ◽  
Salt Tolerant ◽  
Content Type ◽  
Cold Adapted

ABSTRACTAs classified by the Carbohydrate-Active Enzymes (CAZy) database, enzymes in glycoside hydrolase (GH) family 10 (GH10) are all monospecific or bifunctional xylanases (except a tomatinase), and no endo-β-1,4-glucanase has been reported in the family. Here, we identifiedArcticibacterium luteifluviistationiscarboxymethyl cellulase (AlCMCase) as a GH10 endo-β-1,4-glucanase.AlCMCase originated from an Arctic marine bacterium,Arcticibacterium luteifluviistationisSM1504T. It shows low identity (<35%) with other GH10 xylanases. The gene encodingAlCMCase was overexpressed inEscherichia coli. Biochemical characterization showed that recombinantAlCMCase is a cold-adapted and salt-tolerant enzyme.AlCMCase hydrolyzes cello- and xylo-configured substrates via an endoaction mode. However, in comparison to its significant cellulase activity, the xylanase activity ofAlCMCase is negligible. Correspondingly,AlCMCase has remarkable binding capacity for cello-oligosaccharides but no obvious binding capacity for xylo-oligosaccharides.AlCMCase and its homologs are grouped into a branch separate from other GH10 xylanases in a phylogenetic tree, and two homologs also displayed the same substrate specificity asAlCMCase. These results suggest thatAlCMCase and its homologs form a novel subfamily of GH10 enzymes that have robust endo-β-1,4-glucanase activity. In addition, given the cold-adapted and salt-tolerant characters ofAlCMCase, it may be a candidate biocatalyst under certain industrial conditions, such as low temperature or high salinity.IMPORTANCECellulase and xylanase have been widely used in the textile, pulp and paper, animal feed, and food-processing industries. Exploring novel cellulases and xylanases for biocatalysts continues to be a hot issue. Enzymes derived from the polar seas might have novel hydrolysis patterns, substrate specificities, or extremophilic properties that have great potential for both fundamental research and industrial applications. Here, we identified a novel cold-adapted and salt-tolerant endo-β-1,4-glucanase,AlCMCase, from an Arctic marine bacterium. It may be useful in certain industrial processes, such as under low temperature or high salinity. Moreover,AlCMCase is a bifunctional representative of glycoside hydrolase (GH) family 10 that preferentially hydrolyzes β-1,4-glucans. With its homologs, it represents a new subfamily in this family. Thus, this study sheds new light on the substrate specificity of GH10.

Spawning of calanoid copepod Acartia tonsa at low temperature and high salinity improves hatch success for cold-stored egg production

Aquaculture ◽  
2021 ◽  
Vol 530 ◽  
pp. 735725
Author(s):  
Gustavo A. Torres ◽  
German E. Merino ◽  
Martha J. Prieto-Guevara ◽  
John E. Acosta Portillo ◽  
Jesús H. Gamboa ◽  
...  
Keyword(s):  
Low Temperature ◽  
Egg Production ◽  
Calanoid Copepod ◽  
High Salinity ◽  
Acartia Tonsa ◽  
Hatch Success

scholarly journals Tolerance of Ruppia sinensis Seeds to Desiccation, Low Temperature, and High Salinity With Special Reference to Long-Term Seed Storage

2018 ◽  
Vol 9 ◽  
Author(s):  
Ruiting Gu ◽  
Yi Zhou ◽  
Xiaoyue Song ◽  
Shaochun Xu ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Special Reference ◽  
High Salinity ◽  
Seed Storage
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