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1.
Extremophiles ; 28(1): 10, 2024 Jan 12.
Article in English | MEDLINE | ID: mdl-38214762

ABSTRACT

The genera Haloarcula and Halomicroarcula are the most closely related genera within the family Haloarculaceae (class Halobacteria). The respective 16S rRNA genes of type strains from the genus Haloarcula showed 94.7-96.5% similarities to their homologous genes of type strains from the genus Halomicroarcula. The Haloarcula species showed 89.3-92.8% rpoB' gene similarities to Halomicroarcula species. These similarities were higher than the proposed genus boundary. Phylogenomic analysis revealed that these two genera formed a tight cluster separated from Halomicrobium with high bootstrap confidence. The average amino acid identity (AAI) values among Haloarcula and Halomicroarcula were 70.1-74.5%, higher than the cutoff value (67.0%) to differentiate the genera Haloarcula and Halomicroarcula from Halomicrobium. These results indicated that the genus Halomicroarcula should be merged with Haloarcula. Then, six novel species are described based on strains DFY41T, GDY20T, SHR3T, XH51T, YJ-61-ST, and ZS-22-S1T isolated from coarse sea salt, marine solar saltern, and salt lake (China). These six strains formed separate clades (90.1-99.3% 16S rRNA and 89.0-94.9% rpoB' gene similarities) and then clustered with current Haloarcula and Halomicroarcula species (89.4-99.1% 16S rRNA and 87.6-95.0% rpoB' gene similarities), as revealed by phylogenetic analyses. The average nucleotide identity (ANI), digital DNA-DNA hybridization (dDDH), and AAI values among these six strains and current Haloarcula and Halomicroarcula species were 76.2-89.8%, 25.3-46.0%, and 70.3-89.7%, respectively, clearly below the species demarcation threshold. These six strains were distinguished from current Haloarcula and Halomicroarcula species according to differential phenotypic characteristics. Six novel species, Haloarcula halophila sp. nov., Haloarcula litorea sp. nov., Haloarcula rara sp. nov., Haloarcula halobia sp. nov., Haloarcula pelagica sp. nov., and Haloarcula ordinaria sp. nov., are proposed to accommodate strains DFY41T, GDY20T, SHR3T, XH51T, YJ-61-ST, and ZS-22-S1T, respectively.


Subject(s)
Haloarcula , Halobacteriaceae , Halobacteriales , Phylogeny , RNA, Ribosomal, 16S/genetics , DNA, Archaeal/genetics , Base Composition , Sequence Analysis, DNA , Fatty Acids/chemistry , DNA, Bacterial , Bacterial Typing Techniques
2.
Environ Sci Technol ; 58(21): 9091-9101, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38709279

ABSTRACT

People of all ages consume salt every day, but is it really just salt? Plastic nanoparticles [nanoplastics (NPs)] pose an increasing environmental threat and have begun to contaminate everyday salt in consumer goods. Herein, we developed a combined surface enhanced Raman scattering (SERS) and stimulated Raman scattering (SRS) approach that can realize the filtration, enrichment, and detection of NPs in commercial salt. The Au-loaded (50 nm) anodic alumina oxide substrate was used as the SERS substrate to explore the potential types of NP contaminants in salts. SRS was used to conduct imaging and quantify the presence of the NPs. SRS detection was successfully established through standard plastics, and NPs were identified through the match of the hydrocarbon group of the nanoparticles. Simultaneously, the NPs were quantified based on the high spatial resolution and rapid imaging of the SRS imaging platform. NPs in sea salts produced in Asia, Australasia, Europe, and the Atlantic were studied. We estimate that, depending on the location, an average person could be ingesting as many as 6 million NPs per year through the consumption of sea salt alone. The potential health hazards associated with NP ingestion should not be underestimated.


Subject(s)
Spectrum Analysis, Raman , Plastics , Nanoparticles , Sodium Chloride/chemistry
3.
Environ Geochem Health ; 46(8): 300, 2024 Jul 11.
Article in English | MEDLINE | ID: mdl-38990399

ABSTRACT

This study investigated microplastic (MP) contamination in conventional sea salt farming systems. Various crude sea salt samples (n = 22) that were traditionally produced were collected from salt farms and local vendors. Salt water (n = 15), macroalgae (n = 6), and clay of pond floors (n = 6) were collected from ponds subjected to different production (stabilization, evaporation, and concentration and crystallization concentration) processes. All samples were analyzed for MP abundance and characteristics. The potential sources of MP contamination in the salt were also investigated. The mean abundance of MPs in the salt water and clay of pond floor increased progressively throughout the production process and reached its highest level in the concentration and crystallization ponds (7400 MP particles/m3 in salt water and 19,336 MP particles/m2 in the clay of the pond floor). A maximum of 26,500 MP particles/kg of macroalgal material indicated the potential sink of MPs on the surface of the algae. Approximately 34-2377 MP particles/kg salt were found in the crude sea salt samples. However, the mean abundance (378 MP particles/kg of salt) indicated nonsignificant impacts of different harvesting processes on MP contamination. Most MP size distributions, shapes and polymer types in the salts were similar to those found in the salt water, macroalgae and clay of the pond floor. Approximately 99% of the MPs were fragments that were suspected to be decomposed from larger plastic debris and plastic machinery and tools used at the salt farm. Similar patterns of polymer distribution, in which PP > PE > PET > PS, were found for all samples studied.


Subject(s)
Microplastics , Water Pollutants, Chemical , Microplastics/analysis , Water Pollutants, Chemical/analysis , Seawater/chemistry , Environmental Monitoring/methods , Aquaculture , Seaweed/chemistry , Sodium Chloride/chemistry , Sodium Chloride/analysis , Particle Size
4.
Environ Sci Technol ; 57(28): 10295-10307, 2023 07 18.
Article in English | MEDLINE | ID: mdl-37418292

ABSTRACT

Elevated particulate sulfate concentrations have been frequently observed in coastal areas when air masses are influenced by continental emissions, especially combustion sources like biomass burning. We studied the SO2 uptake by laboratory-generated droplets containing incense smoke extracts and sodium chloride (IS-NaCl) under irradiation and found enhanced sulfate production over pure NaCl droplets, attributable to photosensitization induced by constituents in IS. Low relative humidity and high light intensity facilitated sulfate formation and increased the SO2 uptake coefficient by IS-NaCl particles. Aging of the IS particles further enhanced sulfate production, attributable to the enhanced secondary oxidant production promoted by increased proportions of nitrogen-containing CHN and oxygen- and nitrogen-containing CHON species under light and air. Experiments using model compounds of syringaldehyde, pyrazine, and 4-nitroguaiacol verified the enhancements of CHN and CHON species in sulfate formation. This work provides experimental evidence of enhanced sulfate production in laboratory-generated IS-NaCl droplets via enhanced secondary oxidant production triggered by photosensitization in multiphase oxidation processes under light and air. Our results can shed light on the possible interactions between sea salt and biomass burning aerosols in enhancing sulfate production.


Subject(s)
Air Pollutants , Sodium Chloride , Sulfates , Nitrogen , Aerosols/analysis , Oxidants , Air Pollutants/analysis , Particulate Matter/analysis
5.
Environ Sci Technol ; 57(7): 2706-2714, 2023 02 21.
Article in English | MEDLINE | ID: mdl-36758144

ABSTRACT

Sea salt aerosol particles are highly abundant in the atmosphere and play important roles in the global radiative balance. After influence from continental air, they are typically composed of Na+, Cl-, NH4+, and SO42- and organics. Analogous particle systems are often studied in laboratory settings by atomizing and drying particles from a solution. Here, we present evidence that such laboratory studies may be consistently biased in that they neglect losses of solutes to the gas phase. We present experimental evidence from a hygroscopic tandem differential mobility analyzer and an aerosol mass spectrometer, further supported by thermodynamic modeling. We show that, at normally prevailing laboratory aerosol mass concentrations, for mixtures of NaCl and (NH4)2SO4, a significant portion of the Cl- and NH4+ ions are lost to the gas phase, in some cases, leaving mainly Na2SO4 in the dry particles. Not considering losses of solutes to the gas phase during experimental studies will likely result in misinterpretation of the data. One example of such data is that from particle water uptake experiments. This may bias the explanatory models constructed from the data and introduce errors inte predictions made by air quality or climate models.


Subject(s)
Air Pollutants , Air Pollutants/analysis , Sodium Chloride , Aerosols/analysis , Water , Thermodynamics , Ions
6.
Environ Sci Technol ; 57(16): 6609-6615, 2023 04 25.
Article in English | MEDLINE | ID: mdl-37040454

ABSTRACT

Multiphase oxidation of sulfur dioxide (SO2) by ozone (O3) in alkaline sea salt aerosols is an important source of sulfate aerosols in the marine atmosphere. However, a recently reported low pH of fresh supermicron sea spray aerosols (mainly sea salt) would argue against the importance of this mechanism. Here, we investigated the impact of ionic strength on the kinetics of multiphase oxidation of SO2 by O3 in proxies of aqueous acidified sea salt aerosols with buffered pH of ∼4.0 via well-controlled flow tube experiments. We find that the sulfate formation rate for the O3 oxidation pathway proceeds 7.9 to 233 times faster under high ionic strength conditions of 2-14 mol kg-1 compared to the dilute bulk solutions. The ionic strength effect is likely to sustain the importance of multiphase oxidation of SO2 by O3 in sea salt aerosols in the marine atmosphere. Our results indicate that atmospheric models should consider the ionic strength effects on the multiphase oxidation of SO2 by O3 in sea salt aerosols to improve the predictions of the sulfate formation rate and the sulfate aerosol budget in the marine atmosphere.


Subject(s)
Air Pollutants , Ozone , Sulfur Dioxide , Sulfates , Sulfur Oxides , Atmosphere , Water , Aerosols , Osmolar Concentration
7.
Extremophiles ; 26(3): 26, 2022 Aug 03.
Article in English | MEDLINE | ID: mdl-35922580

ABSTRACT

Three halophilic archaeal strains, NEN8T, GDY88T and ZY14T, were isolated from a salt lake in Tibet and coarse sea salt samples from Guangdong and Hebei, China, respectively. These strains formed three separate clades (showing 94.4-95.8% and 87.1-89.4% similarities, respectively) and then clustered with the current Halorientalis members (showing 90.7-97.6% and 87.0-91.2% similarities, respectively), as revealed by phylogenetic analyses based on 16S rRNA and rpoB' genes. The overall genome-related index, average nucleotide identity (ANI), in silico DNA-DNA hybridization (DDH), average amino acid identity (AAI) and the percentage of conserved proteins (POCP) values, among the three strains and members of the genus Halorientalis were 76.0-88.0%, 21.3-37.2%, 69.0-88.3% and 57.7-78.1%, clearly below the threshold values for species demarcation. Strains NEN8T, GDY88T and ZY14T could be distinguished from current Halorientalis species according to differential phenotypic characteristics. The major polar lipids of the three strains were phosphatidylglycerol (PG), phosphatidylglycerol phosphate methyl ester (PGP-Me), sulfated mannosyl glucosyl diether (S-DGD-1) and disulfated mannosyl glucosyl diether (S2-DGD). In addition, mannosyl glucosyl diether (DGD-1) was detected in strain NEN8T and phosphatidic acid (PA), posssulfated galactosyl mannosyl glucosyl diether (S-TGD-1) and sulfated mannosyl glucosyl diether-phosphatidic acid (S-DGD-PA) were observed in strain ZY14T. These results revealed that strains NEN8T (= CGMCC 1.17213T = JCM 34155T), GDY88T (= CGMCC 1.18548T = JCM 34481T) and ZY14T (= CGMCC 1.17178T = JCM 34154T) represent three novel species of the genus Halorientalis, for which the names Halorientalis salina sp. nov., Halorientalis marina sp. nov. and Halorientalis litorea sp. nov. are proposed.


Subject(s)
Halobacteriaceae , Lakes , Base Composition , China , DNA, Archaeal/genetics , Glycolipids/metabolism , Phosphatidic Acids/metabolism , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
8.
Geophys Res Lett ; 49(6): e2021GL097567, 2022 Mar 28.
Article in English | MEDLINE | ID: mdl-35859565

ABSTRACT

Heterogeneous uptake of hypoiodous acid (HOI), the dominant inorganic iodine species in the marine boundary layer (MBL), on sea-salt aerosol (SSA) to form iodine monobromide and iodine monochloride has been adopted in models with assumed efficiency. Recently, field measurements have reported a much faster rate of this recycling process than previously assumed in models. Here, we conduct global model simulations to quantify the range of effects of iodine recycling within the MBL, using Conventional, Updated, and Upper-limit coefficients. When considering the Updated coefficient, iodine recycling significantly enhances gaseous inorganic iodine abundance (∼40%), increases halogen atom production rates (∼40% in I, >100% in Br, and ∼60% in Cl), and reduces oxidant levels (-7% in O3, -2% in OH, and -4% in HO2) compared to the simulation without the process. We appeal for further direct measurements of iodine species, laboratory experiments on the controlling factors, and multiscale simulations of iodine heterogeneous recycling.

9.
J Sci Food Agric ; 102(13): 6005-6013, 2022 Oct.
Article in English | MEDLINE | ID: mdl-35446446

ABSTRACT

BACKGROUND: Salt (sodium chloride) is an essential component of daily food, crucial for many physiological processes. Due to health risks related to salt over consumption, considerable interest is devoted to strategies to reduce dietary salt intake. In this work we evaluated the sensory dimensions of sea salts flavored with Mediterranean aromatic plants with the aim to confirm the role of herbs/spices in the enhancement of salty perception and to validate the use of flavored salts as a strategy to reduce salt intake. To this goal we compared taste dimensions (pleasantness, intensity, and familiarity) of solutions obtained with salt and sea salts flavored with Mediterranean herbs, spices, and fruits. Sensorial differences were analyzed using a seven-point hedonic Likert-type scale on 58 non-trained judges. RESULTS: Main flavor compounds, identified by gas chromatography-flame ionization detection-mass spectrometry (GC-FID-MS) analysis, were α-pinene and 1,8-cineole in myrtle salt (FS 1), verbenone, α-pinene, 1,8-cineole, and rosifoliol in herbs/plants salt (FS 2), and limonene in orange fruits/saffron salt (FS 3). At the dose of 0.04 g mL-1 , saline solutions obtained with flavored salt (containing approximately 6-30% less sodium chloride) were perceived as more intense, less familiar, but equally pleasant than pure salt solution. In particular, sea salt flavored with orange fruits/saffron emerged as the most interesting in potentiating saltiness perception. CONCLUSION: Our study confirmed the important role of Mediterranean aromatic plants in the enhancement of saltiness perception and qualified the use of flavored sea salt during food preparation/cooking instead of normal salt as a potential strategy to reduce the daily salt intake. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Subject(s)
Sodium Chloride, Dietary , Taste , Eucalyptol , Salts , Sodium Chloride/analysis , Sodium Chloride, Dietary/analysis , Spices/analysis , Taste Perception
10.
J Contemp Dent Pract ; 23(2): 169-175, 2022 Feb 01.
Article in English | MEDLINE | ID: mdl-35748445

ABSTRACT

AIM: To compare the efficacy of two naturally based commercially available whitening toothpastes charcoal and sea salt-lemon on stain removal of teeth in terms of color change and surface roughness. MATERIALS AND METHODS: Twenty-seven intact bovine incisors were selected and randomly allocated into three main groups (n = 9) according to the tested toothpaste [I: Signal Complete 8 Charcoal; II: sea salt-lemon essence Closeup natural smile; and III: Signal Complete 8 Original (control)]. Following 4 successive days of staining protocol, each specimen in its corresponding group was brushed with the toothpaste using toothbrush simulator apparatus for three brushing cycles. Color assessment using Vita Easyshade spectrophotometer and surface roughness (Ra) measurement using contact type profilometer were performed for each specimen at baseline, after staining, and after each tooth brushing cycle. RESULTS: Nonparametric color data and parametric surface roughness data were analyzed. The color difference (ΔE) from after-staining protocol to different tooth brushing cycles (1,2,3) showed no significant difference on each cycle between the tested groups (p >0.05). While for color difference (ΔE) from baseline to the last tooth brushing cycle 3, the difference between groups was statistically significant where group II, sea salt-lemon-based toothpaste, had a significantly lowest (ΔE 00) value (p <0.001) indicating more whitening effect in relation to others. However, a significant increase in surface roughness was present in all tested groups (p <0.001); meanwhile, there was no significant difference between tested groups (p >0.05). CONCLUSION: After three tooth brushing cycles, none of the natural whitening toothpastes or conventional toothpastes produced had effective whitening results nor completely removed the stains back to the initial baseline tooth color. Sea salt-lemon-based whitening toothpaste had a whitening effect better than the charcoal-based toothpaste. All of the tested toothpastes increased the degree of surface roughness. CLINICAL RELEVANCE: Charcoal and sea salt-lemon-based whitening toothpastes do not guarantee to whiten nor completely remove the stains back to normal and their effects on enamel surface roughness should be highly clinically considered and managed.


Subject(s)
Tooth Bleaching , Tooth Discoloration , Animals , Cattle , Charcoal , Color , Coloring Agents , Tooth Bleaching/methods , Toothbrushing , Toothpastes
11.
Biotechnol Lett ; 43(1): 213-222, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32851464

ABSTRACT

OBJECTIVES: To determine the effect of sea salt on the resistance of Trichoderma harzianum LZDX-32-08 to hygromycin B and speculate the possible mechanisms involved via transcriptome analysis. RESULTS: Sea salt addition in media to simulate marine environment significantly increased the tolerance of marine-derived fungus Trichoderma harzianum LZDX-32-08 to hygromycin B from 40 to 500 µg/ml. Meanwhile, sea salt addition also elicited the hygromycin B resistance of 5 other marine or terrestrial fungi. Transcriptomic analyses of T. harzianum cultivated on PDA, PDA supplemented with sea salt and PDA with both sea salt and hygromycin B revealed that genes coding for P-type ATPases, multidrug resistance related transporters and acetyltransferases were up-regulated, while genes coding for Ca2+/H+ antiporter and 1,3-glucosidase were down-regulated, indicating probable increased efflux and inactivation of hygromycin B as well as enhanced biofilm formation, which could jointly contribute to the drug resistance. CONCLUSIONS: Marine environment or high ion concentration in the environment could be an importance inducer for antifungal resistance. Possible mechanisms and related key genes were proposed for understanding the molecular basis and overcoming this resistance.


Subject(s)
Drug Resistance, Fungal/drug effects , Hygromycin B/pharmacology , Hypocreales/drug effects , Sodium Chloride/pharmacology , Hypocreales/genetics , Hypocreales/metabolism , Transcriptome/drug effects
12.
Geophys Res Lett ; 47(4): e2019GL085838, 2020 Feb 28.
Article in English | MEDLINE | ID: mdl-32713977

ABSTRACT

Marine cloud brightening (MCB) is proposed to offset global warming by emitting sea salt aerosols to the tropical marine boundary layer, which increases aerosol and cloud albedo. Sea salt aerosol is the main source of tropospheric reactive chlorine (Cl y ) and bromine (Br y ). The effects of additional sea salt on atmospheric chemistry have not been explored. We simulate sea salt aerosol injections for MCB under two scenarios (212-569 Tg/a) in the GEOS-Chem global chemical transport model, only considering their impacts as a halogen source. Globally, tropospheric Cl y and Br y increase (20-40%), leading to decreased ozone (-3 to -6%). Consequently, OH decreases (-3 to -5%), which increases the methane lifetime (3-6%). Our results suggest that the chemistry of the additional sea salt leads to minor total radiative forcing compared to that of the sea salt aerosol itself (~2%) but may have potential implications for surface ozone pollution in tropical coastal regions.

13.
Radiat Environ Biophys ; 59(3): 523-537, 2020 08.
Article in English | MEDLINE | ID: mdl-32462382

ABSTRACT

Accidents resulting in widespread dispersal of radioactive materials have given rise to a need for materials that are convenient in allowing individual dose assessment. The present study examines natural Dead Sea salt adopted as a model thermoluminescence dosimetry system. Samples were prepared in two different forms, loose-raw and loose-ground, subsequently exposed to 60Co gamma-rays, delivering doses in the range 2-10 Gy. Key thermoluminescence (TL) properties were examined, including glow curves, dose response, sensitivity, reproducibility and fading. Glow curves shapes were found to be independent of given dose, prominent TL peaks for the raw and ground samples appearing in the temperature ranges 361-385 ºC and 366-401 ºC, respectively. The deconvolution of glow curves has been undertaken using GlowFit, resulting in ten overlapping first-order kinetic glow peaks. For both sample forms, the integrated TL yield displays linearity of response with dose, the loose-raw salt showing some 2.5 × the sensitivity of the ground salt. The samples showed similar degrees of fading, with respective residual signals 28 days post-irradiation of 66% and 62% for the ground and raw forms respectively; conversely, confronted by light-induced fading the respective signal losses were 62% and 80%. The effective atomic number of the Dead Sea salt of 16.3 is comparable to that of TLD-200 (Zeff 16.3), suitable as an environmental radiation monitor in accident situations but requiring careful calibration in the reconstruction of soft tissue dose (soft tissue Zeff 7.2). Sample luminescence studies were carried out via Raman and Photoluminescence spectroscopy as well as X-ray diffraction, ionizing radiation dependent variation in lattice structure being found to influence TL response.


Subject(s)
Radiometry/methods , Salts , Cobalt Radioisotopes , Gamma Rays , Luminescence , Luminescent Measurements , Oceans and Seas , Temperature
14.
J Environ Sci (China) ; 95: 65-72, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32653194

ABSTRACT

Mineral dust, soil, and sea salt aerosols are among the most abundant primary inorganic aerosols in the atmosphere, and their hygroscopicity affects the hydrological cycle and global climate. We investigated the hygroscopic behaviors of six Na- and K-containing salts commonly found in those primary organic aerosols. Their hygroscopic growths as a function of relative humidity (RH) agree well with thermodynamic model prediction. Temperature dependence of deliquescence RH (DRH) values for five of those salts was also investigated, which are comparable to those in literature within 1%-2% RH, most showing negative dependence on temperature. Hygroscopic growth curves of real-world soil and sea salt samples were also measured. The hygroscopic growths of two more-hydroscopic saline soil samples and of sea salt can be predicted by the thermodynamic model based on the measured water-soluble ionic composition. The substantial amounts of water-soluble ions, including Na+ and K+, in saline soil samples imply that even nascent saline soil samples are quite hygroscopic at high-RH (>80%) conditions. For three less-hygroscopic dust samples, however, measurements showed higher water uptake ability than that predicted by the thermodynamic model. The small amount of water taken up by less-hygroscopic dust samples suggests that dust particles might contain thin layers of water even to very low RH. The results of this study provide a comprehensive characterization of the hygroscopicity of Na- and K-containing salts as related to their roles in the hygroscopic behaviors of saline mineral dusts and sea salt aerosols.


Subject(s)
Air Pollutants/analysis , Dust , Aerosols/analysis , Minerals , Potassium , Salts , Sodium , Wettability
15.
Physiol Mol Biol Plants ; 25(3): 713-726, 2019 May.
Article in English | MEDLINE | ID: mdl-31168234

ABSTRACT

Banana is often grown in coastal-regions, and while known for its sensitivity towards seawater, little is documented on the effect of sea-salt on the growth, physiology and metal homeostasis. Here we report that banana plantlets exposed to sea-salt at extreme (average seawater concentration; 52.7 dS m-1), severe (28.5 dS m-1) or moderate (10.2 dS m-1) salinity levels had reduced root length (2.0-6.0-fold), plant height (1.2-1.6-fold), leaf number (2.0-2.3-fold) and leaf area (3.3-4.0-fold) compared to control plantlets. Degradation of pigments (total chlorophyll: 1.3-12.3-fold, chlorophyll a: 1.3-9.2-fold; chlorophyll b: 1.3-6.9-fold lower and carotenoids: 1.4-3.7-fold lower) reflected vulnerability of photosystems to salt stress. Relative water content showed a maximum decrease of 1.5-fold in salt stress. MDA analysis showed sea-salt exposure triggers 2.3-3.5-fold higher lipid peroxidation. Metal content analysis showed a 73-fold higher Na value from roots exposed to extreme salinity compared to control plantlets. While phenotype was clearly affected, moderate salinity showed no significant alteration of macro (N, P, K and Ca) and micro (Fe, Mn and Cu) metal content. The antioxidant enzymes: SOD (3.2-fold), CAT (1.7-fold) and GR (6-fold) showed higher activity at moderate salinity level compared to control plantlets but lower activity at severe (SOD: 1.3-fold; CAT: 1.5-fold; GR: 2-fold lower) and extreme seawater salinity (SOD: 1.5; CAT: 1.9; GR: 1.3-fold lower). Mild changes in growth and physiology at sea-salt levels equivalent to moderate seawater flooding, indicate that banana will survive such flooding, while extreme seawater inundation will be lethal. This data provides a reference for future salinity-mediated work in banana.

16.
Food Microbiol ; 69: 89-95, 2018 Feb.
Article in English | MEDLINE | ID: mdl-28941913

ABSTRACT

Production of sea salt begins with evaporation of sea water in shallow pools called salterns, and ends with the harvest and packing of salts. This process provides many opportunities for fungal contamination. This study aimed to determine whether finished salts contain viable fungi that have the potential to cause spoilage when sea salt is used as a food ingredient by isolating fungi on a medium that simulated salted food with a lowered water activity (0.95 aw). The viable filamentous fungi from seven commercial salts were quantified and identified by DNA sequencing, and the fungal communities in different salts were compared. Every sea salt tested contained viable fungi, in concentrations ranging from 0.07 to 1.71 colony-forming units per gram of salt. In total, 85 fungi were isolated representing seven genera. One or more species of the most abundant genera, Aspergillus, Cladosporium, and Penicillium was found in every salt. Many species found in this study have been previously isolated from low water activity environments, including salterns and foods. We conclude that sea salts contain many fungi that have potential to cause food spoilage as well as some that may be mycotoxigenic.


Subject(s)
Food Contamination/analysis , Fungi/isolation & purification , Seawater/microbiology , Sodium Chloride/analysis , Fungi/classification , Fungi/genetics , Phylogeny , Seawater/chemistry
17.
Bioprocess Biosyst Eng ; 39(2): 315-21, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26658812

ABSTRACT

Schizochytrium is a marine microalga that requires high concentrations of sea salt for growth, although problems arise with significant amounts of chloride ions in the culture medium, which corrodes the fermenters. In this work, we evaluated that cell growth and docosahexaenoic acid (DHA) production can be improved when using 1 % (w/v) sodium sulfate instead of 2 % (w/v) sea salt in the culture medium for Schizochytrium sp. S056. In practice, the use of sodium sulfate as the sodium salt led to chloride ion levels in the medium that can be completely removed, thus avoiding fermenter corrosion during Schizochytrium sp. S056 growth, reducing cost and increasing DHA production, and simplifying the disposal of fermentation wastewater. Additionally, we demonstrated that the osmolality of growth media did not play a crucial role in the production of DHA. These findings may be significantly important to companies involved in production of PUFAs by marine microbes.


Subject(s)
Docosahexaenoic Acids/biosynthesis , Microalgae/growth & development , Sodium Chloride/pharmacology , Stramenopiles/growth & development , Sulfates/pharmacology
20.
Sci Total Environ ; 916: 170316, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38278236

ABSTRACT

Aerosol particles in two size ranges, namely 0.18-1.4 µm (fine) and larger than 1.4 µm (coarse), were collected in the pre-dust, in-dust, and post-dust air during the passage of a slowly-moving dust event at a coastal site in southwestern Japan. We identified the composition and size of individual particles using a scanning electron microscope to investigate the variations during dust passage. The particles could be classified as mineral-seasalt mixtures, non-mixture minerals, sulfur-containing minerals, and seasalt particles, and the number fractions of these type particles in the two size ranges exhibited significant variation across the three periods. In the coarse size range, mixture particles accounted for 17.6 %, 26.8 %, and 37.8 % of the particles in the pre-dust, in-dust, and post-dust air, respectively. Non-mixture particles made up 36.8 %, 29.2 %, and 24.3 % in the same respective periods. In the in-dust air, the average relative ratio of sulfur content in sulfur-containing mineral particles in the coarse range was 5.5 %, whereas in the fine range, it was 17.2 %. The aging state of sea salt components, described by the Cl loss and reflecting the changes in particles due to chemical reactions, exhibited significant differences in the two size ranges. In the fine range, the aging of >90 % particles was predominantly influenced by sulfate formation in the in-dust air. In contrast, nitrate likely played a certain role in both the pre-dust and post-dust air. In the coarse range, the aging was independent of sulfate formation. These results indicate the close dependence of the aging of dust particles on their size and the notable variations of the aged states, underscoring the essentiality to treat dust particles properly according to time and space for a better understanding on their roles in the marine atmosphere.

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