Occurrence of Dimethyl-β-Propiothetin in Marine Phytoplankton

1966 ◽  
Vol 23 (3) ◽  
pp. 357-364 ◽  
Author(s):  
R. G. Ackman ◽  
C. S. Tocher ◽  
J. McLachlan
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Marine Algae ◽  
Degradation Products ◽  
Skeletonema Costatum ◽  
Marine Phytoplankton ◽  
Dimethyl Sulphide ◽  
Ecological Significance ◽  
Wet Weight ◽  
Cyclotella Cryptica

Dimethyl-β-propiothetin has been reported from several species of freshwater and marine multicellular algae. Cultures of 14 species of unicellular marine algae were treated with cold aqueous alkali. Dimethyl sulphide was liberated from Syracosphaera carterae, Skeletonema costatum, Amphidinium carteri, Phaeodactylum tricornutum, Tetraselmis sp. and Cyclotella cryptica, and is assumed to arise from dimethyl-β-propiothetin. The amounts of alkali-labile material varied, on a wet weight basis, from 0.07 to 2.9% (as thetin salt) in different organisms. The presence of the thetin in S. carterae was confirmed by other means. The thetin, and particularly its degradation products, acrylic acid and dimethyl sulphide, may influence actual fishing operations and also affect the quality of fishery products. The metabolic and ecological significance of these materials are reviewed and discussed.

Production of antibacterial activities by two Bacillariophyceae grown in dialysis culture

1983 ◽  
Vol 29 (3) ◽  
pp. 338-341 ◽  
Author(s):  
Sam Cooper ◽  
Aviva Battat ◽  
Pierre Marsot ◽  
Michel Sylvestre
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Marine Algae ◽  
Skeletonema Costatum ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
High Cell ◽  
Direct Relation ◽  
Algal Extracts ◽  
Time Of Harvest ◽  
Dialysis Culture

Using a dialysis culture system for marine algae which allows for the recovery of high cell yield, we detected in the aqueous phase of the algal extracts an active component which inhibited gram-negative bacteria. Results show a direct relation between cell growth phase at time of harvest and the activity observed. It was possible to confirm previous results whereby Bacillariophyceae produce lipophilic substances inhibiting gram-positive terrestrial and marine bacteria. These findings corroborate the observation that Skeletonema costatum is more active man Phaeodactylum tricornutum against Staphyloccoci.

scholarly journals Effects of copper ions and copper nanomaterials on the output of amino acids from marine algae

2021 ◽  
Author(s):  
Wenqiu Huang ◽  
Yuping Zhou ◽  
Ting Zhao ◽  
Liju Tan ◽  
Jiangtao Wang
Keyword(s):  
Amino Acids ◽  
Marine Algae ◽  
Extracellular Polymeric Substances ◽  
Copper Ions ◽  
Metal Salt ◽  
Skeletonema Costatum ◽  
Cell Number ◽  
Marine Phytoplankton ◽  
Total Output ◽  
Intracellular Amino Acids

Abstract In this study, the effects of different copper’s forms, metal salt (Cu2+), nano-metal (nano-Cu) and nano-metal oxide (nano-CuO), were tested on two marine algae named Skeletonema costatum and Nitzschia closterium. During a 96-hour exposure to nanoparticles (NPs) and salt, cell number, Cu2+ concentration in the culture medium, morphology and intracellular amino acids was measured to assess the toxicity of those copper materials and the toxicity mechanism of NPs. It was found that the toxicity of Cu2+, nano-Cu and nano-CuO on marine phytoplankton decreased in order. The EC50 values of Cu2+ and nano-Cu for S. costatum and N. closterium ranged from 0.356 to 0.991 mg/L and 0.663 to 2.455 mg/L, respectively. Nano-Cu inhibited the growth of marine phytoplankton mainly by releasing Cu2+, however, nano-CuO mainly produced toxic effects on microalgae through the effect of NPs. The secretion of extracellular polymeric substances by microalgae could be another possible reason for nano-Cu and nano-CuO to impose implications for microalgae. S. costatum was more sensitive to copper than N. closterium. Cu2+, nano-Cu and nano-CuO all reduced the total output of algae-derived amino acids by affecting the growth of phytoplankton and per-cell amino acids. This manuscript is of important implications to fill the data gaps for nano-Cu and nano-CuO risk assessment on marine algae.

scholarly journals SPX-related genes regulate phosphorus homeostasis in the marine phytoplankton, Phaeodactylum tricornutum

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Kaidian Zhang ◽  
Zhi Zhou ◽  
Jiashun Li ◽  
Jingtian Wang ◽  
Liying Yu ◽  
...  
Keyword(s):  
Stress Responses ◽  
Phaeodactylum Tricornutum ◽  
Response Regulator ◽  
P Uptake ◽  
Negative Regulator ◽  
Marine Phytoplankton ◽  
Alkaline Phosphatases ◽  
Phosphate Starvation Response ◽  
Essential Nutrient ◽  
Global Oceans

AbstractPhosphorus (P) is an essential nutrient for marine phytoplankton. Maintaining intracellular P homeostasis against environmental P variability is critical for phytoplankton, but how they achieve this is poorly understood. Here we identify a SPX gene and investigate its role in Phaeodactylum tricornutum. SPX knockout led to significant increases in the expression of phosphate transporters, alkaline phosphatases (the P acquisition machinery) and phospholipid hydrolases (a mechanism to reduce P demand). These demonstrate that SPX is a negative regulator of both P uptake and P-stress responses. Furthermore, we show that SPX regulation of P uptake and metabolism involves a phosphate starvation response regulator (PHR) as an intermediate. Additionally, we find the SPX related genes exist and operate across the phytoplankton phylogenetic spectrum and in the global oceans, indicating its universal importance in marine phytoplankton. This study lays a foundation for better understanding phytoplankton adaptation to P variability in the future changing oceans.

scholarly journals A Comparison of Two-Stage and Traditional Co-Composting of Green Waste and Food Waste Amended with Phosphate Rock and Sawdust

2021 ◽  
Vol 13 (3) ◽  
pp. 1109
Author(s):  
Edgar Ricardo Oviedo-Ocaña ◽  
Angélica María Hernández-Gómez ◽  
Marcos Ríos ◽  
Anauribeth Portela ◽  
Viviana Sánchez-Torres ◽  
...  
Keyword(s):  
Organic Matter ◽  
Product Quality ◽  
Food Waste ◽  
Phosphate Rock ◽  
Pilot Scale ◽  
Two Stage ◽  
Green Waste ◽  
Wet Weight ◽  
Two Phases

The composting of green waste (GW) proceeds slowly due to the presence of slowly degradable compounds in that substrate. The introduction of amendments and bulking materials can improve organic matter degradation and end-product quality. However, additional strategies such as two-stage composting, can deal with the slow degradation of green waste. This paper evaluates the effect of two-stage composting on the process and end-product quality of the co-composting of green waste and food waste amended with sawdust and phosphate rock. A pilot-scale study was developed using two treatments (in triplicate each), one being a two-stage composting and the other being a traditional composting. The two treatments used the same mixture (wet weight): 46% green waste, 19% unprocessed food waste, 18% processed food waste, 13% sawdust, and 4% phosphate rock. The traditional composting observed a higher degradation rate of organic matter during the mesophilic and thermophilic phases and observed thermophilic temperatures were maintained for longer periods during these two phases compared to two-stage composting (i.e., six days). Nonetheless, during the cooling and maturation phases, the two treatments had similar behaviors with regard to temperature, pH, and electrical conductivity, and the end-products resulting from both treatments did not statistically differ. Therefore, from this study, it is concluded that other additional complementary strategies must be evaluated to further improve GW composting.

scholarly journals A Milk Foodomics Investigation into the Effect of Pseudomonas fluorescens Growth under Cold Chain Conditions

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1173
Author(s):  
Paolo Bellassi ◽  
Gabriele Rocchetti ◽  
Lorenzo Morelli ◽  
Biancamaria Senizza ◽  
Luigi Lucini ◽  
...  
Keyword(s):  
Pseudomonas Fluorescens ◽  
Degradation Products ◽  
Storage Conditions ◽  
Cold Chain ◽  
Lower Sensitivity ◽  
Multivariate Statistical ◽  
Proteolytic Activities ◽  
Quality Of Milk ◽  
Potential Tool

Pseudomonas fluorescens is a psychrotrophic species associated with milk spoilage because of its lipolytic and proteolytic activities. Consequently, monitoring P. fluorescens or its antecedent activity in milk is critical to preventing quality defects of the product and minimizing food waste. Therefore, in this study, untargeted metabolomics and peptidomics were used to identify the changes in milk related to P. fluorescens activity by simulating the low-temperature conditions usually found in milk during the cold chain. Both unsupervised and supervised multivariate statistical approaches showed a clear effect caused by the P. fluorescens inoculation on milk samples. Our results showed that the levels of phosphatidylglycerophosphates and glycerophospholipids were directly related to the level of contamination. In addition, our metabolomic approach allowed us to detect lipid and protein degradation products that were directly correlated with the degradative metabolism of P. fluorescens. Peptidomics corroborated the proteolytic propensity of P. fluorescens-contaminated milk, but with lower sensitivity. The results obtained from this study provide insights into the alterations related to P. fluorescens 39 contamination, both pre and post heat treatment. This approach could represent a potential tool to retrospectively understand the actual quality of milk under cold chain storage conditions, either before or after heat treatments.

Influence of the Insecticide Diflubenzuron (Dimilin) on the Growth of Marine Diatoms and a Harpacticoid Copepod in Culture

1985 ◽  
Vol 42 (7) ◽  
pp. 1272-1277 ◽  
Author(s):  
N. J. Antia ◽  
P. J. Harrison ◽  
D. S. Sullivan ◽  
T. Bisalputra
Keyword(s):  
Skeletonema Costatum ◽  
Harpacticoid Copepod ◽  
Adult Survival ◽  
Thalassiosira Weissflogii ◽  
Marine Diatoms ◽  
Tigriopus Californicus ◽  
Per Se ◽  
Juvenile Development ◽  
Cyclotella Cryptica ◽  
Injurious Effects

Diflubenzuron (Dimilin) was tested, in the concentration range 0.1–5000 μg∙L−1, for possible injurious effects on the growth and photosynthesis of three chitin-producing (Thalassiosira weissflogii, T. norden-skioldii, Cyclotella cryptica) and one nonchitinaceous (Skeletonema costatum) diatoms. For comparison, the effects of the pesticide were also examined on adult survival and juvenile development of the harpacticoid copepod Tigriopus californicus. While the development of the copepod was hindered at concentrations of the order of 1–10 μg∙L−1, the diatoms were barely affected by Dimilin even at the highest concentration tested (5 mg∙L−1). We conclude that Dimilin acts specifically on insects and crustaceans as a larvicide by interfering with chitin deposition into cuticles during juvenile development through ecdysis. The lack of effect from Dimilin on the chitin-producing diatoms has suggested that the insecticide may not inhibit chitin biosynthesis per se as was previously believed, but that it presumably deregulates one or more of the larval postsynthetic processes responsible for chitin integration into cuticles.

Effects of LED Monochromatic Light Quality of Different Colors on Fucoxanthin Content and Expression Levels of Related Genes in Phaeodactylum Tricornutum

2019 ◽  
Vol 39 (9) ◽  
pp. 0917001 ◽  
Author(s):  
徐润洁 Runjie Xu ◽  
龚一富 Yifu Gong ◽  
陈文婷 Wenting Cheng ◽  
李申睿 Shenrui Li ◽  
陈若莹 Ruoying Chen ◽  
...  
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Light Quality ◽  
Monochromatic Light ◽  
Expression Levels
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