Search

SUMMARY: Ulva prolifera is a green‐tide‐forming macroalga dominating the green tides in the Yellow Sea from 2007 to 2019. The exponential growth of U. prolifera, and the correlating accumulation of biomass, rely heavily on its carbon fixation capability. Despite the importance of carbon fixation in algal growth, to date none of the genes involved in carbon fixation have undergone molecular characterization in U. prolifera. This study used Rapid Amplification of cDNA Ends (RACE) to characterize one full‐length carbonic anhydrase (CA) gene of U. prolifera (UpαCA1). An activity assay showed that UpαCA1 was an active CA. Real‐time quantitative PCR results showed that temperature, irradiance, salinity and pH could influence the transcriptional level of UpαCA1, indicating that UpαCA1 was sensitive to varying environmental factors. The results of this study provided further insights into our understanding of the influence of environmental factors on carbon fixation in U. prolifera and its subsequent role in the formation of green tides. [ABSTRACT FROM AUTHOR]

To further understand the trends in the evolution of mitochondrial genomes (mitogenomes or mt DNAs) in the Ulvophyceae, the mitogenomes of two separate thalli of Ulva pertusa were sequenced. Two U. pertusa mitogenomes (Up1 and Up2) were 69,333 bp and 64,602 bp in length. These mitogenomes shared two ribosomal RNAs ( rRNAs), 28 transfer RNAs ( tRNAs), 29 protein-coding genes, and 12 open reading frames. The 4.7 kb difference in size was attributed to variation in intron content and tandem repeat regions. A total of six introns were present in the smaller U. pertusa mt DNA (Up2), while the larger mt DNA (Up1) had eight. The larger mt DNA had two additional group II introns in two genes ( cox1 and cox2) and tandem duplication mutations in noncoding regions. Our results showed the first case of intraspecific variation in chlorophytan mitogenomes and provided further genomic data for the undersampled Ulvophyceae. [ABSTRACT FROM AUTHOR]

Objective: Dietary n-3 polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acids (EPA) and docosahexaenoic acid (DHA), are proved to be effective in obesity reduction. Microalgal oil (MO) is an important alternative source of n-3 PUFAs that effectively alleviates obesity. The aim of the present study was to explore the anti-obesity effects of microalgal oil from Schizochytrium sp. (SMO) and to compare the effects of 2 SMOs (SMO1 and SMO2) with different levels of purity of n-3 PUFAs on high fat diet (HFD)-induced obesity in male C57BL/6J mice.Methods: Mice were randomly divided into 5 groups: (1) regular chow (RC); (2) HFD; (3) HFD + fish oil (FO); (4) HFD + SMO1; and (5) HFD + SMO2. Body weight and food intake were weekly monitored. After 16 weeks of treatment, a glucose tolerance test (GTT) and an insulin tolerance test (ITT) were performed. Serum lipid profile, morphological changes in the liver and epididymal white adipose tissue (eWAT), and the mRNA expression of lipid metabolism-related genes were also examined.Results: SMO treatment significantly decreased HFD-induced abdominal fat accumulation, lowered the levels of triglycerides, cholesterol, and low-density lipoprotein, as did the positive control treated with FO. Morphological examination revealed a remarkable reduction in lipid droplet formation in the liver tissue and the particle size of eWAT. An alleviation of inflammation infiltration in eWAT caused by a high-fat diet was also observed. Real-time reverse transcription-polymerase chain reaction analysis examination confirmed that microalgal oil inhibited the gene expression of fatty acid synthase, sterol responsive element-binding protein-1c, and acetyl-CoA carboxylase but promoted that of hormone-sensitive lipase and lipoprotein lipase, carnitine palmitoyltransferase-1, and uncoupling proteins in the liver and eWAT. Moreover, similar anti-obesity effects were obtained with the same dosage but different purity of n-3 PUFAs.Conclusions: As an alternative n-3 PUFAs resource, dietary intake of SMO might be beneficial to prevent HFD-induced abdominal fat accumulation. [ABSTRACT FROM AUTHOR]

Magnetic-field-assisted extraction ( MFAE) technique was employed to extract astaxanthin from H aematococcus pluvialis. The process for extraction of astaxanthin was optimized using response surface methodology, employing a three-level, three-variable Box-Behnken experimental design. The results showed that the optimum extraction conditions were as follows: liquid-solid ratio 77:1 (v/w), magnetic intensity 18 mT and extraction 50 min. Under the above mentioned conditions, the astaxanthin yield was 62. 72%. The experimental yield under optimal conditions was in good matching with the predictive yield. Magnetic intensity increased the efficiency of enzymatic treatment with higher extraction yield, which indicated that MFAE is a more efficient process as compared to other extractions. Practical Applications Magnetic field extraction was applied as a novel separation technique, which had many advantages on the extraction of astaxanthin compared to the traditional extraction method, such as good stability. The knowledge provided by this work may promote the application of magnetic field extraction method in the food industry. In addition, the development results in creating environmentally friendly processes. [ABSTRACT FROM AUTHOR]