The utilization of microalgae as a source of carotenoid productions has gained increasing popularity due to its advantages, such as a relatively fast turnaround time. In this study, a newly discovered Coelastrum sp. TISTR 9501RE was characterized and investigated for its taxonomical identity and carotenoid profile. To the best of our knowledge, this report was the first to fully investigate the carotenoid profiles in a microalga of the genus Coelastrum. Upon use of limited nutrients as a stress condition, the strain was able to produce astaxanthin, canthaxanthin, and lutein, as the major carotenoid components. Additionally, the carotenoid esters were found to be all astaxanthin derivatives, and β-carotene was not significantly present under this stress condition. Importantly, we also demonstrated that this practical stress condition could be combined with simple growing factors, such as ambient sunlight and temperature, to achieve even more focused carotenoid profiles, i.e., increased overall amounts of the aforementioned carotenoids with fewer minor components and chlorophylls. In addition, this green microalga was capable of tolerating a wide range of salinity. Therefore, this study paved the way for more investigations and developments on this fascinating strain, which will be reported in due course.

No abstract

In this study, astaxanthin (ASTA), with potential anti-tyrosinase and anti-melanin synthesis in melanoma cells (B16F10) was developed as a cosmetic ingredient in the form of microemulsions (MEs). The results showed that ASTA (1 mg/mL) had no toxic effects on melanoma cells and it exhibited high potential for reduction of tyrosinase and melanin content, representing 80.57% and 75.86%, respectively. However, the use of ASTA is limited due to its low stability resulting from its decomposition under light, heat, and oxygen. In order to overcome this drawback, ASTA was encapsulated within ME. ASTA-MEs, consisting of 0.5% w/w of ASTA, oil, surfactant and water, were prepared using titration method.The effect of IPM concentration into microemulsions were investigated at 10 % w/w (ASTA-ME1) and 20% w/w (ASTA-ME2). The physical stability after accelerated condition of all the formulations was also investigated. The results indicated that a thermodynamically stable of microemulsion could improve the physical stability of ASTA. Nonetheless, the oil concentration had a slight influence on the physical stability of ASTA-ME1 and ASTA-ME2. In conclusion, nanoencapsulation can improve the physical stability of pigment extract to be used as a cosmetic ingredient in skin brightening products.

No abstract

This study reports on the complete genome sequence of Spirosoma sp. strain KCTC 42546, isolated from fresh water in a reservoir in South Korea. The genome contained genes for various glycosyl hydrolases, which are associated with degrading sugars and DNA-repairing enzymes.