Utilization of algae includes both macroalgae for human consumption dating back to thousands of years, as well as the application of microalgae in health promoting dietary supplements. The autotrophic growth of microalgae is slow, but can be accelerated by optimizing their cultivation conditions. Efficiency optimizations for time and economy should be performed in many parallel experiments. A new high-throughput microalgae cultivation method is presented here, applying 24-low-well microplate with varying illumination, in which the cell growth is followed via evaluation of scanned images. A strain of the genus Nannochloropsis and two Chlorella vulgaris species have been chosen as well described and frequently applied model organisms in order to test the recently developed cultivation system. In these scaled down experiments, the custom design lighting panel was tested by studying the effect of the colour of illumination on cell growth kinetics. RGB LEDs (i.e. light emitting diodes, red: 622 nm, green: 528 nm, and blue: 467 nm) were used individually or together providing red, green, blue, and white colours. While the effect of light’s colour on algae growth was evaluated, also the new system was proven to be suitable for comparing maximal growth rates for different microalgae strains. While the tested two Chlorella isolates reached 1.2–1.4 g l–1 concentrations, the Nannochloropsis strain reached 1.4 g l–1 final cell dry weight, and specific growth rates were observed between 0.58–0.62 day–1.
Authors:L. Costantini, R. Molinari, and N. Merendino
Some studies suggested a positive effect against cardiometabolic diseases of supplementation of alpha-linolenic acid (ALA, C18:3 n-3) rich foods in pathological subjects, even if the total literature is controversial. In order to clarify ALA-rich chia seed action in hypertensive model with the overt pathology and without drug interference, in the present study the biochemical markers of cardiometabolic diseases (endothelin-1, ET-1; nitric oxide, NO; and bradykinin, BK) in Spontaneously Hypertensive Rats (SHRs) were analysed after 5% chia seed dietary supplementation for five weeks, and compared with the staple raw material wheat and corn. At the end of the experimental period, also plasma antioxidant capacity and inflammatory condition were evaluated. Our results showed that the chia seed group was more oxidized. On the other hand, ET-1 significantly decreased in chia seed group, and there was no difference between groups for NO, BK, and the inflammatory C-reactive protein (CRP). In conclusion, some positive effects of chia seed consumption on cardiometabolic markers in SHRs were observed, despite this the association of chia seeds with antioxidants is suggested to avoid plasma oxidation increase.