unicellular green blue algae chlorella spirulina with large cells single-cells with lipid droplets. watercolor

algae algal ameoba bacteria bacterium biodiesel biofuel biology biosynthesis biotech biotechnology blue chlorella design diet droplets element emerald energy environment environmental food fuel green illustration lipid macro medical membrane microalgae microscope molecule natural nature oil organism process production research science scientific singlecell spirulina sustainable vegetarian virus watercolor