Improving hydrogen production of Chlamydomonas reinhardtii by reducing chlorophyll content via atmospheric and room temperature plasma

Abstract

Reduction of chlorophyll size has great advantages on improving the photosynthesis efficiency as well as the photolysis algal H2 production. To promote the H2 production, Chlamydomonas reinhardtii was mutated by atmospheric and room temperature plasma (ARTP). After the selection, an algal mutant was observed to have 1.8–5.2 times (28.5–84.1 mL L−1) and 2.7–3.1 times (356.5–405.2 mL L−1) higher H2 production than wild-type during the algal subcultures grown in pure and co-cultures, respectively. In comparison with wild-type alga, the mutant grew as lighter green colonies on agar plate, with about 2 times larger cell diameter and 5.3–6.1 times lower chlorophyll content per unit cell volume. Results from the comparative transcriptomic analysis indicated that most of the genes relating to photosynthesis (photosystem I, II, cytochrome b6/f complex, photosynthetic electron transport, and F-type ATPase) and LHC proteins were have higher expressions in mutant cells, suggesting the improvement of photosynthesis efficiency.