title: Sustainable hydrogen photoproduction by phosphorus-deprived marine green microalgae Chlorella sp.
abstract: Previously it has been shown that green microalga Chlamydomonas reinhardtii is capable of prolonged H2 photoproduction when deprived of sulfur. In addition to sulfur deprivation (-S), sustained H2 photoproduction in C. reinhardtii cultures can be achieved under phosphorus-deprived (-P) conditions. Similar to sulfur deprivation, phosphorus deprivation limits O2 evolving activity in algal cells and causes other metabolic changes that are favorable for H2 photoproduction. Although significant advances in H2 photoproduction have recently been realized in fresh water microalgae, relatively few studies have focused on H2 production in marine green microalgae. In the present study phosphorus deprivation was applied for hydrogen production in marine green microalgae Chlorella sp., where sulfur deprivation is impossible due to a high concentration of sulfates in the sea water. Since resources of fresh water on earth are limited, the possibility of hydrogen production in seawater is more attractive. In order to achieve H2 photoproduction in P-deprived marine green microalgae Chlorella sp., the dilution approach was applied. Cultures diluted to about 0.5-1.8 mg Chl·L-1 in the beginning of P-deprivation were able to establish anaerobiosis, after the initial growth period, where cells utilize intracellular phosphorus, with subsequent transition to H2 photoproduction stage. It appears that marine microalgae during P-deprivation passed the same stages of adaptation as fresh water microalgae. The presence of inorganic carbon was essential for starch accumulation and subsequent hydrogen production by microalgae. The H2 accumulation was up to 40 mL H2 gas per 1iter of the culture, which is comparable to that obtained in P-deprived C. reinhardtii culture.
authors: Institute of Basic Biological Problems RAS, Institutskaya 2, Pushchino, Moscow Region 142290, Russia. horcheska@gmail.com.
authors: Khorcheska
authors: K
authors: Batyrova
authors: Institute of Basic Biological Problems RAS, Institutskaya 2, Pushchino, Moscow Region 142290, Russia. larisa_nastya@mail.ru.
authors: Anastasia
authors: A
authors: Gavrisheva
authors: Institute of Basic Biological Problems RAS, Institutskaya 2, Pushchino, Moscow Region 142290, Russia. cheredova@mail.ru.
authors: Elena
authors: E
authors: Ivanova
authors: Institute of Oceanology, Chinese Academy of Sciences, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China. jgliu@ms.qdio.ac.cn.
authors: Jianguo
authors: J
authors: Liu
authors: Institute of Basic Biological Problems RAS, Institutskaya 2, Pushchino, Moscow Region 142290, Russia. ttt-00@mail.ru.
authors: Anatoly
authors: A
authors: Tsygankov
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism*; D008027:Light; D010100:Oxygen / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism*; D013213:Starch / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism
chemical_list: D002245:Carbon Dioxide; D010758:Phosphorus; D013455:Sulfur; D006859:Hydrogen; D013213:Starch; D010100:Oxygen
references: J Biol Chem. 2011 Nov 25;286(47):40614-23
references: 21930709
references: Bioresour Technol. 2012 Apr;110:1-9
references: 22342581
references: Curr Opin Biotechnol. 2010 Jun;21(3):238-43
references: 20399635
references: Chem Rev. 2007 Feb;107(2):563-76
references: 17256993
references: Photosynth Res. 2005 Sep;85(3):295-305
references: 16170632
references: Trends Biotechnol. 2000 Dec;18(12):506-11
references: 11102662
references: Microbiol Res. 2009;164(2):131-7
references: 17321121
references: Biotechnol Bioeng. 2009 Jan 1;102(1):50-8
references: 18823051
references: Biochim Biophys Acta. 2003 Dec 8;1607(2-3):153-60
references: 14670605
references: J Gen Physiol. 1942 Nov 20;26(2):219-40
references: 19873339
references: Biotechnol Prog. 2006 Mar-Apr;22(2):438-43
references: 16599559
references: Science. 1989 Dec 15;246(4936):1503-4
references: 17756009