Comparative Analysis of Sodium and Lithium Accumulation in Halophilic Archaea Haloarcula hispanica VKM B-1755T and Haloferax gibbonsii VKM B-1756T

Sodium and lithium accumulation by the biomass of halophilic archaea capable of growing at high concentrations of sodium ions was studied. The type strains of the species Haloarcula hispanica VKM B‑1755T and Haloferax gibbonsii VKM B-1756T were used in the work. It was shown that their growth was not inhibited by high concentrations of dissolved lithium, 2.08 M LiCl, in the presence of a comparable amount of sodium ions. However, the growth of halophilic archaea was noticeably suppressed at 3.54 M LiCl and in the absence of sodium ions (at their minimal content limited by introduction with the inoculum). Lithium accumulation in wet biomass was 0.95–1.64%; the maximum values were obtained in H. hispanica when grown in the light. The latter can be evidence of the involvement of archaeal rhodopsin in the transport of lithium ions.