Discovered periodic sublimation activity on four main-belt primitive asteroids led us to conclusions about possible origin of those and similar bodies (or their parent bodies) near or beyond the snow line in the early Solar System making incorporated in them a considerable water ice stock. Water differentiation of the bodies owing to 26A1 decay and their internal thermal evolution might have created conditions for water soluble organics and prebiotic compounds formation. Subsequent longtime periodic changing temperature and other physico-chemical parameters (due to spinning and moving around the Sun) in the near-surface layers of primitive asteroids have led probably to formation of more complex organic compounds of astrobiological significance.

A strain of the lichen mycobiont of Caloplaca erythrantha, isolated from ascospores, was cultured axenically on different solid media. Four of the media employed supported the development of colonies and production of the two major lichen secondary metabolites. These media were: BMYE (mannitol 2%, yeast extract 0·1%, in Bold's basal medium); MEYE (malt extract 2%, yeast extract 0·2%, in distilled water); Hamada's MY10 (malt extract 1%, yeast extract 0·4%, sucrose 10%, in distilled water); and the new BMRM (Bold mannitol rich medium, mannitol 5·3%, malt extract 1%, yeast extract 0·4% in Bold's mineral medium). Percentages refer to final medium volume. The fungal colonies developed well on the four media and produced emodin and 7-chloroemodin, the major secondary compounds of the lichen apothecia. Crystals deposited richly on the external surface of the hyphae, as observed with an optical microscope. The two anthraquinones were purified from the lichen thallus, apothecia and cultured mycelia, and identified by chromatographic (TLC, HPLC) and spectroscopic (NMR, MS) methods. The analysis of lichen apothecia revealed the presence of emodin (0·90% w/w) and 7-chloroemodin (0·56% w/w), whereas colonies cultured for five months generally produced higher percentages than the lichen: 1·72% emodin and 0·30% 7-chloroemodin on BMYE; 0·21% and 0·95% on MEYE; 7·82% and 7·48% on MY10; and 11·70% and 10·80% on BMRM. These results show that the production of both anthraquinones was promoted significantly in mycobiont cultures with high concentrations of the carbon sources sucrose or mannitol, with a higher effect being observed with the latter.

Atmospheric carbon monoxide and methane were studied spectroscopically in the Arctic and Antarctic. Seasonal variations of CO are evident in both polar regions, absolute values of abundance being three times larger in the Arctic than in the Antarctic. Increasing concentration trends were confirmed for both gases: 0.8% per year for Antarctic CO, 0.5% per year for Antarctic CH4 and 3.1% per year for Arctic CH4.