The crucial role of a sterically specified informational macromolecule argues for optical activity as an assay for the presence of biogeny on a planet. Recent developments in the measurement of optical activity and their relevance to exobiology are discussed.
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
GLC analyses were carried out on a Wilkins 600C aerograph using a 5 ft × 1/8-in. (1.53 m × 3.2 mm) column (0.5% EGA on chromosorb W). During the analyses the nitrogen flow was 46 ml/min and the oven temperature was programmed from 140°C to 200°C at a rate of 4°/min. Under these conditions the retention times (min) for the N-TFA-l-prolyl derivatives were d-valine (7.6), l-valine (8.9), d-proline (13.0), l-proline (14.2), d-glutamic acid (20.2), l-glutamic acid (21.4), d-amino butyric acid (9.0), and l-amino butyric acid (10.5).
Soil collected at Moffett Field, California, and characterized by NASA Ames. The organic nitrogen analysis was 1435 ppm and the organic carbon was 6380 ppm. The soil had a pH 6.08.
Soil samples were sterilized by heating at 135°C for 24 h.
Garden soil collected at Stanford in December 1965.
Tables (2)
Table I
Mass Spectral Monitoring of GLC Fractions Corrected for Isotopic Abundance
GLC fraction
Ratio (a:a + 2) m/c 184:186
Fragment (b) m/c
Ratio (b:b + 1)
Molecular weight (b + 156) and identity of amino acid
Optical identity of fraction
1
28:2.5
158
100:8.5
314-alanine
l
2
1:24
158
4.5:100
314-alanine
l
3
38:41
144
97:100
300-glycine
dl
4
55:56
172
100:96
328-aminobutyric acid
dl
5
33:32
172
100:98
328-aminobutyric acid
dl
6
2.5:33
200
8.5:100
356-leucine
d
7
23:2
200
100:8
356-leucine
d
8
100:2
184
100:5
340-proline
l
9
12:31
184
12:100
340-proline
l
Table II
Susceptibility of dl-Amino Acids to Microorganisms in Soils
Soil sample
dl-Amino acid
Unused d/l amino acid concentration after period of incubation (h)a
GLC analyses were carried out on a Wilkins 600C aerograph using a 5 ft × 1/8-in. (1.53 m × 3.2 mm) column (0.5% EGA on chromosorb W). During the analyses the nitrogen flow was 46 ml/min and the oven temperature was programmed from 140°C to 200°C at a rate of 4°/min. Under these conditions the retention times (min) for the N-TFA-l-prolyl derivatives were d-valine (7.6), l-valine (8.9), d-proline (13.0), l-proline (14.2), d-glutamic acid (20.2), l-glutamic acid (21.4), d-amino butyric acid (9.0), and l-amino butyric acid (10.5).
Soil collected at Moffett Field, California, and characterized by NASA Ames. The organic nitrogen analysis was 1435 ppm and the organic carbon was 6380 ppm. The soil had a pH 6.08.
Soil samples were sterilized by heating at 135°C for 24 h.
Garden soil collected at Stanford in December 1965.