Arno Johannes Schocher

The carotenoids of Flavobacterium strain R1560.

The main carotenoid of Flavobacterium strain R1560 has been identified as (3R,3′R)-zeaxanthin. Also present were small amounts of 15-cis-phytoene, phytofluene, “ζ-carotene” (7,8,7′,8′-tetrahydro-ψ, ψ-carotene plus 7,8,11,12-tetrahydro-ψ, ψ-carotene), neurosporene, lycopene, β-zeacarotene, γ-carotene, β-carotene, β-cryptoxanthin, rubixanthin, 3-hydroxy-β-zeacarotene and several apo-carotenals. Zeaxanthin production was inhibited by nicotine (10 mM), and lycopene and rubixanthin accumulated. The biosynthesis of zeaxanthin is discussed in terms of pathways and also of “half-molecule” reaction sequences. The presence of zeaxanthin may be a characteristic of a group of Flavobacterium species, and may thus be useful in the taxonomic classification of these organisms.

Acetobacter bacteriophage A-1

A bacteriophage ofAcetobacter suboxydans was isolated and found to correspond to type A phage according to Bradleys classification. The phage contains double stranded DNA. The length of the latency period and burst size could not be precisely determined because of apparent non-synchronous release of phage from single infective cycles. The host range was determined using 24 strains ofAcetobacter andGluconobacter species. Evidence for a probable occurence of host determined restriction and modification was obtained withAcetobacter suboxydans strain ATCC 621. The phage is designated A-1 and it is the first one to be reported forAcetobacter.

The occurrence and possible biosynthetic significance of 3-hydroxy-β-zeacarotene in a Flavobacterium species

The Gram-negative Flavobacterium R1560 [l] owes its very deep orange-brown colour to the presence of large amounts of the carotenoid zeaxanthin @&carotene-3,3’-diol, I). In addition to zeaxanthin, a wide range of other carotenoids is present, in relatively small amounts [2]. Because of their unusual chromatographic properties and electronic absorption spectra, two of these compounds have been studied further, and their identification as 3-hydroxy-fl-zeacarotene (7’,8’-dihydro-&

Process for the manufacture of zeaxanthin

-caroten-3-01, II) and 3hydroxy-12’-apo-/3-caroten-12’4 (III) is reported. The natural occurrence of these carotenoids has not previously been described, and the possible importance of 3-hydroxy-/3-zeacarotene in relation to the biosynthesis of zeaxanthin in Flavobacterium R-l 560 is discussed.