Microorganisms, pigments from

Pigments from Microalgae and Microorganisms Sources of Food Colorants 401... 

The earliest reference to biological activity of a plant in the family Haemodoraceae seems to have been one by Darwin (73) to the toxic action of Lachnanthes on white pigs and the immunity of the black ones. This has frequently been assumed by later writers to indicate a photodynamic action. Some experimental support for this belief has been obtained by the observation that extracts of Lachnanthes tinctoria induce phototoxicity in microorganisms 74). The Australian plant Haemodorum corymbosum has also been regarded as toxic to animals (75). Haemocorin, the phenalenone pigment from this plant, was shown to have antitumor activity 76) and a wide range of antibacterial activity (77). 

Fig. 1. A generalized scheme showing the kinds of secondary products that arise from the aromatic amino acids in higher plants. Several similarities are found in fungi and bacteria some fungi produce alkaloids ftom tryptophan and lignin-like materials from phenylalanine. Plant pathogenic fungi produce cinnamate and para and meta hydroxy phenyl-acetate from phenylalanine. Certain bacteria produce antibiotics and fluorescent pigments from metabolites in the shikimate pathway. Microorganisms are not known to produce coumarin, substituted coumarins, flavonoids and isoflavonoids.

Hausmann (1953b) and Hausmann et al. (1953) obtained, in addition to the peptides referred to above, other vitamin B 12-like red pigments from cultures of microorganisms and from sheep manure which did not develop hemopoietic activity after proteolysis. They were probably identical with the pseudovitamin B12 (Pfiffner et al., 1952) or related factors such as A, B, or C (Ford et al., 1951, 1952 Ford and Porter, 1952 Coates et al., 1951 Coates et al., 1952 Ford et al., 1954). 

From the Japanese bryozoan Bugula dentata, an antimicrobial blue pigment (121) was isolated (111) and found to be identical with a tetrapyr-role previously isolated from a mutant strain of Serratia marcescens (112). The color of the bryozoan B. dentata is unusually dark blue, suggesting that the pigment 121 is ubiquitously present in the animal. Whether compound 121 is biosynthesized by the bryozoan itself or by an associated microorganism or derived from food sources such as prodigiosin-producing bacteria is still unknown. 

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