Production of Pigments by Microorganisms


Production of Pigments by Microorganisms

Species of bacteria and fungi that live in various environmental conditions are able to produce pigments.

  • Colonies of these bacteria can be coloured gold (as for Staphylococcus aureus), yellow (Sarcina flava), white (Staphylococcus saprophyticus), blue (Pseudomonas aeruginosa), red (as for Serratia marcescens, or actinomycetes and yeasts), pink (Micrococcus roseus), violet (Chromobacterium violaceum), black and brown (Prevotella melaninogenica, yeast and mould fungi). Some microorganisms can synthesize two or more pigments.
  • Theproduction of pigments by bacteria and fungi is stimulated by sunlight, culture aeration and temperature shift to 20-25oC or less.
  • Thepigments can be further analyzed according to their solubility – soluble in water (produced by Pseudomonas aeruginosa), soluble in alcohol and insoluble in water (Serratia marcescens and Staphylococcus aureus pigments), insoluble in water and alcohol (Prevotella melaninogenica, black and brown pigments of yeasts and moulds).
  • According to their chemical structure, pigments are divided into several distinct groups.
  • Carotenoid pigments of orange or yellow colour are produced by Mycobacterium tuberculosis, Actinomyces spp. and some other bacteria.
  • Quinone pigments are usually yellow. They are synthesized by actinomycetes, yeasts, etc.
  • Melanin pigments are produced by some kinds of fungi (Aspergillus niger), bacteroids and related bacteria (Prevotella melaninogenica).
  • Pyrrole pigments are red or orange. The example of bacteria producing this pigment is Serratia marcescens (prodigiosin pigment).
  • Phenazine pigments are green-blue. Such a pigment (pyocyanine) is produced by Pseudomonas aeruginosa.
  • Pigment production in bacteria has evident physiological value. In the process of bacterial respiration, the pigments are supposed to work as electron and hydrogen acceptors.
  • They are also able to confer protection against natural ultraviolet radiation and were shown to possess certain antibiotic activity.
  • Microbial pigments can be produced either by solid substrate fermentation or by submerged fermentation. In solid substrate fermentation (SSF), the cultivation of microbial biomass occurs on the surface of a solid substrate
Production of Pigments by Microorganisms
Uses of Microbial pigments