Adopt a Bacterial Pigment : Serratia marcescens' Prodigiosin.

Serratia marcescens is a Gram-negative, facultative anaerobe bacillus that is short (small size) and motile, has no capsule and produce no spores and belonging to the family Enterobacteraciae. This bacterium is found naturally in soil and water and can utilize a wide range of nutrients. This bacterium is known for it's characteristic as an opportunistic pathogen in a large proportion of hospital acquired infections as it commonly prefer to inhabit damp areas (bathroom showers). S. marcescens has a unique ability to produce extracellular enzymes including proteases, chitinases, a nuclease, and a lipase. Such enzymes have been shown to have the ability to degrade chitin, a substance which mainly comprises fungal cell walls. The Serratia marcescens bacterial colonies have red colonies which is due to the production of the red pigment prodigion, helping them thrive in environments.

What is so special about Serratia marcescens' prodigiosin?

Pigment production is highly variable among species and is dependence on many factors such as species type and incubation time. S. marcescens is the main source of the red pigment prodigion. Prodigiosins has a chemical formula C20H25N3O and is more susceptible to a non-polar solvent than the polar one. Pigmentation is only present in a small percentage of isolated cultures only under aerobic conditions. The production of prodigiosin in S. marcescens is susceptible to temperature and is substantially inhibited at temperatures higher than 37⁰C. Certain nutrients like thiamine and ferric acid are particularly crucial for the production of prodigiosin, whereas phosphate, adenosine triphosphate, and ribose have an inhibitory effects on the prodigiosin yield. This pigment has a tri-pyrrole structure and may have a role in competition for environmental niches, as it has antimicrobial activity. Prodigiosin has also been correlated with hydrophobicity-mediated bacterial adhesion and aerosol-based dispersion. In laboratories, addition of silica gel carriers to a liquid culture of S. marcescens leads to marked increase in cell growth and the production of prodigiosin. In presence of Fe2+, some strains of Serratia marcescens produce a water-soluble pink pigment pyrimine, L-2-(2-pyridyl-D/-pyrroline-5-carboxylic acid), which diffuses into the agar surrounding the colonies. Prodigiosin pigment is localized in vesicles (extracellular and cell associated) or as intracellular granules. Prodigiosin is reported to display a characteristic absorption spectrum in ethanol, with a maximum at 534 nm and single peak absorbance at 535 nm. pH can play a crucial role in the pigmentation of the prodigion pigment as in pH 2, the pigmentation is red, at nueutral pH the color changes to pink and in alkali conditions the pigmentation turns orange.

Prodigiosin gene expression

Prodigiosin is expressed as a secondary metabolite in the general method of gene expression called quorum sensing. Growth in liquid culture at low cell density allows low-level expression of a membrane permeable positive regulator of prodigiosin expression. The intracellular concentration of the regulator remains low at low cell density due to its diffusion across the cell membrane after synthesis. However, as cell density increases in a closed system, the intracellular concentration of regulator increases to a threshold needed for activation of prodigiosin expression. The cyclic nucleotide 3′,5′-cyclic AMP (cAMP) is a signaling molecule in prokaryotes that has a global impact upon gene expression through binding with the transcription factor, cAMP-receptor, which can positively and negatively regulate expression of target genes. cAMP has a positive role in regulation of prodigiosin production. Exogenous glucose inhibits the prodigion pigment. The cAMP-associated genes in S. marcescens that were mutated by cyaA and crr (mutated strains) show a severe reduction in intracellular camp levels, and strains with crp mutations were unresponsive to exogenous cAMP. The increase in the red pigment production of the colonies under these mutated strain conditions led tells us that the cyclic AMP positively regulates the production of the red pigment prodigiosin in S. marcescens. S. marcescens strain lacking adenylate cyclase (CyaA) and cAMP phosphodiesterase activity exhibited reduced pigment production and this deficiency could be rescued by exogenous cAMP

T-cell specific immunosuppression by prodigiosin isolated from Serratia marcescens

The prodigiosin pigment isolated from serratia marcescens has a wide range of biological applications in various industries. these include activities as combat agents against fungi, bacteria, malaria, transplant rejection (immunosupressants) and cancer. In biotechnology this pigment is utilized, for an example, as a pH indicator and in chemical application one example is it's function as an immuno-suppressant drug.
Prodigiosin can be used as a valuable tool for immunologic studies on T cells and is worthy of further investigation for preclinical and clinical applications as T-cell specific immunosuppressive agents. In in vivo conditions, prodigiosin suppressed T-cell participating immune functions such as local graft vs host reaction and T-dependent antibody response without in vivo toxicity. Prodigiosin is a potent immunosuppressant which is selective to T cells with little effect on B-cells. Because T-dependent antibody response requires B cells as antibody secreting cells and other cells such as helper T cell and antigen presenting cells the suppression of in vivo and in vitro T-dependent antibody response by prodigiosin supported that it also suppressed the functions of accessory cells such as helper T-cells. Cyclosporin A suppressed helper T cells CD4+ by suppressing lymphokine production such as IL-2 and clonal expansion of CD4+ and CD8+ T cells.

Prodigion pigment in textile industries application

Prodigiosin is applied to textile industries in order to give fabric a desirable color in the red color spectrum. The broad range of red color spectrum is due to mutations that occur naturally and synthetically. Prodigiosin is often located on the cell envelope, which makes it easier to enhance the recovery efficiency for prodigiosins by addition of surfactants like sodium dodecyl sulphate. In one study during the wash performance studies with the textile materials treated with pigment, scientists found that the pigment is lost from the cloth after washing in soap solution at room temperature, 28 ± 2°C and also at 40°C but the loss of pigment from the same textile materials treated with mordant was found to be less. This suggests that thiourea is an effective mordant for treating the prodigiosin dyed textile materials and can withstand at hot wash conditions. the pigment produced by Serratia sp. BTWJ8 has the dyeing property and could be used to dye different grades of textile materials. Dyeing is performed by a simple procedure consisting of either dipping in the pigment extract or boiling with the bacterial cells. Prodigiosin has the ability to color different materials with different degrees in the following dyeing order: polyester> nylon> cotton> rubber> muslin. Effects of technical parameters including dyeing temperature, dyeing time and dye liquor pH on dyeing effect and antibacterial capability of dyed fabrics. The effluent from these textile industries poses serious threat to the environment, which is often very difficult to treat and dispose. The effluent released from the dyeing of the synthetic dyes are toxic and cause environmental pollution and harmful to health.

The miraculous microbes of Bolsena

This microbe dates back int the ancient times in Bolsena when Pope Urban instituted the feast of the Body of Christ, this was way before the first bacteria was identified by Antonie van Leeuwenhoek under a microscope. Serratia marscescens is one of the most frequent contaminants of Petri plates in the lab. This same organism also grows on bread and communion wafers which have been stored in a damp place.
One of the most celebrated miracles of the Catholic church may have been more microbial than divine. In the 'miracle of Bolsena', blood appeared on the sacramental bread during a mass in 13th-century Italy. But the 'blood of Jesus', it turns out, was probably a culture of the bacterium Serratia marcescens. In 1263, a Bohemian priest travelling to Rome stopped to celebrate mass
in nearby Bolsena. As he bent over the sacramental wafer, he began to wonder
if it was truly the body of Christ. Suddenly, the host appeared to ooze
blood, staining the altar and the priest’s fingers.

Serratia sp. ATCC 39006 produces the carbapenem antibiotic, carbapen‐2‐em‐3‐carboxylic acid and the red pigment, prodigiosin. We have previously reported the characterization of a gene, carR, contr...