Encyclopedia
Please note this is a comparison between Version 1 by Laurent Dufossé and Version 2 by Peter Tang.
Marine bacterial species contribute to a significant part of the oceanic population, which substantially produces biologically effectual moieties having various medical and industrial applications. The use of marine-derived bacterial pigments displays a snowballing effect, being natural, environmentally safe, and health beneficial compounds. Marine-derived bacterial pigments serve as valuable products in the food, pharmaceutical, textile, and cosmetic industries due to their beneficial attributes, including anticancer, antimicrobial, antioxidant, and cytotoxic activities. Biodegradability and higher environmental compatibility further strengthen the use of marine bio-pigments over artificially acquired colored molecules. Besides that, hazardous effects associated with the consumption of synthetic colors further substantiated the use of marine dyes as color additives in industries as well.
- natural colors
- bio-pigments
- quorum sensing
- marine bacteria
- biosynthesis
- biological activities
- industrial applications
- therapeutic insights
1. Introduction
The production of bio-pigments from bacterial species is being conducted globally with soaring interest under the research of microbial autecology. A massive array of these compounds, also referred to as “bioactive pigmented molecules”, can be derived from both Gram-positive and Gram-negative bacterial species. Production of these pigments in the marine environment is mediated through the complex mechanism of “quorum sensing” [1] or also can be induced through exposure to different stress conditions in external environments. Quorum sensing is the mechanism whereby individual bacterial cells can coordinate with others in their colony to carry out constitutive functions especially involving the secretion of numerous specific chemical compounds. These compounds can help them with survival, competence, bioluminescence, biofilm formation, and even sporulation, etc. Bio-pigments can be produced by triggering regulatory quorum sensing mechanisms of these species and can be extensively used in various bio-medical and bio-industrial sectors, including textiles, food, pharmaceutical, and cosmetic industries, owing to their beneficial attributes and biological activities [2][3][2,3]. These are moreover convenient to harvest in large volumes through utilizing simple gene manipulating strategies. The rising consumer concerns regarding safety and quality of industrial products holds a significant ground as to why scientists are shifting their focus towards naturally derived, non-toxic, and eco-friendly pigment alternatives [4].
2. Marine Bacterial Species as Sources of Bio-Pigments
The marine environment has been investigated for almost 300,000 known species, which constitutes only a small fraction of the total number of explorable pigment producing bacterial species. Bacterial species isolated from marine sediments or seawater such as Streptomyces sp., Pontibacter korlensis sp., Pseudomonas sp., Bacillus sp., and Vibrio sp. produce an array of pigmented compounds including prodigiosin, astaxanthin, pyocyanin, melanin, and beta carotene, respectively (Table 1). These pigments belong to a range of compound classes, for instance, carotenes are a subclass of carotenoids that have unsaturated polyhydrocarbon structures, prodiginines have a pyrrolyldipyrromethene core structure, tambjamines are alkaloid molecules, while violacein compounds are indole derivatives derived from tryptophan metabolism (Figure 1) [1][2][5][1,2,21]. These and other such pigments, despite their class diversity, share a functional likeness due to the presence of aromatic rings in their structures.
Figure 1.
Chemical structures of various bacterial pigments.
Table 1.
Marine bacterial sources of colored pigmented compounds.
|
Pigments |
Marine Bacterial Species |
References |
|---|---|---|
|
Prodigiosin |
Hahella chejuensis sp. Pseudoalteromonas rubra sp. Streptomyces sp. SCSIO 11594 Vibrio sp. (Strain MI-2) Serratia marcescens sp. IBRL USM 84 Zooshikella ganghwensis gen. nov., sp. nov. |
|
|
Undecylprodigiosin |
Streptomyces sp. UKMCC_PT15 Streptomyces sp.SCSIO 11594 Novel strain of Actinobacterium sp., Saccharopolyspora sp. |
|
|
Heptylprodigiosin |
Spartinivicinus ruber gen. nov., sp. nov |
|
|
Cycloprodigiosin |
Pseudoalteromonas denitrificans sp. Pseudoalteromonas rubra sp. ATCC 29570 |
|
|
Norprodigiosin |
Serratia sp. WPRA3 |
|
|
Astaxanthin |
Brevundimonas scallop sp. Zheng & Liu Corynebacterium glutamicum sp. Brevundimonas sp. strain N-5 Sphingomicrobium astaxanthinifaciens sp. nov Rhodovulum sulfidophilum sp. Pontibacter korlensis sp. AG6 Exiguobacterium sp. Altererythrobacter ishigakiensis sp. NBRC 107699 Rhodotorula sp. Paracoccus haeundaensis sp. |
[18][19][20][21][22][23][24][25][,3726,38],39,40[,4127][33,34,35,36,42] |
|
Zeaxanthin |
Sphingomonas phyllosphaerae sp. KODA19-6 Mesoflavibacter aestuarii sp. nov. Aquibacter zeaxanthinifaciens gen. nov., sp. nov. Zeaxanthinibacter enoshimensis gen. nov., sp. nov Gramella planctonica sp. nov Mesoflavibacter zeaxanthinifaciens gen. nov., sp. nov Formosa sp. KMW Sphingomonas phyllosphaerae sp. FA2T Sphingomonas (Blastomonas) natatoria sp. DSM 3183T Muricauda lutaonensis sp. CC-HSB-11T |
[13][28][29][30][31][32[35][29,43][,4433][,4534,46],47,48,49,50] |
|
Lycopene |
Blastochloris tepida sp. Salinicoccus roseus sp. |
|
|
Beta carotene |
Cyanobacterium Synechococcus sp. Micrococcus sp. Vibrio owensii sp. Flavicella marina gen. nov., sp. nov. Gordonia terrae sp.TWRH01 |
|
|
Canthaxanthin |
Brevibacterium sp. Gordonia sp. Dietzia sp. |
|
|
Pyocyanin |
Pseudomonas aeruginosa sp. |
|
|
Scytonemin |
Cyanobacterial sp. Nostoc punctiforme sp. ATCC |
|
|
Violacein |
Pseudoalteromonas luteoviolacea sp. Pseudoalteromonas ulvae sp. TC14 Pseudoalteromonas sp. 520P1 Microbulbifer sp. D250 Pseudoalteromonas amylolytica sp. nov Chromobacterium violaceum sp. Collimonas sp. |
|
|
Melanin |
Streptomyces sp. Pseudomonas sp. Marinomonas mediterranea sp. MMB-1T Pseudomonas stutzeri sp. Bacillus sp. BTCZ31 Streptomyces sp. MVCS13 Providencia rettgeri sp. strain BTKKS1 Marinobacter alkaliphilus sp. Leclercia sp. Halomonas meridian sp. Nocardiopsis dassonvillei sp. strain JN1 Vibrio alginolyticus sp. strain BTKKS3 |
[53]]62][68[54][55,69[,7056],71[57],72[58],73[59],74[60],75[61],76[,77] |
|
Tambjamines |
Pseudoalteromonas tunicata sp. Pseudoalteromonas citrea sp. |
3. Biosynthesis of Bacterial Pigments
The potential of marine bacterial isolates as a leading source of bio-pigments demands an extensive understanding of bio-mechanisms responsible for yielding pigmented molecules. Different studies have reported the proposed biosynthetic pathways of pigment production by marine bacterial isolates along with biochemically characterized enzymatic transformations (Figure 2). However, it is still unclear if the proposed pathways are distinct for marine or terrestrial bacterial species, or may be the same in both cases.
Figure 2. Proposed biosynthetic pathways of few bacterially produced bio-pigments. (a) Biosynthesis of Prodiginine analogs; MAP biosynthesis; MBC biosynthesis; Tambjamine biosynthesis; Cyloprodigiosin biosynthesis; 2-(p-hydroxybenzyl)prodigiosin (HBPG) biosynthesis. (b) Biosynthesis of carotenoids. (c) Biosynthesis of scytonemin. (d) Biosynthesis of salinixanthin and retinal pigments. (a) Biosynthesis of prodigioinine analogs. MAP Biosythesis (Green): (1) 2octenal, (2) Pyruvate, (3) 3-acetyloctanal, (4) H2MAP, (5) MAP. MBC Biosynthesis (Blue), (6) L-proline, (7) L-prolyl-S-PCP intermediate, (8) Pyrrolyl2-carboxyl-S-PCP, (9) Pyrrole-2-carboxyl thioester, (10) Malonyl-CoA, (11) Bound malonyl, (12) pyrrolyl-β-ketothioester on PigH, (13) 4-hydroxy-2,20-bipyrrole-5methanol (HBM), (14) 4-hydroxy-2,20-bipyrrole-5-carbaldehyde (HBC), (15) MBC, (16) Prodigiosin. Tambjamine Biosynthesis, (17) Dodecenoic acid, (18) Activated fatty acid, (19) CoA-ester, (20) Enamine, (21) Tambjamine, (22) Cycloprodigiosin (cPrG) &, (23) 2-(p-hydroxybenzyl)prodigiosin(HBPG) Biosynthesis. (b). Biosynthesis of carotenoids: CrtE: GGPP synthase, IPP: Isopentenyl pyrophosphate, GGPP: Geranylgeranyl pyrophos, CrtB: Phytoene synthase, CrtI: Phytoene desaturase, CrtY: lycopene β-cyclase, CrtW: β-carotene ketolase, CrtZ: β-carotene hydroxylase, CrtG: Astaxanthin 2,2′-β-ionone ring hydroxylase gene. (c). Biosynthesis of scytonemin: Scytonemin biosynthetic enzymes: ScyA, ScyB, ScyC (ScyA: a thiamin-dependent enzyme, ScyC: enzyme annotated as a hypothetical protein), ThDP: Thiamine diphosphate, NAD: Nicotinamide adenine dinucleotide, Mg2+: Magnesium ion.
4. Industrial and Therapeutic Applications
4.1. Therapeutic Applications
4.1.1. Antibacterial Activity
Antibacterial properties of various bacterially produced bio-pigments of marine origin have been reported against an array of bacterial species, e.g., prodigiosin, cycloprodiogisin (from Z. rubidus sp. S1-1), and the yellow pigment (extracted from Micrococcus sp. strain MP76) have shown antibacterial activity against Staphylococcus aureus sp. and Escherichia coli sp. [65][66][98,99]. Other bacterial strains that are reportedly inhibited by prodigiosin and cycloprodigiosin are Bacillus subtilis sp. and Salmonella enterica serovar Typhimurium [65][98]. Likewise, the yellow pigment has shown activity against P. aeruginosa sp. as well [66][99]. Norprodigiosin synthesized by marine Serratia sp. has also been reported to exhibit inhibition activity against Vibrio paraheamolyticus sp. and B. subtilis sp. [17][32]. These studies strengthen the utilization of bpBPs as potential alternatives to synthetic medicinal compounds.
Furthermore, inhibition activities recorded against Citrobacter sp. by pyocyanin and pyorubin [43][58] and P. aeruginosa sp. by violacein pigment (purified from Antarctic Iodobacter sp.) [67][100], further stretches the range of marine-derived bpBP’s potential against pathogenic bacterial species to opportunistic bacterial species. There are numerous correspondingly published studies. The pigment “melanin” from marine Streptomyces sp., for instance, demonstrated antibacterial activity against E. coli sp., S. typhi sp., S. paratyphi sp., Proteus mirabilis sp., Vibrio cholera sp., S. aureus sp., and Klebsiella oxytoca sp. [53][68]. A bright pink-orange colored pigment extracted from Salinicoccus sp. (isolated from Nellore sea coast) also showed antimicrobial potential against several bacterial strains including E.coli sp., Klebsiella pneumoniae sp., B. subtilis sp., Proteus vulgaris sp., P. aeruginosa sp., and S. aureus sp. [68][101]. Hence, these and similar other studies all indicate the exploration of marine bacterial species as a dynamic approach to derive antibacterial compounds.
4.1.2. Antifungal Activity
Studies have also been carried out to determine the antifungal potential of natural pigmented compounds. Several studies have reported the antifungal activity of marine-derived bacterial pigments, among which violacein from Chromobacterium sp. and prodiginine pigments (prodigiosin and cycloprodigiosin) extracted from Indonesian marine bacterium P. rubra sp. reported to exhibit antagonistic activity against Candida albicans sp. [7][69][23,103]. Violacein also inhibited several other fungal strains, including Penicillium expansum sp., Fusarium oxysporum sp., Rhizoctonia solani sp., and Aspergillus flavus sp. Studies have also reported that violacein (extracted from a pure Chromobacterium sp.) shows comparable antifungal activity to that of bavistin and amphotericin B, highlighting the potential of marine-derived bpBPs as effective antifungal agents over existing synthetic antifungal compounds [69][103].
4.1.3. Anticancer Activity
Exploring anticancer compounds from marine microbes has been considered a hot spot in natural product research. Several studies have been carried out in order to examine the antitumor ability of marine bacterial pigments. Anticancer activity of marine-derived bpBPs has been explored against several cancerous cell lines. Astaxanthin and 2-(p-hydroxybenzyl) prodigiosin (HBPG) isolated from P. kolensis sp. and P. rubra sp. displayed significant cytotoxicity against human breast cancer cell line (MCF-7) and human ovarian adenocarcinoma cell line, respectively [23][70][38,104]. PCA (Phenazine -1-carboxylic acid) pigment extracted from marine P. aeruginosa sp. GS-33 correspondingly showed inhibition against SK-MEL-2 (human skin melanoma cell line) [71][105]. Another pigment violacein extracted from Antarctic bacterium isolate, identified as a member of the genus Janthinobacterium (named as Janthinobacterium sp. strain UV13), revealed its antiproliferative activity in HeLa cells.
4.1.4. Antioxidant Activity
Marine-derived bpBPs are also being explored for their antioxidant activity. 3R saproxanthin and myxol pigments (from marine bacterium belonging to genus Flavobacteriacae) exhibited antioxidant activity against lipid peroxidation and also showed neuroprotective activity against L-glutamate toxicity [72][110]. The antioxidant activities of zeaxanthin (extracted from marine bacterium of genus Muricauda) [73][111] and melanin (from marine Pseudomonas stutzeri sp.) [74][112] have also been identified. Another pigment, phycocyanin extracted from marine bacterium Geitlerinema sp TRV57, demonstrated appreciable antioxidant activity [75][113]. Crude pigment extracted from the marine bacterium Streptomyces bellus sp. MSA1 also displayed 82% of DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) activity and said to exhibit radical scavenging activity [76][114]. Likewise, pigment crude extract from Zobellia laminarie sp. 465 (isolated from sea sponge) reported to exhibit high antioxidant values for ABTS-L (capture of the 2,2-azino-bis(3-ethylbenzothiazoline)-6-sulphonic acid (ABTS+) radical of the lipophilic fraction) [77][115], suggesting the importance of marine derived bacterial pigments in pharmaceutical and medicinal industries.
4.1.5. Antiviral Activity
The advancing viral pandemics have taken a toll over the limited pool of existing antiviral agents, which has led to a rigorous search for newer, natural compounds with better antiviral capacities. Various studies on marine bpBPs suggest them as potential candidates. Prodigiosin extracted from Serratia rubidaea sp. RAM_Alex showed antiviral activity against hepatitis C virus (HCV) upon injecting HepG2 (human liver cancer cell line) cells with 2% of HCV infected serum [78][116]. Other carotenoid pigments (from Natrialba sp. M6) have also displayed complete elimination of HCV and clearance of 89.42% of hepatitis B virus (HBV) [79][117], indicating the use of marine pigments as availing antiviral agents.
4.2. Industrial Applications
4.2.1. Bio-Pigments as Food Colorants
Researchers have concluded that marine-derived bpBPs can be utilized to provide full-scale commercial production of food-grade pigments, owing to their little or no threats to consumer health. They also showed pleasant colors at low concentrations. Pyorubrin and pyocyanin, for example, extracted from P. aeruginoasa sp., when assessed for their utilization as food colorings with agar, gave pleasing colors at 25 mg mLG−1 [43][58]. The utilization of bpBPs was also suggested as a feed additive to promote growth and enhance the coloration of ornamental fishes [80][119]. Furthermore, prodigiosin (from marine bacterium Zooshikella sp.) has been reported to exhibit good staining properties and a three months shelf life [81][120], which hints toward a sustainable aspect of marine-derived pigmented molecules as food colorants.
4.2.2. Bio-Pigments as Dyeing Agents
The worldwide demand for clothes is rising exponentially. Newly, there is an increase in the insistence of incorporating antimicrobial properties in fabrics. Lee et al. identified a novel marine bacterium Z. rubidus sp. S1-1 that produced two significant pigments, i.e., prodigiosin and cycloprodigiosin. These were used to dye cotton and silk fabrics. Results revealed that the application of red-pigmented extract solution on fabrics reduced the growth rate of S. aureus sp. KCTC 1916 by 96.62% to 99.98% and E. coli sp. KCTC 1924 by 91.37% to 96.98% [65][98]. Furthermore, Vibrio sp. isolated from marine sediment produced a bright red colored prodiginine pigment that was used to dye nylon 66, silk, wool, acrylic, and modacrylic fabrics to obtain a pretty deep-colored shade. The dyed silk and wool fabrics also showed antibacterial activity against E. coli sp. and S. aureus sp. [82][121]. Researchers at Ulsan National Institute have also reported the synthesis of antibacterial fabric by using violacein pigment extracted from C. violacea sp. [83][84][122,123]. Prodigiosin pigment extracted from Serratia sp. BTWJ8 effectively dyed paper, PMMA (Polymethyl methacrylate sheets), and rubber latex. Rubber is commonly used in day to day life either in houses or industries. PMMA have been widely utilized for the construction of lenses for exterior lights of automobiles. Different concentrations of prodigiosin produced variable color shades that revealed its affectivity as a coloring agent [85][124].
4.2.3. Use in Cosmetics
The cosmetic industry is an expeditiously emerging global business market. About 2000 companies in the United States of America are cosmetic manufacturers. It is estimated that American adults use seven different skincare products per day for everyday grooming [86][125]. The cosmetic industry has a worth of 10.4, 10.6, and 13.01 billion euros in the UK, France, and Germany, respectively [87][126]. Considering the cosmetic market value worldwide, researchers have also made efforts to explore the use of marine-derived bpBPs in skincare products. The addition of the pigment PCA in a solution of commercial sunscreen enhanced its UV-B (ultraviolet B-rays) protection and increased the SPF (sun protection factor) values up to 10% to 30% [71][105].
Similarly, melanin incorporated cream (named cream F3) was synthesized by concentrates of seaweed (Gelidium spinosum) and melanin pigment (extracted from marine bacterium Halomonas venusta sp.). Cream F3 showed high SPF values and photoprotective activity and demonstrated great effectivity in wound healing as well. Moreover, the formulated cream also exhibited antibacterial activity against skin pathogens; Streptococcus pyogenes sp. (MTCC 442), and S. aureus sp. (MTCC 96) [88][127]. Another research reported the effectivity of melanin (extracted from marine bacterium Vibrio natriegens sp.) in protecting mammalian cells from UV irradiation. Results revealed 90% survival rate of HeLa cells in melanized cell culture [89][128]. In another report, Bio lip balm made from crude pigment (extracted from S. bellus sp. MSA1) in a mixture of coconut oil, lanolin, and shredded bee wax [76][114] suggested the use of melanin pigment as a significant ingredient in several beauty care products as well.
4.2.4. Antifouling Agent
Billions of dollars have been spent each year to control fouling activities on different objects placed in the marine environment. Biofouling on ships such as dreadnoughts increased the roughness of the hull, which promotes frictional resistance, ultimately leading to an increase in fuel consumption and other corresponding environmental compliances. Heavy metal-based antifoulants cause severe environmental complications, which further mandate the need for “eco-friendly” antifouling agents. Researchers have also revealed the use of marine-derived bpBPs for their role as an antifouling agent, for instance, prodigiosin extracted from Serratia. sp. was reported to exhibit antifouling activity against marine fouling bacterial species such as Gallionella sp. and Alteromonas sp. It also inhibited the adhesion of Cyanobacterium sp. on the glass surface [90][129]. Likewise, another pigment, polymelanin synthesized by the marine bacterium P. lipolytica sp., prevented metamorphosis and decreased the invertebrate larval settlement [91][130], hence indicating the role of marine bacterial pigments as potential antifoulants.
4.2.5. Photosensitizers
The use of prodigiosin has also been reported as photosensitizers in solar cells. The high photostability of extracted prodigiosin demonstrated its use as a sensitizer in dye-sensitized solar cells (DSSC) [92][131]. This study suggests the viability of bpBPs in addition to that of prodigiosin for the construction of cost-effective and low tech industrially produced DSSC.
