Resourcefulness of propylprodigiosin isolated from Brevundimonas olei strain RUN-D1

Abstract

A novel red-pigmented bacterium was isolated from a water sample collected at Osun River, Ede. Morphological and 16 S rRNA gene sequencing revealed that the bacterium is a strain of Brevundimonas olei, while its red pigment was identified using UV-visible, FTIR and GCMS as a derivative of propylprodigiosin. The maximum absorbance of 534 nm, the FTIR's 1344 cm^{- 1} peak of prodigiosin's methoxyl C-O interaction, and the molecular ions from GCMS confirmed the pigment's identity. The pigments production was temperature-sensitive (25 °C), lost at > 28 °C, and in the presence of urea and humus. In addition, the pigment turned pink in the presence of hydrocarbons, while its red colour was retained with KCN and Fe₂SO_4, and enhanced by methylparaben. Furthermore, the pigment is stable in high temperature, salt, and acidic conditions, but changed to yellow in alkaline solution. The pigment, identified as propylprodigiosin (m/z 297), demonstrated broad-spectrum antibacterial activities against clinically important strains of Staphylococcus aureus (ATCC25923), Pseudomonas aeruginosa (ATCC9077), Bacillus cereus (ATCC10876), Salmonella typhi (ATCC13311), and Escherichia coli (DSM10974). The ethanol extract has the highest zones of inhibition of 29 ± 3.0, 26 ± 1.2, 22 ± 3.0, 22 ± 1.5, and 20 ± 2.0 mm, respectively. Furthermore, the acetone pigments interacted with cellulose and glucose such that increasing glucose concentrations showed linearity at 425 nm. Finally, the fastness of the pigments to fabrics was excellent, with percentage fadedness of 0 and - 43% light and washing tests, respectively, in the presence of Fe₂SO₄ as the mordant. The antibacterial nature of prodigiosin solutions and their good textile fastness to fabrics could be essential in manufacturing antiseptic materials such as bandages, hospital clothing and agricultural applications such as tubers preservation.Key points.

Keywords: Antibacterial; Biomarker; Percentage fadedness; Pigment; Prodigiosin; Textile dyes.

Fig. 1

Neighbor-joining tree based on partial 16S rRNA gene sequences showing the phylogenetic position of Brevundimonas olei strain RUN-D1 among closely related taxa at a percentage of 1000 bootstrap replicates. Branches corresponding to partitions reproduced in less than 50% of bootstrap replicates are collapsed. The evolutionary distances were computed using the Maximum Composite Likelihood method and are in the units of the number of base substitutions per site. This analysis involved 13 nucleotide sequences

Fig. 2

Isolated Brevundimonas olei (RUN-D1) on nutrient agar, A; Gram’s staining of pigment-producing bacterium B; Solutions of extracted pigments in different solvents. C; UV-visible spectral of the various extracts of the pigments from strain D1. D

Fig. 3

Fourier-transform infrared spectroscopy (FT-IR) of the red pigment from strain D1 extracted with acetone (Ac), Ethyl Acetate (EA), Ethanol (EtOH), and Methanol (Me)

Fig. 4

Mass spectra of the two prominent compounds identified in the GCMS analysis of the pigment showing compound 1 (A) and compound 10 (B) and their fragment ions

Fig. 5

Acid (A) and alkaline (B) stability tests of propylprodigiosin extracted from Brevundimonas olei strain RUN-D1

Fig. 6

Antimicrobial activities of red pigment and chloramphenicol (control) on five renowned Gram-positive and Gram-negative bacteria

Fig. 7

Interaction of red pigment with different biomolecules (BSA –Bovine serum albumin, palmitate, cellulose, and glucose) and quantification of glucose using the pigment

Fig. 8

Textile fabrics dyed with ethanol and acetone extracts of the red pigment and colour hues obtained after applying different mordant to the textile materials

Fig. 9

Light (A) and washing (B) Fastness tests showing the percentage fadedness of satin, chiffon and linen fabrics dyed with prodigiosin in the presence of NAHCO₃ or Fe₂SO₄ as a mordant