Characterization of Bioactive Colored Materials Produced from Bacterial Cellulose and Bacterial Pigments

Abstract

A Bacterial Cellulose (BC) film was developed and characterized as a potential functional bioactive material. BC films, obtained from a microbial consortium of bacteria and yeast species, were functionalized with the bacterial pigment prodigiosin, produced by Serratia plymuthica, and flexirubin-type pigment, from Chryseobacterium shigense, which exhibit a wide range of biological properties. BC was successfully functionalized at 15% over the weight of the fiber at 40 °C during 60 min, and a color strength of 1.00 ± 0.01 was obtained for BC_prodigiosin and 0.38 ± 0.02 for BC_flexirubin-type pigment. Moreover, the BC films showed moderate hydrophilic character following alkaline treatment, which was maintained after both pigments were incorporated. The porosity and mechanical performance of the functionalized BC samples also remained unaffected. Furthermore, the BC samples functionalized with prodigiosin presented antibacterial activity and were able to inhibit the growth of pathogenic bacteria Staphylococcus aureus and Pseudomonas aeruginosa, with inhibition rates of 97.89 ± 0.60% and 85.12 ± 0.17%, respectively, while BC samples functionalized with flexirubin-type pigment exhibited the highest antioxidant activity, at 38.96 ± 0.49%. This research provides an eco-friendly approach to grant BC film-based material with color and advantageous bioactive properties, which can find application in several fields, especially for medical purposes.

Natural Deep Eutectic Solvent Extraction of Bioactive Pigments from Spirulina platensis and Electrospinning Ability Assessment

“…Other studies [ 17 ] performed in our research group focused on the electrospinning of bacterial pigments for packaging applications, which also showed lower antioxidant activities (38.96 ± 0.49%) than those of the NADES/PVA-based nanofibers. Thus, the results obtained for the nanofibers functionalized with bioactive pigments extracted from Spirulina platensis in a green process using NADES and UAE show promising antioxidant capabilities that are valuable for packaging, textile, and pharmaceutical applications.…”

“…ABTS+ radical scavenging assay is an electron transfer-based assay widely used for the assessment of the antioxidant capabilities of natural products. This spectrophotometric technique is based on the ability of compounds to donate hydrogen to free radicals; thus, the antioxidants reduce the ABTS+ radical to a colorless compound [ 17 ].…”

“…Antioxidant activity was evaluated by the ABTS radical decolorization assay as previously described by other authors [ 17 ]. Briefly, the ABTS radical cation (ABTS+) was produced by reacting 5 mL of ABTS (7 mM) stock solution with 88 μL of potassium persulfate (2.4 mM).…”

Upcycling Wool Waste into Keratin Gel-Based Nanofibers Using Deep Eutectic Solvents

“…The antioxidant activity of the produced gel-based electrospun PVA/L-Cys:LA DES-WK nanofibrous membranes was explored through ABTS assay. ABTS+ is a stable free radical commonly used for assessing the total antioxidant capacity of natural compounds, and displays a maximum absorption peak at 734 nm [ 39 , 40 ].…”

Transcriptomic analysis of cell envelope inhibition by prodigiosin in methicillin-resistant Staphylococcus aureus

“…Prodigiosin is a secondary metabolite of many microorganisms, including Serratia marcescens , Serratia nematodiphila , Zooshikella sp., Serratia plymuthica , etc., characterized by a relatively simple structure of three pyrrole rings and a methoxy group ( Darshan and Manonmani, 2016 ; Woodhams et al, 2018 ; Ramesh et al, 2020 ; Amorim et al, 2022 ). In the past decade, various biological effects of prodigiosin were revealed, including immunosuppressive, anticancer, antimalarial and fungicidal activities ( Han et al, 2005 ; Wang et al, 2016 ; Li et al, 2018 ; Han et al, 2021 ; Nguyen et al, 2022 ).…”