Halochromic properties and antimicrobial potential of crude extracts from five species of ornamental plants
DOI:
https://doi.org/10.22458/urj.v11i3.2586Keywords:
antimicrobial, halochromism, Thunbergia erecta, anthocyanin, Xanthomonas oryzae pv. oryzae, Pantoea agglomerans, Bacillus subtilisAbstract
Introduction: the colours of flowers are a result of secondary metabolites that have long been used in the medical and textile industries, and those that are halochromic are used in colour display because they change color according to pH changes, but many species are yet to be studied in detail. Objective: to explore the halochromic properties and the antimicrobial potentials of the crude extracts of several ornamental plants. Methods: we used aqueous and organic solvents to extract pigments from petals of five fascinating flowers planted around International Institute of Tropical Agriculture station, Cotonou, Benin: Allamanda blanchetii, Cascabela thevetia, Eichhornia crassipes, Ixora casei and Thunbergia erecta, followed by an investigation into their halochromic properties. Antibacterial potentials of the extracts were tested on important rice pathogens: Xanthomonas oryzae pv. oryzae, and Pantoea agglomerans, which are gram-negative bacteria; and on Bacillus subtilis, a gram-positive bacterium. Results: The crude extracts of T. erecta and A. blanchetii have good halochromic properties within pH 2 – 12, exhibiting distinct colours. The chromophores of the C. thevetia, E. crassipes, and I. casei are not halochromic as the colours of the crude extracts remain the same at the pH range except pH 12 which is similar for the five extracts. Crude extracts of T. erecta inhibited growth of P. agglomerans without development of resistance, whereas the bacteria developed resistance against Penicillin after 18 hrs of incubation. T. erecta and A. blanchetii were able to inhibit growth of X. oryzae and both inhibited B. subtilis. Conclusion: Pigments from both T. erecta and A. blanchetii are good pH indicators; however, T. erecta is a better antibacterial agent than A. blanchetii because it has broad-spectrum activities against bacteria.
Published
Issue
Section
License
Note: This abstract contains an incorrect copyright due to technical issues. Authors who publish with this journal agree to the following terms: Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal
All journal contents are freely available through a CC BY 4.0 license.
CC BY 4.0 is a Creative Commons: you can copy, modify, distribute, and perform, even for commercial reasons, without asking permission, if you give appropriate credit.
Contents can be reproduced if the source and copyright are acknowledged according to the Open Access license CC BY 4.0. Self-storage in preprint servers and repositories is allowed for all versions. We encourage authors to publish raw data and data logs in public repositories and to include the links with all drafts so that reviewers and readers can consult them at any time.
The journal is financed by public funds via Universidad Estatal a Distancia and editorial independence and ethical compliance are guaranteed by the Board of Editors, UNED. We do not publish paid ads or receive funds from companies.
