# Comparative evaluation of aqueous Beta vulgaris extract as a natural microbial dye relative to standard stains through image processing

**Authors:** Sheetal Gouda, Navya Shetty, H. A. Arundathi, V. N. Venkatesh, Sooraj Mohan, P. Dinesha

PMC · DOI: 10.1038/s41598-025-23508-8 · 2025-11-13

## TL;DR

This study compares beetroot extract to traditional dyes for staining microbes, finding it works well for fungi but needs improvement for bacteria.

## Contribution

The novel use of Beta vulgaris extract as a natural microbial dye is evaluated for its staining effectiveness and sustainability.

## Key findings

- Beta vulgaris extract provides better morphological detail for fungal staining compared to standard dyes.
- Bacterial staining with Beta vulgaris extract is less sharp visually.
- No significant differences were found in most image quality parameters between the extract and standard dyes.

## Abstract

The growing environmental concerns about synthetic dyes have increased interest in finding natural, non-toxic alternatives for microbiological staining. This study assesses the effectiveness of aqueous Beta vulgaris (beetroot) extract as a staining agent for microorganisms, comparing its performance with traditional dyes. Microbial smears containing bacteria and fungi were prepared using both standard dyes and Beta vulgaris extract. Microscopic images were taken and analyzed quantitatively, using measures such as sharpness, entropy, contrast, signal-to-noise ratio, and edge intensity. While statistical analysis with the Wilcoxon Signed-Rank test showed no significant differences in most parameters (p > 0.05), the Beta vulgaris extract showed clear advantages in fungal staining, providing better morphological detail. However, bacterial staining was less sharp visually. These results suggest that aqueous Beta vulgaris extract has potential as a sustainable alternative for specific microbial staining, especially for identifying fungi, though further refinement and broader microbial testing are needed.

## Linked entities

- **Species:** Beta vulgaris (taxon 161934)

## Full-text entities

- **Species:** Beta vulgaris (beet, species) [taxon 161934], Bacteria Latreille et al. 1825 (Bacteria stick insect, genus) [taxon 629395], Fungi (kingdom) [taxon 4751]

## Figures

5 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12615709/full.md

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Source: https://tomesphere.com/paper/PMC12615709