# Compost Tea as a Natural Bioactive Solution: Unlocking the Antimicrobial and Antiviral Potential of Bell Pepper and Citrus Wastes

## TL;DR

Compost teas from bell pepper and citrus waste show strong antibacterial and antiviral properties, offering sustainable natural alternatives for biomedical use.

## Contribution

The study demonstrates the antimicrobial and antiviral potential of compost teas derived from specific agro-industrial wastes.

## Key findings

- Compost tea from bell pepper (CT-BP) was more effective against Gram-positive bacteria like Staphylococcus aureus and Enterococcus faecalis.
- CT-BP showed potent antiviral activity against herpes simplex virus type 1 (HSV-1) and respiratory syncytial virus (RSV).
- Gram-negative bacteria like Escherichia coli and Pseudomonas aeruginosa were more resistant to the compost teas.

## Abstract

The growing demand for sustainable medical applications has sparked interest in the valorisation of agro‐industrial waste for bioactive compounds. Compost teas (CTs) from agrifood waste, rich in phenolics and lignin derivatives, offer promising biological properties. This study analysed CTs from bell pepper (CT‐BP) and citrus (CT‐C) composted waste, assessing their antioxidant, antiviral, and antimicrobial activities. NMR spectroscopy and thermochemolysis revealed that CT‐BP had more oxidised lignin derivatives, while CT‐C contained intact lignin structures. Both CTs effectively inhibited Gram‐positive bacteria (
Staphylococcus aureus
and
Enterococcus faecalis
), with CT‐BP showing greater efficacy. However, Gram‐negative bacteria (
Escherichia coli
and
Pseudomonas aeruginosa
) were more resistant. CT‐BP also exhibited potent antiviral effects against enveloped viruses like herpes simplex virus type 1 (HSV‐1) and respiratory syncytial virus (RSV). These findings support the use of compost‐derived extracts as sustainable bioactive agents, offering natural alternatives to conventional treatments. Further research could enhance the extraction and scalability of these materials for biomedical applications, aligning with principles of the circular economy.

Compost teas derived from bell pepper and citrus waste are rich in bioactive phenolics and lignin derivatives, showing strong antibacterial activity against gram‐positive bacteria and potent antiviral effects against HSV‐1 and RSV. These findings highlight their potential as sustainable, circular bioresources for biomedical applications.