# Optimized collagenase biosynthesis (Bacillus siamensis strain Z1) and its application in collagen hydrolysate-mediated silver and zinc oxide nanoparticles synthesis and characterization with antibacterial, antioxidant and cytotoxic activities

## TL;DR

This study explores a marine bacterium that produces collagenase, which breaks down collagen waste and is used to create nanoparticles with antibacterial, antioxidant, and cancer-fighting properties.

## Contribution

The study introduces an optimized method for collagenase biosynthesis and its novel application in nanoparticle synthesis with biomedical potential.

## Key findings

- Collagenase production was optimized to 4.55 U/mL with a 17.93-fold enhancement using central composite design.
- Collagen hydrolysate was used to synthesize AgNP and ZnONP with antibacterial effects against B. cereus and E. coli.
- AgNP and ZnONP showed antioxidant activity and cytotoxicity on MCF-7 breast cancer cells with IC50 values of 8.87 µg/mL and 25.21 µg/mL, respectively.

## Abstract

Globally, environmental pollution caused by resilient protein like collagen is escalating due to inefficient disposal practices. Accumulation of collagen waste poses ecological threat, necessitating management strategies. Current study discloses collagenolytic bacterium, Bacillus siamensis strain Z1, isolated from marine water (Goa) demonstrating collagen breakdown and inducing collagenase biosynthesis. Production kinetics revealed optimal collagenase production (4.55 U/mL) on 2nd day with a protein content of 0.69 mg/mL. Influence of physiochemical parameters, including inoculum size, metal ions, carbon and nitrogen sources, pH and temperature on collagenase yield was optimized achieving 17.93 folds enhancement by central composite design. Silver (AgNP) and Zinc oxide (ZnONP) nanoparticles were biosynthesized using collagen hydrolysate derived from marine collagen through collagenase action and characterized using UV-Visible spectroscopy, Fourier Transform Infrared Spectroscopy, X-ray Diffraction, Scanning Electron Microscopy with Energy Dispersive X-ray, Thermogravimetric Analysis and Atomic Force Microscopy elucidated thermostability, structure and surface characteristics. Antibacterial effect of nanoparticles was observed against B. cereus and E. coli. AgNP and ZnONP demonstrated antioxidant properties assessed by ABTS and DPPH assays. AgNP and ZnONP exhibited cytotoxicity on MCF-7 breast cancer cell lines, with IC50 values 8.87 µg/mL and 25.21 µg/mL respectively. The study highlights biotechnological potential of collagenase in generating bioactive products for therapeutical and biomedical advancements.