# Protein Extraction from Chlorella pyrenoidosa Using Bacillus spp. Isolated from Jeotgal: Strain isolation, Characterization, and Fermentation

## TL;DR

Researchers isolated Bacillus strains from Korean fermented food to improve protein extraction from Chlorella pyrenoidosa, a microalga with a rigid cell wall.

## Contribution

A novel microbial fermentation approach using Bacillus spp. for efficient protein extraction from Chlorella pyrenoidosa is proposed.

## Key findings

- Eight Bacillus strains were selected for high enzymatic activity, including cellulases, proteases, and lipases.
- Bacillus amyloliquefaciens F2 achieved the highest protein extraction yield of 35.45 ± 1.21%.
- Four strains did not produce biogenic amines, indicating potential safety for food industry applications.

## Abstract

Chlorella pyrenoidosa, a versatile microalga with a rich nutritional profile and functional components, has various applications. However, rigid cell walls pose challenges for the effective extraction of proteins. Microbial fermentation is a promising solution for large-scale production and industrial applications. This study aimed to isolate Bacillus spp. with high enzymatic activity from Jeotgal, a Korean traditional fermented food, and enhance protein extraction from C. pyrenoidosa using microbial fermentation with the isolated Bacillus spp. Twenty-two strains of Bacillus spp. were isolated, and eight Bacillus species were selected based on their ability to produce cellulases, proteases, and lipases. Microbial safety was further assessed by testing for biogenic amine production and hemolytic activity. All eight strains exhibited γ-hemolysis, with four strains not producing biogenic amines. Notably, fermentation using Bacillus amyloliquefaciens F2 showed the highest protein extraction yield at 35.45 ± 1.21% (v/v). In conclusion, this study demonstrates the potential of microbial fermentation for protein extraction from C. pyrenoidosa, offering a novel approach for its utilization in the food industry.