In vitro screening and safety assessment of novel bacterial strains as potential probiotic candidates

¹ Department of Microbiology, School of Science, RK University, Rajkot - 360020, Gujarat, India
² Department of Microbiology, Bhagwan Mahavir College of Basic & Applied Sciences, Bhagwan Mahavir University, Surat - 395007, Gujarat, India

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it. , This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 21 January 2026

Abstract

This study aimed to screen novel bacterial strains available in the laboratory, derived from previous research, for potential probiotic attributes and safety. Primary screening included microscopic and biochemical characterization using Gram, negative, and endospore staining, along with oxidase and catalase assays. Safety evaluation involved hemolysis and serum coagulation tests. Most of the tested isolates were Gram-positive, bacilli, non-spore-forming, oxidase- and catalase-negative, and coagulase-negative. The majority displayed gamma hemolysis, indicating nonpathogenic nature, while some showed alpha or beta hemolysis. Five out of nine isolates were non-hemolytic and salt-tolerant up to 2.5%. Among nine tested isolates, five exhibited high salt tolerance and favorable probiotic properties, suggesting their potential use in food preservation and supplementation. The non-hemolytic and coagulase-negative characteristics of these strains indicate safety for human application. Further in-vivo studies are planned to assess their gastrointestinal survivability and health-promoting potential.