Isolation and Identification of Bacillus subtilis for usage as probiotic bacteria

Elkholy, Ashraf Ibrahim; Nour, Maher Ahmed; Ali, Hesham Mohamed; Soliman, Selim Abdalaziz

doi:10.21608/ejds.2023.199272.1010

Isolation and Identification of Bacillus subtilis for usage as probiotic bacteria

Document Type : Original Article

Authors

¹ Department of Dairy, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt.

² Department of Dairy, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt

10.21608/ejds.2023.199272.1010

Abstract

Bacteria known as probiotics can help the host's health when given in sufficient doses. For many years, Bacillus species have been utilized as probiotics. In the present study, one bacterial isolate of bacteria from Human milk was isolated and identified by morphological, biochemical tests and then confirmed by 16S rRNA sequencing. The strain was positive for Gram stain, Spore formation, Motility, Catalase, Nitrate reduction, Acidity production from glucose, Starch and Casein hydrolysis, Gelatin liquefied, Citrate utilization and Voges-Proskauer reaction. While this strain was negative for KOH, Egg-yolk lecithinase, and Toxin crystal produced. After polymerase chain reaction (PCR) amplification, DNA sample fragments were obtained. These fragments were sequenced and submitted to GenBank (NCBI) under the accession number "OP522284". Isolate Bacillus was identified as Bacillus subtilis strain AZ1EGY through 16S rRNA sequencing. In addition, the outcomes also revealed that the Bacillus subtilis strain AZ1EGY presented probiotic characteristics such as tolerance of acidic and bile salt, and as well tolerance of gastric and intestinal juice.

Keywords