GC-MS profile and antibacterial potency of thermophilic <em>Bacillus licheniformis</em> LMB3701 isolated from Dbagh hot spring in Algeria

Bacillus genus is known as an auspicious reservoir of active compounds with diversity in chemical structure. Although, thermophilic Bacillus and their antimicrobial compounds are little explored. Based on this, the objective of this work is to determine GC-MS profile and evaluate the antibacterial potency of a strain designated as LMB3701 isolated from water of Dbagh’s hot spring, Guelma, Northeast, Algeria. The LMB3701 strain was identified as B.licheniformis (Accession No.:KX100031) using 16S rRNA gene (98% of similarity). The ethyl acetate extract of thermophilic B.licheniformis showed an antibacterial activity against multidrug-resistant Staphylococcus aureus NR_075000.1 (6 mm ± 0 mm) and Pseudomonas aeruginosa NR_0754828.1 (8 mm ± 0.580 mm) using Radia Diffusion Assay. Five major groups [Polyphenolic macrocycle (34.087 %), Phenol (14.672 %), Stearic acid methyl ester (4.745 %), Fatty alcohol (4.082 %) and triterpene (1.177 %)] were identified using gas chromatography–mass spectrometry (GC-MS). To the best of our knowledge, this is the first report showing production of p-tert-butylcalix[4]arene and 2,4-di-tert-butylphenol as extremolytes compounds from thermophilic Bacillus licheniformis at 55 C.