Antimicrobial screening and molecular identification of active endophytic bacterial isolates from Ferula varia

Dorivor o‘simliklarning endofit bakteriyalari antimikrob metabolitlarning istiqbolli manbai hisoblanadi. Ushbu tadqiqotda Ferula varia o‘simligining endofit izolyatlari (ildiz, poya, barg va gullardan ajratilgan 40 dan ortiq izolyat) Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis va Candida albicans test-organizmlariga qarshi faolligi bo‘yicha baholandi. Olti izolyat antimikrob faollik namoyon qildi va 16S rRNA genini sekvenirlash asosida Bacillus pumilus, B. atrophaeus, B. rugosus va Serratia odorifera sifatida identifikatsiya qilindi; ketma-ketliklar NCBI GenBank ma‘lumotlar bazasiga kiritildi. Ushbu izolyatlardan to‘rttasi (FV1i, FV3i, FVP1.1 va FVB1) beshala test-organizmga qarshi faol bo‘lib chiqdi, shu bois ular biologik faol metabolitlarini keyingi o‘rganish uchun istiqbolli nomzodlar hisoblanadi.

FUNDAMENTAL VA AMALIY MIKROBIOLOGIYANING BUGUNGI HOLATI VA RIVOJLANISH ISTIQBOLLARI: YOSH OLIMLAR NIGOHI Respublika ilmiy-amaliy anjumani · Toshkent, 2026-yil 30-oktabr

I FUNDAMENTAL VA AMALIY MIKROBIOLOGIYA DOI 10.66073/ReFocus-Conf/3010016

ANTIMICROBIAL SCREENING AND MOLECULAR IDENTIFICATION OF ACTIVE ENDOPHYTIC BACTERIAL ISOLATES FROM FERULA VARIA Murodullayev Dilmurod Dilshodovicha, Alimova Dildora Farxod qizia, Temirova Marg‘ubab, Rayimberdiyeva Sanobarb, Absattorova Xursanoyb, & Rustamova Nigoraa* a Institute of Microbiology, Academy of Sciences of the Republic of Uzbekistan, Tashkent, Shaykhantakhur district, street Abdulla Kadiriy, 7 B, 100128, Uzbekistan b Qarshi davlat universiteti Abstract: Endophytic bacteria from medicinal plants are a promising source of antimicrobial metabolites, and this study evaluated the endophytic isolates of Ferula varia (more than 40 isolates from roots, stems, leaves, and flowers) against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Candida albicans. Six isolates showed antimicrobial activity and were identified by 16S rRNA gene sequencing as Bacillus pumilus, B. atrophaeus, B. rugosus, and Serratia odorifera, with the sequences deposited in NCBI GenBank. Four of these isolates (FV1i, FV3i, FVP1.1, and FVB1) were active against all five test organisms, making them promising candidates for further study of their bioactive metabolites. Keywords: Ferula varia, endophytic bacteria, antimicrobial activity, inhibition zone, 16S rRNA gene sequencing, molecular identification, antimicrobial metabolites. Introduction Endophytic bacteria are microorganisms that live within the internal tissues of plants, usually without causing disease symptoms in the host plant, and are regarded as a promising source of biologically active metabolites. Medicinal plants play an important role in studying the diversity of endophytic microorganisms and in the search for new antimicrobial agents. Studying the antimicrobial properties of endophytic bacteria associated with Ferula varia makes it possible to identify biotechnologically significant microorganisms. The aim of this study was to evaluate the antimicrobial activity of endophytic bacteria isolated from F. varia against selected bacterial and fungal test organisms and to identify the active isolates at the molecular level using 16S rRNA gene sequencing. Materials and Methods In the primary screening, more than 40 endophytic bacterial isolates obtained from the roots, stems, leaves, and flowers of F. varia were tested for antimicrobial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Candida albicans. Antimicrobial activity was determined by measuring the diameters of the growth inhibition zones of the test organisms. The active isolates were identified at the molecular level by 16S rRNA gene sequencing, and the resulting nucleotide sequences were analyzed to determine the taxonomic affiliation of the isolates. Results and Discussion Among the endophytic bacteria isolated from F. varia, isolates FV1i, FV3i, FV8i, FVP2, FVP1.1, and FVB1 exhibited antimicrobial activity against the test organisms (Table 1) and were selected for further studies.

FOR CITATION Murodullayev D., Alimova D., Temirova M., Rayimberdiyeva S. et al. Antimicrobial screening and molecular identification of active endophytic bacterial isolates from Ferula varia // Proceedings of the Republican Scientific and Practical Conference “Status and Development Prospects of Fundamental and Applied Microbiology: The Viewpoint of Young Scientists”. – Tashkent, 2026. – P. 74–76. DOI: https://doi.org/10.66073/ReFocus-Conf/3010016

Table 1. Antimicrobial activity of the isolates (diameter of the growth inhibition zone) Isolates S. aureus (mm) Ps. aeruginosa B. subtilis E. coli (mm) C. albicans (mm) (mm) (mm) FV1i 20 28 20 29 16 FV3i 21 29 26 33 16 FV8i − − − 12 − FVP2 − − 12 18 − FVP1.1 33 12 14 12 12 FVB1 27 14 18 28 14 The selected isolates were identified at the molecular level using the 16S rRNA gene marker. According to the identification results, five of the six selected isolates belonged to the genus Bacillus and one to the genus Serratia. The resulting nucleotide sequences were deposited in the NCBI GenBank database under the accession numbers listed in Table 2. Table 2. Results of the molecular identification of the isolates based on the 16S rRNA gene Isolated Strains Sequences Closest Match among Bacteria Deposited in GenBank (16S rRNA Genes) (GenBank) Strains Accession Species Source ID% Number FV1i PZ582851 Bacillus pumilus F. varia 100%

FV3i PZ583085 Bacillus F. varia 100% atrophaeus FV8i PZ583143 Bacillus F. varia 99,86% atrophaeus FVP2 PZ583123 Bacillus rugosus F. varia 99,38%

FVP1.1 PZ054243 Bacillus rugosus F. varia 99,86% FVB1 PZ331847 Serratia F. varia 99,93% odorifera Conclusion In this study, six active isolates of endophytic bacteria associated with F. varia were investigated with respect to their antimicrobial activity and molecular identification. The activity of the isolates against the test organisms E. coli, S. aureus, P. aeruginosa, B. subtilis, and C. albicans was evaluated, and 16S rRNA gene sequencing showed that five of them belonged to the genus Bacillus and one to the genus Serratia. These data provide a basis for the further characterization of these isolates, a more detailed investigation of their antimicrobial potential, and the identification of their biologically active metabolites.