Research Article

Comprehensive Characterization of Janthinobacterium kumbetense sp. nov. (GKT): Industrial Enzyme Production, Antimicrobial Resistance and Optimization of Violacein Production with Its Bioactive Properties

Volume: 54 Number: 2 March 31, 2026
EN TR

Comprehensive Characterization of Janthinobacterium kumbetense sp. nov. (GKT): Industrial Enzyme Production, Antimicrobial Resistance and Optimization of Violacein Production with Its Bioactive Properties

Abstract

In this study, we aimed to screen for Janthinobacterium kumbetense GKT strain production of industrially important enzymes and to assess its antimicrobial resistance profile. Additionally, to enhance violacein production by GKT strain, we investigated the optimum cultivation conditions for this bacterium and the biological properties of crude violacein extract, including its antimicrobial and antioxidant activities. The GKT strain demonstrated proteolytic, lipolytic, and chitinolytic activities. Furthermore, the antibiotic susceptibility test showed that it was resistant to 5 out of the 15 antibiotics tested. Subsequently, the effects of different growth media, temperatures, pH levels, agitation rates, inoculum amounts, incubation times, carbon and nitrogen sources, and NaCl concentrations on violacein production by the GKT strain were examined. The maximum violacein yield of 28.7 μg/ml was achieved when the strain was incubated at 22°C for 72 hours under static conditions in nutrient broth with a pH of 6.4. Also, violacein yield increased with the addition of 1% pepton and 1% glucose as nitrogen and carbon sources, respectively. Violacein pigment, extracted using either methanol or ethanol, was found to inhibit the growth of S. aureus, S. epidermidis, B. cereus and E. faecalis. However, no-activity was seen on tested fungus strains. Additionally, violacein showed antioxidant activity against ABTS and DPPH radicals with IC50 values of 307 μg/ml and 261 μg/ml, respectively. Current research findings suggest that violacein pigment of GKT strain has potent antimicrobial and antioxidant activities and can be used in applications in the pharmaceutical industry.

Keywords

Thanks

The authors gratefully acknowledge Prof. Dr. Berna Tunali (Department of Plant Protection, Faculty of Agriculture, Ondokuz Mayıs University) and Hatice Karadeniz (Giresun Food Control Laboratory) for providing the fungal isolates used in this study.

References

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Details

Primary Language

English

Subjects

Biochemistry and Cell Biology (Other)

Journal Section

Research Article

Publication Date

March 31, 2026

Submission Date

July 31, 2025

Acceptance Date

February 9, 2026

Published in Issue

Year 2026 Volume: 54 Number: 2

APA
Karaca, B., Nalcacioglu, R., & Katı, H. (2026). Comprehensive Characterization of Janthinobacterium kumbetense sp. nov. (GKT): Industrial Enzyme Production, Antimicrobial Resistance and Optimization of Violacein Production with Its Bioactive Properties. Hacettepe Journal of Biology and Chemistry, 54(2), 109-121. https://doi.org/10.15671/hjbc.1754147
AMA
1.Karaca B, Nalcacioglu R, Katı H. Comprehensive Characterization of Janthinobacterium kumbetense sp. nov. (GKT): Industrial Enzyme Production, Antimicrobial Resistance and Optimization of Violacein Production with Its Bioactive Properties. HJBC. 2026;54(2):109-121. doi:10.15671/hjbc.1754147
Chicago
Karaca, Burak, Remziye Nalcacioglu, and Hatice Katı. 2026. “Comprehensive Characterization of Janthinobacterium Kumbetense Sp. Nov. (GKT): Industrial Enzyme Production, Antimicrobial Resistance and Optimization of Violacein Production With Its Bioactive Properties”. Hacettepe Journal of Biology and Chemistry 54 (2): 109-21. https://doi.org/10.15671/hjbc.1754147.
EndNote
Karaca B, Nalcacioglu R, Katı H (March 1, 2026) Comprehensive Characterization of Janthinobacterium kumbetense sp. nov. (GKT): Industrial Enzyme Production, Antimicrobial Resistance and Optimization of Violacein Production with Its Bioactive Properties. Hacettepe Journal of Biology and Chemistry 54 2 109–121.
IEEE
[1]B. Karaca, R. Nalcacioglu, and H. Katı, “Comprehensive Characterization of Janthinobacterium kumbetense sp. nov. (GKT): Industrial Enzyme Production, Antimicrobial Resistance and Optimization of Violacein Production with Its Bioactive Properties”, HJBC, vol. 54, no. 2, pp. 109–121, Mar. 2026, doi: 10.15671/hjbc.1754147.
ISNAD
Karaca, Burak - Nalcacioglu, Remziye - Katı, Hatice. “Comprehensive Characterization of Janthinobacterium Kumbetense Sp. Nov. (GKT): Industrial Enzyme Production, Antimicrobial Resistance and Optimization of Violacein Production With Its Bioactive Properties”. Hacettepe Journal of Biology and Chemistry 54/2 (March 1, 2026): 109-121. https://doi.org/10.15671/hjbc.1754147.
JAMA
1.Karaca B, Nalcacioglu R, Katı H. Comprehensive Characterization of Janthinobacterium kumbetense sp. nov. (GKT): Industrial Enzyme Production, Antimicrobial Resistance and Optimization of Violacein Production with Its Bioactive Properties. HJBC. 2026;54:109–121.
MLA
Karaca, Burak, et al. “Comprehensive Characterization of Janthinobacterium Kumbetense Sp. Nov. (GKT): Industrial Enzyme Production, Antimicrobial Resistance and Optimization of Violacein Production With Its Bioactive Properties”. Hacettepe Journal of Biology and Chemistry, vol. 54, no. 2, Mar. 2026, pp. 109-21, doi:10.15671/hjbc.1754147.
Vancouver
1.Burak Karaca, Remziye Nalcacioglu, Hatice Katı. Comprehensive Characterization of Janthinobacterium kumbetense sp. nov. (GKT): Industrial Enzyme Production, Antimicrobial Resistance and Optimization of Violacein Production with Its Bioactive Properties. HJBC. 2026 Mar. 1;54(2):109-21. doi:10.15671/hjbc.1754147

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