Evaluation of the antibacterial effect of silver nanoparticles synthesized from the liquid cultivation of Trichoderma spp. Isolated from farming soil

Do Tan Khang; Tran Trung Vinh; Tran Thi Cam Lien; Nguyen Pham Anh Thi

Do Tan Khang, Tran Trung Vinh, Tran Thi Cam Lien, Nguyen Pham Anh Thi

Abstract: Silver nanoparticles (AgNPs) synthesized by the biological method are an inexpensive and straightforward approach that offers several advantages over physicochemical processes, particularly in terms of environmental friendliness. In this study, AgNPs were synthesized using the fungus Trichoderma virens (T. virens) isolated from farming soil. The fungal filtrate containing a silver ion-reducing agent reacted with a silver nitrate solution, resulting in the formation of AgNPs. The synthesis of nano silver is optimized for various factors, including AgNO3 concentration, the ratio of AgNO3 solution to fungal filtrate, pH level, and synthesis time. Optical properties, shape, and structure of the synthesized AgNPs were characterized using visual analysis, ultraviolet‐visible (UV‐Vis) spectroscopy, and scanning electron microscopy (SEM). The antibacterial activity of synthesized AgNPs against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Propionibacterium acnes (P. acnes) at concentrations of 100%, 75%, 50%, and 25% was investigated using the agar well diffusion method. The particle sizes of the synthesized AgNPs ranged from 70 to 100 nm. For the synthesis conditions, the optimized AgNO3 concentration, ratio VAgNO3/Vfungal filtrate, pH, and reaction time were 1.6 mM, 27.4%, 7.9, and 71.2 h, respectively. The AgNPs with a 100% concentration showed the highest antibacterial effect against Escherichia coli, Staphylococcus aureus, and Propionibacterium acnes, with the diameter of the inhibited zone being approximately 11.93 ± 0.24 mm, 8.83 ± 0.18 mm, and 6.67 ± 0.29 mm, respectively.

Keywords: antibacterial; nano silver; Propionibacterium acnes; Staphylococcus aureus; Trichoderma fungus

Citation: Khang, D. T., Vinh, T. T., Tran, L. Th. C., Tran, N. Q. & Nguyen, Ph. A. Th. (2025). Evaluation of the antibacterial effect of silver nanoparticles synthesized from the liquid cultivation of Trichoderma spp. Isolated from farming soil. Bulg. J. Agric. Sci., 31(5), 895–904

References: (click to open/close)

Berdy, J. (2005). Bioactive microbial metabolites. A personal view. The J. Antibiot., 58(1), 1 - 26.
Bui, L., Huynh, P., Luu, M. C. & Nguyen, N. T. (2021). Optimization of the lactic acid fermentation from tofu sour liquid and application in the production of antibacterial soap against Propionibacterium acnes PO. TNU Journal of Science and Technology, 226(10), 9 - 17.
Choi, O., Deng, K. K., Kim, N. J., Ross, L. Jr., Surampalli, R. Y. & Hu, Z. (2008). The inhibitory effects of silver nanoparticles, silver ions, and silver chloride colloids on microbial growth. Water Res., 42(12), 3066 - 3074. doi: 10.1016/j.watres.2008.02.021.
Elad, Y., Chet, I. & Henis, Y. (1982). Degradation of plant pathogenic fungi by Trichoderma harzianum. Can. J. Microbiol., 28(7), 719 - 725. doi: 10.1139/m82-110.
Li, W., Raoult, D. & Fournier, P-E. (2009). Bacterial strain typing in the genomic era. FEMS Microbiol. Rev., 33(5), 892 - 916.
Lok, C. N., Ho, C. M., Chen, R., He, Q. Y., Yu, W. Y., Sun, H., Tam, P. K., Chiu, J. F. & Che, C. M. (2006). Proteomic analysis of the mode of antibacterial action of silver nanoparticles. J. Proteome Res., 5(4), 916 - 924.
Loo, Y. Y., Rukayadil, Y., Nor−Khaizura, M. A. R., Kuan, C. H., Chieng, B. W., Nishibuchi M. & Radu, S. (2018). In vitro antimicrobial activity of green synthesized silver nanoparticles against selected gram-negative foodborne pathogens. Front. Microbiol., 9, 1555.
Morones, J. R., Elechiguerra, J. L., Camacho, A., Holt, K., Kouri, J. B., Ramírez, J. T. & Yacaman, M. J. (2005). The bactericidal effect of silver nanoparticles. Nanotechnology, 16(10), 2346 - 2353.
Ramage, G., Tunney, M. M., Patrick, S., Gorman, S. P. & Nixon, J. R. (2003). Formation of Propionibacterium acnes biofilms on orthopaedic biomaterials and their susceptibility to antimicrobials. Biomaterials, 24(19), 3221 - 3227.
Rifai, M. A. (1969) A revision of the genus Trichoderma. Mycol. Pap., 116, 1 - 56.
Saravanan, K., Anitha, M., Rajabairavi, N., Arivazhagan, P. & Jayakumar, S. (2019). Biosynthesis of silver nanoparticles from Trichoderma Harzianum and its impact on germination status of rice and brinjal. Int. J. Pharma Bio Sci., 9(1), 157 - 162.
Shelar, G. B. & Chavan, A. M. (2015). Myco-synthesis of silver nanoparticles from Trichoderma harzianum and its impact on germination status of oil seed. Biolife, 3(1), 109 - 113.
Shrivastava, S., Bera, T., Roy, A., Singh, G., Ramachandrarao, P. & Dash, D. (2007). Characterization of enhanced antibacterial effects of novel silver nanoparticles. Nanotechnology, 18(22), 22510.
Wang, X. J., Hayes, J. D., Henderson, C. J. & Wolf, C. R. (2007). Identification of retinoic acid as an inhibitor of transcription factor Nrf2 through activation of retinoic acid receptor alpha. PNAS USA, 104(49), 19589 - 19594.
Sangaonkar, G. M. & Pawar, K. D. (2018). Garcinia indica mediated biogenic synthesis of silver nanoparticles with antibacterial and antioxidant activities. Colloids and surfaces. B, Biointerfaces, 164, 210 - 217.
Shahzadi, S., Fatima, S., Ul Ain, Q., Shafiq, Z. & Janjua, M. R. S. A. (2025). A review on green synthesis of silver nanoparticles (SNPs) using plant extracts: a multifaceted approach in photocatalysis, environmental remediation, and biomedicine. RSC advances, 15(5), 3858 - 3903.

Date published: 2025-10-28

Download full text