Inactivation of fungal spores from clinical environment by silver bio-nanoparticles; optimization, artificial neural network model and mechanism

Efaq Noman; Adel Al-Gheethi; Radin Maya Saphira Radin Mohamed; Balkis Talip; Norzila Othman; Sohrab Hossain; Dai-Viet N Vo; Nayef Alduais

doi:10.1016/j.envres.2021.111926

Inactivation of fungal spores from clinical environment by silver bio-nanoparticles; optimization, artificial neural network model and mechanism

Environ Res. 2022 Mar;204(Pt A):111926. doi: 10.1016/j.envres.2021.111926. Epub 2021 Aug 28.

Authors

Efaq Noman¹, Adel Al-Gheethi², Radin Maya Saphira Radin Mohamed³, Balkis Talip⁴, Norzila Othman³, Sohrab Hossain⁵, Dai-Viet N Vo⁶, Nayef Alduais⁷

Affiliations

¹ Department of Applied Microbiology, Faculty of Applied Sciences, Taiz University, Taiz, Yemen; Faculty of Applied Sciences and Technology, Universiti Tun Hussein Onn Malaysia (UTHM), Pagoh Higher Education Hub, KM 1, Jalan Panchor, 84000, Panchor, Johor, Malaysia.
² Micro-Pollutant Research Centre (MPRC), Department of Water and Environmental Engineering, Faculty of Civil Engineering & Built Environment, Universiti Tun Hussein Onn Malaysia, 86400, Parit Raja, Batu Pahat, Johor, Malaysia. Electronic address: adel@uthm.edu.my.
³ Micro-Pollutant Research Centre (MPRC), Department of Water and Environmental Engineering, Faculty of Civil Engineering & Built Environment, Universiti Tun Hussein Onn Malaysia, 86400, Parit Raja, Batu Pahat, Johor, Malaysia.
⁴ Faculty of Applied Sciences and Technology, Universiti Tun Hussein Onn Malaysia (UTHM), Pagoh Higher Education Hub, KM 1, Jalan Panchor, 84000, Panchor, Johor, Malaysia. Electronic address: balkis@uthm.edu.my.
⁵ School of Industrial Technology, Universiti Sains Malayisa (USM), 11800, Penang Malaysia.
⁶ Center of Excellence for Green Energy and Environmental Nanomaterials (CE@GrEEN), Nguyen Tat Thanh University, 300A Nguyen Tat Thanh, District 4, Ho Chi Minh City, 755414, Viet Nam.
⁷ Faculty of Computer Science and Information Technology (FSKTM), Universiti Tun Hussein Onn Malaysia (UTHM), Parit Raja, Malaysia.

PMID: 34461120
DOI: 10.1016/j.envres.2021.111926

Abstract

The present study aimed to assess the efficiency of silver bio-nanoparticles (Ag-NPs) in inactivating of the Aspergillus fumigatus, A. parasiticus and A. flavus var. columnaris and A. aculeatus spores. The AgNPs were synthesized in secondary metabolic products of Penicillium pedernalens 604 EAN. The inactivation process was optimized by response surface methodology (RSM) as a function of Ag NPs volume (1-10 μL/mL); time (10-120 min); pH (5-8); initial fungal concentrations (log₁₀) (3-6). The artificial neural network (ANN) model was used to understand the behavior of spores for the factors affecting inactivation process. The best conditions to achieved SAL 10^-6 of the fungal spores were recorded with 3.46 μl/mL of AgNPs, after 120 min at pH 5 and with 6 log of initial fungal spore concentrations, at which 5.99 vs. 6.09 (SAL 10^-6) log reduction was recorded in actual and predicted results respectively with coefficient of 87.00%. The ANN revealed that the timehas major contribution in the inactivation process compare to Ag NPs volume. The fungal spores were totally inactivated (SAL 10^-6, 6 log reduction with 99.9999%) after 110 min of the inactivation process, 10 min more was required to insure the irreversible inactivation of the fungal spores. The absence of protease and cellulase enzymes production confirm the total inactivation of the fungal spores. FESEM analysis revealed that the AgNPs which penetrated the fungal spores leading to damage and deform the fungal spore morphology. The AFM analysis confirmed the total spore surface damage. The bands in the range of the Raman spectroscopy from 1300 to 1600 cm^-1 in the inactivated spores indicate the presence of CH_3, CH₂ and the deformation of lipids released outside the spore cytoplasm. These finding indicate that the AgNPs has high potential as a green alternative inactivation process for the airborne fungal spores.

Keywords: Aspergillus aculeatus: Inactivation; Chemical structure; Enzymes; Mechanism; Spore morphology.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Nanoparticles*
Neural Networks, Computer
Penicillium*
Silver
Spores, Fungal

Substances

Silver