scholarly journals The Effects of Silicon Dioxide Nanoparticles and Zinc Oxide Nanoparticles on Waste Land soil Bacterial and Fungal Isolates

Author(s):  
P. Jayashree Lakshmi ◽  
K. Vanmathi Selvi

Objective: Different bacterial and fungal isolates were collected from the wasteland municipality site, Tambaram. The antimicrobial activity of two types of nanoparticles ZnO & SiO2 [Zinc oxide and Silicon dioxide] against several types of Gram-negative bacteria and fungi was investigated in this work. Methods: P. aeruginosa, B. subtilis, Penicillium oxalicum and Aspergillus fumigatus were isolated from 5 soil samples taken from three sites of Tambaram Municipality wasteland (Chennai). After collecting the samples, we used culturing and biochemical tests to identify the microbes and then used a chemical approach to make ZnO and SiO2 nanoparticles with altered structure and morphological features. Minimum inhibitory concentration (MIC) was used to assess the antibacterial activity of these nanoparticles against various microorganisms. Results: The best inhibition zone was found in Pseudomonas sps and Bacillus sps growth at concentrations of 10 µg/ml and 5 µg /ml of nano-ZnO, respectively, whereas the lower inhibition zone was found in Penicillium oxalicum and Aspergillus fumigatus at a dosage of 2.5 µg /ml of the same nanoparticle. It was also discovered that no inhibitory zone existed in any of the bacteria and fungi at a concentration of 10 µg /ml nano-SiO2. We found that all of the bacteria and  fungi we tested were completely inhibited at a concentration of 1.25 g/ml nano-ZnO (MIC), with no antibacterial activity below this concentration. When compared to data that showed that all tested bacteria were not completely inhibited even at a concentration of 0.625 g/ml of nano-SiO2. Conclusion: In comparison to the two nanoparticles (ZnO and SiO2), nano-ZnO outperformed nano-SiO2 in inhibiting most bacteria and fungi at the quantities tested in wasteland soil.

2014 ◽  
Vol 597 ◽  
pp. 45-48
Author(s):  
Qun Li ◽  
Xi Hui Zhao ◽  
Xiao Wen Li ◽  
Li Ping Wang ◽  
Qian Qian Liu ◽  
...  

Zinc oxalate dihydrate as the precursor of anometer zinc oxide (nano-ZnO) was prepared by direct precipitation method. The zinc oxalate dihydrate was dispersed in a silver nitrate solution, and then the resulting solution was filtered and dried under 120°C. The silver doping nano-Zinc oxide (nano-SDZO) was obtained by decrepitating the zinc oxalate dihydrate cake under 500°C. The microstructure of nano-ZnO and nano-SDZO were characterized by TEM, and the chemical reaction in the heat burst process was described. The nano-ZnO particles were 50-60 nm in diameter, and the particle size of nano-SDZO in the range of 20-100 nm. Antibacterial activity of the nano-ZnO and nano-SDZO were compared. The results show that all of the ZnO samples inhibited the growth of S. aureus and E. coli, and nano-SDZO showed a relatively higher inhibition rate than other samples. Two possible mechanisms were proposed to explain the inhibition of bacteria.


2020 ◽  
Vol 11 (SPL4) ◽  
pp. 3104-3110
Author(s):  
Keerthy Reghunandanan ◽  
Aleena Jolly ◽  
Manjusha P V ◽  
Kavitha M

This study was aimed to isolate the endophytic bacteria and fungi from the fruit and root of Musa Paradisiaca, commonly called as Nendran banana cultivar in the southern Indian state of Kerala. Endophytes are microbes living in plant tissue without harming the plants rather existing as potential beneficial organisms. Musa paradisiaca is a less explored variety of banana cultivar which possess anti-disease potential apart from nutritional quality. The total number of twelve root and fruit associated endophytes were isolated. The fruit associated endophytes were seven with four bacterial isolates and three fungal isolates. The number of root-associated endophytes were five with three bacterial isolates and two fungal isolates. The morphological characterisation of both root and fruit endophytes were performed by Gram staining for bacteria and lacto-phenol cotton blue staining for fungi. The bacterial colony examination of the fruit associated culture revealed a specific pink strain with an inhibitory zone proving antibacterial activity which was further investigated through agar well diffusion test.  The strain exhibited potential antibacterial activity against five human clinical pathogens. A significant zone of inhibition was observed against Bacillus subtilis  (22 mm), Escherichia coli (21 mm), Klebsiella pneumonia  and Pseudomonas aeruginosa (18 mm) which confirmed the potential antibacterial property of the fruit endophytic strain.


Author(s):  
Hams H. H. Alfattli ◽  
Ghufran Zuhair Jiber ◽  
Ghaidaa Gatea Abbass

This study which designed to evaluate the inhibitory effect of Ethanolic extract of (Quercusrobur) and Zinc oxide nanoparticles on the growth of one genus of enterobacteriacae (Salmonella). In vitro. For this purpose graduate concentrates for plant extract (50, 100, 200, 400 )mg/ml which prepared and compared with Zinc oxide nanoparticles of different concentration (2, 1, 0.5, 0.25) μg/ml,and examined. The result showed that the studied medicinal plant has antibacterial activity against this bacteria which used. The result showed that the plant has good activity in decrease the growth of this bacteria. The results of the study also showed that the nano-ZnO has very effective antibacterial action against the studied bacteria which was Salmonella,nanoparticles concentrations lead to increasing in the inhibition zones of tested bacterial growth. We also study the effect of three antibiotics Lomefloxacin (LOM), Ciprofloxacin (SIP) and Rifampin (RA) and the result showed,in a comparison within the tested bacteria,Salmonella had a significant inhibition increase in Lomefloxacin ; the ciprofloxacin showed effect on tested bacteria. However,Rifampin does not show any effect on tested bacteria.


Author(s):  
Eric Kwabena Droepenu ◽  
Ebenezer Aquisman Asare ◽  
Boon Siong Wee ◽  
Rafeah Binti Wahi ◽  
Frederick Ayertey ◽  
...  

Abstract Background Various parts of Anacardium occidentale plant possess curative qualities like antidiabetic, anti-inflammatory, antibacterial, antifungal, and antioxidant. Aqueous extract of this plant leaf was used in biosynthesizing zinc oxide (ZnO) nanoaggregates using two precursors of zinc salt (zinc acetate dihydrate [Zn(CH3COO)2∙2H2O] and zinc chloride [ZnCl2]). The synthesized ZnO samples were used in a comparative study to investigate the antibacterial activity against selected Gram-positive and Gram-negative microbes [Staphylococcus aureus, Exiguobacterium aquaticum (Gram +ve) and Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii (Gram −ve)]. The synthesized ZnO nanoaggregates from the two precursors were characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive x-ray spectroscopy (EDX) techniques. Results Micrographs of SEM and TEM confirmed nanoparticles agglomerated into aggregates. While spherical nanoaggregates were identified in samples prepared from Zn(CH3COO)2∙2H2O, flake-like structures were identified in samples synthesized from ZnCl2. Particle size determined by TEM was 107.03 ± 1.54 nm and 206.58 ± 1.86 nm for zinc acetate dihydrate and zinc chloride precursors respectively. ZnO nanoaggregate synthesized using zinc acetate as precursor gave higher antibacterial activity than its counterpart, zinc chloride with K. pneumonia recording the highest inhibition zone of 2.08 ± 0.03 mm (67.53%) whereas S. aureus recorded the least inhibition zone of 1.06 ± 0.14 mm (34.75%) for ZnO nanoaggregate from zinc chloride precursor. Also, antibacterial activity increases with increasing concentration of the extract in general. However, A. baumannii, E. aquaticum, and K. pneumoniae did not follow the continuity trend with regards to the 250 ppm and 500 ppm concentrations. Conclusion Biosynthesis of ZnO nanoaggregates using aqueous extract of A. occidentale leaf from zinc acetate dihydrate and zinc chloride as precursors was successful with the formation of nanospheres and nanoflakes. The study suggested that A. occidentale sp. could be an alternative source for the production of ZnO nanoparticles and are efficient antibacterial compounds against both Gram +ve and Gram −ve microbes with its promising effect against infectious bacteria.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1111
Author(s):  
Changmei Lin ◽  
Duo Chen ◽  
Zifeng Hua ◽  
Jun Wang ◽  
Shilin Cao ◽  
...  

Cellulose paper has been functionalized by nanoparticles such as Ag nanoparticles, TiO2, and BaTiO3 for versatile applications including supercapacitor, sensors, photoactivity, and packaging. Herein, zinc oxide (ZnO) nanosheet-modified paper (ZnO@paper) with excellent antibacterial properties was fabricated via a mild ZnCl2-urea eutectic solvent. In this proposed method, cellulose fibers as the raw material for ZnO@paper were treated by an aqueous solvent of ZnCl2-urea; the crystalline region was destroyed and [ZnCl]+-based cations were adsorbed on the surface of cellulose fibers, facilitating more ZnO growth on ZnO@paper. A flexible paper-based triboelectric nanogenerator (P-TENG) was made of ZnO@paper paired with a PTFE film. The P-TENG presents high triboelectric output performance and antibacterial activity. For instance, the output voltage and current of the P-TENG were 77 V and 0.17 μA, respectively. ZnO@paper showed excellent antibacterial activity against E. coli and S. aureus, suggesting that a P-TENG can restrain and kill the bacteria during the working process. The results also indicated that ZnO could improve the surface roughness of cellulose paper, enhancing the output performance of a flexible P-TENG. In addition, the potential application of a P-TENG-based pressure sensor for determining human motion information was also reported. This study not only produced a high-performance P-TENG for fabricating green and sustainable electronics, but also provides an effective and novel method for ZnO@paper preparation.


2021 ◽  
Vol 17 ◽  
Author(s):  
Bambang Susilo ◽  
Abd. Rohim ◽  
Midia Lestari W. H.

Background: S. cristaefolium is the brown seaweed extracted using the serial technique with different solvents. Methods: S. cristaefolium powder (50 mesh) was extracted with hexane, ethyl acetate, and methanol respectively. The S. cristaefolium powder residue had been dried before being re-extracted with the next different solvents. Three serial extracts were obtained and named as the 1-stage extract, 2-stage extract, and 3-stage extract. Besides, a single-step extract (extraction using only methanol) was also produced to compare with three serial extracts in antibacterial activity tests (against E. coli and S. aureus). The three serial extracts were detected their antibacterial compounds using GC-MS, LC-HRMS, and FT-IR. Results: The 3-stage extract had the highest extraction yield. On S. aureus, the inhibition zone in all extracts was not significantly different. On E.coli, the highest inhibition zone (5.42±0.14 mm) was the 3-stage extract, indeed it is higher than both antibiotic and a single-step extract. Phenol, 9-Tricosene(Z)-, palmitic acid, and oleamide were contained in all extracts. Other antibacterial compound types, both the 1-stage and 2-stage extracts contained 8 types whilst the 3-stage extract contained the most types (12 types). Particularly, hexyl cinnamic aldehyde and betaine were detected only in the 3-stage extract with the dominant area. The carboxylic acid groups were detected in all extracts to confirm the fatty acid structure. Several cinnamic aldehyde groups were detected only in the 3-stage extract. Conclusions: Thus, the extraction technique serially could produce the 3-stage extract which has the strongest antibacterial activity and the richest antibacterial compounds.


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