156
O. M. Darwesh et al.
concentrations (Salama 2012; Sharma et al. 2012; Taha et al. 2016; Azeez et al.
2019a, b, 2020; Chhipa 2019; Hussein et al. 2019b). Some studies reported over
a 50% increase in plant growth (e.g., maize and tobacco) due to the application CuO and carbon nanotubes, respectively, as nanofertilizers (Adhikari et al.
2016; Khodakovskaya et al. 2012). Moreover, the importance of nanotechnology
for producing nanofertilizers in the agriculture rely not only on increasing the fertilization efficacy and bioavailability of such fertilizers but also on decreasing the
contaminating effect of these fertilizers on surrounding environment (Shebl et al.
2019).
With regard to macronutrients, nano phosphorus was synthesized by Aspergillius
tubingensis from tricalcium phosphate (Tarafdar et al. 2012). On the other hand,
synthesis of several nano-micronutrient including Zn, Fe, Mn, Mg, Co among others
that have vast application in agricultural sector (plant and/or animal production) is
mediated by different microorganisms (Sohair et al. 2018; Yusof et al. 2019). Raliya
et al. (2015) reported significant increase in plant vegetative parameters of mung bean
(shoot length (17.02%), root length (49.6%), root area (43%), root nodule (67.5%),
chlorophyll content (46.4%)) as well as total protein content (94%) when TiO 2 NPs
mediated by Aspergillus flavus TFR 7 were sprayed on leaves after 14 days of cultivation. In addition, their results revealed an increase in rhizosphere microbiome
(21.4–48.1%), acid and alkaline phosphatase (72 and 67.3%, respectively), phytase
(64%) and dehydrogenase (108.7%) compared to control owing to application of
TiO 2 NPs.
5.2 Microbial Nano-Pest Control Agents
Agricultural sustainability requires reducing the agricultural inputs including agrochemicals as well as preventing loss in production as a result of plant diseases. Thus,
searching for more safe alternatives for chemical pesticides gains more attention
through the last decades. Recently, nanoparticles have been introduced to the field of
pest control as an ecofriendly alternative to chemical pesticides (Masum et al. 2019;
Suman et al. 2013; Elshahawy et al. 2018). As reviewed by Ali et al. (2020), biologically mediated metallic NPs including Ag, Cu, Au and Zn displayed prevention
effect against both Gram (+) and (−) bacteria such as B. subtilis, E. coli and Staphylococcus aureus as well as some pathogenic fungi, e.g., A. niger, F. oxysporum, A.
fumigatus and other disease causing microbes. The green synthesis of silver NPs
through plants, bacteria, fungi or yeasts increased the attention toward it (Rafique
et al. 2017). In this respect, Ag-NPs mediated by Streptomyces showed great effect
to control well-known plant pathogenic fungi, e.g., Alternaria alternata, A. niger,
F. oxysporum and Pythium ultimum (Fouda et al. 2020). Also, a concentration of
200 µg/ml from AuNPs and Ag-AuNPs biosynthesized using cell-free extract of
Bacillus safensis LAU 13 has been reported to display 66.67–90.78% growth inhibitions against strains of A. fumigatus and A. niger, respectively (Ojo et al. 2016). While,
100 µg/mL of Ag-NPs synthesized by the cell-free extract of the same bacterial strain
O. M. Darwesh et al.
concentrations (Salama 2012; Sharma et al. 2012; Taha et al. 2016; Azeez et al.
2019a, b, 2020; Chhipa 2019; Hussein et al. 2019b). Some studies reported over
a 50% increase in plant growth (e.g., maize and tobacco) due to the application CuO and carbon nanotubes, respectively, as nanofertilizers (Adhikari et al.
2016; Khodakovskaya et al. 2012). Moreover, the importance of nanotechnology
for producing nanofertilizers in the agriculture rely not only on increasing the fertilization efficacy and bioavailability of such fertilizers but also on decreasing the
contaminating effect of these fertilizers on surrounding environment (Shebl et al.
2019).
With regard to macronutrients, nano phosphorus was synthesized by Aspergillius
tubingensis from tricalcium phosphate (Tarafdar et al. 2012). On the other hand,
synthesis of several nano-micronutrient including Zn, Fe, Mn, Mg, Co among others
that have vast application in agricultural sector (plant and/or animal production) is
mediated by different microorganisms (Sohair et al. 2018; Yusof et al. 2019). Raliya
et al. (2015) reported significant increase in plant vegetative parameters of mung bean
(shoot length (17.02%), root length (49.6%), root area (43%), root nodule (67.5%),
chlorophyll content (46.4%)) as well as total protein content (94%) when TiO 2 NPs
mediated by Aspergillus flavus TFR 7 were sprayed on leaves after 14 days of cultivation. In addition, their results revealed an increase in rhizosphere microbiome
(21.4–48.1%), acid and alkaline phosphatase (72 and 67.3%, respectively), phytase
(64%) and dehydrogenase (108.7%) compared to control owing to application of
TiO 2 NPs.
5.2 Microbial Nano-Pest Control Agents
Agricultural sustainability requires reducing the agricultural inputs including agrochemicals as well as preventing loss in production as a result of plant diseases. Thus,
searching for more safe alternatives for chemical pesticides gains more attention
through the last decades. Recently, nanoparticles have been introduced to the field of
pest control as an ecofriendly alternative to chemical pesticides (Masum et al. 2019;
Suman et al. 2013; Elshahawy et al. 2018). As reviewed by Ali et al. (2020), biologically mediated metallic NPs including Ag, Cu, Au and Zn displayed prevention
effect against both Gram (+) and (−) bacteria such as B. subtilis, E. coli and Staphylococcus aureus as well as some pathogenic fungi, e.g., A. niger, F. oxysporum, A.
fumigatus and other disease causing microbes. The green synthesis of silver NPs
through plants, bacteria, fungi or yeasts increased the attention toward it (Rafique
et al. 2017). In this respect, Ag-NPs mediated by Streptomyces showed great effect
to control well-known plant pathogenic fungi, e.g., Alternaria alternata, A. niger,
F. oxysporum and Pythium ultimum (Fouda et al. 2020). Also, a concentration of
200 µg/ml from AuNPs and Ag-AuNPs biosynthesized using cell-free extract of
Bacillus safensis LAU 13 has been reported to display 66.67–90.78% growth inhibitions against strains of A. fumigatus and A. niger, respectively (Ojo et al. 2016). While,
100 µg/mL of Ag-NPs synthesized by the cell-free extract of the same bacterial strain