Biosynthesis, characterization, and evaluation of antibacterial and photocatalytic dye degradation activities of silver nanoparticles biosynthesized by Chlorella sorokiniana

Chlorella minutissima-assisted silver nanoparticles synthesis and evaluation of its antibacterial activity

“…The change in color of the solution indicated the synthesis of Ag-NPs [ 23 , 35 , 36 ]. Similar results were shown for the synthesis of Ag-NPs using microalga Chlorella sorokiniana [ 16 ]. Factors such as pH of the solution, ratio of algal extract to precursor metal salt solution plays an important role in determining the morphology and stability of Ag-NPs.…”

“…C. minutissima culture was obtained from Centre for Conservation and Utilisation of Blue Green Algae, Indian Agricultural Research Institute (IARI), New Delhi-India. The culture of C. minutissima was inoculated at 10% ratio in five different growth media in 500 mL flask respectively, BG11: NaNO 3 (17.6 mM), CaCl 2 ·2H 2 O (0.24 mM), MgSO 4 ·7H 2 O (0.3 mM), K 2 HPO 4 (0.23 mM), Citric acid (0.031 mM), C 6 H 8 FeNO 7 -Ferric ammonium citrate (0.021 mM), Na 2 EDTA (0.0027 mM), Na 2 CO 3 (0.91 mM), Trace element solution (1 mL/L) [ 16 ], Zarrouk’s medium: NaHCO 3 (162 mM), Na 2 CO 3 (38 mM), K 2 HPO 4 (2.9 mM), NaNO 3 (29.4 mM), K 2 SO 4 (5.74 mM), NaCl (17.1 mM), MgSO 4 .7H 2 O (0.27 mM), CaCl 2 .2H 2 O (0.27 mM) [ 29 ], Bold’s basal medium (BBM): NaNO 3 (2.94 mM), CaCl 2 .2H 2 O (0.17 mM), MgSO 4 .7H 2 O (0.3 mM), K 2 HPO 4 (0.43 mM), KH 2 PO 4 (1.29 mM), NaCl (0.43 mM), Trace element solution [ 30 ], Bristol medium (SE Media): NaNO 3 (2.94 mM), CaCl 2 .2H 2 O (0.17 mM), MgSO 4 .7H 2 O (0.3 mM), KH 2 PO 4 (1.29 mM), NaCl (0.43 mM) [ 31 ] and Bold 3N medium: NaNO 3 (8.82 mM), CaCl 2 ·2H 2 O (0.17 mM), MgSO 4 ·7H 2 O (0.3 mM), K 2 HPO 4 (0.43 mM), KH 2 PO 4 (1.29 mM) and NaCl (0.43 mM) [ 32 ]. The inoculated medium was incubated in white light chamber with 12 h of illumination followed by 8 h of dark period.…”

“…In the present study, we have optimized a few parameters of synthesis such as pH of the solution and ratio of algal extract to precursor metal solution. The algal extract was incubated with 10 mM AgNO 3 [ 16 , 17 ] solution for biogenic-NP synthesis in the ratio of 1:10, 1:1 and 10:1. The pH of the solution was varied from 4–10.…”

“…Algal species have not received much focus but are promising candidates due to their limited requirement of nutrition, ability to grow on wastewater, limited space requirements and availability of a diverse variety of biomolecules which can act as capping and reducing agents. Several algae such as Caulepra , Bifurcaria , Chlamydomonas , Chlorella and Sargassum have been recently used for NPs synthesis for applications such as antimicrobial agents and for environmental remediation [ 15 , 16 , 17 ]. Algal mediated synthesis of NPs are obtained using following steps: (1) selection and identification of algal species, (2) harvesting algal biomass, (3) preparation of algal extract by boiling biomass in water or suitable solvent, (4) selection of suitable precursor metal salt solution, (5) preparation of molar salt solution, (6) incubation of algal extract and metal solution for certain period, at suitable temperature and pH [ 18 ].…”

“…Ag-NPs derived from Chlorella sp has been used as antimicrobial agents against Staphylococcus aureus, Escherichia. coli with zone of inhibition 15 mm and 20 mm respectively [ 16 ]. Ag-NPs prepared using methanol extract of A. millefolium demonstrated a zone of inhibition of 14.33 mm and 13.67 mm against S. aureus and Pseudomonas aeruginosa respectively [ 20 ].…”