Green synthesis of silver nanoparticles using fresh water green alga Pithophora oedogonia (Mont.) Wittrock and evaluation of their antibacterial activity

Abstract

In the present study, we report the aqueous extract of Pithophora oedogonia to produce silver nanoparticles (AgNPs) by reduction of silver nitrate. It was noted that synthesis process was considerably rapid and silver nanoparticles were generated within few minutes of silver ions coming in contact with the algal extract. A peak at 445 nm corresponding to the plasmon absorbance of AgNPs was noted in the UV-vis spectrum of the aqueous medium that contained silver ions. Scanning electron microscopic (SEM) and dynamic light scattering analysis of colloidal AgNPs indicated the size of 34.03 nm. Energydispersive X-ray spectroscopy revealed strong signals in the silver region and confirmed of the AgNPs. Fourier transform infrared spectroscopic analysis of the nanoparticles indicated the presence of protein which was regarding a capping agent surrounding the AgNPs. Moreover, the antibacterial activity of synthesized nanoparticles exhibited potential inhibitory activity against seven tested pathogenic bacteria.

Taxonomy and biodiversity of the genus Oscillatoria Vauch. ex Gom. (Cyanoprokaryota: Oscillatoriales) with ecological notes from Hooghly in West Bengal, India

“…8, fig. 8 & 10, 1992 (Biswas, 1925(Biswas, , 1927(Biswas, , 1949Banerji, 1938;Kachroo, 1959;Sinha and Mukherjee, 1975;Santra et al, 1988;Sen and Gupta, 1998;Sen and Naskar, 2003;Naskar et al, 2008;Chakraborty et al 2010;Sikdar and Keshri, 2014).…”

“…Indian distribution: Jammu and Kashmir, Himachal Pradesh, Uttarakhand, Punjab, Haryana, Rajasthan, Uttar Pradesh, Madhya Pradesh, Maharashtra, Gujarat, Chhattisgarh, Andhra Pradesh, Karnataka, Kerala, Tamil Nadu, Bihar, Orissa, Manipur, Meghalaya, Nagaland, Assam, (Gupta, 2012); West Bengal (Martens, 1871;Prain, 1905;Biswas, 1926;Kachroo, 1959;Gupta, 1987, 1998;Santra et al, 1988;Sen and Naskar, 2003;Naskar et al, 2008;Chakraborty et al 2010, Sen Sarkar et al, 2013Sikdar and Keshri, 2014).…”

“…They show variations in thallus organizations (unicellular, colonial to filamentous) and measurement of vegetative as well as reproductive structures due to response of changes in environmental conditions. They can thrive or adapt in adverse climatic conditions of any ecological ecosystems, being photosynthetic prokaryotes (Seal et al, 2015;Halder, 2016a) and possessing simple thallus structures. Oscillatoria Vauch.…”

“…Among them, AvaI is well known restriction enzyme from Anabeaena variabilis. Saravanan et al (2003) purified (through column chromatography) and characterized a new type II restriction endonuclease, OfoI from a nonheterocystous cyanobacterium Oscillatoria foreaui and the recognition sequence has been detected with the help of primer extension analysis. This enzyme recognizes and cleaves the palindromic hexanucleotide sequence 5'-C↓YCGRG-3' in DNA and producing 5'-protruding ends of defined sizes.…”

“…Abroad India, the commendable algological work of Komarek and Anagnostidis (2005) Biswas (1926Biswas ( , 1932, Santra (1985, 1987), Santra et al (1988), Gupta (1987, 1998) …”