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Assam Agricultural University, Jorhat

Assam Agricultural University is the first institution of its kind in the whole of North-Eastern Region of India. The main goal of this institution is to produce globally competitive human resources in farm sectorand to carry out research in both conventional and frontier areas for production optimization as well as to disseminate the generated technologies as public good for benefitting the food growers/produces and traders involved in the sector while emphasizing on sustainability, equity and overall food security at household level. Genesis of AAU - The embryo of the agricultural research in the state of Assam was formed as early as 1897 with the establishment of the Upper Shillong Experimental Farm (now in Meghalaya) just after about a decade of creation of the agricultural department in 1882. However, the seeds of agricultural research in today’s Assam were sown in the dawn of the twentieth century with the establishment of two Rice Experimental Stations, one at Karimganj in Barak valley in 1913 and the other at Titabor in Brahmaputra valley in 1923. Subsequent to these research stations, a number of research stations were established to conduct research on important crops, more specifically, jute, pulses, oilseeds etc. The Assam Agricultural University was established on April 1, 1969 under The Assam Agricultural University Act, 1968’ with the mandate of imparting farm education, conduct research in agriculture and allied sciences and to effectively disseminate technologies so generated. Before establishment of the University, there were altogether 17 research schemes/projects in the state under the Department of Agriculture. By July 1973, all the research projects and 10 experimental farms were transferred by the Government of Assam to the AAU which already inherited the College of Agriculture and its farm at Barbheta, Jorhat and College of Veterinary Sciences at Khanapara, Guwahati. Subsequently, College of Community Science at Jorhat (1969), College of Fisheries at Raha (1988), Biswanath College of Agriculture at Biswanath Chariali (1988) and Lakhimpur College of Veterinary Science at Joyhing, North Lakhimpur (1988) were established. Presently, the University has three more colleges under its jurisdiction, viz., Sarat Chandra Singha College of Agriculture, Chapar, College of Horticulture, Nalbari & College of Sericulture, Titabar. Similarly, few more regional research stations at Shillongani, Diphu, Gossaigaon, Lakhimpur; and commodity research stations at Kahikuchi, Buralikson, Tinsukia, Kharua, Burnihat and Mandira were added to generate location and crop specific agricultural production packages.

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Subject: Animal Biochemistry × End date: 2017 × Start date: 2016 × Thesis Type: M.V.Sc. ×
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    ThesisItemOpen Access
    GREEN SYNTHESIS & CHARACTERISATION OF SILVER NANOPARTICLES AND ASSESSMENT OF ITS ANTIOXIDANT & ANTIMICROBIAL ACTIVITY
    (College of Veterinary Science, Assam Agricultural University Khanapara, Guwahati-781022, 2017-07) Deka, Naba Jyoti; Nath, Rita
    The present study was undertaken to green synthesis of silver nanoparticles using leaves of Neem (Azadirachta indica) and Tulsi (Ocimum tenuiflorum) and to evaluate their antimicrobial & in-vitro antioxidant activities. The plants Neem (Azadirachta indica) and Black Tulsi (Ocimum tenuiflorum) were procured from different nearby places of Guwahati, Kamrup (metro) district, Assam. The dried leaves were pulverized and methanolic and aqueous extracts were prepared. The preliminary qualitative hytochemical analysis of Neem (Azadirachta indica) and Tulsi (Ocimum tenuiflorum) leaves showed the presence of steroid, phenol, tannin, saponin, flavonoid, alkaloid and triterpenes. The mean ± SE of total phenol of Neem and Tulsi were 0.019 ± 0.001 and 0.022 ±0.002 (mg/ml) respectively with no significant difference (P>0.05) between the two plants. The tannin content of Neem and Tulsi were 0.61 ± 0.010 and 0.580 ± 0.000 (mg/ml), flavonoid content were 0.34 ± 0.010 and 0.240 ± 0.010 (%) alkaloid content were 2.67 ± 0.010 and 2.030 ± 0.020 (%) and saponin content were 0.52 ± 0.01 and 0.410 ± 0.01 (%) respectively. Neem showed a significantly (P<0.05) higher concentration of flavonoid, alkaloid and saponin. Though tannin content was higher in Neem than Tulsi but it was found non-significant (P>0.05). The formation of silver nanoparticles were confirmed by the colour change followed by UV-Vis spectrophotometer analysis. The zeta potential measurement of the nanoparticles using Neem and Tulsi leaf extract were found to be -48.9 mV and -18.4 mV respectively. The synthesized nanoparticle were found to be almost spherical in shape in SEM images in both cases. The synthesized nanoparticles showed sensitive response against both gram positive (Staphylococcus aureus) and gram negative bacteria (Escherichia coli) which indicates that it has antimicrobial activity. The antioxidant activity of the methanolic extract, aqueous extract and silver nanoparticles from both Neem and Tulsi were evaluated by using four different standard methods. In DPPH antioxidant assay, the aggregate percent inhibition of aqueous, methanolic and silver nanoparticle of Neem leaf extract was 80.57±0.74, 63.55±0.34 and 85.16±1.44 while that of Tulsi was 68.28±0.59, 67.42±0.26 and 77.12±0.58 respectively. In nitric oxide radical assay ,The percent inhibition of nitric oxide of AgNPs of Neem extract at 50, 80 and 110 ug/ml were 73.29±0.22, 74.32±0.13 and 75.46±0.22 and of Tulsi were 12.61±0.15, 14.67±0.07 and 16.37±0.05 respectively . The aggregate value of super oxide radical scavenging activity of methanolic extract of Neem and Tulsi at different concentration were from 58.04±1.74 and 54.60±1.15 respectively and that of aqueous extract were 72.08±2.04 and 68.98±1.29 respectively .Again, in reductive ability evaluation, both aqueous and methanolic extracts of Neem and Tulsi showed higher reducing power than the standard Butylated hydroxytoluenme .Though silver nanoparticles of both the plants showed reducing power but it was found to be weaker than the standard . It may be concluded that AgNPs derived from Azadirachta indica (Neem) is richer in phytochemicals, antioxidant property and antibacterial activity than AgNPs derived from Ocimum tenuiflorum and can be further exploited for their medicinal and industrial properties.