Antibacterial screening of silver nanoparticles synthesized by marine micro algae

Objective:To explore the biosynthesis of silver nanoparticles synthesized by marine microalgae. Methods:Marine microalgae was collected from Central Marine Fisheries Research Institute (CMFRI,tuticorin) and cultured in the lab.Silver nanoparticles synthesis were observed in normal and microwave irradiated microalgae and screened against human pathogens for the presence of antimicrobials.Results:The presence of silver nanoparticle was confirmed by UV-Visible spectroscopy at 420 nm by the presence of plasmon peak.Further confirmation was done by scanning electron microscope(SEM).Conclusions:These results not only provide a base for further research but are useful for drug development in the present and future.

Comparative study on production,purification of penicillin by Penicillium chrysogenum isolated from soil and citrus samples

Objective:To explore various unexplored locations where Penicillium spp.would be available and study the production of penicillin from the isolated Penicillium spp.in different media with altered carbohydrate source.Methods:The collected soil samples were screened for the isolation of Penicillium chrysogenum(P.chrysogenum) by soil dilution plate.The isolated Penicillium species were further grown in different production media with changes in the carbohydrate source.The extracted penicillin from various isolates was analyzed by HPLC for the efficacy of the product.Further the products were screened with various bacterial species including methicillin resistant Staphylococcus aureus(MRSA).And the work was extended to find the possible action on MRSA,along with characterization using other pathogens.Results:From the various soil and citrus samples used for analysis,only the soil sample from Government General Hospital of Bangalore,India,and Sanjay Gandhi Hospital,Bangalore,India,showed some potential growth of the desired fungi P.chrysogenum.Different production media showed varied range of growth of PenicilUum.Optimum production of penicillin was obtained in maltose which proved maximum zone of inhibition during assay.Characterization of penicillin on pathogens,like wild Escherichia coli strain,Klebsiella spp.,and MRSA,gave quite interesting results such as no activity on the later strain as it is resistant.HPLC data provided the analytical and confirmation details of the penicillin produced.Accordingly,the penicillin produced from the soil sample of Government General Hospital had the high milli absorbance unit of 441.5 mAu compared with that of the penicillin produced from Sanjay Gandhi Hospital sample,8S.S2 mAu.Therefore,there was a considerable change in quantity of the penicillin produced from both the samples.Conclusions: The Penicillium spp.could be possibly rich in hospital contaminants and its environments.This research focuses on various unexplored sources of medical ailments,and also shows that the growth of penicillin is high in maltose rich media that could possibly enhance the growth.

Isolation and identification of MDR-Mycobacterium tuberculosis and screening of partially characterised antimycobacterial compounds from chosen marine micro algae

Objective:To isolate the multiple drug resistance(MDR) Mycobacterium tuberculosis(M. tuberculosis) and to screen for the bioactive compounds extracted from marine microalgae. Methods:Sixty seven collected samples that were confirmed by 16S rDNA analysis as positive with M.tuberculosis infection were subjected to sensitivity test against commercially used front line and second line drugs by absolute concentration method using LJ slants.Seven bacterial isolates numbered I-78,I-101,I-127,I-173,I-202,I-262,I-327 showed resistant for more than 3 drugs were considered as MDR M.tuberculosis.Thus the percentage of 10.4 were recorded MDR-TB. Fifteen marine micro algal extracts were screened for antimycobacterial activity and partial characterization of the active principles was done.Results:The percentage contribution of marine micro algal species on the extraction of antimycobacterials indicated Isochrysis galbana(I. galbana) contain rich bioactive compounds and accounted for 60%inhibition of the total isolates. The percentage contribution of solvents on the extraction of antimicrobials from I.galbana showed that the methanol,chloroform,n-Butanol showed maximum of extraction.The purified eluted compounds(R,0.43) from TLC plate were chromatographed by gas chromatography.The eluted sterol compounds showed 13 unsaturated sterols with 3 major sterols.Conclusions:The present study indicates the presence of unsaturated fatty acids may have the effect on MDR M. tuberculosis,indicating a potential natural alternative to antibiotics.

Anticancer and Antimicrobial Activity of Aspergillus protuberus SP1 Isolated from Marine Sediments of South Indian Coast

AIM:To explore the antimicrobial and anticancer activity of the fungi isolated from marine sediments of south India coastal belt.METHODS:Marine sediments were collected from different coastal locations of Kanyakumari District,South India.Aseptically collected marine sediment samples were serially diluted and cultured using SDA media with seawater under appropriate culture conditions.Antimicrobial activity was confirmed by crowded plate techniques.Antimicrobial activity of marine fungi isolate was evaluated against six human pathogenic bacteria viz.,Enterobacter aerogenes.,Escherichia coli,Proteus mirabilis,Bacillus subtilis,Staphylococcus aureus,and Klebsiella pneumoniae.,with different solvents like n-butanol,chloroform,water and acetone.Anticancer activity of the selective fungal extracts was tested against Hep 2 cells using MTT assay.RESULTS:Fungus isolated from Muttom coast of south India showed activity against human pathogens.The fungi isolate Aspergillus protuberus SP1 was identified by partial sequence of large subunit ribosomal RNA(GenBank accession No.:HQ 386016).Different polar and non-polar solvent extracts of the marine-derived fungus isolate showed antibacterial activity towards various Gram-positive and Gram-negative human pathogens.The n-butanol extract of mycelium showed maximum inhibition.Based on antibacterial activity,the n-butanol extract was selected for anticancer test against Hep 2 cell line.The n-butanol extract was subjected to column chromatographic separation using different solvent compositions with ethanol:methanol(9:1) giving better sepeartion.The fraction was analyzed by GC-MS study showing the presence of nine compounds.CONCLUSION:These results are useful for further investigation of the fungus in the future.

In vitro cytotoxicity and antimicrobial activity of Talaromyces flavus SP5 inhabited in the marine sediment of Southern Coast of India

Marine sediment samples were collected from the coastal areas of Southern India, particularly in Kanyakumari District. Twenty-eight different fungal strains were isolated. The screening of fungi from marine sediment was done to isolate a potent fungus that can produce bioactive compounds for biomedical applications. Only three strains viz Trichoderma gamsii SP4, Talaromyces flavus SP5 and Aspergillus oryzae SP6 were screened for further studies. The intracellular bioactive compounds were extracted using solvent extraction method. The crude extracts were tested for its anti-microbial and anti-cancer properties and analytically characterized using Gas Chromatography Mass Spectrometry(GC-MS). All the three extracts were active, but the extract from T. flavus SP5 was found to be more active against various human pathogens, viz., Pseudomonas aeruginosa ATCC 27853(17.8 ± 0.1), Escherichia coli ATCC 52922(18.3 ± 0.3), and Candida tropicalis ATCC 750(17.7 ± 0.4). It also exhibited cytotoxic activity against HEp2 carcinoma cell line with the LC_(50) value of 25.7 μg·mL^(-1). The GC-MS data revealed the presence of effective bioactive compounds. These results revealed that the extract from isolated fungus T. flavus SP5 acted as a potent antimicrobial, antifungal, and anticancer agent, providing basic information on the potency of marine fungi towards biomedical applications; further investigation may lead to the development of novel anticancer drugs.

A multi coding technique to reduce transition activity in VLSI circuits

Advances in VLSI technology have enabled the implementation of complex digital circuits in a single chip, reducing system size and power consumption. In deep submicron low power CMOS VLSI design, the main cause of energy dissipation is charging and discharging of internal node capacitances due to transition activity. Transition activity is one of the major factors that also affect the dynamic power dissipation. This paper proposes power reduction analyzed through algorithm and logic circuit levels. In algorithm level the key aspect of reducing power dissipation is by minimizing transition activity and is achieved by introducing a data coding technique. So a novel multi coding technique is introduced to improve the efficiency of transition activity up to 52.3% on the bus lines, which will automatically reduce the dynamic power dissipation. In addition, 1 bit full adders are introduced in the Hamming distance estimator block, which reduces the device count. This coding method is implemented using Verilog HDL. The overall performance is analyzed by using Modelsim and Xilinx Tools. In total 38.2% power saving capability is achieved compared to other existing methods.