Asian Journal of Biotechnology
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Open Access journal
ISSN (Print) 1996-0700
Published by Science Alert [64 journals]
- Biochemical and Molecular Characterization of Cell Wall Degrading Enzyme,
Pectin Methylesterase Versus Banana Ripening: An Overview
Abstract: Ripening of fruit is very important process but in some fruits, early ripening leads to a great damage during long distance transportation. There are various biochemical changes taking place during ripening such as changes in respiration, aroma, flavor, ethylene production and activity of cell wall degrading enzymes. Pectin methylesterase is one of the cell wall degrading enzymes, which acts on pectin, (a primary cell wall constituent) and releases methanol and hydrogen ions. The present compilation includes the studies on biochemical and molecular characterization of pectin methylesterase from Musa acuminata (banana). This study also deals with the in silico study reflecting inhibition of enzyme activity in context to delayed ripening in banana. It mainly deals with the identification of a PME1 gene from Grand nain variety of banana, the expression of which is related to the process of ripening. Using cross species analysis, researchers found that banana has maximum homology with carrot. The validation and verification of the designed model has been performed and found to be of good quality and further used for docking studies. Docking results suggested that green tea catechin and salicin were the best inhibitors having good interaction energies which bind at third motif, Asp381 residue on active site of PME in Musa acuminata. It was found that green tea catechin was better than salicin probably because of being a natural inhibitor, antioxidant and thus inhibiting the activity of PME. Salicin is a chemical compound that inhibits ripening at some specific concentrations only, although the binding energies of both the inhibitors have been monitored to be approximately same. The information of binding sites of ligand provides new insights into the predictable functioning of relevant protein.
PubDate: 16 February, 2017
- Antioxidant Potential of Penicillium expansum and Purification of its
Abstract: Background: Fungi are the good source of various biological active secondary metabolites. Materials and Methods: The antioxidant potential of Penicillium expansum isolated from soil of Punjab, India was studied and a three-step optimization strategy which includes, one-factor-at-a-time classical method and different statistical approaches (Plackett-Burman design and response surface methodology) were applied to enhance the antioxidant potential. Antioxidant activity was assayed by different procedures and compared with total phenolic content. Results: Primarily, different carbon and nitrogen sources were screened by classical methods, which revealed sucrose as carbon source is most suitable for antioxidant activity. Sodium nitrate, yeast extract and peptone were good sources of nitrogen but sodium nitrate was the best among them. Significance of the components of Czapek doxs medium with respect to antioxidant activity was evaluated with Plackett-Burman design, which supported sucrose and NaNO3 to be the most significant. In second step, sucrose and NaNO3 along with temperature were taken as three variables for response surface methodology to study their interaction. Response surface analysis showed significant enhancement in the antioxidant potential of Penicillium expansum. A compound was purified from the ethyl acetate extract which demonstrated potent antioxidant activity. Conclusion: The present study demonstrated potential of soil fungi to have antioxidant activity similar to plants and mushrooms thus further highlighting their significance as new sources of natural antioxidants and thus endorse the future prospects for the commercial production of natural and safer antioxidant compounds from such fungi. The fungi may provide easier set up for production and purification of natural antioxidants as compared to higher plants.
PubDate: 16 February, 2017
- Optimization of DNA Extraction Methods from Garcinia species for ISSR-PCR,
RAPD-PCR and DNA Barcoding
Abstract: Background: Genetic analysis and DNA barcoding technology of plant relies on high yields of pure DNA samples. The DNA barcoding has the potential to provide an alternative means of estimating species richness without high level expertise in field identification skills and in a much shorter time frame. Western Ghats of India is one of the mega diversity centres in the world. There are 15 species of Garcinia reported of which many are endemic in nature. Genus Garcinia store large amounts of phenolics, polysaccharides, polyphenols, tannins and other metabolites within their leaf tissue making genomic DNA extraction difficult. While many DNA extraction methods exist that contend with the presence of phenolics and polysaccharides, these methods rely mainly on selection of material. Materials and Methods: The DNA of G. indica and G. xanthochymus was extracted by using DNAzol® kit, modified SDS and C-TAB methods. A modified C-TAB and SDS method was optimized for removal of polyphenolics. Results: The protocol developed yielded 2000-2500 ng μL1 of quality DNA without any impurities as evident by A260/280 ratio ranging from 1.78-1.81 and 260/230 ratio ranging from 2.15-2.18 for 3 g of the leaf tissue. The extraction of DNA by SDS was most effective from young leaves. In this study the properties of Triton X in the second purification step to remove lipid and protein component of the cellular membranes has been exploited. Triton X helps in decreasing the surface tension and along with that it helps in solubilization of nonpolar entities. High Concentration of LiCl2 (0.5 M) in presence of ethanol helps in salting out of DNA. The resulted genomic DNA showed fine Random Amplified Polymorphic DNA (RAPD) Inter Simple Sequence Repeat (ISSR) banding pattern. The DNA obtained was also amenable to rbcL barcode gene amplification of plant. Conclusion: The protocol optimized is reproducible and useful for other members of Garcinia species.
PubDate: 16 February, 2017