Purification and characterization of xylanase from Aspergillus fumigatus isolated from soil

The objectives of the present study were to purify and characterize xylanase enzyme from the fungus obtained from soil. A total of 40 fungi were isolated from 25 soil samples collected after primary screening on Potato Dextrose Agar. In the secondary screening (malt extract agar, 0.5% birch wood xylan), based on the diameter of the clear zone, the fungus was identified as Aspergillus fumigatus by microbial type culture collection (MTCC), Chandigarh, India and was selected for xylanase enzyme production in solid state fermentation using wheat bran. Xylanase was subjected to a three-step purification scheme involving ammonium sulphate precipitation, gel filtration chromatography and anion exchange chromatography. Purity was verified by running the extracted protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and a single band was observed. When compared with the standard wide range protein molecular markers on SDS-PAGE, it was found to have a molecular weight of 43 KDa. The Km and Vmax value of xylanase was 3.12 mg/ml and 2857 μmol/min/mg protein as obtained from a Lineweaver-Burk plot. The optimal temperature and pH was found to be 30 and 10°C, respectively. After 4 h of incubation, enzyme retained 100% activity at 30°C. Xylanase was incubated at various pH levels (2 to 12) for 4 h at 30°C, and the residual activity was measured. More than 65% of the original activity was retained at pH ranging from 4 to 10 after 4 h.Keywords: Xylanase, Aspergillus fumigatus, production, enzyme purification, enzyme characterization, Lineweaver–Burk plotAfrican Journal of Biotechnology Vol. 12(20), pp. 3049-305

Selection of solvent and extraction method for determination of antimicrobial potential of Taxus wallichiana Zucc.

Antimicrobial potential of different plant parts (needle, stem and bark) of Himalayan yew (Taxus wallichiana Zucc.) has been investigated with particular reference to selection of solvents and extraction methods. Two extraction methods (maceration and soxhlet), seven solvents (methanol, ethanol, acetone, chloroform, ethyl  acetate, di chloro methane and Petroleum ether), and 3 groups of microorganisms (bacteria, actinobacteria and fungi) were considered for detection of antimicrobial activity. While qualitative estimations were done using agar well diffusion method, quantitative analysis was based on dilution method. All the plant part showed significant activity against all 3 groups of microorganisms in qualitative bioassays; maximum being in case of needles. Among solvents, ethanolic extract of needles (maceration) showed highest antibacterial activity (15.33 ± 0.25 mm). Growth of actinobacteria was inhibited maximum (22.0±0.26 mm) by the methanolic extracts of needles (maceration). Ethyl acetate extract of needles (soxhlet) showed higher antifungal activity (7.84±0.21 mm). Antibacterial and antifungal activities were higher in maceration and soxhlet methods, respectively. The most affected group among the test microorganisms was bacteria which may be due to their prokaryotic organization. This was also supported by the low minimum inhibitory concentration (MIC) values. Di chloro methane and petroleum ether did not show any antifungal activity. The antimicrobial activity of various plant parts of T. wallichiana varied with respect to the solvent as well as the extraction method. The study will have implications in selection of the use of solvent and the extraction procedure in obtaining the antimicrobial metabolites from various plant parts of T. wallichiana

The Impact of Processing Methods and Conditions on Nutritional Properties of Soybean-Based Tofu: A Review

The soybean seed is used for the preparation of protein rich tofu. Along with protein, it is also rich in many other nutrients including carbohydrate, crude fibre, carbohydrate, fat, minerals, and isoflavones. Antinutrients are also present in tofu, although the concentration is less that the raw grains. The nutrient content is affected by the tofu preparation method used starting from selection of suitable soybean seed, seed soaking, sprouting, soymilk production and coagulation using different types of natural and artificial coagulants. These procedures also affect the textural properties of the tofu and their shelf life

A Review on Antihyperglycemic and Antihepatoprotective Activity of Eco-Friendly Punica granatum

Over the past decade, pomegranate (Punica granatum) is entitled as a wonder fruit because of its voluminous pharmacological properties. In 1830, P. granatum fruit was first recognized in United States Pharmacopeia; the Philadelphia edition introduced the rind of the fruit, the New York edition the bark of the root and further 1890 edition the stem bark was introduced. There are significant efforts and progress made in establishing the pharmacological mechanisms of peel (pericarp or rind) and the individual constituents responsible for them. This review provides an insight on the phytochemical components that contribute too antihyperglycemic, hepatoprotective, antihyperlipidemic effect, and numerous other effects of wonderful, economic, and eco-friendly pomegranate peel extract (PP)

HPLC Evaluation of Phenolic Profile, Nutritive Content, and Antioxidant Capacity of Extracts Obtained from Punica granatum

This study revealed polyphenolic content, nutritive content, antioxidant activity, and phenolic profile of methanol and aqueous extracts of Punica granatum peel extract. For this, extracts were screened for possible antioxidant activities by free radical scavenging activity (DPPH), hydrogen peroxide scavenging activity and ferric-reducing antioxidant power (FRAP) assays. The total phenolics and flavonoid recovered by methanolic (MPE) and the water extract (AQPE) were ranged from 185 ± 12.45 to 298.00 ± 24.86 mg GAE (gallic acid equivalents)/gm and 23.05 ± 1.54 to 49.8 ± 2.14 quercetin (QE) mg/g, respectively. The EC50 of herbal extracts ranged from 100 µg/ml (0.38 quercetin equivalents), for AQPE, 168 µg/ml (0.80 quercetin equivalents), for MPE. The phenolic profile in the methanolic extracts was investigated by chromatographic (HPLC) method. About 5 different flavonoids, phenolic acids, and their derivatives including quercetin (1), rutin (2), gallic acid (3), ellagic acid (4), and punicalagin as a major ellagitannin (5) have been identified. Among both extracts, methanolic extract was the most effective. This report may be the first to show nutritive content and correlation analysis to suggest that phenols and flavonoids might contribute the high antioxidant activity of this fruit peel and establish it as a valuable natural antioxidant source applicable in the health food industry

PRODUCTION OF INDUSTRIALLY IMPORTANT ENZYMES BY THERMOBACILLI ISOLATED FROM HOT SPRINGS OF INDIA

Enzymes from thermophilic bacteria have received great attention for their potential applications in various industrial sectors. The present study deals with the production of five thermozymes (amylase, lipase, xylanase, protease and cellulase) from 10 thermophilic bacterial species, originally isolated from two hot springs namely Soldhar and Ringigad in Uttarakhand Himalaya, India. The bacterial isolate GBPI_25 produced maximum amylase (1217.86 U/ml) at 45 °C and 5 pH, GBPI 3 produced maximum lipase (22.59 U/ml) at 65 °C and 9 pH, GBPI_25 produced maximum xylanase (98.07 U/ml) at45 °C and 9 pH, GBPI_35 produced maximum protease (16.66 U/ml) at 55 °C and 9 pH, and GBPI 4 produced maximum cellulose (108.68 U/ml) at 45 °C and 5 pH. Crude enzyme preparations showed thermal and pH activities at broad temperature and pH range between 10-100 °C and 3-11 pH, respectively, with different temperature and pH optima. Amylase, xylanase and cellulase showed maximum activity at 50 °C while lipase and protease showed higher activity at 40 and 60 °C, respectively. Enzyme activity at wide temperature range-cellulase and protease from 10-100 °C, amylase and xylanasefrom10-90 °C, and lipase activity from 10-80 °C were the remarkable records from this study. Similarly, pH range for amylase and lipase activity was recorded from 4-11, for xylanase from 3-9, and for protease and cellulase from 3-10. All the thermozymes showed maximum stability at 40 °C and pH 5 except cellulase that showed higher stability at40 °C and neutral pH

Recognition of fold- and function-specific sites in the ligand-binding domain of the thyroid hormone receptor-like family

Background: The thyroid hormone receptor-like (THR-like) family is the largest transcription factors family belonging to the nuclear receptor superfamily, which directly binds to DNA and regulates the gene expression and thereby controls various metabolic processes in a ligand-dependent manner. The THR-like family contains receptors THRs, RARs, VDR, PPARs, RORs, Rev-erbs, CAR, PXR, LXRs, and others. THR-like receptors are involved in many aspects of human health, including development, metabolism and homeostasis. Therefore, it is considered an important therapeutic target for various diseases such as osteoporosis, rickets, diabetes, etc. Methods: In this study, we have performed an extensive sequence and structure analysis of the ligand-binding domain (LBD) of the THR-like family spanning multiple taxa. We have use different computational tools (information-theoretic measures; relative entropy) to predict the key residues responsible for fold and functional specificity in the LBD of the THR-like family. The MSA of THR-like LBDs was further used as input in conservation studies and phylogenetic clustering studies. Results: Phylogenetic analysis of the LBD domain of THR-like proteins resulted in the clustering of eight subfamilies based on their sequence homology. The conservation analysis by relative entropy (RE) revealed that structurally important residues are conserved throughout the LBDs in the THR-like family. The multi-harmony conservation analysis further predicted specificity in determining residues in LBDs of THR-like subfamilies. Finally, fold and functional specificity determining residues (residues critical for ligand, DBD and coregulators binding) were mapped on the three-dimensional structure of thyroid hormone receptor protein. We then compiled a list of natural mutations in THR-like LBDs and mapped them along with fold and function-specific mutations. Some of the mutations were found to have a link with severe diseases like hypothyroidism, rickets, obesity, lipodystrophy, epilepsy, etc. Conclusion: Our study identifies fold and function-specific residues in THR-like LBDs. We believe that this study will be useful in exploring the role of these residues in the binding of different drugs, ligands, and protein-protein interaction among partner proteins. So this study might be helpful in the rational design of either ligands or receptors