Showing papers by "Department of Biotechnology published in 2012"

Probiotics, their health benefits and applications for developing healthier foods: a review

Abstract: In the industrialized world, functional foods have become a part of an everyday diet and are demonstrated to offer potential health benefits beyond the widely accepted nutritional effects. Currently, the most important and frequently used functional food compounds are probiotics and prebiotics, or they are collectively known as ‘synbiotics’. Moreover, with an already healthy image, dairy products appear to be an excellent mean for inventing nutritious foods. Such probiotic dairy foods beneficially affect the host by improving survival and implantation of live microbial dietary supplements in the gastrointestinal flora, by selectively stimulating the growth or activating the catabolism of one or a limited number of health-promoting bacteria in the intestinal tract, and by improving the gastrointestinal tract's microbial balance. Hence, the paper reviews the current scenario of probiotics and their prospective potential applications for functional foods for better health and nutrition of the society.

Mechanisms of biocontrol and plant growth-promoting activity in soil bacterial species of Bacillus and Pseudomonas: a review

Abstract: Plant pathogens are responsible for many crop plant diseases, resulting in economic losses. The use of bacterial agents is an excellent option to fight against plant pathogens and an excellent alternative to the use of chemicals, which are offensive to the environment and to human health. Two of the most common biocontrol agents are members of the Bacillus and Pseudomonas genera. Both bacterial genera have important traits such as plant growth-promoting (PGP) properties. This review analyzes pioneering and recent works and the mechanisms used by Bacillus and Pseudomonas in their behaviour as biocontrol and PGP agents, discussing their mode of action by comparing the two genera. Undoubtedly, future integrated research strategies for biocontrol and PGP will require the help of known and novel species of both genera.

Cholesterol-Lowering Probiotics as Potential Biotherapeutics for Metabolic Diseases

Abstract: Cardiovascular diseases are one of the major causes of deaths in adults in the western world. Elevated levels of certain blood lipids have been reported to be the principal cause of cardiovascular disease and other disabilities in developed countries. Several animal and clinical trials have shown a positive association between cholesterol levels and the risks of coronary heart disease. Current dietary strategies for the prevention of cardiovascular disease advocate adherence to low-fat/low-saturated-fat diets. Although there is no doubt that, in experimental conditions, low-fat diets offer an effective means of reducing blood cholesterol concentrations on a population basis, these appear to be less effective, largely due to poor compliance, attributed to low palatability and acceptability of these diets to the consumers. Due to the low consumer compliance, attempts have been made to identify other dietary components that can reduce blood cholesterol levels. Supplementation of diet with fermented dairy products or lactic acid bacteria containing dairy products has shown the potential to reduce serum cholesterol levels. Various approaches have been used to alleviate this issue, including the use of probiotics, especially Bifidobacterium spp. and Lactobacillus spp.. Probiotics, the living microorganisms that confer health benefits on the host when administered in adequate amounts, have received much attention on their proclaimed health benefits which include improvement in lactose intolerance, increase in natural resistance to infectious disease in gastrointestinal tract, suppression of cancer, antidiabetic, reduction in serum cholesterol level, and improved digestion. In addition, there are numerous reports on cholesterol removal ability of probiotics and their hypocholesterolemic effects. Several possible mechanisms for cholesterol removal by probiotics are assimilation of cholesterol by growing cells, binding of cholesterol to cellular surface, incorporation of cholesterol into the cellular membrane, deconjugation of bile via bile salt hydrolase, coprecipitation of cholesterol with deconjugated bile, binding action of bile by fibre, and production of short-chain fatty acids by oligosaccharides. The present paper reviews the mechanisms of action of anti-cholesterolemic potential of probiotic microorganisms and probiotic food products, with the aim of lowering the risks of cardiovascular and coronary heart diseases.

Structure and Ligand Based Drug Design Strategies in the Development of Novel 5-LOX Inhibitors

Abstract: Lipoxygenases (LOXs) are non-heme iron containing dioxygenases involved in the oxygenation of polyunsaturated fatty acids (PUFAs) such as arachidonic acid (AA). Depending on the position of insertion of oxygen, LOXs are classified into 5-, 8-, 9-, 12- and 15-LOX. Among these, 5-LOX is the most predominant isoform associated with the formation of 5-hydroperoxyeicosatetraenoic acid (5- HpETE), the precursor of non-peptido (LTB4) and peptido (LTC4, LTD4, and LTE4) leukotrienes. LTs are involved in inflammatory and allergic diseases like asthma, ulcerative colitis, rhinitis and also in cancer. Consequently 5-LOX has become target for the development of therapeutic molecules for treatment of various inflammatory disorders. Zileuton is one such inhibitor of 5-LOX approved for the treatment of asthma. In the recent times, computer aided drug design (CADD) strategies have been applied successfully in drug development processes. A comprehensive review on structure based drug design strategies in the development of novel 5-LOX inhibitors is presented in this article. Since the crystal structure of 5-LOX has been recently solved, efforts to develop 5-LOX inhibitors have mostly relied on ligand based rational approaches. The present review provides a comprehensive survey on these strategies in the development of 5-LOX inhibitors.

Isolation, Purification, and Characterization of Xylanase Produced by a New Species of Bacillus in Solid State Fermentation

Abstract: A thermoalkalophilic new species of Bacillus, similar to Bacillus arseniciselenatis DSM 15340, produced extracellular xylanase under solid state fermentation when wheat bran is used as carbon source. The extracellular xylanase was isolated by ammonium sulfate (80%) precipitation and purified using ion exchange chromatography. The molecular weight of xylanase was ~29.8 kDa. The optimum temperature and pH for the enzyme activity were 50°C and pH 8.0. The enzyme was active on birchwood xylan and little active on p-nitrophenyl xylopyranoside but not on Avicel, CMC, cellobiose, and starch, showing its absolute substrate specificity. For birchwood xylan, the enzyme gave a Km 5.26 mg/mL and Vmax 277.7 μmol/min/mg, respectively. In addition, the xylanase was also capable of producing high-quality xylo-oligosaccharides, which indicated its application potential not only in pulp biobleaching processes but also in the nutraceutical industry.

Myco-Biocontrol of Insect Pests: Factors Involved, Mechanism, and Regulation

Abstract: The growing demand for reducing chemical inputs in agriculture and increased resistance to insecticides have provided great impetus to the development of alternative forms of insect-pest control. Myco-biocontrol offers an attractive alternative to the use of chemical pesticides. Myco-biocontrol agents are naturally occurring organisms which are perceived as less damaging to the environment. Their mode of action appears little complex which makes it highly unlikely that resistance could be developed to a biopesticide. Past research has shown some promise of the use of fungi as a selective pesticide. The current paper updates us about the recent progress in the field of myco-biocontrol of insect pests and their possible mechanism of action to further enhance our understanding about the biological control of insect pests.

RNA interference therapeutics for cancer: challenges and opportunities (review).

Abstract: RNA interference (RNAi) is a sequence-specific, post-transcriptional gene silencing mechanism in animals and plants, which is mediated by double-stranded RNA (dsRNA). There has recently been an increasing interest in harnessing the gene silencing activity of dsRNA to develop novel drugs for the treatment of various diseases, such as cancer, neuro- logical disorders, age-related macular degeneration and viral infections. Small interfering RNA (siRNA)-based drugs have distinct advantages over conventional small molecule or protein-based drugs, including high specificity, higher potency and reduced toxicity. However, there are several technical obstacles to overcome before siRNA-based drugs reach the clinic. Delivery of siRNA to the target tissues and stability in the serum remain a major challenge and are the main focus of current research and development efforts. This review focused primarily on the progress made in developing RNAi as therapeutics for cancer and the challenges associ- ated with its clinical development. Use of ligands recognizing cell-specific receptors to achieve tumor-specific delivery of siRNA, methods for enhanced siRNA delivery, improving the bioavailability and pharmacokinetic properties of siRNA and reducing the off-target effects and non-specific gene silencing are discussed in the light of current evidence. Contents

PTEN, a widely known negative regulator of insulin/PI3K signaling, positively regulates neuronal insulin resistance

Abstract: Lipid and protein tyrosine phosphatase, phosphatase and tension homologue (PTEN), is a widely known negative regulator of insulin/phosphoinositide 3-kinase signaling. Down-regulation of PTEN is thus widely documented to ameliorate insulin resistance in peripheral tissues such as skeletal muscle and adipose. However, not much is known about its exact role in neuronal insulin signaling and insulin resistance. Moreover, alterations of PTEN in neuronal systems have led to discovery of several unexpected outcomes, including in the neurodegenerative disorder Alzheimer's disease (AD), which is increasingly being recognized as a brain-specific form of diabetes. In addition, contrary to expectations, its neuron-specific deletion in mice resulted in development of diet-sensitive obesity. The present study shows that PTEN, paradoxically, positively regulates neuronal insulin signaling and glucose uptake. Its down-regulation exacerbates neuronal insulin resistance. The positive role of PTEN in neuronal insulin signaling is likely due to its protein phosphatase actions, which prevents the activation of focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK), the kinases critically involved in neuronal energy impairment and neurodegeneration. Results suggest that PTEN acting through FAK, the direct protein substrate of PTEN, prevents ERK activation. Our findings provide an explanation for unexpected outcomes reported earlier with PTEN alterations in neuronal systems and also suggest a novel molecular pathway linking neuronal insulin resistance and AD, the two pathophysiological states demonstrated to be closely linked.

Effect of vitamin D3 in reducing metabolic and oxidative stress in the liver of streptozotocin-induced diabetic rats.

Abstract: Diabetes mellitus is a growing health problem worldwide and is associated with severe liver complications. The aim of the present study is to analyse the status of metabolic and free-radical-scavenging enzymes and second messengers in the liver of streptozotocin (STZ)-induced diabetic rats, and to determine the hepatoprotective role of vitamin D(3). All studies were performed using the liver of adult male Wistar rats. Gene expression studies were carried out using real-time PCR with specific probes. Second messenger levels were determined using (3)H-labelled Biotrak assay kits, and glucose uptake assay with D-[(14)C]glucose. The present results show that there was a decrease in hepatic glucose uptake, malate dehydrogenase activity, glycogen content, inositol triphosphate (IP(3)) and cyclic GMP levels, and superoxide dismutase, glutathione peroxidase, phospholipase C, cyclic AMP-responsive element-binding protein, vitamin D receptor (VDR) and insulin receptor (INSR) gene expression in the diabetic rats when compared with the controls (all P < 0·05), while cyclic AMP levels and GLUT2 expression were increased (P < 0·05). Treatment of the diabetic rats with vitamin D(3) and insulin reversed the altered parameters to near control values. In conclusion, the data suggest a novel role of vitamin D(3) in restoring impaired liver metabolism in STZ-induced diabetic rats by regulating glucose uptake, storage and metabolism. We demonstrated that the restoring effect of vitamin D(3) is mediated through VDR modulation, thereby improving signal transduction and controlling free radicals in the liver of diabetic rats. These data suggest a potential role for vitamin D(3) in the treatment of diabetes-associated hepatic complications.

Optimization of solid state fermentation conditions for the production of cellulase by Trichoderma reesei.

Abstract: Cellulase production studies have been carried out using the fungal strain Trichoderma reesei NCIM 992 by using three different lignocellulosic materials by solid state fermentation (SSF). The effect of basic fermentation parameters (pH, temperature, moisture content, particle size of substrate and moistening agent) on enzyme production was studied. Maximum cellulase production was 2.63 U ml(-1) using wheat bran as substrate. The optimal conditions forcellulase production forwheat bran were found to be: initial moisture content - 70%, initial medium pH-5.0, temperature-30 degrees C, moistening agents (MSS) and particle size of substrate (500 microm).The optimal incubation time for production was six days. Results indicate the scope for further optimization of the production conditions to obtain higher cellulase titres using the strain under SSF.

l -Asparaginase as Potent Anti-leukemic Agent and Its Significance of Having Reduced Glutaminase Side Activity for Better treatment of Acute Lymphoblastic Leukaemia

Abstract: Acute lymphoblastic leukaemia (ALL) is one of the leading types of malignant disorder seen in children. Viral infections, genetic factors and exposure to chemical carcinogens are some of the factors responsible for causing ALL. Treatment strategies followed for curing ALL include chemotherapy or radiation therapy, wherein, chemotherapy involves the use of the enzymatic drug l-Asparaginase. The enzyme can be produced from various plants, animals, bacterial and fungal sources but, among them, bacterial sources are widely used for production of this enzyme. The enzyme is non-human in origin having certain bottle necks with l-Asparaginase therapy in the form of side effects such as pancreatitis, thrombosis which are mainly due to glutaminase side activity. Hence, present-day research is mainly focussed on minimizing or completely eliminating the glutaminase activity of the enzyme l-Asparaginase. This review is focussed on the complications associated with glutaminase side activity and use of glutaminase free enzymatic drug l-Asparaginase in treating ALL and the other developments related to the modification of the drug for quality treatment.

Production of bacteriocin and their application in food products

Abstract: Objective To isolate bacteriocin- producing lactic acid bacteria (LAB) and to asses its preservative effects on food products. Methods Lactobacillus strain was isolated from chicken intestine using MRS broth (Hi-Media, India) at 37 °C for 48 h. The isolate was identified by 16s rRNA sequencing and phylogenetic analysis. Bacteriocin was produced, purified by ammonium sulphate precipitation and dialyzed. Antagonistic characteristics of bacteriocin were studied by agar well diffusion method. Bacteriocin stability was studied in different temperature, pH and enzymes. Biopreservative efficacy was determined for fish and fresh juice. Results Lactobacillus fermentum (L. fermentum) strain isolated from chicken intestine was capable of producing bacteriocins, inhibiting the widest range of pathogenic bacteria. The bacteriocin was stable at 37 °C and acidic pH and proteinaceous in nature. Their biopreservative effect on refrigerated food products (apple juice and fish) show low count of colonies. Lactobacillus isolate was sequenced which shows high similarity with reference strain L. fermentum CECT 5716. Conclusions Bacteriocin producing L. fermentum UN01 could be successfully used as biopreservative and to increase the shelf life of the food products.

Evaluation of the wound-healing activity of Hibiscus rosa sinensis L (Malvaceae) in Wistar albino rats

Abstract: Objective: To investigate the wound-healing potency of the ethanolic extract of the flowers of Hibiscus rosa sinensis. Materials and Methods: The wound-healing activity of H. rosa sinensis (5 and 10% w/w) on Wistar albino rats was studied using three different models viz., excision, incision and dead space wound. The parameters studied were breaking strength in incision model, granulation tissue dry weight, breaking strength and collagen content in dead space wound model, percentage of wound contraction and period of epithelization in excision wound model. The granulation tissue formed on days 4, 8, 12, and 16 (post-wound) was used to estimate total collagen, hexosamine, protein, DNA and uronic acid. Data were analyzed by Analysis of Variance (ANOVA) test. P Results: The extract increased cellular proliferation and collagen synthesis at the wound site, as evidenced by increase in DNA, total protein and total collagen content of granulation tissues. The extract-treated wounds were found to heal much faster as indicated by improved rates of epithelialization and wound contraction. The extract of H. rosa sinensis significantly (P Conclusion: The ethanolic extract of H. rosa sinensis had greater wound-healing activity than the nitrofurazone ointment.

Difference in keratinase activity of dermatophytes at different environmental conditions is an attribute of adaptation to parasitism.

Abstract: Dermatophytes are a group of morphologically and physiologically related moulds, which cause well-defined infection called dermatophytosis. The enzymatic ability of fungi to decompose keratin has long been interpreted as a key innovation in the evolution of animal dermatology. In the present study, keratinase activity profile among Trichophyton mentagrophytes, Trichophyton rubrum, Microsporum canis and Microsporum gypseum isolated on keratin substrates such as human hair, human nail and chicken feather at variable environmental conditions of temperature, pH and metal ions was elucidated. All the above-mentioned fungal strains were isolated from soil using To-KA-Va baiting technique and keratinolytic activity was measured spectrophotometrically. In the temperature range of 30-40 °C and slightly alkaline pH (7.0-8.0), Trichophyton produced the highest activity of keratinase. It can be presumed that high enzyme production of Trichophyton species at normal body temperature range and pH could be an attribute for obligate anthropization in some dermatophytes.

In vitro clonal propagation of Achyranthes aspera L. and Achyranthes bidentata Blume using nodal explants

Abstract: Objective To develop the reproducible in vitro propagation protocols for the medicinally important plants viz., Achyranthes aspera (A. aspera) L. and Achyranthes bidentata (A. bidentata) Blume using nodal segments as explants.

Antibacterial activity of mangrove leaf extracts against human pathogens

Abstract: The antibacterial activity of leaf extract of mangroves, namely, Rhizophora mucronata, Sonneratia alba and Exoecaria agallocha from Chorao island, Goa was investigated against human bacterial pathogens Staphylococcus aureus, Streptococcus sp., Salmonella typhi, Proteus vulgaris and Proteus mirabilis. As compared to aqueous, ethanol extract showed broadâ??spectrum activity. The multidrugâ??resistant (MDR) bacteria Salmonella typhi was inhibited by the ethanol extract of S. alba leaf whereas the other two resistant bacteria Staphylococcus aureus and Streptococcus sp. were inhibited by the ethanol extract of leaves of all the species. The aqueous extract of S. alba and E. agallocha showed their activity against P. vulgaris and P. mirabilis, respectively. Phytochemical analysis revealed the presence of saponins, glycosides, tannins, flavonoids, phenol and volatile oils in the leaves of mangroves. Further studies using different solvents for extraction are necessary to confirm that mangroves are a better source for the development of novel antibiotics.

Analyzing microarray data of Alzheimer's using cluster analysis to identify the biomarker genes.

Abstract: Alzheimer is characterized by the presence of senile plaques and neurofibrillary tangles in cortical regions of the brain The experimental data is taken from Gene Expression Omnibus A hierarchical Cluster analysis and TreeView were performed to group genes on the basis of the expression pattern The dynamic change of expression over time and diverse patterns of expression support the concept of a complex local milieu TreeView allows the organized data to be visualized List of 24 genes were obtained which showed high expression levels Three genes, SORL1, APP, and APOE, are suspected to cause Alzheimer’s whereas the other 21 genes are related to other diseases but may also be found to be associated with Alzheimer’s, and these are TMEM59, CCT4, IGF2R, SFPQ, PRDX3, RNF14, IDS, SSBP1, SYNE2, TXNL4A, STXBP3, SMARCB1, ULK2, AGTPBP1, FABP7, CALB1, H2AFY, COPA, SAP18, ATIC and SYNCRIP

Optimization of immobilization of α-amylase in alginate gel and its comparative biochemical studies with free α-amylase

Abstract: Sachin Talekar and Sandeep Chavare Department of Biotechnology Engineering, Kolhapur Institute of Technology’s College of Engineering, Kolhapur, Maharashtra, India. Abstract The α-amylase was immobilized by entrapment in calcium alginate beads. The effect of concentration of sodium alginate, calcium chloride and curing time on immobilization yield of α-amylase in calcium alginate beads were investigated and immobilized α-amylase was characterized. Three percent (w/v) sodium alginate, 1M calcium chloride and 2 h curing time were used and 90% immobilization yield of α-amylase was achieved with enhanced thermal and acidic condition stabilities. Significant changes in optimum pH and temperature values of the enzyme were recorded after immobilization. The activity of immobilized enzyme was affected by the size of the bead and bead size of 2.4mm was found to be most effective for starch hydrolysis. From the enzyme kinetic study, decrease in substrate affinity and velocity of enzyme reaction were observed after immobilization of enzyme. Immobilized α-amylase retained 35% activity after 10 reuses with 30 min of each reaction time. Keywords: calcium alginate, enzyme immobilization, entrapment, α-amylase, starch hydrolysis INTRODUCTION The α-amylase (EC 3.2.1.1) enzyme which hydrolyzes starch to maltooligosaccharide is of great importance in present day biotechnology with applications ranging from food, baking, brewing, fermentation, detergent applications, textile desizing, paper industries, etc. [1, 2]. This starch degrading enzyme has received a great deal of attention because of its perceived technological significance and economic benefits. The industrial application of enzymes is often hampered by a lack of availability, high price and limited stability under operational conditions. The use of enzymes in a free form is very uneconomical because the enzymes generally cannot be recovered at the end of the reaction. These drawbacks can be overcome by immobilization of the enzyme thereby rendering it more stable and easy to recover and recycle [3, 4]. Immobilized enzymes pave the way to industrial development of continuous enzyme reactors. This procedure prevents enzyme losses due to washout and at the same time maintains enzymes at high concentrations in order to reduce the cost of the enzymes [5]. The above features would be important in the development of an economically feasible continuous bioreactor for the starch hydrolysis industry. Thus immobilizing α- amylasewould be of great significance. Several efforts have been taken to immobilize α-amylase by binding it to solid carriers [6-16].However; these covalent binding techniques involve chemical modification of the enzyme. It is preferable that the method employed for immobilization of enzyme should cause as little disturbance to the enzyme as possible. Entrapment fulfills this criterion. Entrapment technology has been designed to entrap materials within a semi-permeable polymeric membrane and/or a gel matrix [17]. Enzyme immobilization by entrapment produces the particle structure which allows contact between the substrate and enzyme to be achieved and, additionally, it is possible to immobilize several enzymes at the same time [18]. Among the many matrices available, one of the most frequently used is entrapment within porous matrices, such as alginate often in the form of beads [19]. This sort of system is reasonably safe, simple, cheap and offering good mechanical strength, high porosity for substrate and product diffusion and above all the simple procedural requirements for immobilization [20]. Thus, in the present study, α-amylase (Diastase) was immobilized in calcium alginate gel beads. The conditions of entrapment like concentration of sodium alginate, calcium chloride and bead size were optimized for highest apparent activity. The entrapped α-amylase was characterized in terms of optimum temperature and pH, kinetic parameters and compared with those of free α-amylase. MATERIALS AND METHODS Materials Sodium alginate, calcium chloride, α-amylase (Diastase), starch and DNSA (3, 5-Dinitrosalycyclic acid) were purchased from Himedia (Mumbai). All the other chemicals used were of analytical grade. Preparation of enzyme solution Freeze-dried α-amylase (Diastase) was added to 0.1 M sodium phosphate buffer (pH 7.0) to the concentration of 1 mg/ml. This enzyme stock solution was stored at 4°C for future tests.

Analysis of the opportunities and challenges of solar water heating system (SWHS) in India: Estimates from the energy audit surveys & review

Abstract: A solar water heating system (SWHS) is a device that makes available the thermal energy of the incident solar radiation for use in various water heating applications. SWHS largely depends on the performance of the collector's efficiency at capturing the incident solar radiation and transferring it to the water. With today's SWHS, water can be heated up to temperatures of 60–80 °C. Heated water is collected in a tank insulated to prevent heat loss. Circulation of water from the tank through the collectors and back to the tank continues automatically due to the thermosiphon principle. The hot water generated finds many end-use applications in domestic, commercial, and industrial sectors. India has the highest energy intensities in Asia. Very little investment and priority are being given to increase of the efficiency. On the other hand, the India has a high potential for developing energy production from renewable energy sources (RES): solar, water, wind and biomass. However, these potentials are not studied and exploited enough and the present situation for their utilization is not so good. Although energy is a critical foundation for economic growth and social progress of any country, there are many constraints for RES development in all of them (political, technological, financial, legislative, educational, etc.). Obviously, defining development strategies and new support measures is necessary since renewable energy sources can make an important contribution to the regional energy supply and security. The main purpose of this paper is to explore the solar water heating system (opportunities) in India.