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Since a decade, there has been a strong consumer demand for more natural products. This has augmented inclination towards substitution of synthetic colorants with natural pigments. Natural pigments not only have the capacity to increase the marketability of products, they also demonstrate valuable biological activities as antioxidants and anticancer agents. There is a long history of exploitation of natural products produced by bacteria as sources of pharmaceutically important, bioactive compounds. Among natural pigments, pigments from microbial sources are potentially suitable alternatives to synthetic pigments. The red pigment prodigiosin (PG) has unusual properties, which have long been documented. The red-pigmented prodiginines are bioactive secondary metabolites produced by both Gram-negative and Gram-positive bacteria. Prodigiosins are characterized by a common pyrrolyl pyrromethene skeleton, and the biological role of these pigments in the producer organisms remains unclear. Bacterial prodigiosins and their synthetic derivatives are effective proapoptotic agents against various cancer cell lines, with multiple cellular targets including multi-drug resistant cells with little or no toxicity towards normal cell lines. However, research into the biology of pigment production will stimulate interest in the bioengineering of strains to synthesize useful prodiginine derivatives. This review article highlights the characteristics and potential applications of prodigiosin pigment from Serratia as prodigiosins are real potential therapeutic drugs.

l -asparaginase from Cladosporium sp. grown on wheat bran by SSF was purified. Enzyme appeared to be a trimer with homodimer of 37 kDa and another 47 kDa amounting to total mass of 121 kDa as estimated by SDS-PAGE and 120 kDa on gel filtration column. The optimum temperature and pH of the enzyme were 30 °C and 6.3, respectively with Vmax of 4.44 μmol/mL/min and Km of 0.1 M. Substrate specificity studies indicated that, l -asparaginase has greater affinity towards l -asparagine with substrate hydrolysis efficiency (Vmax/Km ratio) eightfold higher than that of l -glutamine. l -asparaginase activity in presence of thiols studied showed decrease in Vmax and increase in Km, indicating nonessential mode of inactivation. Among the thiols tested, β-mercaptomethanol, exerted inhibitory effect, suggesting a critical role of disulphide linkages in maintaining a suitable conformation of the enzyme. Metal ions such as Ca 2+ , Co 2+ , Cu 2+ , Mg 2+ , Na + , K + and Zn 2+ significantly affected enzyme activity whereas presence of Fe 3+ , Pb 2+ and KI stimulated the activity. Detergents studied also enhanced l -asparaginase activity. In-vitro half-life of purified l -asparaginase in mammalian blood serum was 93.69 h. The enzyme inhibited acrylamide formation in potato chips by 96 % making it a potential candidate for food industry to reduce acrylamide content in starchy fried food commodities.

Acrylamide, 2-propenamide, has the chemical formula [Formula: see text]. It is produced at elevated levels in high temperature fried and baked foods. It has adverse effects on human health and is proven to be neurotoxic, genotoxic, carcinogenic, and toxic to reproductive system. The aim of this paper was to reduce acrylamide formation in bakery products such as sweet bread by enzyme treatment. L-Asparaginase produced from Cladosporium sp. was treated to wheat-based dough at different concentrations (50–300 U). There was no change in the rheological properties of wheat flour and physico-sensory characteristics of bread with L-asparaginase treatment. Moisture, sugars, L-asparagine, acrylamide, and some indicators of Millard reaction (hydroxymethylfurfural (HMF), color, browning) were estimated. With increase in L-asparaginase level the acrylamide formation was reduced. At 300 U, there was 97 % and 73 % reduction of acrylamide formation in the crust and crumb regions of bread, respectively. HMF, a common intermediate product in the Maillard reaction and a genotoxic compound via 5-sulfoxymethylfurfural, also decreased in L-asparaginase-treated bread samples. These results indicated the potential of L-asparaginase enzyme for industrial and domestic applications in reducing harmful Maillard reaction compounds.

The antimicrobial activity of prodigiosin from Serratia nematodiphila darsh1 , a bacterial pigment was tested against few food borne bacterial pathogens Bacillus cereus , Staphylococcus aureus , Pseudomonas aeruginosa and Escherichia coli . The mode of action of prodigiosin was studied. Prodigiosin induced bactericidal activity indicating a stereotypical set of biochemical and morphological feature of Programmed cell death (PCD). PCD involves DNA fragmentation, generation of ROS, and expression of a protein with caspase-like substrate specificity in bacterial cells. Prodigiosin was observed to be internalized into bacterial cells and was localized predominantly in the membrane and the nuclear fraction, thus, facilitating intracellular trafficking and then binding of prodigiosin to the bacterial DNA. Corresponding to an increasing concentration of prodigiosin, the level of certain proteases were observed to increase in bacteria studied, thus initiating the onset of PCD. Prodigiosin at a sub-inhibitory concentration inhibits motility of pathogens. Our observations indicated that prodigiosin could be a promising antibacterial agent and could be used in the prevention of bacterial infections.

Monsooned coffee is one of the world specialty coffees processed only in India. Monsooned Malabar (MM) and Monsooned Robusta (MR) are processed from native Arabica and Robusta coffees. Few of the parameters like moisture, density, pH, color, soluble solids, phenols, caffeine and chlorogenic acids differed significantly compared to the native coffees. Antioxidant activity of MM and MR were 62.23 and 69.53%, respectively. The in vitro antimicrobial activities of the water-soluble extracts of MM and MR were investigated on food-borne pathogens by the well diffusion method and the results indicated maximum inhibition in E. coli followed by Yersinia and Listeria species. Fungal isolates were resistant to water-soluble extracts compared to bacteria. MR was more sensitive in inhibition of growth compared to MM. The chromatographical fractions other than caffeine, chlorogenic acid and theobromine, MC4 and MC5 exhibited antimicrobial activity. The fractions MC4 and MC5 were identified as quinic acid and spinasterol by LC-MS analyses. The antioxidant and antimicrobial activity of the water-soluble extracts of monsooned coffee have been reported for the first time.

A triterpene glycoside (TG) fraction isolated and purified from ethanolic extract of Gymnema sylvestre (EEGS) was investigated for blood glucose control benefit using in vitro methods. The HPLC purified active fraction TG was characterized using FTIR, LC-MS, and NMR. The purified fraction (TG) exhibited effective inhibition of yeast α-glucosidase, sucrase, maltase, and pancreatic α-amylase with IC50 values 3.16 ± 0.05 μg/mL, 74.07 ± 0.51, 5.69 ± 0.02, and 1.17 ± 0.24 μg/mL, respectively, compared to control. TG was characterized to be a mixture of triterpene glycosides: gymnemic acids I, IV, and VII and gymnemagenin. In vitro studies were performed using mouse pancreatic β-cell lines (MIN6). TG did not exhibit any toxic effects on β-cell viability and showed protection against H2O2 induced ROS generation. There was up to 1.34-fold increase in glucose stimulated insulin secretion (p<0.05) in a dose-dependent manner relative to standard antidiabetic drug glibenclamide. Also, there was further one-fold enhancement in the expression of GLUT2 compared to commercial standard DAG (deacylgymnemic acid). Thus, the present study highlights the effective isolation and therapeutic potential of TG, making it a functional food ingredient and a safe nutraceutical candidate for management of diabetes.

l -Asparaginase (E.C. 3.5.1.1) is used as an anti-neoplastic drug in the treatment of acute lymphoblastic leukemia. l -Asparaginase from Pseudomonas fluorescens was cloned and overexpressed in E. coli BL21. The Enzyme was found to be a Fusion protein-asparaginase complex which was given a lysozyme treatment and sonication, and then was purified in a Sepharose 6B column. The enzymatic properties of the recombinant enzyme were studied and the kinetic parameters were determined with kilometre of 109.99 mM and V max of 2.88 µM/min. Recombinant enzyme showed pH optima at 6.3 and temperature optima at 34 °C. Asp gene was successfully cloned into E. coli BL21 which produced high level of asparaginase intracellularly with 85.25 % recovery of enzyme with a specific activity of 0.94 IU/mg protein. The enzyme was a tetramer with molecular weight of approximately 141 kDa.

A multiplex real-time isothermal amplification assay was developed using molecular beacons for the detection of Bacillus cereus and Staphylococcus aureus by targeting four important virulence genes. A correlation between targeting highly accessible DNA sequences and isothermal amplification based molecular beacon efficiency and sensitivity was demonstrated using phi(Φ)29 DNA polymerase at a constant isothermal temperature of 30 °C. It was very selective and consistently detected down to 10 1 copies of DNA. The specificity and sensitivity of this assay, when tested with pure culture were high, surpassing those of currently used PCR assays for the detection of these organisms. The molecular beacon based real-time isothermal amplification (MBRTIA) assay could be carried out entirely in 96 well plates or well strips, enabling a rapid and high-throughput detection of food borne pathogens.

Interference of Luria broth and other bacteriological media with the starch-iodine colour assay of the dextrinizing activity of alpha -amylase (Fuwa's method) was observed, complete bleaching occurring with 0.4 ml of the Luria broth. The interference was found to be due to the thiol groups present in the medium which compete with starch for iodine. Among the various metal salts tested for counteracting the interference, ZnSO sub(4) was found to be the best which reverted the colour to about 73-85% of that of the blank. A combination of hydrogen peroxide (10 mu l of 30% solution) and CuSO sub(4) times 5H sub(2)O (50 mu l of 0.1M solution) completely protected the starch-iodine reaction in the presence of even 0.5 ml of Luria broth and a modified assay was developed based on this finding. The colour intensity, however, was almost double than that obtained for the same amount of starch and iodine in the absence of these protective agents. Nevertheless, with different concentrations of starch as well as with varying amounts of enzymes, the modified method showed perfect linearity and could be effectively used for estimation of dextrinizing activity of alpha -amylase in the presence of thiol groups.

alpha -Amylase gene from Bacillus laterosporus P sub(3) was cloned and expressed in Escherichia coli HB101 and DH5 alpha . Up to 92% of the cloned gene product was secreted into the medium by the recombinant E. coli. The recombinant crude enzyme showed improved functionality in terms of activity at a wider pH range and at higher temperature, as compared to the crude enzyme from the donor strain. The improved functionality of the cloned enzyme was due to the absence of a contaminating protease which was co-produced in the donor strain. Sub-cloning of the alpha -amylase gene using the promoter-probe vector, pKT240 in E. coli DH5 alpha indicated the presence of a promoter of B. laterosporus P sub(3) in the cloned fragment.