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Lipolytic enzymes are produced by animals, plants and microorganisms. With their chemo-, regio-, and enantio-specific characteristics, lipolytic enzymes are important biocatalysts useful in several industrial applications. They are widely used in the processing of fats and oils, detergents, food processing, paper and cosmetics production. In this work, we used a new functional metaproteomics approach to screen sediment samples of the Indian Bakreshwar hot spring for novel thermo- and solvent-stable lipolytic enzymes. We were able to identify an enzyme showing favorable characteristics. DS-007 showed high hydrolytic activity with substrates with shorter chain length \((C_{10}\), significantly less hydrolytic activity was observed. A preference for short chain acyl groups is characteristic for esterases, suggesting that DS-007 is an esterase. Consistent with the high temperature at its site of isolation, DS-007 showed a temperature optimum at 55°C and retained 80% activity even after prolonged exposure to temperatures as high as 60°C. The enzyme showed optimum activity at pH 9.5, with more than 50% of its optimum activity between pH 8.0 and pH 9.5. DS-007 also exhibited tolerance toward organic solvents at a concentration of 1% (v/v). One percent of methanol increased the activity of DS-007 by 40% in comparison to the optimum conditions without solvent. In the presence of 10% methanol, DMSO or isopropanol DS-007 still showed around 50% activity. This data indicates that DS-007 is a temperature- and solvent-stable thermophilic enzyme with reasonable activity even at lower temperatures as well as a catalyst that can be used at a broad range of pH values with an optimum in the alkaline range, showing the adaptation to the habitat's temperature and alkaline pH.

Department of Chemistry, The University of Burdwan, Burdwan-713 104, West Bengal, India Department of Microbiology, The University of Burdwan, Burdwan-713 104, West Bengal, India ICMR Virus Unit, ID & BG Hospital, 57, Dr. S. C. Banerjee Road, Kolkata-700 010, India Departamento de Química Inorgánica, Facultade de Química, Avda. Das Ciencias s/n, 15782, Santiago de Compostela, Spain Manuscript received online 08 January 2013, accepted 21 May 2013 9-Acridone-4-carboxylic acid has been established as a cheap, non-carcinogenic fluorescence dye. It can differentiate living and dead cells in a eukaryotic microbial population viz. Candida sp. Moreover, the dye has been tagged with specific antibody (Ab) without compromising its fluorescence property and used for detection of specific antigen in natural samples. The dye crystallizes in the monoclinic space group C2/c with unit cell dimensions : a = 17.7608(10) Å, b = 7.3009(4) Å and c = 16.7328(9) Å while other unit cell parameters are : α = 90º, β = 103.093(4)º, ϒ = 90º, V = 2113.3(2) Å3 and Z = 8. The dye is soluble in HEPES buffer at pH 7.4.

Fluorescence bioimaging potential, both in vitro and in vivo, of a yellow emissive triazole-based molecular marker has been investigated and demonstrated. Three different kinds of cells, viz Bacillus thuringiensis, Candida albicans, and Techoma stans pollen grains were used to investigate the intracellular zinc imaging potential of 1 (in vitro studies). Fluorescence imaging of translocation of zinc through the stem of small herb, Peperomia pellucida, having transparent stem proved in vivo bioimaging capability of 1. This approach will enable in screening cell permeability and biostability of a newly developed probe. Similarly, the current method for detection and localization of zinc in Gram seed sprouts could be an easy and potential alternative of the existing analytical methods to investigate the efficiency of various strategies applied for increasing zinc-content in cereal crops. The probe-zinc ensemble has efficiently been applied for detecting phosphate-based biomolecules Refereed/Peer-reviewed

Three TRIS-based molecular probes, L1 / L2 / L3 , were screened for their ability to detect Zn 2+ at nanomolar level. Keeping in mind the criteria for a molecular probe to be utilized as bioimaging material, L2 was chosen as model compound for biological studies due to its higher excitation/emission wavelengths. While investigating the potential of L2 , intracellular Zn 2+ was successfully imaged using fluorescence microscopy. As the fluorescence emission of L2 -Zn 2+ ensemble was stable for longer duration, more than 3 h, L2 was successfully utilized in in vivo imaging of Zn 2+ in a whole plant ( Peperomia pellucida ) in real-time. Further to its in vivo imaging capability, L2 was found to be successful in imaging zinc pool of gram seed sprouts.

A benzo[h]chromene derivative, 2-amino-4-phenyl-4H-benzo[h]chromene-3-carbonitrile 1, has been utilized as ‘Turn On’ fluorescence chemosensor for the selective detection of Pb2+. The title compound 1 was synthesized in one step using a multicomponent condensation reaction (MCR), and characterized using various spectroscopic techniques. The selectivity was tested over a range of 17 different metal and non-metal ions. Compound 1 was found to be weak fluorescent (Φ1=0.06) because of photoinduced electron transfer (PET). The presence of 2 equiv of Pb2+ showed a significant increase in fluorescence quantum yield ( Φ 1 − Pb 2 + =0.132). A change in weak blue emission of 1 to a glowing green emission along with a prominent red shift (26 nm) in emission band was observed upon addition of Pb2+ to a methanolic solution of 1. The complexation of 1 with Pb2+ was proved by mass spectroscopy and NMR studies. Some of our experimental findings have been supported by theoretical studies. Compound 1 was found to be easily permeable to living cells without causing any harm and ultimately was used to detect effectively Pb2+ in living system.