Response Surface Optimization for Decaffeination and Theophylline Production by Fusarium solani.

Coffee processing industries generate caffeine-containing waste that needs to be treated and decaffeinated before being disposed. Five fungal isolates obtained on caffeine-containing mineral media were tested for their ability to utilize caffeine at high concentrations. An isolate identified as Fusarium solani could utilize caffeine as a sole source of carbon and nitrogen up to 5 g/l and could degrade it to an extent of 30-53 % in 120 h.

Methylcobalamin--a form of vitamin B12 identified and characterised in Chlorella vulgaris.

Vitamin B12 is among the most essential biomolecules required for crucial metabolic processes in humans. Vitamin B12 was extracted from Chlorella vulgaris biomass under aqueous conditions, partially purified by passing the extract through amberlite XAD-2, Sep-Pak columns, and further purified by HPLC. The target peak eluent was subjected to characterisation by tandem mass spectrometry (MS/MS), selected ion recording (SIR) and multiple reaction monitoring (MRM) and identified as methylcobalamin (Me-Cbl).

Quantum dots as optical labels for ultrasensitive detection of polyphenols.

Considering the fact that polyphenols have versatile activity in-vivo, its detection and quantification is very much important for a healthy diet. Laccase enzyme can convert polyphenols to yield mono/polyquinones which can quench Quantum dots fluorescence. This phenomenon of charge transfer from quinones to QDs was exploited as optical labels to detect polyphenols.

Facile synthesis and photophysical characterization of luminescent CdTe quantum dots for Forster resonance energy transfer based immunosensing of staphylococcal enterotoxin B.

Aqueous phase synthesis of CdTe quantum dots (QDs) with surface functionalization for bioconjugation remains the best approach for biosensing and bioimaging applications. We present a facile aqueous phase method to prepare CdTe QDs by adjusting precursor and ligand concentrations. CdTe QDs had photoluminescence quantum yield up to ≈33% with a narrow spectral distribution.

An immunoreactor-based competitive fluoroimmunoassay for monitoring staphylococcal enterotoxin B using bioconjugated quantum dots.

Extensive research on avian systems has proved hens as an alternate source for polyclonal antibody generation necessary for immunosensing applications. Herein, we present the immobilization of avian antibody raised against staphylococcal enterotoxin B (SEB) and its applicability for a competitive fluoroimmunoassay technique. White leghorn hens immunized with SEB generated high affinity antibodies with a highest yield of 3.

Quantum dots as nano plug-in's for efficient NADH resonance energy routing.

The routing of fluorescent signals from NADH to quantum dots (QDs) has been a subject of extensive research for FRET based applications. In the present study, the spectral cross talk of NAD(+)/NADH with QDs was used to monitor the reaction of NAD(+)-dependent dehydrogenase enzyme. CdTe QD may undergo dipolar interaction with NADH as a result of broad spectral absorption due to multiple excitonic states resulting from quantum confinement effects.

Development of dipstick-based immuno-chemiluminescence techniques for the rapid detection of dichlorodiphenyltrichloroethane.

The occurrence of organochlorine pesticides in the environment has been a major concern, due to their high persistence and the possible impacts of their exposure to humans. Dichlorodiphenyltrichloroethane (DDT) is most hazardous and one of the most widely used organochlorine insecticides. DDT and its main metabolites are highly stable to physical, chemical and biological degradation and are therefore still being detected in many parts of the world.

A membrane protein based biosensor: use of a phosphate--H+ symporter membrane protein (Pho84) in the sensing of phosphate ions.

A label free biosensor for direct detection of inorganic phosphate based on potential-step capacitance measurements has been developed. The high-affinity Pho84 plasma membrane phosphate/proton symporter of Saccharomyces cerevisiae was used as a sensing element. Heterologously expressed and purified Pho84 protein was immobilized on a self-assembled monolayer (SAM) on a capacitance electrode.

Photoabsorption and resonance energy transfer phenomenon in CdTe-protein bioconjugates: an insight into QD-biomolecular interactions.

Luminescent quantum dots (QDs) possess unique photophysical properties, which are advantageous in the development of new generation robust fluorescent probes based on Forster resonance energy transfer (FRET) phenomena. Bioconjugation of these QDs with biomolecules create hybrid materials having unique photophysical properties along with biological activity. The present study is aimed at characterizing QD bioconjugates in terms of optical behavior.

Purification, identification, and characterization of methylcobalamin from Spirulina platensis.

The present study reports methylcobalamin in Spirulina platensis using high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC), microbiological assay, chemiluminescence assay, liquid chromatography-mass spectrometry (LC-MS), and tandem mass spectrometry (MS/MS). Extraction of vitamin B12 from S. platensis was carried out without using cyanide.

Trace-level detection of atrazine using immuno-chemiluminescence: dipstick and automated flow injection analyses formats.

A sensitive chemiluminescence (CL)-based immunoassay technique based on both dipstick and flow injection analytical formats is reported for the detection of atrazine. In the dipstick-based immunoassay technique, antibody (anti-atrazine) was first immobilized on the nitrocellulose membranes. The dipstick was then treated with atrazine and atrazine-horseradish peroxidase conjugate (atra-HRP) to facilitate the competitive binding.

Thiol-stabilized luminescent CdTe quantum dot as biological fluorescent probe for sensitive detection of methyl parathion by a fluoroimmunochromatographic technique.

Quantum dots (QDs) are preferred as high-resolution biological fluorescent probes because of their inherent optical properties compared with organic dyes. This intrinsic property of QDs has been made use of for sensitive detection of methylparathion (MP) at picogramme levels. The specificity of the assay was attributed to highly specific immunological reactions.

Enhancement of chemiluminescence for vitamin B12 analysis.

In the current article, chemiluminescence (CL) from the vitamin B(12) and luminol reaction was studied under alkaline conditions to develop a sensitive analytical method for vitamin B(12) using the carbonate enhancement effect. The method was successfully applied to the determination of vitamin B(12) in vitamin B(12) tablets, multivitamin capsules, and vitamin B(12) injections. Experimental parameters were optimized, including luminol concentration, urea-hydrogen peroxide (urea-H(2)O(2)) concentration, effect of pH, and sequence of addition of reactants for obtaining maximum CL, which was not explored previously.

Thermal inactivation of glucose oxidase. Mechanism and stabilization using additives.

Thermal inactivation of glucose oxidase (GOD; beta-d-glucose: oxygen oxidoreductase), from Aspergillus niger, followed first order kinetics both in the absence and presence of additives. Additives such as lysozyme, NaCl, and K2SO4 increased the half-life of the enzyme by 3.5-, 33.