In the unicellular green alga Chlamydomonas reinhardi (strain y-1), synthesis of the enzymes required for urea hydrolysis is under substrate induction control by urea and under end product repression control by ammonia. Hydrolysis of urea if effected by the sequential action of the discrete enzymes urea carboxylase and allophanate lyase, collectively called urea amidolyase. The carboxylase conv...

An cu-L-fucosidase has been purified from rat epididymis by fractionation of extracts with ammonium sulfate and subsequent chromatography on ion exchange celluloses. It is a glycoprotein with a molecular weight of 210,000 to 220,000 and dissociates in the presence of mercaptoethanol and guanidine hydrochloride or sodium dodecyl sulfate. The dissociated material behaves as two components with mo...

Gln-tRNA is synthesized from Glu-tRNA in most microorganisms by a tRNA-dependent amidotransferase in a reaction requiring ATP and an amide donor such as glutamine. GatDE is a heterodimeric amidotransferase that is ubiquitous in Archaea. GatD resembles bacterial asparaginases and is expected to function in amide donor hydrolysis. We show here that Methanothermobacter thermautotrophicus GatD acts...

Anaerobic digestion of autoclaved (160°C, 6.2 bar) and untreated source segregated food waste (FW) was compared over 473 days in semi-continuously fed mesophilic reactors with trace elements supplementation, at organic loading rates (OLRs) of 2, 3, 4 and 6 kg volatile solids(VS)/m(3)d. Methane yields at all OLR were 5-10% higher for untreated FW (maximum 0.483±0.013 m(3) CH4/kg VS at 3 kg VS/m(...

The effect of cyclodextrin (CD) inclusion complexes on the degradation of benzylpenicillin in aqueous solutions was investigated at several different pH values and 37°C. The effects of neutral as well as both positively and negatively charged CDs were evaluated; all together 13 different CDs. Kinetic studies with HPβCD and RMβCD at pH ranging from 1.2 to 9.6 showed that CDs have stabilizing eff...

Cross-linked enzyme aggregates (CLEAs) have emerged as interesting biocatalyst design for immobilization. These new generation enzyme biocatalysts, CLEAs, in addition to exhibiting good mechanical stability, can be highly active, since they do not include large amounts of foreign particulate nonenzymatic material and may have increased stability. Naringinase (NGase) is an enzyme complex with hi...

The chemical budget in the upper troposphere over the tropical South Pacific is analyzed using aircraft measurements made at 6-12 km altitude in September 1996 during the Global Tropospheric Experiment (GTE) Pacific Exploratory Mission (PEM) Tropics A campaign. Chemical loss and production rates of along the aircraft flight tracks are calculated with a photochemical model constrained by observa...

cow’s milk allergy is one of the most common food allergies in childhood. beta- lactoglobulin (β-  lg) is  a dominant  allergen in  cow’s milk. hydrolysis is  known as  an effective method to reduce the allergenicity of proteins. thus, the objective of this study was to compare the allergenicity of β-lg and its hydrolysates using an animal model. twenty four balb/c mice were divided into three ...

Abstract Background The objective of the work carried out was to assess toxicity degradation products (DPs) for drug felbamate. Stress studies were performed in condition specified international council harmonization (ICH) guideline Q1A (R2). Results degraded under alkaline stress conditions generate two (DPs). They separated on a Phenomenex C8 column (250 mm × 4.6 mm, 5 µm); mobile phase compo...

Nitrogen-containing compounds that enter concrete together with raw materials, in particular chemical modifiers of mixture and concrete, as well those present Portland cement, are capable forming ammonia a result decomposition. The processes formation emission cause both deterioration the atmosphere residential premises reason for decrease strength operational safety indicators reinforced struc...