This work verifies that amitraz and oxalic acid treatment affect honeybee cuticle proteolytic enzymes (CPE). Three bee groups were monitored: oxalic acid treatment, amitraz treatment, control. Electrophoresis of hydrophilic and hydrophobic CPE was performed. Protease and protease inhibitor activities (in vitro) and antifungal/antibacterial efficiencies (in vivo), were analyzed. Amitraz and oxal...

Highly self-ordered alumina nanopore arrays were fabricated using hard anodization technique in different mixtures of oxalic/phosphoric acid. The phosphoric acid concentration was varied from 0.05 to 0.3 M while the oxalic acid concentration was changed between 0.3 and 0.4 M. The self ordered nanoporous arrays were obtained in anodization voltage changing from 130 to 200 V. The interpore distan...

A simple, automated colorimetric method for determining oxalic acid in plant material is based on the quantitative reduction in colour of a zirconium/3,4-dihydroxyazobenzene-2'-carboxylic.acid complex by microgram quantities of oxaIic acid. I t is suitable for use over a wide range of oxalic acid concentrations. Interference from phosphate, sulphate, citric acid and malic acid was encountered b...

Oxalic acid is widely distributed in plants. Although its concentration is not normally high, certain plants such as Oxalis sp., Begonia sp., rhubarb, and spinach contain large amounts of the acid. Cotyledons of spinach, for example, have been reported to contain up to 26% dry weight of oxalic acid (4). The only enzyme system previously reported to metabolize oxalate in plants is oxalate oxidas...

Response surface methodology was used to evaluate optimal time, temperature and oxalic acid concentration for simultaneous saccharification and fermentation (SSF) of corncob particles by Pichia stipitis CBS 6054. Fifteen different conditions for pretreatment were examined in a 2(3) full factorial design with six axial points. Temperatures ranged from 132 to 180 degrees C, time from 10 to 90 min...

The syntheses and characterization of four new hybrid coordination networks based on lanthanide ions (Ln = Nd, Sm) and 1,3-carboxymethylimidazolium (L) salt in the presence of oxalic acid (H2ox) are reported. The influence of the synthesis parameters, such as the nature of the lanthanide ion (Nd3+ or Sm3+), the nature of the imidazolium source (chloride [H2L][Cl] or zwitterionic [HL] form) and ...

The ability of commercially-available citric, oxalic and gluconic acids to bind Co#+ and Zn#+ was investigated and compared with culture filtrates from Aspergillus niger, a fungus capable of citric, gluconic and oxalic acid production, grown in the presence and absence of cobalt or zinc phosphate. This work demonstrated that citric and oxalic acid and the A. niger culture filtrates can bind Co#...

Although it has been recognized that oxalic acid is decomposed by a variety of microorganisms (2-6), relatively little is known of the details of oxalic acid metabolism. The present study represents an attempt to establish the mechanism of oxalate degradation at the enzyme level by the use of a bacterium isolated from soil. Partially purified enzyme preparations obtained from the organism catal...

Brown-rot decay results in rapid reduction in degree of polymerization of holocellulose, with concomitant strength loss without removing lignin. Development of new methods of wood protection will require focusing on early events in the sequence of fungal attack during colonization. Pit membranes (sapwood) of wood cell walls represent a readily available source of nonlignified carbohydrate, i.e....