A rapid purification of bovine testicular hyaluronidase by chromatography on dermatan sulphate-substituted 1,6-diaminohexane--sepharose 4B.

Dimensionless apparent ionization constants of charged low-molecular-weight species may be obtained from paper-electrophoretic data at 20-25 degrees C with buffers (I0.1-0.5) of measured pH (1.5-12.5) containing oxalate ions. Relative mobilities rather than absolute mobilities were measured by using glycerol and m-nitrobenzenesulphonate respectively as standards of zero and unit mobility. Application of the procedure to ionizations of adenine, adenosine, 2'-deoxyadenosine, 3'-deoxyadenosine, 3':5'-cyclic AMP, ADP, ADP-glucose-agrocin 84 and ATP is described.     

Microbial Metabolism of the Plant Phenolic Compounds Ferulic and Syringic Acids under Three Anaerobic Conditions

Abstract Ferulic and syringic acids are methoxylated aromatic compounds that often serve as models of the subunits of lignin. Although these compounds have important implications for global carbon cycles, there is limited information on their fate in anoxic environments. Enrichment cultures were established on these two model compounds under methanogenic, sulfidogenic, and denitrifying conditions, using a Raritan River (New Jersey) marsh sediment as the inoculum. All cultures completely degraded ∼1.5 mm of both substrates. Methane production in the methanogenic cultures corresponded to the stoichiometric values expected for complete mineralization to CO₂ and CH₄. Sulfate and nitrate reduction in their respective cultures were both greater than 60% of the amounts predicted for complete mineralization. Aromatic intermediates of ferulic and syringic acid metabolism were identified, and pathways of degradation under sulfidogenic and denitrifying conditions are proposed. Syringic acid is sequentially O-demethylated to gallic acid under both sulfate and nitrate-reducing conditions before ring cleavage occurs. Ferulic acid undergoes propenoate side chain reduction, O-demethylation, removal of an acetate moiety from the side chain, and decarboxylation to form catechol. Catechol is further degraded under sulfidogenic conditions. Under denitrifying conditions, ferulic acid undergoes loss of an acetate moiety, prior to O-demethylation, to form protocatechuic acid, the last product detected before ring cleavage. Received: 23 February 1996; Revised: 20 May 1996; Accepted: 24 May 1996     

Commentary on Gressel's review

Transgenic Research -     

Vernalization in calabrese (Brassica oleracea var. italica) - a model for apex development

Using data from an experiment in controlled environment cabinets,with temperatures between 7 C and 23 C, a model of vernalizationwas developed which predicts the change in apex diameter ofcalabrese with temperature. The model does not include a juvenilephase and the rate of diameter growth is maximal at 15.8 C.When tested on field-grown crops of two cultivars, the modeldescribed apex expansion well. Key words: Model, cardinal temperatures, juvenility, vernalization, initiation     

Effects of nutrient dosing on subsurface methanotrophic populations and trichloroethylene degradation

In in situ bioremediation demonstration at the Savannah River Site in Aiken, South Carolina, trichloroethylene-degrading microorganisms were stimulated by delivering nutrients to the TCE-contaminated subsurface via horizontal injection wells. Microbial and chemical monitoring of groundwater from 12 vertical wells was used to examine the effects of methane and nutrient (nitrogen and phosphorus) dosing on the methanotrophic populations and on the potential of the subsurface microbial communities to degrade TCE. Densities of methanotrophs increased 3–5 orders of magnitude during the methane- and nutrient-injection phases; this increase coincided with the higher methane levels observed in the monitoring wells. TCE degradation capacity, although not directly tied to methane concentration, responded to the methane injection, and responded more dramatically to the multiple-nutrient injection. These results support the crucial role of methane, nitrogen, and phosphorus as amended nutrients in TCE bioremediation. The enhancing effects of nutrient dosing on microbial abundance and degradative potentials, coupled with increased chloride concentrations, provided multiple lines of evidence substantiating the effectiveness of this integrated in situ bioremediation process. Received 13 November 1995/ Accepted in revised form 12 September 1996