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Although there is a consensus on the definition of agricultural sustainability, there is a dearth of empirical evidence because of methodological challenges. The analytical framework will require incorporation of economic and ecological dimensions of agricultural sustainability and policy environment to promote it or otherwise. This study is an attempt to capture these dimensions and develop a composite index of agricultural sustainability for the Indo-Gangetic Plains of India using the indicator framework. The identification of the sustainability indicators was based on the review of literature followed by their revalidation by the experts based on the criteria of relevance and objectivity. In total, 79 indicators relating to soil, water, agro-biodiversity and productivity were selected, representing the status of the sustainability, pressures on it, and policy response to address the concerns. The robustness of the sustainability index was checked by employing various normalization methods and weighting schemes. The benchmark method of normalization representing a desirable range of the indicators, was found to be superior due to its usefulness in spatio-temporal comparison of the sustainability index. The results showed a moderate level of agricultural sustainability with an index of 0.52 for Haryana and Punjab. The framework has a wider applicability to assess the sustainability across the agro-climatic regions of India.

Whole-cell syntheses of representative modified purine and pyrimidine 2′-deoxy-β-D-ribonucleosides are described. The transglycosylation reactions were carried out at 55¡C using the thermostable bacteria, Bacillus stearothermophilus. These transformations were efficient and gave yields close to or greater than 50% (conversions >70%).

Whole cells of Escherichia coli and the thermostable bacteria, Bacillus stearothermophilus, were used for the efficient synthesis of the biologically and industrially important compound, thymidine, using 2'-deoxyinosine and thymine as substrates. In this conversion, the 2'-deoxyribose moiety of 2'-deoxyinosine was transferred to thymine by the transdeoxyglycosylation activity of these bacterial cells. For example, in the case of Bacillus stearothermophilus, the yield of pure thymidine was 56% (78% conversion). When xanthine oxidase was added to this whole cell process, the product yield increased to 68% (90% conversion). In this transformation, Bacillus stearothermophilus was used at a temperature of 55°C where the solubility of thymine is much higher than at 25°C. The bacterial cells have activity over a broad pH range (approximately 4.0 to 8.0) and the yield of product varied within this pH range with the optimum pH being at 5.2. Both bacterial cells showed a sharp decrease in activity at alkaline pHs. Cells of both bacteria can be used repeatedly without appreciable loss of activity. Thymidine was also produced from thymine and 2'-deoxyinosine using isolated purine nucleoside phos-phorylase. A dramatic increase in conversion occurred with PNPase in the presence of xanthine oxidase.

Abstract: Cathepsin B was purified to an apparent homogeneity from goat brain utilizing the techniques of homogenization, autolysis at pH 4, 30–70% (NH4)2SO4 fractionation, Sephadex G-100 column chromatography, organomercurial afinity chromatography and ion-exchange chromatography on CM-Sephadex C-50. The enzyme had a pH optima of 6 with α-N-benzoyl-D, L-arginine-β-naphthIylamide, benzyloxycarbonyl-arginine-arginme-4-methoxy -β-naphthylamide and azocasein as substrates. TheKm values for the hydrolysis of α-N-benzoyl-D, L-arginine-β-naphthylamide and benzyloxycarbonyl-arginine-arginine-4-methoxy -β-naphthylamide were 2.36 and 0.29 mM respectively in 2.5% dimethylsulphoxide. However, the correspondingKm values for these substrates in 1 % dimethylsulphoxide were 0.51 and 0.09 mM. The enzyme was strongly inhibited by thiol inhibitors and tetrapeptidyl chloromethylketones. Leupeptin inhibited the enzyme competitively withK i value of 12.5 � l0−9M. Dithioerythritol was found to be the most potent activator of this sulfhydryl protease. Molecular weight estimations on sodium dodecyl sulphate-polyacrylamide gel electrophoresis and on analytical Sephadex G-75 column were around 27,000 and 29,000 daltons respectively. Cathepsin B was found to reside in the lysosomes of goat brain. The highest percentage of cathepsin B was in cerebrum. However, the specific activity of the enzyme was maximum in pituitary gland.

2'-Deoxynucleoside diphosphates and triphosphates were synthesized from 2'-deoxy-nucleoside monophosphates by using nucleoside monophosphate kinase and nucleoside diphosphate kinase enzymes. This biocatalytic procedure is superior to chemical methods for obtaining these compounds and can be extended to other applications. © Rapid Science Ltd. 1998