Purification and Some Properties of Alkaline Proteinase Produced by Pseudomonas maltophilia
An organism capable of producing an alkaline proteinase was isolated and identified as Pseudomonas maltophilia.By simple Sephadex-gel chromatographies, the alkaline proteinase was purified to homogeneity with a specific activity 74-fold higher than that of the culture broth. The purified enzyme had a molecular weight of 46,000 consisting of 19,000 and 27,000 molecular subunits. The optimum pH and temperature were pH 10.5 and 55°C, respectively. Calcium ion activated and stabilized the enzyme activity. The enzyme was inhibited by ethylenediaminetetraacetate, phenylmethylsulfonyl fluoride and chymostatin, indicating that the enzyme was a serine metalloenzyme.
The lake sediments have registered the information of palaeoclimate and palaeoenvironment in the lake itself and the regional scale. This also leads to a complexity in study of the palaeolimnology by all kinds of proxies. How to purify these proxies to indicate the palaeoclimate has become a problem to be solved. Most of the proxies can qualitively identify the percentage of allochthonous and autochthonous organic components, e.g. δ13corg CD/TC. The model introduced in this note has provided a method of quantitatively calculating the amount of allochthonous organic carbon. As for determination of regulating parameters, i.e. A1 and As, further work is still in need.