Polygalacturonase characterization

Endo-polygalacturonases I and II (PGI and PGII) isolated from recombinant A. niger were characterized with respect to pH optimum, activity on polygalacturonic acid (pga), mode of action and kinetics on oligogalacturonates. 

In order to characterize the pectinolytic enzymes encoded by these clones, the culture supernatants of all these clones were tested for pectate lyase and polygalacturonase activity, using thiobarbutiric acid as described in materials and methods. Absorption at 550 nm indicates the activity of pectate lyase whereas absorption at 510 nm indicates the activity of polygalacturonase. 

Characterization of some endo-polygalacturonases from Sclerotinia sclerotiorum... 

The exo-polygalacturonase from Aspergillus tubingensis characterization and cloning of the gene... 

Candida boidinii is a further yeast producer of pectic enzymes complex. The production is induced by the presence of pectin as a C-source in the medium the primary methabolic path is the utilization of methanol and the secondary the utilization of pectate chains. The pectic enzymes were bound on the cell walls or released on the cultivation medium. The main enzyme of pectic complex, polygalacturonase, was briefly characterized and the possibility to influence the production of its multiple forms discussed. 

This study reports on the production of pectic enzymes and partial characterization of polygalacturonases produced by Candida boidinii. Candida boidinii belongs to the so called methylotrophic yeasts with famous utilization of methanol. Pectin, the natural substrate of pectic enzymes complex, can serve for microorganisms as a C - source by two different ways after deesterification with pectinesterase as methanol and after hydrolytic cleavage with... 

The poor activities of pectic enzymes in the cultivation medium led us to prove the cell cytosole and the cell walls for these activities. The cytosole contains only traces of polygalacturonase activity, but the suspension of cell walls established the activity which seems to be widely sufficient for yeast growth and development. The characterization of this cell wall bound enzymes will be the object of our next studies. 

Gainvors, A., Nedjaoum, N., Gognies, S., Muzart, M., Nedjma, M., and Belarbi, A., Purification and characterization of acidic endo-polygalacturonase encoded by the PGL1-1 gene from Saccharomyces cerevisiae. FEMS Microbiol Lett 2000, 183 (1), 131-135. 

Kapoor, M., Khalil, B., Qasim, Bhushan, Bharat, et al., Production and partial purification and characterization of a thermo-alkali stable polygalacturonase from Bacillus sp. MG-cp-2. Process Biochemistry 2000, 36 (5), 467-473. 

Polygalacturonases in Other Plant Tissues. PG activity is usually associated with ripe fruit tissues and, as we have seen, the activity can he due to an endo-PG, exo-PG, or to hoth enzymes. However, I have already mentioned the occurrence of PG activity in unripe tomatoes (21). pears (45). and cucumbers (52). The enzymes in green tomatoes and cucumbers have been characterized as exo-PG s. 

SakeUaris, G., Nikolaropoulos, S., Evangelopoulos, A. E. (1989). Purification and characterization of an extraceUular polygalacturonase from Lactobacillus plantarum strain BA 11. Journal of Applied Bacteriology, 7, 77-85. 

Pectinesterases.—The pectinesterase activities in tomatoes stored at different temperatures have been determined. The level of activity is low in mature green fruit but increased rapidly at ca. 20 °C - but not at either 4 or 33 C. The storage-life of tomatoes kept at 33 °C for several days is increased, owing to suppression of the polygalacturonase activity. Multiple forms of the enzyme are responsible for the pectinesterase activity of tomatoes one of the forms has been characterized. ... 

---