Cell wall-associated 1,4-beta-D-xylanase in Cryptococcus albidus var. aerius: in situ characterization of the activity

Journal of General Microbiology
V NotarioJ R Villanueva


1,4-beta-D-Xylanase (1,4-beta-D-xylan xylanohydrolase; EC has been detected in both cell-free extracts and culture fluids of the yeast Cryptococcus albidus var. aerius grown on glucose as the only carbon source. Mild acid treatment of whole cells proved that the enzyme was extracellularly located. The activity remained almost completely linked to the wall after cell breakage, only being liberated in the presence of salt at high concentration. After release, the enzyme became very unstable and so has been characterized in situ in 'permeabilized' cells. The maximum production took place at the beginning of the exponential growth phase. The optimum pH and temperature for activity were 5.0 and 40 degrees C, respectively. The enzyme degraded xylan and xylo-oligosides by an endo-splitting mechanism giving xylobiose, xylotriose and xylose as the main end-products. Activation energy and kinetic constants for xylan degradation were determined. Several metal ions such as Ag+ and Hg2+ inhibited the enzyme. The possible function of this endo-xylanase in Cr. albidus var. aerius is discussed.


Aug 29, 2003·Phytochemistry·D M RastG O Hollenstein

Related Concepts

Cell Wall
Cell-Free System
Hydrogen-Ion Concentration
Substrate Specificity
Xylanase D

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Synthetic Genetic Array Analysis

Synthetic genetic arrays allow the systematic examination of genetic interactions. Here is the latest research focusing on synthetic genetic arrays and their analyses.

Neural Activity: Imaging

Imaging of neural activity in vivo has developed rapidly recently with the advancement of fluorescence microscopy, including new applications using miniaturized microscopes (miniscopes). This feed follows the progress in this growing field.

Computational Methods for Protein Structures

Computational methods employing machine learning algorithms are powerful tools that can be used to predict the effect of mutations on protein structure. This is important in neurodegenerative disorders, where some mutations can cause the formation of toxic protein aggregations. This feed follows the latests insights into the relationships between mutation and protein structure leading to better understanding of disease.

Congenital Hyperinsulinism

Congenital hyperinsulinism is caused by genetic mutations resulting in excess insulin secretion from beta cells of the pancreas. Here is the latest research.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Epigenetic Memory

Epigenetic memory refers to the heritable genetic changes that are not explained by the DNA sequence. Find the latest research on epigenetic memory here.

Cell Atlas of the Human Eye

Constructing a cell atlas of the human eye will require transcriptomic and histologic analysis over the lifespan. This understanding will aid in the study of development and disease. Find the latest research pertaining to the Cell Atlas of the Human Eye here.

Femoral Neoplasms

Femoral Neoplasms are bone tumors that arise in the femur. Discover the latest research on femoral neoplasms here.