28 research outputs found
Development of a transformation system for Aspergillus sojae based on the Agrobacterium tumefaciens-mediated approach
Improved biomass and protein production in solid-state cultures of an Aspergillus sojae strain harboring the Vitreoscilla hemoglobin
Microbial strain improvement for enhanced polygalacturonase production by Aspergillus sojae
Assessment of pectinase production by Bacillus mojavensis I4 using an economical substrate and its potential application in oil sesame extraction
Strain improvement of Aspergillus sojae for increased l-leucine aminopeptidase and protease production
Optimizing Production of Pectinase from Orange Peel by Penicillium oxalicum PJ02 Using Response Surface Methodology
Flow paths of water and sediment in a tidal marsh: Relations with marsh developmental stage and tidal inundation height
Further experimental and neuroanatomical investigations of the nerve tracts of the pineal complex in anura
Pectinase Activity Determination: An Early Deceleration in the Release of Reducing Sugars Throws a Spanner in the Works!
Recently, it has been suggested that pectinases could be used to hydrolyze pectin in biorefineries based on pectin-rich agro-industrial wastes. However, for this to be viable, the cost of their production would need to be lowered significantly. In fact, over the last few decades, there have been many attempts to improve pectinase production by existing strains or to screen for new strains from environmental isolates. In these studies, it is necessary to measure pectinase activities. Many researchers use single-time-point assays that involve incubation of pectinolytic extracts with pectic substrates for a fixed time, followed by determination of the liberated reducing sugars. However, different researchers use quite different conditions for this assay. Furthermore, no attention has been given to the reaction profile during the assay. In the current work, we show, for the first time, that a significant deceleration of the rate of liberation of reducing sugars occurs over the first ten minutes of the reaction. As a consequence, the incubation time used in a single-time-point assay has a large effect on the value obtained for the activity. In fact, we demonstrate that, depending on the particular combination of incubation time, pectin concentration and reaction temperature, the same extract could be reported to have activities that differ by an order of magnitude. In addition, we show that the relative activities obtained with polygalacturonic acid do not correlate with those obtained with pectin. We conclude that it is currently impossible to make meaningful comparisons between pectinase activities reported in the literature by workers who have used different assay conditions. Therefore there is an urgent need for the development of a standardized assay for evaluating the saccharification potential of pectinase complexes