Column bioreactor use for optimization of pectinase production in solid substrate cultivation

Abstract

This study aimed to determine the influence of process variables and production, of polygalacturonase (PG) and polymetylgalacturonase (PMG) by solid substrate cultivation using a fixed bed column bioreactor. A fractional factorial design (FFD) was used to study the effect of the following variables: microorganism (Aspergillus oryzae and Aspergillus niger), substratum (wheat bran and defatted rice bran), aeration (40 and 60 ml h -1 g -1 ), pectin (5 and 10 g g -1 ) and nitrogen (urea and ammonium sulfate). Microorganism, aeration and initial pectin were identified in FFD as significant variables (p<0.05) on PG production. A central composed design to optimize PG and PMG productions indicated that Aspergillus niger presents higher PG production; substratum and nitrogen do not affect PG production; the aeration rate affects positively the production of PG and negatively the production of PMG and the initial pectin concentration affects positively both PG and PMG production. The optimal point of aeration and initial pectin concentration for PG production are 66.13 ml h -1 g -1 and 12.8 g g -1 , respectively and for PMG production are 40 ml h -1 g -1 and 15.0 g g -1 , respectively.

Valorization of wheat bran for the production of polygalacturonase in SSF of Aspergillus sojae

“…On the other hand, the maximum productivity value of the current study (5.58 U/g substrate −1 h −1 ) was lower than those calculated as 6.15 and 7.71 U/g substrate −1 h −1 from the data of Linde et al (2007) and Fontana et al (2005), respectively. However, it was in line with the productivity of Taş kın and Eltem (2008) calculated as 5.53 U/g substrate −1 h −1 .…”

“…Besides it is even higher than the higher range of the PG activities of 368.37 and 385 U/g reported by Linde et al (2007), Fontana et al (2005) and Taş kın and Eltem (2008), respectively. At this point, it should be noted that the authors preferred to use nutritive supplementation to the fermentation media in all of these mentioned reports contrary to our process that is composed of only wheat bran and water.…”

Xylanase production by Aspergillus awamori under solid state fermentation conditions on tomato pomace

“…In addition, a plate-type SSF bioreactor at lab scale was used in order to evaluate the effect of aeration on enzymes production. This type of bioreactor was selected for these experiments because its configuration allows the application of adjustable forced air flow and the distribution of the substrate along different layers of low bed height improves heat and mass transfer and these effects presumably encourages the development of the fermentative process (34,46). Finally, due to xylanase was the enzyme produced in higher levels (see Results and Discussion section) and in order to ensure that the obtained data are reliable, a complete revision of the optimal conditions for the determination of the xylanase activity was performed.…”

Bioconversion of wheat bran for polygalacturonase production by Aspergillus sojae in tray type solid-state fermentation

“…On the other hand, the maximum PG activity obtained in the current study (298 U/g substrate) is thought to be promising as it is significantly higher than the maximum PG activity produced by A. niger CCT0916 using cashew apple bagasse and tray type bioreactor (Alcantara and Silva, 2012). It should be considered that the process conditions should be optimized in a more controlled bioreactor to reach the PG activity level of 387 U/g dried medium obtained by an A. niger in a fixed-bed column bioreactor (Linde et al, 2007).…”