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

Abstract

a b s t r a c tWheat bran was tested as the solid substrate for the tray-type solid-state fermentation (SSF) production of polygalacturonase (PG) enzyme by A. sojae mutant strain e a high-PG activity producer. PG production of A. sojae was found to reduce as the thickness of the substrate increase from 8 mm to 14 mm at 90% relative humidity. An interaction between the thickness of the bed and relative humidity of the environment was determined with the help of experimental design and statistical analysis tools. As a result, the PG activity could be enhanced by 31% as the process conditions optimized. Additionally, 11 mm thickness and 70% relative humidity were selected as the PG production favoring conditions with the maximum PG activity of 298 U/g substrate in tray type of SSF without the addition of any nutritive or inducing supplements into wheat bran. The kinetic study conducted in the trays revealed the presence of reduction in the water activity on the 4th day of the SSF process under stated conditions. The productivity of the process conducted under optimized conditions was 3.41 U/g substrate À1 h À1 for the 4th day of the SSF.

Optimization of Protease and Amylase Production by Rhizopus oryzae Cultivated on Bread Waste Using Solid-State Fermentation

“…e maximum protease and amylase activities were recorded at the layer thickness of 1 cm with respective values of 2400 U/g and 100 U/g. Similarly, results were observed (11 mm thickness) by Demir and Tari [72] with wheat bran SSF by Aspergillus sojae for polygalacturonase production. In fact, an increase of the layer thickness may reduce oxygen for fungus inducing a poor growth [73].…”

Effect of physicochemical parameters on the polygalacturonase of an Aspergillus sojae mutant using wheat bran, an agro‐industrial waste, via solid‐state fermentation

“…The drum bioreactor sample was taken from the 55th hour of the SSF process using wheat bran . The enzyme sample from tray‐type fermentation was obtained at 70% relative humidity using wheat bran . The commercial pectinase was diluted to 1/100 with sodium acetate buffer (pH 4.8); however, the other samples were not diluted since they had low protein concentrations close to each other.…”

Pectinolytic enzymes-solid state fermentation, assay methods and applications in fruit juice industries: a review

“…Wheat bran along with orange peel and lemon peels has been reported as best substrate combination for pectinase production by Aspergillus giganteus NRRL10 (Ortiz et al 2017). Demir and Tari (2016) have reported the effect of moisture content on wheat bran thickness, which affects polygalacturonase production in SSF. In earlier reports, Demir and Tari (2014) have used wheat bran as most suitable solid substrate without the addition of any nutritive supplement for the production of polygalacturonase in SSF by mutant strain of A. sojae.…”