Wheat bran as substrate for enzyme production and its application in the bio-deinking of mixed office waste (MOW) paper

Abstract

Judicial utilization of various low-cost agro-industrial wastes and optimization of various process parameters can reduce production costs of enzymes. Wheat bran was found to be the best carbon source among various agro-industrial wastes explored for Penicillium citrinum NCIM-1398. Additionally, ammonium sulphate was found as the optimum nitrogen source at moisture content 70%, pH 5.5, and temperature 30 °C for enzyme production. The maximal enzyme activities of endo β-1,4-glucanase, xylanase, FPase, and amylase were 21.0 IU/gds, 3140 IU/gds, 3.59 FPU/gds, and 73.4 IU/gds, respectively. Bio-deinking of mixed office waste paper improved the pulp brightness by 9.5%, and the effective residual ink concentration were decreased by 26.3% in comparison to MOW after pulping. Similarly, dirt counts were reduced from 4880 to1360 ppm at an enzyme dose of 6.0 IU/g compared to deinking without enzyme. The strength properties of enzymatically deinked pulp such as tear index, tensile index, and burst index increased by 6.92%, 11.31%, and 7.61%, respectively, compared with the control.

Xylanase Production by Solid-State Fermentation for the Extraction of Xylooligosaccharides from Soybean Hulls

“…Therefore, it has been recognised that using agricultural waste as the sole carbon source for xylanase synthesis could be a good solution. Although wheat bran is considered a waste, there is strong evidence that the bran is recognised as a suitable substrate for xylanase production because of its hemicellulosic nature (presence of nonstarch polysaccharides, 41 to 60 %), favourable degradability and the presence of some nutrients ( 24 , 25 ). Furthermore, the biochemical composition shows that after hydrolysis of wheat bran, significant amounts on dry mass basis of soluble sugars such as glucose (42.5 %), xylose (15.4 %), arabinose (3.1 %) and galactose (2.7 %) are produced, which are necessary to initiate the growth of microorganism and promote their further growth ( 26 ).…”

Horseradish and potato peroxidase biobleaching of mixed office waste paper

“…Kopania et al (2008) reported a 5% increase in pulp brightness during the peroxidase bleaching of MOW paper with MgSO4 and EDTA. Brogdon et al (1998) also reported enhanced brightness at high-temperature peroxide bleaching of MOW using formulated bleach stabilizers.…”

“…MOW paper also shows poor bleachability with the commonly used chemical bleaching agents, including chlorine dioxide, oxygen, hydrogen peroxide, and sodium dithionite (Knutson et al 2005). To overcome the poor bleachability of MOW pulp by chemical agents, a wide number of enzymes, including cellulase (Tiwari et al 2018), xylanase (Kumar et al 2017), laccase (Riva 2006;Singh and Arya 2019), and peroxidase (Archibald 1992), have been studied (Biswas et al 2019b). The enzyme application in pulp and paper industry are limited due to their high cost, and it is hard to maintain their stability during the industrial process (Kumar et al 2018b(Kumar et al ,c, 2019aLin et al 2018).…”

“…In addition, toxic byproducts are produced during the chemical process (Kumar et al 2018a), which results in environmental pollution. In comparison, a biobleaching process is a less intrusive, less expensive method (An et al 2002;Biswas et al 2019b) and it has been shown to be an eco-friendly technology compared to chemical processes (Biswas et al 2019a;Kumar et al 2019b). Therefore, microbial degradation of dyes is gaining popularity in the paper and textile industries.…”