&lt;b&gt;Reuse of wastewater from pulp industry for the optimization of fungal xylanase production

Geisiany Maria De Queiroz-Fernandes,Bruna Letícia Martins,Cynthia Barbosa Rustiguel

doi:10.4025/actascibiolsci.v39i1.34459

<b>Reuse of wastewater from pulp industry for the optimization of fungal xylanase production

Geisiany Maria De Queiroz-Fernandes, Bruna Letícia Martins + Show 1 more

Open Access

https://doi.org/10.4025/actascibiolsci.v39i1.34459

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Abstract

The production of enzymes using agro-industrial waste is a low cost alternative for the reuse of byproducts, with the subsequent impact decrease on the environment. Current analysis produced xylanase using fungus Aspergillus niger , with two types of wastewater generated during the pulp chemical bleaching phase as inducers. Xylanase was produced by submerged liquid fermentation and factorial design optimized parameters that influence production (concentration of wastewater and production period). Initial culture conditions (pH, temperature and agitation) were optimized independently. Alkaline wastewater was more effective than acidic wastewater for the induction of xylanase in optimized conditions: 50% of culture medium, 7-day production, 30°C, pH 6.0 and agitation at 160 rpm. Despite different results, acidic and alkaline wastewaters induced xylanase production by A. niger when employed in concentrations lower than or equal to 50% of culture medium and in the most optimal conditions described above. Alkaline wastewater is highlighted as the most efficient for such production.

Highlights

The production of wastewater by the pulp industry resulting from the chemical bleaching stage has exponentially increased due to rise in demands for the product (Muthezhilan, Ashok, & Jayalakshmi, 2007)
Wastewater concentration and production period were the two independent variables evaluated by factorial design to obtain xylanase, Codified axial points were calculated with (2k) 1⁄4, where k is the number of independent variables in the study
The factorial design developed for acidic wastewater, referring to the specific activity (Figure 1), showed R2 = 0.95, and proved to be significant for variables wastewater type and production period, at the linear and quadratic level, with p ≤ 0.1

Summary

Introduction

The production of wastewater by the pulp industry resulting from the chemical bleaching stage has exponentially increased due to rise in demands for the product (Muthezhilan, Ashok, & Jayalakshmi, 2007). 21-26, Jan.-Mar., 2017 improvement in the quality of animal feed (Bakri, Al-Jazairi, & Al-kayat, 2008) It has been generally studied in its application in pulp industry acting on the hydrolysis of xylan linkages, an important structural component of hemicellulolytic polysaccharide which occurs in the constitution of the wall of the plants cell (Gupta & Kar, 2009). Its function is the manufacture of cellulose fiber, formed by linkages between lignin and hemicellulose It becomes more permeable and facilitates the release of lignin, reducing chemical products at the bleaching stage (Techapun, Sinsuwongwat, Poosaran, Watanabe, & Sasaki, 2001; Muthezhilan et al, 2007; Sharma et al, 2014). The use of pulp industry wastewater represents the possibility of using a low-cost substrate (Fang, Chang, Hsieh, & Fang, 2007; Bakri et al, 2008; Pérez-Rodríguez et al, 2014)

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Conclusion