Page | 1450 Evaluation of possibility to produce green biocellulose nanofibers in simultaneous saccharification and fermentation of sustainable agro-industrial residues Wahib Al Abdullah 1 , Yaser Dahman 1,* 1 Department of Chemical Engineering, Ryerson University, Toronto, Ontario CANADA M5B 2K3 *corresponding author e-mail address: ydahman@ryerson.ca ABSTRACT The present study evaluates possibility to produce biocellulose nanofibers (BC) in simultaneous saccharification and fermentation (SSF). Pre-treated wheat straws (WS) were further incubated in the fermentation broth in the presence of Gluconacetobacter xylinus bacterium in the presence and absence of hydrolysis enzymes. WS were not filtered as common during separate hydrolysis and fermentation (SHF). Generally, results in the present study demonstrate that BC production in SSF is rather challenging, especially in the presence of hydrolysis enzymes. Total sugars produced during SSF were higher than SHF, and were generally identical under different pre-treatment and hydrolysis conditions (~54 g/L). This represents maximum amounts at complete hydrolysis of biomass due to the longer incubation time compared to SHF. Maximum BC production of 10.8 g/L was achieved when WS was chemically pretreated with 1% (by volume) dilute acid for 30 minutes at 121°C. Sample pre-treated with 2% acid at similar conditions resulted in 8.93 g/L BC produced. Typically, increasing duration and temperature of thermal treatment produced slightly more sugars, however, resulted in inhibited bacterial cells growth and resulted in slightly lower BC production. Considering that BC is also a good substrate for the cellulase, explains the higher concentration of remaining sugars (i.e., 15.50 g/L) when enzymatic hydrolysis was used. This led to lower yield of the final BC produced. Keywords: Biocellulose Nanofibers; Simultaneous Saccharification and Fermentation; Agro-Industrial Residues; Renewable Resources. 1. INTRODUCTION Cellulose is one of the most abundant components of biomass which is traditionally extracted from plant tissues (trees, cotton, etc.) [1]. Pure form of cellulose attains extraordinary biological and physical properties that are especially attractive in advanced applications in our everyday life [2-4]. The disadvantage of cellulose extracted from plant tissues is its contamination with organic impurities (hemicellulose and lignin). The purification process of these impurities requires insensitive chemical treatment that changes the polymer structure and significantly impacts its advanced characteristics [5, 6]. Cellulose can also be produced by certain bacterial species in fermentation yielding a very pure cellulose product with unique properties called Biocellulose Nanofibers (BC) [6, 7]. Microbial biocellulose (BC) is a highly crystalline and mechanically stable nanopolymer, which has excellent potential as a material in many novel applications [3-5]. The high surface-to-volume ratio of BC nanofibers combined with their unique properties such as the higher capacity for water, the higher permeability to oxygen, poly functionality, hydrophilicity and biocompatibility makes it an important material for different green biomedical applications [7-9]. Conventional production methods focus on BC synthesis by Acetobacter bacterial strain fermentation in an aerobic static or agitated culture containing nitrogen and carbon sources [9, 10]. A wide variety of simple sugars had been investigated and confirmed as a suitable carbon source feedstock in the fermentation media, the most common being glucose, fructose, xylose and sucrose [11- 13]. The high economical cost and low production rate of BC using this conventional method form the main barrier of an industrial scale production of BC worldwide [9]. Various attempts had been made to overcome these challenges by investigating alternative feedstock as a carbon source in the process. Fruit juice, molasses, mixtures of sugars and many others had been investigated to decrees the process economical cost and improve its production rate [14-19]. Nevertheless, with the repetitive world food price crisis in recent years it is highly controversial to use highly demanded agricultural corpse in industrial production of materials. To solve these challenges and reach an economically feasible BC production in industrial scale we need to utilize renewable feedstock resources that have the ability to develop higher production yield than currently reached, and overcome the use of expensive carbon source feedstock in the culture media [4, 20]. The utilization of agricultural wastes is increasingly forming a new trend in biomaterials production research. The row materials commonly referred to as cellulosic wastes are widely agreed on as cheap renewable and sustainable organic source for fermentation [21, 22]. Biofuels, such as biodiesel, bioethanol, and biobutanol represent an industry that utilizes cellulosic wastes as a carbon source in their fermentation production [23, 24]. In the same manner earlier studies reported successful BC production from cellulosic wastes, like the use of cotton fabrics waste, liquor pulping and rice bark [25-27]. Moreover, earlier studies showed that wheat straws (WS), a widely available agricultural waste, hold high potential as an effective and economical feedstock in fermentation reaction [28, 29]. In two of our recent studies, we investigated two successful methods of BC production by utilizing Volume 6, Issue 5, 2016, 1450 -1456 ISSN 2069-5837 Open Access Journal Received: 10.05.2016 / Revised: 25.08.2016 / Accepted: 18.09.2016 / Published on-line: 13.10.2016 Original Research Article Biointerface Research in Applied Chemistry www.BiointerfaceResearch.com