## 1 Introduction  
Dextran is a high molecular weight homo-polysaccharide composed of D-glucose units largely linked by type \(\alpha\) (1\(\rightarrow\)6) bonds and to a lesser extent \(\alpha\) (1\(\rightarrow\)3), \(\alpha\) (1\(\rightarrow\)4), and \(\alpha\) (1\(\rightarrow\)2) bonds [1]. The structure of a dextran, such as the type of bond and the degree of branching, depends on the dextranascentase responsible for its synthesis [2, 3]. Dextranscraes (EC2.4.1.5) are secreted by lactic acid bacteria (LAB) of the genera Leuconostoc, _Lactobacillus_, _Streptococcus_, _Pediococcus_, and _Weissella_[4,5]. Dextran is widely used in industrial applications. In the health area, it is used as a blood plasma extender, heparin substitute, and for anticoagulant therapy [3,6]. However, in the sugar industry this polymer has a negative effect. The formation of dextran results in a costly loss of sucrose and considerably decreases the yield in the sugar manufacturing process [7]. Accordingly, dextran is an undesirable compound in the sugar production process from sugarcane (_Saccharum officinalarum_). Dextran formation is due to the presence of LAB producers of dextransucrases. Furthermore, dextran increases the viscosity of the sugarcane juices, decreasing the efficiency of clarification, filtration, and crystallization during sugar production. Increased dextran is a measure of sugarcane deterioration, affecting the quality of the final product, as well as production efficiency [8, 9, 10]. The use of dextranase (EC 3.2.1.11) preparations to eliminate dextran in sugar is an effective practice [8]. Dextranases called \(\alpha\)-D-(1\(\rightarrow\)6)-glucan-6-glucanohydrolases hydrolyze the glycosidic bond of dextran and release glucose or isomaltose molecules. They are found in the glucohydrolase families (GH) GH-49 and GH-66, and according to the catalytic specificity, they are divided into two groups: exodext that hydrolyze dextran at its ends and release glucose units, and endodextnanases that cut the polymer within the chain to yield isomaltooligosaccharides [11]. These low molecular weight oligosaccharides do not influence the viscosity of the sugarcane juice. Thus, enzyme addition improves the performance of the cane sugar production process [12]. The enzyme source must be considered as one of the key factors when considering its use on an industrial scale, where it is essential to be cost competitive. These enzymes are found in different ecosystems and are produced by a variety of filamentous fungi, bacteria, and, to a lesser extent, yeasts [11,13]. Dextranases produced by fungi have received much attention because of their high specific enzyme activity and isomaltooligosaccharide products [14]. Recombinant dextranase production is a viable option to obtain enzyme preparations in large volumes [13,15]. The biochemical properties of the filamentous fungus _Talaromyces minioluteus_ dextranase native and recombinant (_Tm_DEX49A and _r-Tm_DEX49A, respectively) have been extensively studied [16,17]. The gene was cloned, sequenced (GenBank accession number L41562), and expressed in the yeast _Pichia pastoris_ (currently _Komagataella phaffii_) using the methanol-regulated alcohol oxidase 1 (AOX1) promoter [15,18]. The 3D structure of _r-Tm_DEX49A was solved in the apo-enzyme and product-bound forms. The _r-Tm_DEX49A folds into two domains [19,20]. As an endodextranase, _r-Tm_DEX49A yielded isomaltose as the major product of dextran hydrolysis. This reaction occurs with net inversion at the anomeric carbon, implying a single displacement mechanism [19]. Fed-batch fermentation of _K. phaffii_ expressing _r-Tm_DEX49A under the AOX1 and GAP promoter was reported [13,15]. The production was scaled up to 30 L under the AOX1 promoter [21]. _K. phaffii_ seems to be a suitable heterologous host for the recombinant production of crude dextranase preparations to be used in the sugar industry, since it does not produce endogenous sucrose-transforming enzymes, neither dextranolytic activity nor endogenous dextranase enzymes.