# Effect of Ultrasound on Fermentation of Thick Molasses Worts by Distiller's Yeast
###### Abstract  
This study investigates the effect of ultrasonic treatment on the fermentation of molasses worn with a density range of 18-24 \({}^{\circ}\)Blg, using two high-performance _Saccharomyces cerevisiae_ yeast strains: Thermosacc Dry and Ethanol Red. The primary objective was to determine if ultrasound could accelerate fermentation and increase ethanol yield. The research showed that ultrasonic treatment at 24 kHz significantly increased fermentation dynamics and ethanol yield by 5 to 20%, depending on the yeast strain and word density. Higher word densities (22-24 \({}^{\circ}\)Blg) showed more pronounced positive effects. Ultrasound treatment caused visible indentations in the yeast cell walls and promoted cell aggregation. In addition, the study investigated the influence of different ultrasound amplitudes on fermentation efficiency and showed that higher amplitudes further improved ethanol production in 22-24 \({}^{\circ}\)Blg works. These results suggest that ultrasound can improve the efficiency and profitability of ethanol production, highlighting the potential for further research to optimise industrial fermentation processes. The application of ultrasound in biotechnology, particularly in fuel ethanol production, could lead to significant economic benefits on a global scale. urlrasounds; distillery yeast; sugar beet molasses; ethanol yield 2020  
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the second largest in the world. In addition, beet molasses, sugar beets, sweet sorghum, and fruit are popular raw materials, especially in Europe. Starchy raw materials are also necessary, with corn being the most commonly used due to its extensive use in the U.S. [3]. Each raw material has its own unique properties, and one key metric is the ethanol yield (see Table 1). It is understood that this value is a crucial determinant for choosing a raw material for an ethanol production process. Another critical factor that affects the choice of raw material is its price. According to the literature, financial expenses constitute 45-86% of the total production costs of ethanol [4; 5; 6; 7; 8; 9]. Therefore, ways of reducing costs should be sought in making cheap feedstock choices [3]. The efficiency and profitability of the fermentation process, as well as the quality of the final product, are contingent upon the selection of industrially relevant microorganisms [11]. Irrespective of the type of microorganism, they must possess several essential characteristics that are indispensable for an effective fermentation process: high tolerance to ethanol, tolerance for low pH values, tolerance to elevated temperatures, stability under process conditions, high fermentation ability, and high yield of the product per unit of the substrate assimilated [12]. The first listed feature--the ability of microorganisms to withstand high ethanol concentrations--is the key to successful fermentation. However, several factors are thought to contribute to the tolerance of ethanol, which are the following: toxicity of ethanol or intermediates, genetic components, environmental influence, physiological yeast condition, and composition of word [13]. Yeast is the most employed microorganism in ethanol production. During glycolysis, they convert sugars, mostly hexoses, including glucose and fructose, into pyruvate, which is later reduced to ethanol. Overall, two moles of ATP and ethanol are derived per molecule of converted hexose [14]. _Saccharomyces cerevisiae_ yeast, isolated from fermentation environments and improved over many years to efficiently carry out targeted fermentation of selected media, has relatively narrow fermentation capabilities compared to other yeast genera. _S. cerevisiae_ strains usually are able to ferment glucose, fructose, sucrose, galactose, mannose, and maltose. Sugars such as cellobiose, lactose, arabinose, xylose, and sorbose are not metabolised. Some saccharides, including trehalose and raffinose, are metabolised, but relatively slowly or to a partial extent [15].