## 1 Introduction  
_Bacillus cereus_ is an aerobic facultative, spore-forming Gram-positive bacteria, widely distributed in the natural environment and considered an important food contaminant responsible for food spoilage. It can grow in highly variable conditions, including a broad pH range between 4.5 and 9.5, a minimum water activity (a\({}_{w}\)) for growth of 0.93, a broad range of temperature from 4 \({}^{\circ}\)C (psychotrophic or psychotherapeutic strains) to 48 \({}^{\circ}\)C, and NaCl concentrations up to 7% [1]. Furthermore, it is an opportunistic human pathogen producing virulence factors, such as toxins, associated with two forms of food poisoning, depending on the context in which it grows: emetic and diarral syndrome. The emetic syndrome, characterized by intense vomiting, is caused by a heat-stable peptide toxin, called cereulide, which is pre-formed in food or ingredients under various conditions, whereas diarral is caused by three heat-labile enterotoxins, the tripartite haemolysin BL (HbI), the non-haemolytic enterotoxin (Nhe), and the single protein cytotoxin K (CytK), produced in the small intestine after contaminated food is consumed [2,3]. However, a human dose-response relationship has not been described for either the emetic or diarral toxin produced by _B. cereus_[1]. Current consumer demands for complex and mildly processed food with limited refrigerated shelf-life as ready-to-eat (RTE) products are leading to an increase on the _B. cereus_ outbreaks all over the world, being associated with concentrations higher than 10\({}^{5}\) cfu/g in implicated foods [4]. _B. cereus_ is responsible for a large number of cases of food poisoning, resulting in 155 outbreaks, 1636 cases, 44 hospitalizations, and 7 deaths reported by EFSA in 2019 [5]. Due to its ubiquity, it can contaminate a great variety of food products, such as pasta, rice, soups, sauces, meat, or dairy products, and most cases are attributed to incorrectly preserved food, including temperatures as high as 14 \({}^{\circ}\)C or long-term storage of the food at room temperature [6; 7]. Moreover, its ability to produce endospores provides great resistance to heat, radiation, chemicals, and desiccation, allowing this bacteria to cope with adverse conditions for prolonged periods of time [8]. In this sense, it represents a concern in the dairy industry due to spores' resistance to pasteurization and standard sanitation processes, being found in pasteurized milk and milk-derived products, such as milk powder and infant formulas [9; 10]. _B. cereus_ is also considered one of the main spoilage microorganisms in milk and dairy products. Its growth at levels over 5 log cfu/g is considered hazardous for the consumer and is also responsible for the spoilage [11; 12]. Among dairy products, fresh cheese constitutes a very suitable food matrix for the growth of this pathogen because of its physicochemical characteristics (pH 5.8-6.8, a\({}_{\text{w}}\) 0.94-0.99, 0.1-1.2% NaCl). Thus, a fresh cheese highly consumed in Catalan regions of Spain, called \"mat6\", was selected as a food model in this study since its pH (6.78), a\({}_{\text{w}}\) (0.99), and NaCl (0.1%) values make it suitable for the growth of _B. cereus_. In addition, evidence has placed cheese products as a great reservoir of this pathogen since it has been widely described in a variety of cheeses, i.e., with a count range of 2-6 log cfu/g in buffalo mozzarella cheese [13], 5.5-5.7 log cfu/g in artisanal cheeses, such as Requeson, Cotija, or Adobero from Mexico [14], or 1-3.1 log cfu/g in Ricotta cheese [15].The main focus of the contamination of raw milk in the dairy chain is farms during milking via soil-contaminated udders and teats and the milking equipment, although additional contamination can occur in dairy plants [16].