## Materials and Methods  
### Bacterium Isolation and Characterization of Geobacillus  
Sediment samples were obtained from a geothermal spring in the Calientes geothermal field, Candarave, Tacna, Peru. The spring, designated as G8, was selected based on the presence of sediment, elevated temperatures (>60 \({}^{\circ}\)C), and accessibility. The G8 spring, with a water temperature of 65.3 \({}^{\circ}\)C and a pH of 7.35, is located at an altitude of 4162 m above sea level (UTM coordinates: 0.379908 E, 81.09185 N). The area surrounding the spring was characterized by sparse vegetation and the accumulation of brownish sediments (Figure 1). Approximately 250 g of sediment was collected from the upper 3 cm layer of the sediment bed, at a depth of up to 15 cm from the water surface, at the edge of the geothermal spring using a sterile plastic bottle. A suspension of sediment and spring water was transferred into a sterile thermos bottle to maintain a temperature close to that of the sample during both sampling and transport to preserve microbial viability. A sediment sample (10 g) was initially enriched in Luria-Bertani (LB) liquid medium (consisting of 10 g/L peptone, 5 g/L yeast extract, and 10 g/L sodium chloride) at a 10% (\(\
u\)/\(v\)) concentration. The enrichment culture was incubated at 60 \({}^{\circ}\)C for 48 h. After incubation, 100 \(\mu\)L of the enriched culture (OD 600 nm = 0.2) was spread onto LB agar plates supplemented with 1% (\(w\)/\(v\)) starch as the sole carbon source to selectively isolate amyloid bacteria. The plates were incubated at 60 \({}^{\circ}\)C until bacterial colonies appeared. After two days, bacterial colonies were individually collected and streaked three times on the same LB agar to ensure purity. Five amyloid colonies (G1, G2, G4, G16, and G23) were isolated, and the strain G4, which exhibited the highest amylase activity levels, was chosen for further characterization and genomic analysis. Amylase activity was quantified using the Miller method [24]: 100 \(\mu\)L of starch solution (0.5% \(w\)/\(v\)) and 100 \(\mu\)L of G4 culture supernatant were incubated at 60 \({}^{\circ}\)C for 15 min. Then, 300 \(\mu\)L of DNS reagent was added, and absorbance was measured at 540 nm. The morphology of the G4 strain was evaluated by analyzing colony shape, pigmentation, and microscopic characteristics using Gram staining, endospore formation assays, and motility tests. The effect of temperature on the growth of strain G4 was assessed by culturing it in LB liquid medium (pH 7) at a range of temperatures (37, 45, 50, 55, 60, 65, 70, 75, and 80 \({}^{\circ}\)C) for 48 h. Similarly, the effect of pH on growth was evaluated by incubating G4 in LB medium buffered at pH values ranging from 4 to 8 (100 mM sodium citrate for pH 4 and 5, 100 mM sodium phosphate for pH 6 and 7, and 100 mM Tris-HCl for pH 8) at a fixed temperature of 60 \({}^{\circ}\)C for 48 h. For acid production assays, substrates such as lactose, cellobiose, glycerol, sucrose, and xylose were used, following the methodology described by [PERSON] (2000) [25]. Carbon utilization of strain G4 was determined by culturing it in LB liquid medium (pH 7) supplemented with various substrates, including carboxymethylcellulose (CMC), starch, pectin, microcrystalline cellulose, casein, lactose, xylose, glucose, sucrose, cellobiose, and maltose, each at 1% (\(w/v\)) as a carbon source (Sigma Aldrich, St. Louis, MO, USA). Cultures were incubated at 60 \({}^{\circ}\)C for 48 h. Bacterial growth was monitored by measuring optical density at 600 nm. The extracellular hydrolytic enzyme activities, including cellulase, pectinase, xylanase, amylase, protease, and lipase, were assessed. The G4 isolate was cultivated on LB agar plates supplemented individually with specific substrates: carboxymethylcellulose (CMC) 1% (\(w/v\)), pectin 0.5% (\(w/v\)), oat spelt xylan 1% (\(w/v\)), potato starch 1% (\(w/v\)), casein 1% (\(w/v\)), and tributyrin 0.5% (\(v/v\)), following the protocol described by [PERSON] et al. (2024) with minor modifications [26].