Fig. 3: Thermal variability in Red Sea coastal sediments and metabolic response of associated bacterial communities.

a Temperature monitoring over 18 months in high temperature variability (HTV, red), intermediate temperature variability (ITV, blue), and low temperature variability (LTV, black) sediments. Temperatures are expressed as average values from the three stations belonging to each level of thermal variability (see Source Data). Black arrows indicate the sampling sessions. b Width of the temperature variability in the sediments from the three stations. The three sites do not show significantly different MAT (Dunnett’s multiple comparisons test, all p-values <0.05) but significantly different temperature distribution (i.e., temperature variability; Levene’s test F_2,52700 = 7328.2, p < 2.2E-16). c Frequency distribution (percentages) of temperatures across different levels of temperature variability. d, e Activities of esterases extracted from HTV, ITV and LTV sediments. The relative specific activity of the protein extracted from the sediments (units/g of sediment) is expressed as the mean ± SD (n = 3 replicates per station per temperature variability, see Source Data) for each temperature tested for the August and December samples, respectively. f, g Thermal unfolding patterns of proteins (stability) are measured by CD and expressed as degrees of ellipticity (θ). The normalized CD melting curves of proteins extracted during August and December, respectively, report the θ₂₂₀(T) recorded at 220 nm from 4 °C to 95 °C; data are plotted as the mean of three replicates (see Source Data).