A novel thermoactive phosphatidylcholine-specific phospholipase C (PC-PLC_Bs) was identified from Bacillus stearothermophilus isolated from a soil sample from an olive oil mill. Enhanced PLC_Bs production was observed after 10 h of incubation at 55 °C in a culture medium containing 1 mM of Zn²⁺ with an 8% inoculum size and 6 g/L glucose and 4/L yeast extract as the preferred carbon energy and nitrogen sources, respectively. PLC_Bs was purified to homogeneity by heat treatment, ammonium sulfate fractionation, and anion exchange chromatography, resulting in a purification factor of 17.6 with 39% recovery. Interestingly, this enzyme showed a high specific activity of 8450 U/mg at pH 8–9 and 60 °C, using phosphatidylcholine PC as the substrate, in the presence of 9 mM sodium deoxycholate and 0.4 mM Zn²⁺. Remarkable stability at acidic and alkali pH and up to 65 °C was also observed. PLC_Bs displayed a substrate specificity order of phosphatidylcholine > phosphatidylethanolamine > phosphatidylserine > sphingomyelin > phosphatidylinositol > cardiolipin and was classified as a PC-PLC. In contrast to phospholipases C previously isolated from Bacillus strains, this PLC_Bs substrate specificity was correlated to its hemolytic and anti-bacterial potential against erythrocytes and Gram-positive bacterial membranes, which are rich in glycerophospholipids and cardiolipin. An evaluation of PLC_Bs soybean degumming process efficiency showed that the purified enzyme reduced the phosphorus content to 35 mg/kg and increased the amount of diacylglycerols released, indicating its ability to hydrolyze phospholipids in the crude soybean oil. Collectively, PLC_Bs could be considered as a potential catalyst for efficient industrial oil degumming, advancing the edible oil industry by reducing the oil gum volume through transforming non-hydratable phospholipids into their hydratable forms, as well as through generating diacylglycerols, which are miscible with triacylglycerols, thereby reducing losses.

Streptomyces strains are renowned for their ability to produce a wide array of secondary metabolites, which play crucial roles in ecological interactions and have significant pharmaceutical applications. The optimization of culture conditions is a key factor in maximizing the production of these bioactive compounds. This study investigated the growth patterns and bioactivity of a newly isolated Streptomyces gobitricini cultured on different media: R5, R5E, R2YE, and YEME. Data showed that R5 and R2YE media supported higher biomass accumulation, achieving peak dry weights of 225 mg/L and 175 mg/L, respectively, after 96 h-incubation, compared to R5E (52 mg/L) and YEME (48 mg/L). Growth phases, especially the exponential phases, were longer and more pronounced in nutrient-rich media like R5 and R2YE. Furthermore, the inherent antioxidant activities, enzyme inhibitory properties against α-amylase, α-glucosidase, lipase, and trypsin, as well as secreted phospholipase A2, cyclooxygenases and lipooxygenase, showed significant variations influenced by the growth media, with R5 exhibiting the highest overall bioactivity. Specifically, R2YE extracts demonstrated potent inhibitory effects on α-glucosidase and phospholipases, while YEME showed promising lipase inhibition. These findings emphasized the critical role of media composition in promoting secondary metabolite production in S. gobitricini, ultimately enhancing its potential medicinal applications for several human diseases such as obesity and inflammation. Consequently, optimizing bacterial culture conditions could significantly improve yield and efficiency of bioactive compounds.