Fig. 4: The effect of programmed lysis system on PLH production.

a The process of producing PLH using programmed lysis system. Stage I was producing PLH and stage II was a programmed lysis system that took effect, lysed E. coli, and released PLH. b PLH production of engineered populations PLH-1 and PLH-5 in shake flasks. PLH-1 consists of B0032, and PLH-5 consists of B0033 which harbors PLS based on PS3361. PLH released into the medium was defined as ‘free PLH’. (P values = 0.655746; 0.000873.) c Fluorescence microscopy was used to detect PLH production in cells stained with Nile red. The PLH granule was stained by Nile red. d Morphological of PLH-1 and PLH-5. Three experiments were repeated independently with similar results. e PI staining to detect cell mortality in fermentation broth at different times. The percentage of fluorescence intensity represented the mortality ratio. The fluorescence intensity of living cells was less than 10³, and that of dead cells was more than 10³. The fluorescence intensity of living cells was less than 10³, and that of dead cells was more than 10³. For each sample, at least 20,000 counts were recorded using a 0.5 mL/s flow rate. All data were exported in FCS3 format and processed using Flow Jo software (FlowJo-V10). f pH-stat fed-batch cultures of PLH-5 in a 5-L bioreactor. Values are shown as mean ± s.d. from three biological replicates. Values are shown as mean ± s.d. from three (n = 3) biological replicates. Two-tailed t-tests were used to determine statistical significance. Statistical significance was indicated as * P < 0.05, ** for P < 0.01 and *** for P < 0.001, respectively. Source data are provided as a Source Data file.