Probiotic-derived polyphosphates have attracted interest as potential therapeutic agentsto improve intestinal health. The current study discovered the intracellular accumulation ofpolyphosphates in a marine cyanobacteriumSynechococcussp. PCC 7002 as nano-sized granules.The maximum accumulation of polyphosphates inSynechococcussp. PCC 7002 was found atthe late logarithmic growth phase when the medium contained 0.74 mM of KH2PO4, 11.76 mMof NaNO3, and 30.42 mM of Na2SO4. Biogenic polyphosphate nanoparticles (BPNPs) wereobtained intact from the algae cells by hot water extraction, and were purified to remove theorganic impurities by Sephadex G-100 gel filtration... More
Probiotic-derived polyphosphates have attracted interest as potential therapeutic agentsto improve intestinal health. The current study discovered the intracellular accumulation ofpolyphosphates in a marine cyanobacteriumSynechococcussp. PCC 7002 as nano-sized granules.The maximum accumulation of polyphosphates inSynechococcussp. PCC 7002 was found atthe late logarithmic growth phase when the medium contained 0.74 mM of KH2PO4, 11.76 mMof NaNO3, and 30.42 mM of Na2SO4. Biogenic polyphosphate nanoparticles (BPNPs) wereobtained intact from the algae cells by hot water extraction, and were purified to remove theorganic impurities by Sephadex G-100 gel filtration. By using 100 kDa ultrafiltration, BPNPs werefractionated into the larger and smaller populations with diameters ranging between 30–70 nmand 10–30 nm, respectively. 4′,6-diamidino-2-phenylindole fluorescence and orthophosphateproduction revealed that a minor portion of BPNPs (about 14–18%) were degraded during simulatedgastrointestinal digestion.In vitrostudies using lipopolysaccharide-activated RAW264.7 cells showedthat BPNPs inhibited cyclooxygenase-2, inducible nitric oxide (NO) synthase expression, and theproduction of proinflammatory mediators, including NO, tumor necrosis factor-α, interleukin-6,and interleukin-1βthrough suppressing the Toll-like receptor 4/NF-κB signaling pathway. Overall,there is promise in the use of the marine cyanobacteriumSynechococcussp. PCC 7002 to produceBPNPs, an anti-inflammatory postbiotic.