Polyhydroxyalkanoates (PHA) synthesis by activated sludge using volatile fatty acids (VFAs) in fermentation liquid of excess sludge as carbon source is a hotspot in the field of environmental biotechnology. However, there is no unified conclusion on the effects of non-VFAs, mainly dissolved organic matter (DOM), on PHA production. Thus, this critical review mainly introduces the main characteristics and common analysis methods of DOM in anaerobic fermentation liquid. The effects of DOM on PHA production are analyzed from the aspects of microbiology, metabolic regulation and sludge properties. The results of different studies showed that high concentration of DOM is bad for PHA production, but an appropriate amount of DOM is conducive to the stability of sludge properties, reducing the final PHA purification cost. Finally, suitable strategies were proposed to regulate the PHA synthesis by activated sludge with DOM for PHA production by anaerobic fermentation liquid.
Anaerobiosis ; Bioreactors ; Fatty Acids, Volatile ; Fermentation ; Polyhydroxyalkanoates ; Sewage

Objective : To investigate the effect of sinomenine on proliferation and migration of multiple myeloma (MM) cells by regulating STAT3 and NF-κB signaling pathway． Methods : The cultured U266 cells were treated with different concentrations of sinomenine (0，0．5，1，2 mmol / L) ．The control group was added DMSO with 0．5% concentration．CCK-8 assay was used to detect the proliferation of U266 cells．Flow cytometry was used to detect the apoptosis of U266 cells．Western blot assay was used to detect the expression levels of apoptosis-related proteins， STAT3 and NF-κB signaling pathway proteins in the each group. Results : Compared with CON group，the apopto- sis of U266 cells increased after Sinomenine treatment，the proliferation was inhibited ; B lymphoma-2 (Bcl-2) mye- loid and cell leukemia-1 (Mcl-1) expression level decreased ; activated Caspase-3 (cleaved Caspase-3) and PARP (Cleaved Caspase-3) expression levels increased ; the activity of STAT3 and NF-κB signaling pathway decreased. Conclusion Sinomenine can down-regulate the activity of STAT3 and NF-κB signaling pathway，promote the apop- tosis of U266 cells and inhibit the proliferation of U266 cells.