Syntrophic methane production from volatile fatty acids: Focus on interspecies electron transfer.

Methane is a renewable biomass energy source produced via anaerobic digestion (AD). Interspecies electron transfer (IET) between methanogens and syntrophic bacteria is crucial for mitigating energy barriers in this process. Understanding IET is essential for enhancing the efficiency of syntrophic methanogenesis in anaerobic digestion. Interspecies electron transfer mechanisms include interspecies H2/formate transfer, direct interspecies electron transfer (DIET), and electron-shuttle-mediated transfer. This review summarizes the mechanisms, developments, and research gaps in IET pathways. Interspecies H2/formate transfer requires strict control of low H2 partial pressure and involves complex enzymatic reactions. In contrast, DIET enhances the electron transfer efficiency and process stability. Conductive materials and key microorganisms can be modulated to stimulate the DIET. Electron shuttles (ES) allow microorganisms to interact with extracellular electron acceptors without direct contact; however, their efficiency depends on various factors. Future studies should elucidate the key functional groups, metabolic pathways, and regulatory mechanisms of IET to guide the optimization of AD processes for efficient renewable energy production.

[Influence of harvest times and processing methods on contents of total flavonoids and total saponins in roots of Ophiopogon japonicus].

OBJECTIVE: To study the patterns of dynamic accumulation of total flavonoids and total saponins in the roots of Ophiopogon japonicus collected from different harvest times, and compare the contents of total flavonoids and total saponins in roots of O. japonicus which were processed with different methods. METHOD: The total flavonoids and total saponins contents in O. japonicus were determined by ultraviolet spectrophotometry. RESULT AND CONCLUSION: From December to January, the total contents of flavonoids and saponins in the roots of O. japonicus gradually decreased, and gradually increased from February to March, and kept stable in April. The contents of total flavonoids and total saponins in the O. japonicus were influenced by different processing methods.

[Study of application fertilizer on Aconitum carmichaeli].

OBJECTIVE: To study N, P, K and organic fertilizer on the action of the yield and quality of Aconitum carmichaeli. METHODS: Four factors quadratic regression rotation combination design and agricultural biological statistics were applicated. RESULTS: The amount and proportion of N, P, K and organic fertilizer had evident influence on the yield and quality of Radix Aconiti Lateralis Preparata. The regression equation really reflected the fact. CONCLUSION: The application of N 13.04 - 15.13 kg, P 38.70 - 44.34 kg, K 22.50 - 26.46kg and organic fertilizer 1900 - 2200 kg per mu can gain high yield (> or =550 kg/mu) at great possibilities in the experiment.