AIM: To study the benef icial effects of triterpene α,β-amyrin and the underlying mechanisms in an experimental pancreatitis model. METHODS: Acute pancreatitis was induced in five groups of rats (n = 8) by L-arginin...AIM: To study the benef icial effects of triterpene α,β-amyrin and the underlying mechanisms in an experimental pancreatitis model. METHODS: Acute pancreatitis was induced in five groups of rats (n = 8) by L-arginine (2 × 2.5 g/kg, intraperitoneal, 1 h apart) and 1 h later, they received a single oral dose of α,β-amyrin (10, 30 and 100 mg/kg),methylprednisolone (30 mg/kg) and vehicle (3% Tween 80). A saline (0.9% NaCl) treated group served as a normal control. Efficacy was assessed at 24 h by determination of serum levels of amylase, lipase and proinflammatory cytokines [tumor necrosis factor (TNF)-α and interleukin (IL)-6], pancreatic myeloperoxidase (MPO) activity, lipid peroxidation [thiobarbituric acid reactive substances (TBARS)], nitrate/nitrite levels, and the wet weight/body weight ratio. Tissue histology and the immunoreactivity for TNF-α and inducible nitric oxide synthetase (iNOS) were performed. RESULTS: α,β-amyrin and methylprednisolone treatments significantly (P < 0.05) attenuated the L-arginine-induced increases in pancreatic wet weight/body weight ratio, and decreased the serum levels of amylase and lipase, and TNF-α and IL-6, as compared to the vehicle control. Also, pancreatic levels of MPO activity, TBARS, and nitrate/nitrite were signifi cantly lower. Histological f indings and TNF-α and iNOS immunostaining further confirmed the amelioration of pancreatic injury by α,β-amyrin. CONCLUSION: α,β-amyrin has the potential to combat acute pancreatitis by acting as an anti-in? ammatory and antioxidant agent.展开更多
Mixed culture fermentation(MCF)is challenged by the unqualified activity of enriched bacteria and unwanted methane dissolution under low temperatures.In this work,caproate production from xylose was investigated by MC...Mixed culture fermentation(MCF)is challenged by the unqualified activity of enriched bacteria and unwanted methane dissolution under low temperatures.In this work,caproate production from xylose was investigated by MCF at a low temperature(20°C).The results showed that a 9 d long hydraulic retention time(HRT)in a continuously stirred tank reactor was necessary for caproate production(~0.3 g/L,equal to 0.6 g COD/L)from xylose(10 g/L).The caproate concentration in the batch mode was further increased to 1.6 g/L.However,changing the substrate to ethanol did not promote caproate production,resulting in~1.0 g/L after 45 d of operation.Four genera,Bifidobacterium,Caproiciproducens,Actinomyces,and Clostridium_sensu_stricto_12,were identified as the enriched caproate-producing bacteria.The enzymes in the fatty acid biosynthesis(FAB)pathway for caproate production were identified via metagenomic analysis.The enzymes for the conversion of(C_(n+2))-2,3-Dehydroxyacyl-CoA to(C_(n+2))-Acyl-CoA(i.e.,EC 1.3.1.8 and EC 1.3.1.38)in the reverseβ-oxidation(RBO)pathway were not identified.These results could extend the understanding of low-temperature caproate production.展开更多
浓香型白酒酿造过程中离不开窖泥中微生物的相互作用,本项目利用宏基因组高通量测序监测人工窖泥中微生物变化。该窖泥采用优质塘泥培养,通过两轮(各三个排次)的发酵产酒,发现窖泥己酸含量从3.86 g/L下降到1.33 g/L,基酒中己酸乙酯含量...浓香型白酒酿造过程中离不开窖泥中微生物的相互作用,本项目利用宏基因组高通量测序监测人工窖泥中微生物变化。该窖泥采用优质塘泥培养,通过两轮(各三个排次)的发酵产酒,发现窖泥己酸含量从3.86 g/L下降到1.33 g/L,基酒中己酸乙酯含量降低60%左右,同时,乳酸乙酯含量升高85%以上;窖泥取样提取宏基因组高通量测序,通过Illumina Miseq对16s r DNA V3+V4区进行测序分析,未发酵窖泥中含有大量的Fimicutes(厚壁菌门)占据优势地位,发酵49 d菌群比例占比较均衡,发酵两轮后菌群比例变化较大,发酵两轮后由于大量的Lactobacillus(耐酸乳酸杆菌)繁殖以及Clostridium(梭菌属)等产己酸微生物含量的降低,抑制了产己酸微生物的生长,导致乳酸大量堆积,窖池pH降低,窖泥板结,碳酸盐等堆积造成窖池老化,可以通过人工老窖泥菌群变化监测判断窖泥质量。展开更多
Caproate, produced by microbial chain elongation process, is potential to replace the diversified fossilbased products, contributing to carbon neutrality. However, its production performance is far from industrial app...Caproate, produced by microbial chain elongation process, is potential to replace the diversified fossilbased products, contributing to carbon neutrality. However, its production performance is far from industrial application, so the cost-effective enhancement measures are highly needed. This study confirmed powdered activated carbon(PAC) has a significant effect on enhancing caproate production performance.The production, yield, and selectivity of caproate were improved by more than 1-fold by the optimized PAC dosage of 15 g/L, comparing with control. Mechanism investigation from a new visual angle showed that PAC accelerated ethanol oxidation to generate acetyl-Co A, and simultaneously boosted the efficiency of reverse β oxidation(RBO) by promoting the timely reaction of butyrate and acetyl-Co A to synthesis caproate. The addition of PAC also shifted the microbial community by enriching more caproateproducing bacteria but eliminating irrelevant ones. Furthermore, metagenomic analysis revealed that PAC effectively up-regulated the functional genes encoding key enzymes responsible for ethanol oxidation and RBO pathway, which was the root cause for the improved caproate production. This study presented the intrinsic insights into the mechanism of PAC promoting caproate generation, laying a foundation to the scale production of caproate.展开更多
基金Supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil
文摘AIM: To study the benef icial effects of triterpene α,β-amyrin and the underlying mechanisms in an experimental pancreatitis model. METHODS: Acute pancreatitis was induced in five groups of rats (n = 8) by L-arginine (2 × 2.5 g/kg, intraperitoneal, 1 h apart) and 1 h later, they received a single oral dose of α,β-amyrin (10, 30 and 100 mg/kg),methylprednisolone (30 mg/kg) and vehicle (3% Tween 80). A saline (0.9% NaCl) treated group served as a normal control. Efficacy was assessed at 24 h by determination of serum levels of amylase, lipase and proinflammatory cytokines [tumor necrosis factor (TNF)-α and interleukin (IL)-6], pancreatic myeloperoxidase (MPO) activity, lipid peroxidation [thiobarbituric acid reactive substances (TBARS)], nitrate/nitrite levels, and the wet weight/body weight ratio. Tissue histology and the immunoreactivity for TNF-α and inducible nitric oxide synthetase (iNOS) were performed. RESULTS: α,β-amyrin and methylprednisolone treatments significantly (P < 0.05) attenuated the L-arginine-induced increases in pancreatic wet weight/body weight ratio, and decreased the serum levels of amylase and lipase, and TNF-α and IL-6, as compared to the vehicle control. Also, pancreatic levels of MPO activity, TBARS, and nitrate/nitrite were signifi cantly lower. Histological f indings and TNF-α and iNOS immunostaining further confirmed the amelioration of pancreatic injury by α,β-amyrin. CONCLUSION: α,β-amyrin has the potential to combat acute pancreatitis by acting as an anti-in? ammatory and antioxidant agent.
基金the National Natural Science Foundation of China(Nos.51808120 and 52170127)China Postdoctoral Science Foundation(No.2019M652235)the Program for Innovative Research Team in Science and Technology in Fujian Province University(China)(IRTSTFJ).
文摘Mixed culture fermentation(MCF)is challenged by the unqualified activity of enriched bacteria and unwanted methane dissolution under low temperatures.In this work,caproate production from xylose was investigated by MCF at a low temperature(20°C).The results showed that a 9 d long hydraulic retention time(HRT)in a continuously stirred tank reactor was necessary for caproate production(~0.3 g/L,equal to 0.6 g COD/L)from xylose(10 g/L).The caproate concentration in the batch mode was further increased to 1.6 g/L.However,changing the substrate to ethanol did not promote caproate production,resulting in~1.0 g/L after 45 d of operation.Four genera,Bifidobacterium,Caproiciproducens,Actinomyces,and Clostridium_sensu_stricto_12,were identified as the enriched caproate-producing bacteria.The enzymes in the fatty acid biosynthesis(FAB)pathway for caproate production were identified via metagenomic analysis.The enzymes for the conversion of(C_(n+2))-2,3-Dehydroxyacyl-CoA to(C_(n+2))-Acyl-CoA(i.e.,EC 1.3.1.8 and EC 1.3.1.38)in the reverseβ-oxidation(RBO)pathway were not identified.These results could extend the understanding of low-temperature caproate production.
文摘浓香型白酒酿造过程中离不开窖泥中微生物的相互作用,本项目利用宏基因组高通量测序监测人工窖泥中微生物变化。该窖泥采用优质塘泥培养,通过两轮(各三个排次)的发酵产酒,发现窖泥己酸含量从3.86 g/L下降到1.33 g/L,基酒中己酸乙酯含量降低60%左右,同时,乳酸乙酯含量升高85%以上;窖泥取样提取宏基因组高通量测序,通过Illumina Miseq对16s r DNA V3+V4区进行测序分析,未发酵窖泥中含有大量的Fimicutes(厚壁菌门)占据优势地位,发酵49 d菌群比例占比较均衡,发酵两轮后菌群比例变化较大,发酵两轮后由于大量的Lactobacillus(耐酸乳酸杆菌)繁殖以及Clostridium(梭菌属)等产己酸微生物含量的降低,抑制了产己酸微生物的生长,导致乳酸大量堆积,窖池pH降低,窖泥板结,碳酸盐等堆积造成窖池老化,可以通过人工老窖泥菌群变化监测判断窖泥质量。
基金supported by the Natural Science Foundation of Sichuan Province (No. 2022NSFSC1042)Fundamental Research Funds for the Central Universities+1 种基金National Natural Science Foundation of China (No. 52000132)supported by the Sichuan Province College Students’ Innovation and Entrepreneurship Training Plan (No. S202210610415)。
文摘Caproate, produced by microbial chain elongation process, is potential to replace the diversified fossilbased products, contributing to carbon neutrality. However, its production performance is far from industrial application, so the cost-effective enhancement measures are highly needed. This study confirmed powdered activated carbon(PAC) has a significant effect on enhancing caproate production performance.The production, yield, and selectivity of caproate were improved by more than 1-fold by the optimized PAC dosage of 15 g/L, comparing with control. Mechanism investigation from a new visual angle showed that PAC accelerated ethanol oxidation to generate acetyl-Co A, and simultaneously boosted the efficiency of reverse β oxidation(RBO) by promoting the timely reaction of butyrate and acetyl-Co A to synthesis caproate. The addition of PAC also shifted the microbial community by enriching more caproateproducing bacteria but eliminating irrelevant ones. Furthermore, metagenomic analysis revealed that PAC effectively up-regulated the functional genes encoding key enzymes responsible for ethanol oxidation and RBO pathway, which was the root cause for the improved caproate production. This study presented the intrinsic insights into the mechanism of PAC promoting caproate generation, laying a foundation to the scale production of caproate.
