Anti-inflammation mechanisms of a homogeneous polysaccharide from Phyllanthus emblica L. on DSS induced colitis mice via the gut microbiota and metabolites alteration.

Phyllanthus emblica L. offers promising therapeutic potential for inflammatory diseases. This study revealed the molecular structure of a homogeneous polysaccharide purified from Phyllanthus emblica L. (PEP-1) and evaluated its anti-inflammatory effects on ulcerative colitis (UC) in mice. In the in vivo experiment, administered in varying dosages to dextran sulfate sodium (DSS)-induced UC models, PEP-1 significantly alleviated colonic symptoms, histological damages and reshaped the gut microbiota. Notably, it adjusted the Firmicutes/Bacteroidetes ratio and reduced pro-inflammatory species, closely aligning with shifts in the fecal metabolites and metabolic pathways such as the metabolism of pyrimidine, beta-alanine, and purine. These findings underscore the potential of PEP-1 as a therapeutic agent for UC, providing insights into the mechanisms through gut microbiota and metabolic modulation.

The alleviating effect of ellagic acid on DSS-induced colitis via regulating gut microbiomes and gene expression of colonic epithelial cells.

The anti-inflammatory effect of ellagic acid (EA) and its possible underlying mechanism in dextran sulfate sodium (DSS)-induced mouse chronic colonic inflammation were studied. It was observed that EA administration significantly alleviated the colonic inflammation phenotypes, including decreasing the disease activity index (DAI), enhancing the body weight loss, and improving the shortened length of the colon and pathological damage of colon tissue. Additionally, EA reshaped the constitution of the gut microbiota by elevating the ratio of Bacteroidetes along with Bacteroides and Muribaculaceae, while decreasing the proportion of Firmicutes. The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2 (PICRUSt2) revealed that the metabolic function of the gut microbiota was also changed. Furthermore, mouse colon transcriptome analysis showed that the tight junction and peroxisome proliferator-activated receptor (PPAR) signaling pathways were activated and the expressions of related genes were upregulated after EA intervention. These results showed that EA could remodel the gut bacterial composition, change the intestinal epithelial cell gene expressions in mice, and consequently improve the colonic inflammatory symptoms.

Dextran-Sulfate-Sodium-Induced Colitis-Ameliorating Effect of Aqueous Phyllanthus emblica L. Extract through Regulating Colonic Cell Gene Expression and Gut Microbiomes.

The anti-inflammation effect of aqueous Phyllanthus emblica L. extract (APE) and its possible underlying mechanism in dextran sulfate sodium (DSS)-induced mice chronic colonic inflammation were studied. APE treatment significantly improved the colitic symptoms, including ameliorating the shortening of the colon, increasing the DSS-induced body weight loss, reducing the disease activity index, and reversing the condition of colon tissue damage of mucus lost and goblet cell reduction. Overproduction of serum pro-inflammatory cytokines were suppressed by the treatment of APE. Gut microbiome analysis showed that APE remodeled the structure of gut bacteria in phylum and genus levels, upregulating the abundance of phylum Bacteroidetes, family Muribaculaceae, and genus Bacteroides and downregulating the abundance of phylum Firmicutes. The reshaped gut microbiome caused metabolic functions and pathway change with enhanced queuosine biosynthesis and reduced polyamine synthesis pathway. Colon tissue transcriptome analysis further elucidated APE-inhibited mitogen-activated protein kinase (MAPK), cytokine-cytokine receptor interaction, and tumor necrosis factor (TNF) signaling pathways and the expressions of the genes that promote the progress of colorectal cancer. It turned out that APE reshaped the gut microbiome and inhibited MAPK, cytokine-cytokine receptor interaction, and TNF signaling pathways as well as the colorectal-cancer-related genes to exert its colitis protective effect.

Integrated lipid production, CO2 fixation, and removal of SO2 and NO from simulated flue gas by oleaginous Chlorella pyrenoidosa.

CO2, SO2, and NO are the main components of flue gas and can cause serious environmental issues. Utilization of these compounds in oleaginous microalgae cultivation not only could reduce air pollution but could also produce feedstock for biodiesel production. However, the continuous input of SO2 and NO inhibits microalgal growth. In this study, the toxicity of simulated flue gas (15% CO2, 0.03% SO2, and 0.03% NO, balanced with N2) was reduced through automatic pH feedback control. Integrated lipid production and CO2 fixation with the removal of SO2 and NO was achieved. Using this technique, a lipid content of 38.0% DW was achieved in Chlorella pyrenoidosa XQ-20044. The lipid composition and fatty acid profile indicated that lipid production by C. pyrenoidosa XQ-20044 cultured with flue gas is suitable as a biodiesel feedstock; 81.2% of the total lipids were neutral lipids and 99.5% of the total fatty acids were C16 and C18. The ratio of saturated fatty acids to monounsaturated fatty acids in the microalgal lipid content was 74.5%. In addition, CO2, SO2, and NO from the simulated flue gas were fixed and converted to biomass and lipids with a removal efficiency of 95.9%, 100%, and 84.2%, respectively. Furthermore, the utilization efficiencies of CO2, SO2, and NO were equal to or very close to their removal efficiencies. These results provide a novel strategy for combining biodiesel production with biofixation of flue gas.

Sequential phototrophic-mixotrophic cultivation of oleaginous microalga Graesiella sp. WBG-1 in a 1000 m2 open raceway pond.

BACKGROUND: Microalgae are an important feedstock in industries. Currently, efforts are being made in the non-phototrophic cultivation of microalgae for biomass production. Studies have shown that mixotrophy is a more efficient process for producing algal biomass in comparison to phototrophic and heterotrophic cultures. However, cultivation of microalgae in pilot-scale open ponds in the presence of organic carbon substrates has not yet been developed. The problems are heterotrophic bacterial contamination and inefficient conversion of organic carbon. RESULTS: Laboratory investigation was combined with outdoor cultivation to find a culture condition that favors the growth of alga, but inhibits bacteria. A window period for mixotrophic cultivation of the alga Graesiella sp. WBG-1 was identified. Using this period, a new sequential phototrophic-mixotrophic cultivation (SPMC) method that enhances algal biomass productivity and limits bacteria contamination at the same time was established for microalgae cultivation in open raceway ponds. Graesiella sp. WBG-1 maximally produced 12.5 g biomass and 4.1 g lipids m-2 day-1 in SPMC in a 1000 m2 raceway pond, which was an over 50% increase compared to phototrophic cultivation. The bacterial number in SPMC (2.97 × 105 CFU ml-1) is comparable to that of the phototrophic cultivations. CONCLUSIONS: SPMC is an effective and feasible method to cultivate lipid-rich microalgae in open raceway ponds. Successful scale-up of SPMC in a commercial raceway pond (1000 m2 culture area) was demonstrated for the first time. This method is attractive for global producers of not only lipid-rich microalgae biomass, but also astaxanthin and ß-carotene.

Effective cultivation of microalgae for biofuel production: a pilot-scale evaluation of a novel oleaginous microalga Graesiella sp. WBG-1.

BACKGROUND: Commercial production of microalgal biodiesel is not yet economically viable, largely because of low storage lipid yield in microalgae mass cultivation. Selection of lipid-rich microalgae, thus, becomes one of the key research topics for microalgal biodiesel production. However, the laboratory screening protocols alone cannot predict the ability of the strains to dominate and perform in outdoor ponds. Comprehensive assessment of microalgae species should be performed not only under the laboratory conditions, but also in the fields. RESULTS: Laboratory investigations using a bubbled column photobioreactor indicated the microalga Graesiella sp. WBG-1 to be the most productive species among the 63 Chlorophyta strains. In a 10 L reactor, mimicking the industrial circular pond, Graesiella sp. WBG-1 produced 12.03 g biomass m(-2) day(-1) and 5.44 g lipids (45.23 % DW) m(-2) day(-1) under 15 mol m(-2) day(-1) artificial light irradiations. The lipid content decreased to ~34 % DW when the microalga was cultured in 30 L tank PBR under natural solar irradiations, but the decline of lipid content with scaling up was the minimum among the tested strains. Based on these results, the microalga was further tested for its lipid production and culture competitiveness using a pilot-scale raceway pond (200 m(2) illuminated area, culture volume 40,000 L). Consequently, Graesiella sp. WBG-1 maintained a high lipid content (33.4 % DW), of which ~90 % was storage TAGs. Results from the outdoor experiments indicated the nice adaptability of the Graesiella sp. WBG-1 to strong and fluctuating natural solar irradiance and temperature, and also demonstrated several other features, such as large cell size (easy for harvest and resistant to swallow by protozoa) and tolerance to high culture pH (helpful to CO2 fixation). CONCLUSIONS: Graesiella sp. WBG-1 was a promising strain capable of accumulating large amount of storage lipid under nature solar irradiance and temperature. The high lipid content of 33.4 % DW was achieved for the first time in pilot-scale raceway pond. The results also provide evidence for the feasibility of using low-cost raceway pond for autotrophic cultivation of microalgae for biodiesel production.