ABSTRACT
This study investigated the effectiveness of successive bioaugmentation, conventional bioaugmentation, and biostimulation of biodegradation of B10 in soil. In addition, the structure of the soil microbial community was assessed by polymerase chain reaction-denaturing gradient gel electrophoresis. The consortium was inoculated on the initial and the 11th day of incubation for successive bioaugmentation and only on the initial day for bioaugmentation and conventional bioaugmentation. The experiment was conducted for 32 days. The microbial consortium was identified based on sequencing of 16S rRNA gene and consisted as Pseudomonas aeruginosa, Achromobacter xylosoxidans, and Ochrobactrum intermedium. Nutrient introduction (biostimulation) promoted a positive effect on microbial populations. The results indicate that the edaphic community structure and dynamics were different according to the treatments employed. CO2 evolution demonstrated no significant difference in soil microbial activity between biostimulation and bioaugmentation treatments. The total petroleum hydrocarbon (TPH) analysis indicated a biodegradation level of 35.7 and 32.2 % for the biostimulation and successive bioaugmentation treatments, respectively. Successive bioaugmentation displayed positive effects on biodegradation, with a substantial reduction in TPH levels.
Subject(s)
Achromobacter denitrificans/physiology , Biofuels , Brucellaceae/physiology , Gasoline , Hydrocarbons/metabolism , Pseudomonas aeruginosa/physiology , Soil Pollutants/metabolism , Achromobacter denitrificans/isolation & purification , Biodegradation, Environmental , Brucellaceae/isolation & purification , Carbon Dioxide/metabolism , DNA, Bacterial/genetics , Denaturing Gradient Gel Electrophoresis , Microbial Consortia/physiology , Polymerase Chain Reaction , Pseudomonas aeruginosa/isolation & purification , RNA, Ribosomal, 16S/genetics , Soil MicrobiologyABSTRACT
BACKGROUND: Type 2 diabetes mellitus is associated with an increased risk of cardiovascular diseases and accelerated atherosclerosis, which has been associated to hyperglycemia and chronic inflammation. Activated macrophages are described to participate in atherosclerosis due to foam cell formation and pro-inflammatory mediators production. Bacterial infections are described to accelerate atherosclerosis, moreover, gram-positive and negative bacterial DNA was described in atherosclerotic plaques. METHODS: We studied the glucose modulation of RAW 264.7 macrophages activation by the gram-positive bacterial antigen lipoteichoic acid (LTA), evaluating nitrite production, tumor necrosis factor alpha secretion and matrix metalloproteinase 9 activity. RESULTS: High glucose increased macrophages activation by LTA, evidenced by exacerbated nitric oxide and tumor necrosis factor alpha production, as well matrix metalloproteinase 9 secretion. CONCLUSIONS: These effects could contribute to atherosclerotic risk parameters, like atherome plaque instability, and participate in chronic inflammation present in type 2 diabetes.
