ENV-610: EFFECT OF NUTRIENTS ON METHANOTROPHIC OXIDATION ACTIVITY IN BATCH EXPERIMENTAL STUDIES

Methane biofiltration (MBF) has been proposed as an effective and cost efficient method for mitigating methane emissions from anthropogenic sources. Previous MBF studies have successfully demonstrated effective methane oxidation using compost, soil and biodegradable organic materials as the filter medium because they are a natural source of nutrients, organic matter content, and provide adequate space to support microbiological growth. However, these media types will inevitably decompose over time and lose their effectiveness. This study investigates the use of biologically stable media mixtures of lava rock and biochar in batch oxidation studies to determine their ability to support a methanotrophic bacterial population for the oxidation of methane. A screening experiment was performed using an unreplicated 23 factorial design to understand the influence of nutrient content, water holding capacity (WHC), and mixture ratios of lava rock and biochar, by volume, on the methane oxidation rate (MOR). Virtually no activity was observed when 3300 ppm of nitrogen were added to the batches. Methane oxidation activities were only observed when lower nutrient additions were made at 96 ppm of nitrogen with values reaching 2.2 - 2.5 mol/mL∙hr when the WHC was adjusted to 50% regardless of the media composition. Subsequent replicates performed at the lower nitrogen level additions and 30% WHC demonstrated similar MORs. Results demonstrate the supplementation of nutrients to a mixture of lava rock and biochar is possible in supporting a methanotrophic population and that lava rock can be used as a bulking agent

ENV-623: ANALYSIS OF REACTION KINETIC PARAMETERS IN ENZYME CATALYSED AEROBIC WASTE DEGRADATION

The study discussed here is an attempt at comparing three of the most important kinetic parameters in an enzyme catalysed aerobic system; overall reaction kinetic constant, hydrolysis rate constant and oxygen assimilation constant. The kinetic parameters are compared with each other as well as between uncatalyzed and enzyme catalyzed reactions. Theatrical reaction kinetic models were developed for the analysis. Batch experiments were conducted to characterize solid waste behaviour and the results used to calibrate the developed models. Lignin content, cellulose/hemicellulose content, total organic content, oxygen depletion and CO2 production was used as responses in the experiments. Manganese peroxidase from white-rot-fungi is used as the enzyme for catalysing treatments. The catalyzed reactions showed higher reaction rates than the un-catalyzed reactions. Further analysis revealed that catalyzed reactions have higher hydrolysis rates compared to the overall rates of metabolism. The O2 assimilation analysis revealed that catalyzed reactions require 1.66 times more O2 than un-catalyzed reactions

Association between promoter -1607 polymorphism of MMP1 and Lumbar Disc Disease in Southern Chinese

<p>Abstract</p> <p>Background</p> <p>Matrix metalloproteinases (MMPs) are involved in the degradation of the extracellular matrix of the intervertebral disc. A SNP for guanine insertion/deletion (G/D), the -1607 promoter polymorphism, of the <it>MMP1 </it>gene was found significantly affecting promoter activity and corresponding transcription level. Hence it is a good candidate for genetic studies in DDD.</p> <p>Methods</p> <p>Southern Chinese volunteers between 18 and 55 years were recruited from the population. DDD in the lumbar spine was defined by MRI using Schneiderman's classification. Genomic DNA was isolated from the leukocytes and genotyping was performed using the Sequenom^®platform. Association and Hardy-Weinberg equilibrium checking were assessed by Chi-square test and Mann-Whitney U test.</p> <p>Results</p> <p>Our results showed substantial evidence of association between -1607 promoter polymorphism of <it>MMP1 </it>and DDD in the Southern Chinese subjects. D allelic was significantly associated with DDD (p value = 0.027, odds ratio = 1.41 with 95% CI = 1.04–1.90) while Genotypic association on the presence of D allele was also significantly associated with DDD (p value = 0.046, odds ratio = 1.50 with 95% CI = 1.01–2.24). Further age stratification showed significant genotypic as well as allelic association in the group of over 40 years (genotypic: p value = 0.035, odds ratio = 1.617 with 95% CI = 1.033–2.529; allelic: p value = 0.033, odds ratio = 1.445 with 95% CI = 1.029–2.029). Disc bulge, annular tears and the Schmorl's nodes were not associated with the D allele.</p> <p>Conclusion</p> <p>We demonstrated that individuals with the presence of D allele for the -1607 promoter polymorphism of <it>MMP1 </it>are about 1.5 times more susceptible to develop DDD when compared with those having G allele only. Further association was identified in individuals over 40 years of age. Disc bulge, annular tear as well as Schmorl's nodes were not associated with this polymorphism.</p