Remediation of industrial wastewater is important for preventing environmental contamination and enabling water reuse. Biological treatment for one industrial contaminant, thiocyanate (SCN), relies upon microbial hydrolysis, but this process is sensitive to high loadings. To examine the activity and stability of a microbial community over increasing SCN loadings, we established and operated a continuous-flow bioreactor fed increasing loadings of SCN.
View Article and Find Full Text PDFPlant microbial fuel cells are a recently developed technology that exploits photosynthesis in vascular plants by harnessing solar energy and generating electrical power. In this study, the model moss species , and other environmental samples of mosses, have been used to develop a non-vascular bryophyte microbial fuel cell (bryoMFC). A novel three-dimensional anodic matrix was successfully created and characterized and was further tested in a bryoMFC to determine the capacity of mosses to generate electrical power.
View Article and Find Full Text PDFGold ore processing uses cyanide (CN(-) ), which often results in large volumes of thiocyanate- (SCN(-) ) contaminated wastewater requiring treatment. Microbial communities can degrade SCN(-) and CN(-) , but little is known about their membership and metabolic potential. Microbial-based remediation strategies will benefit from an ecological understanding of organisms involved in the breakdown of SCN(-) and CN(-) into sulfur, carbon and nitrogen compounds.
View Article and Find Full Text PDFImprovements in lipid productivity would enhance the economic feasibility of microalgal biodiesel. In order to optimise lipid productivity, both the growth rate and lipid content of algal cells must be maximised. The lipid content of many microalgae can be enhanced through nitrogen limitation, but at the expense of biomass productivity.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
March 2014
Chlorella vulgaris accumulates lipid under nitrogen limitation, but at the expense of biomass productivity. Due to this tradeoff, improved lipid productivity may be compromised, despite higher lipid content. To determine the optimal degree of nitrogen limitation for lipid productivity, batch cultures of C.
View Article and Find Full Text PDFBackground: Biocatalyst improvement through molecular and recombinant means should be complemented with efficient process design to facilitate process feasibility and improve process economics. This study focused on understanding the bioprocess limitations to identify factors that impact the expression of the terminal hydroxylase CYP153A6 and also influence the biocatalytic transformation of n-octane to 1-octanol using resting whole cells of recombinant E. coli expressing the CYP153A6 operon which includes the ferredoxin (Fdx) and the ferredoxin reductase (FdR).
View Article and Find Full Text PDFCYP153A6 is a well-studied terminal alkane hydroxylase which has previously been expressed in Pseudomonas putida and Escherichia coli by using the pCom8 plasmid. In this study, CYP153A6 was successfully expressed in E. coli BL21(DE3) by cloning the complete operon from Mycobacterium sp.
View Article and Find Full Text PDFThe attachment of Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum spp. grown on ferrous medium or adapted to a pyrite mineral concentrate to four mineral substrata, namely, chalcopyrite and pyrite concentrates, a low-grade chalcopyrite ore (0.5 wt%) and quartzite, was investigated.
View Article and Find Full Text PDFKinetic constants (μ(max) and K(s)) describing the predominance of lactate oxidation and fermentation were determined in chemostat cultures. The kinetics of sulfate reduction and lactate utilization were determined from 0.5 to 5d residence times at feed sulfate concentrations of 1.
View Article and Find Full Text PDFOptical density is used as a convenient indirect measurement of biomass concentration in microbial cell suspensions. Absorbance of light by a suspension can be related directly to cell density using a suitable standard curve. However, inaccuracies can be introduced when the pigment content of the cells changes.
View Article and Find Full Text PDFBiological sulfate reduction (BSR) has been reported to have potential for the treatment of acid mine drainage (AMD). The provision of a suitable carbon source and electron donor for this process remains a challenge. Lactate offers potential advantages as carbon source and electron donor in the biological sulfate reduction process.
View Article and Find Full Text PDFPurpose: The objective of this study was to compare the effectiveness of a short-term pulmonary rehabilitation program with brief advice given to patients with severe ventilatory impairment due to chronic obstructive pulmonary disease (COPD).
Methods: One hundred three patients with severe COPD, defined as having forced expiratory volume in 1 second < 40% predicted, were randomly assigned to rehabilitation or to brief advice. Fifty-four patients attended a rehabilitation program twice a week for 6 weeks.