Valorising nutrient-rich digestate: Dilution, settlement and membrane filtration processing for optimisation as a waste-based media for microalgal cultivation.

Digestate produced from the anaerobic digestion of food and farm waste is primarily returned to land as a biofertiliser for crops, with its potential to generate value through alternative processing methods at present under explored. In this work, valorisation of a digestate resulting from the treatment of kitchen and food waste was investigated, using dilution, settlement and membrane processing technology. Processed digestate was subsequently tested as a nutrient source for the cultivation of Chlorella vulgaris, up to pilot-scale (800L).

Light Intensity and Nitrogen Concentration Impact on the Biomass and Phycoerythrin Production by .

Several factors have the potential to influence microalgae growth. In the present study, nitrogen concentration and light intensity were evaluated in order to obtain high biomass production and high phycoerythrin accumulation from . The range of nitrogen concentrations evaluated in the culture medium was 0.

Formulation and utilisation of spent anaerobic digestate fluids for the growth and product formation of single cell algal cultures in heterotrophic and autotrophic conditions.

Spent anaerobically digested effluents of agricultural origin were collected and treated using membrane filtration to achieve three-large particle free-nutrient streams of N:P ratios of 16.53, 3.78 and 14.

Determination of volumetric gas-liquid mass transfer coefficient of carbon monoxide in a batch cultivation system using kinetic simulations.

A mathematical model of microbial kinetics was introduced to predict the overall volumetric gas-liquid mass transfer coefficient (ka) of carbon monoxide (CO) in a batch cultivation system. The cell concentration (X), acetate concentration (C), headspace gas (N and [Formula: see text] ), dissolved CO concentration in the fermentation medium (C), and mass transfer rate (R) were simulated using a variety of ka values. The simulated results showed excellent agreement with the experimental data for a ka of 13/hr.

Utilising light-emitting diodes of specific narrow wavelengths for the optimization and co-production of multiple high-value compounds in Porphyridium purpureum.

The effect of specific narrow light-emitting diode (LED) wavelengths (red, green, blue) and a combination of LED wavelengths (red, green and blue - RGB) on biomass composition produced by Porphyridium purpureum is studied. Phycobiliprotein, fatty acids, exopolysaccharides, pigment content, and the main macromolecules composition were analysed to determine the effect of wavelength on multiple compounds of commercial interest. The results demonstrate that green light plays a significant role in the growth of rhodophyta, due to phycobiliproteins being able to harvest green wavelengths where chlorophyll pigments absorb poorly.

Moving towards sustainable resources: Recovery and fractionation of nutrients from dairy manure digestate using membranes.

The fractionation of nitrogen (as ammonia/ammonium) and phosphorus (as phosphate ions) present in the dairy manure digestate was investigated using a nanofiltration membrane NF270. The filtration and separation efficiencies were correlated to pH across the range 3 < pH < 11. Filtration at pH 11 enabled higher permeate flux of 125-150 LMH at 20 bar, however rejection of ammonia was high at 30-36% and phosphate was 96.

Microbial synthesis gas utilization and ways to resolve kinetic and mass-transfer limitations.

Microbial conversion of syngas to energy-dense biofuels and valuable chemicals is a potential technology for the efficient utilization of fossils (e.g., coal) and renewable resources (e.

Minimizing the energy requirement of dewatering scenedesmus sp. by microfiltration: performance, costs, and feasibility.

The harvesting of the microalgae Scenedesmus species using a 200 L pilot-scale microfiltration system was investigated and critically assessed. The energy requirement was determined and correlated to the different operating parameters, such as transmembrane pressure (ΔP), membrane area, temperature, and initial biomass concentration. A filtration model was developed and showed a strong correlation with experimental data up to 20.

Selection for fitness at the individual or population levels: modelling effects of genetic modifications in microalgae on productivity and environmental safety.

A mechanistic model of microalgae is used to explore the implications of modifying microalgal chlorophyll content and photosynthetic efficiency with an aim to optimising commercial biomass production. The models show the potential for a 10 fold increase in microalgae productivity in genetically modified versus unmodified configurations, while also enabling the use of bioreactors of greater optical depth operating at lower dilution rates. Analysis suggests that natural selection of a trait benefiting the individual (high Chl:C(max), i.

Use of an industrial grade medium and medium enhancing effects on high cell density CO fermentation by Eubacterium limosum KIST612.

Studies were made on the composition of the growth medium to increase the cell concentration in a cell-recycled continuous culture (Eubacterium limosum KIST612) with carbon monoxide as a sole energy source using phosphate-buffered basal medium (PBBM) and modified PBBM. One of major limiting factors in PBBM might be nitrogen during the high cell density culture. This limitation could be overcome by increasing of inorganic nitrogen or yeast extract concentration in the medium.

Performance assessment of malolactic fermenting bacteria Oenococcus oeni and Lactobacillus brevis in continuous culture.

The growth performance of malolactic fermenting bacteria Oenococcus oeni NCIMB 11648 and Lactobacillus brevis X(2) was assessed in continuous culture. O. oeni grew at a dilution rate range of 0.

The measurement of Bacillus mycoides spore adhesion using atomic force microscopy, simple counting methods, and a spinning disk technique.

An atomic force microscope has been used to study the adhesion of Bacillus mycoides spores to a hydrophilic glass surface and a hydrophobic-coated glass surface. AFM images of spores attached to the hydrophobic-coated mica surface allowed the measurement of spore dimensions in an aqueous environment without desiccation. The spore exosporium was observed to be flexible and to promote the adhesion of the spore by increasing the area of spore contact with the surface.

Atomic Force Microscopy Study of the Adhesion of Saccharomyces cerevisiae.

An atomic force microscope (AFM) has been used to quantify directly the adhesion of metabolically active Saccharomyces cerevisiae cells at a hydrophilic mica surface, a mica surface with a hydrophobic coating, and a protein-coated mica surface in an aqueous environment. The measurements used "cell probes" constructed by immobilizing a single cell at the apex of a tipless AFM cantilever. Adhesion was quantified from force-distance data for the retraction of the cell from the surface.