Pervaporation of ethanol from lignocellulosic fermentation broth.

Pervaporation can be applied in ethanol production from lignocellulosic biomass. Hydrophobic pervaporation, using a commercial PDMS membrane, was employed to concentrate the ethanol produced by fermentation of lignocellulosic hydrolysate. To our knowledge, this is the first report describing this.

Preparation and evaluation of lignocellulosic biomass hydrolysates for growth by ethanologenic yeasts.

Lignocellulosic biomass is a potential feedstock for bioethanol production. Biomass hydrolysates, prepared with a procedure including pretreatment and hydrolysis, are considered to be used as fermentation media for microorganisms, such as yeast. During the hydrolysate preparation procedure, toxic compounds are released or formed which may inhibit the growth of the microorganism and thus the product formation.

Microbial renewable feedstock utilization: a substrate-oriented approach.

Increasingly lignocellulosic biomass hydrolysates are used as the feedstock for industrial fermentations. These biomass hydrolysates consist of complex mixtures of different fermentable sugars, but also contain inhibitors and salts that affect the performance of the product-generating microbes. The performance of six industrially relevant microorganisms, i.

Microbial production host selection for converting second-generation feedstocks into bioproducts.

Background: Increasingly lignocellulosic biomass hydrolysates are used as the feedstock for industrial fermentations. These biomass hydrolysates are complex mixtures of different fermentable sugars, but also inhibitors and salts that affect the performance of the microbial production host. The performance of six industrially relevant microorganisms, i.

Performance and population analysis of a non-sterile trickle bed reactor inoculated with Caldicellulosiruptor saccharolyticus, a thermophilic hydrogen producer.

Non-axenic operation of a 400 L trickle bed reactor inoculated with the thermophile Caldicellulosiruptor saccharolyticus, yielded 2.8 mol H2/mol hexose converted. The reactor was fed with a complex medium with sucrose as the main substrate, continuously flushed with nitrogen gas, and operated at 73 degrees C.

Influence of synthetic packing materials on the gas dispersion and biodegradation kinetics in fungal air biofilters.

The biodegradation of toluene was studied in two lab-scale air biofilters operated in parallel, packed respectively with perlite granules (PEG) and polyurethane foam cubes (PUC) and inoculated with the same toluene-degrading fungus. Differences on the material pore size, from micrometres in PEG to millimetres in PUC, were responsible for distinct biomass growth patterns. A compact biofilm was formed around PEG, being the interstitial spaces progressively filled with biomass.

An innovative process of simultaneous desulfurization and denitrification by Thiobacillus denitrificans.

Thiobacillus denitrificans, a species of autotrophic facultative anaerobic bacterium, was found to be capable of oxidizing sulfide into elemental sulfur when nitrate was adopted as its electron acceptor and carbon dioxide as its sole carbon source under anoxic conditions. In this way, sulfur was accumulated extracellularly and nitrate was converted into nitrogen gas. Based on these special physiological characteristics, an innovative process of simultaneous desulfurization and denitrification (SDD) was developed to obtain sulfur from sulfide.

Mite growth on fungus under various environmental conditions and its potential application to biofilters.

The effects of relative humidity, temperature, pH and vapor-phase toluene concentration on Tyrophagus putrescentiae growth on Cladophialophora sp. were tested in controlled environmental chambers. It was observed that the mites were able to reproduce readily at relative humidities between 90% and 97% as well as on porous perlite support material pre-soaked in nutrient media of pH 2.

Biofouling reduction in recirculating cooling systems through biofiltration of process water.

Biofouling is a serious problem in industrial recirculating cooling systems. It damages equipment, through biocorrosion, and causes clogging and increased energy consumption, through decreased heat transfer. In this research a fixed-bed biofilter was developed which removed assimilable organic carbon (AOC) from process water, thus limiting the major substrate for the growth of biofouling.

Optimum operation conditions of nitrogen and phosphorus removal by a biofilm-activated-sludge system.

In the biofilm and activated sludge combined system, denitrifying bacteria attached on the fibrous carriers in the anoxic tank, while the sludge containing nitrifying and phosphorus removal bacteria was only recirculated between the aerobic and anaerobic tanks. Therefore, the factors affected and restricted nitrification, denitrification and phosphorus removal in a traditional A/A/O process were resolved. This paper describes the optimum operation conditions for nitrogen and phosphorus removal using this system.

Reducing environmental emissions in tanneries.

Tanning, in particular chrome leather production, is still characterised by an inefficient use of raw material and the production of highly polluted wastewater and solid wastes. A part of the emissions can be prevented by introducing clean tanning technologies, the remaining emissions can be treated. Clean production technologies and waste (water) treatment technologies should have a designed complimentarity.

Addition of anaerobic tanks to an oxidation ditch system to enhance removal of phosphorus from wastewater.

The oxidation ditch has been used for many years all over the world as an economic and efficient wastewater treatment technology. It can remove COD, nitrogen and a part of phosphorus efficiently. In the experiment described, a pilot scale Pasveer oxidation ditch system has been tested to investigate the removal of phosphorus from wastewater.

Substrate interactions during the biodegradation of benzene, toluene, ethylbenzene, and xylene (BTEX) hydrocarbons by the fungus Cladophialophora sp. strain T1.

The soil fungus Cladophialophora sp. strain T1 (= ATCC MYA-2335) was capable of growth on a model water-soluble fraction of gasoline that contained all six BTEX components (benzene, toluene, ethylbenzene, and the xylene isomers). Benzene was not metabolized, but the alkylated benzenes (toluene, ethylbenzene, and xylenes) were degraded by a combination of assimilation and cometabolism.

Dynamic bioreactor operation: Effects of packing material and mite predation on toluene removal from off-gas.

Recent studies have focused on using vapor-phase bioreactors for the treatment of volatile organic compounds from contaminated air streams. Although high removal capacities have been achieved in many studies, long-term operation is often unstable at high pollutant loadings due to biomass accumulation and drying of the packing medium. In this study, three bench-scale bioreactors were operated to determine the effect of packing material and fungal predation on toluene removal efficiency and pressure drop.

Biofilters based on the action of fungi.

Traditional biofilters for waste gas treatment are mainly based on the degradation activity of bacteria. The application of fungi in biofilters has several advantages: fungi are more resistant to acidification and drying out, and the aerial mycelia of fungi form a larger surface area in the gas phase than bacterial biofilms, which may facilitate the uptake of hydrophobic volatile compounds. The research described here identifies important conditions for the operation of fungal-based biofilters.

Influence of environmental parameters on polyphosphate accumulation in Acinetobacter sp.

The regulation of and the optimum conditions for polyphosphate accumulation in Acinetobacter sp. were determined. Acinetobacter strain 210A accumulated polyphosphate in the presence of an intra- or extracellular energy source.

Polyphosphate-degrading enzymes in Acinetobacter spp. and activated sludge.

Polyphosphate-degrading enzymes were studied in Acinetobacter spp. and activated sludge. Polyphosphate: AMP phosphotransferase activity in Acinetobacter strain 210A decreased with increasing growth rates.

Role of Cations in Accumulation and Release of Phosphate by Acinetobacter Strain 210A.

Cells of the strictly aerobic Acinetobacter strain 210A, containing aerobically large amounts of polyphosphate (100 mg of phosphorus per g [dry weight] of biomass), released in the absence of oxygen 1.49 mmol of P(i), 0.77 meq of Mg, 0.

Microthrix parvicella, a filamentous bacterium from activated sludge: growth on Tween 80 as carbon and energy source.

Microthrix parvicella, cultivated in a medium with Tween 80 and Casamino acids, utilized only the oleic acid moiety of Tween 80 as carbon and energy source. The cell yield from Tween 80 was about 0.32 g dry weight of cells per g of Tween 80 consumed.