Biomedical subjects

B Mattiasson

Publications and source records attributed to B Mattiasson.

At least 19 recordsLinked to original sources

PubMed2006

Influence of temperature on process efficiency and microbial community response during the biological removal of chlorophenols in a packed-bed bioreactor.

Two reactors, initially operated at 14 and 23+/-1 degrees C (RA and RB, respectively), were inoculated with a bacterial consortium enriched and acclimatized to the respective temperatures over 4 months. The biofilms, formed in the reactors, were studied using scanning electron microscopy, cultivation of the biofilm microflora, and physiological analysis of the isolates. Two bacteria able to mineralize chlorophenols under a large range of temperature (10-30 degrees C) were isolated from the biofilm communities of reactors RA and RB and characterized as Alcaligenaceae bacterium R14C4 and Cupriavidus basilensis R25C6, respectively. When temperature was decreased by 10 degrees C, the chlorophenols removal capacity was reduced from 51.6 to 22.8 mg l(-1) h(-1) in bioreactor RA (from 14 to 4 degrees C) and from 59.3 to 34.7 mg l(-1) h(-1) in bioreactor RB (from 23+/-1 to 14 degrees C). Fluorescence in situ hybridization (FISH) of the biofilm communities showed that, in all temperatures tested, the beta-proteobacteria were the major bacterial community (35-47%) followed by the gamma-proteobacteria (12.0-6.5%). When the temperature was decreased by 10 degrees C, the proportions of gamma-proteobacteria and Pseudomonas species increased significantly in both microbial communities.

Alcaligenaceae↗

PubMed2006

Extremum-seeking with variable gain control for intensifying biogas production in anaerobic fermentation.

A state-dependent variable-gain control system is implemented to follow the characteristics of a laboratory-scale up-flow anaerobic fixed-bed reactor dynamically. The transition from one state to another is determined on an hourly basis, depending on difference between the setpoint of the reactor pH and its true value. Considerable improvement of the process stability--reduction of oscillation in both the reactor pH and biogas production rate during high-rate operation, has been achieved, although the control structure is simple and intuitive.

Algorithms↗

PubMed2006

Removal of trace contaminants using molecularly imprinted polymers.

This work was conducted to study the potential of molecularly imprinted polymers (MIPs) for the removal of oestradiol at trace concentrations (1 ppm-1 ppb). An MIP synthesised with 17beta-oestradiol as template was compared to non-imprinted polymers (NIP) synthesised under the same conditions but without template, a commercial C18 extraction phase and granulated activated carbon. At 1 ppb oestradiol was recovered by 98 +/- 2% when using the MIP, compared to 90 +/- 1, 79 +/- 1, and 84 +/- 2% when using the NIP, a C18 phase, or granulated activated carbon, respectively. According to these levels, the MIP was capable of producing an effluent with a quality 5-10 times higher than the other materials. The same levels of oestradiol recovery were achieved with the MIP when supplying 17beta-oestradiol at 0.1 ppm. Phenolic compounds added as interferences bound less to the MIP than to the NIP, confirming the selectivity of the MIP. Oestradiol biodegradation was also demonstrated at high concentrations (50 ppm), showing the pollutants can be safely destructed after being enriched by molecular extraction. This study demonstrates the potential of molecular imprinted polymers as a highly efficient specific adsorbent for the removal of trace contaminants.

Dose-Response Relationship, Drug↗

PubMed2006

Biological treatment of industrial wastes in a photobioreactor.

An algal-bacterial consortium was tested for the treatment from a coke factory. A Chlorella vulgaris strain and a phenol-degrading Alcaligenes sp. were first isolated from the wastewater treatment plant to serve as inocula in the subsequent biodegradation tests. Batch tests were then conducted with samples from the real wastewater or using a synthetic wastewater containing 325 mg phenol/l and 500 mg NH4+/l as target pollutants. Direct biological treatment of the real wastewater was not possible due to the toxicity of organic compounds. Activated carbon adsorption and UV(A-B)-irradiation were efficient in detoxifying the effluent for subsequent biological treatment as inoculation of pretreated samples with the algal-bacterial consortium was followed by complete phenol removal and NH4+ removal of 45%. Complete phenol removal and 33% NH4+ removal were achieved during the fed-batch treatment of artificial wastewater at 6 d hydraulic retention time (HRT). Under continuous feeding at 3.6 d HRT, phenol and NH4+ removal dropped to 58 and 18%, respectively. However, complete phenol removal and 29% NH4+ removal were achieved when 8 g NaHCO3/l was added to the artificial wastewater to enhance algal growth. This study confirms the potential of solar-based industrial wastewater treatment based on solar-based UV pretreatment followed by algal-bacterial biodegradation.

Alcaligenes↗

PubMed2005

Functional activity of insulinoma cells (INS-1E) and pancreatic islets cultured in agarose cryogel sponges.

Here, we describe the preparation, structure, and properties of cryogel sponges, which represent a new type of macroporous biomaterial for tissue engineering. Cryogels were produced through freeze-thawing techniques, either from agarose alone or from agarose with grafted gelatin. The aim of this study was to evaluate agarose cryogel sponges as scaffolds for culturing both isolated pancreatic islets and insulinoma cells (INS-1E). In order to evaluate the effect of cell entrapment in artificial scaffolds, cell function reflected by insulin secretion and content was studied in cells cultivated for a 2-week period either in culture plastic plates or in cryogel sponge disks. Our results show that tumor-derived INS-1E cells grown either on plastic or on cryogels do not differ in their proliferation, morphology, insulin release, and intracellular insulin content. However, isolated pancreatic islets cultivated on cryogels sponge show 15-fold higher basal insulin secretion at 3.0 mM glucose than islets cultivated on plastic plates and fail to respond to stimulation with 16.7 mM glucose. In addition, these islets have about 2-fold lower insulin content compared to those grown in plastic plates. It is possible that the cell dysfunction noted in these in vitro experiments is due to the effect of the limited oxygen supply to the islets cultivated in cryogel sponge. Further in vivo studies are needed to clarify the nature of such an observation since according to previous reports, agarose and gelatin induce new vessel formation supporting enhanced oxygen supply.

Animals↗

PubMed2005

Purification of His6-organophosphate hydrolase using monolithic supermacroporous polyacrylamide cryogels developed for immobilized metal affinity chromatography.

Organophosphate hydrolase containing hexahistidine tag at the N-terminus of recombinant protein (His6-OPH) and expressed in Escherichia coli cells was purified using supermacroporous polyacrylamide-based monolith columns with immobilized metal affinity matrices [Me2+-iminodiacetic acid (IDA)-polyacrylamide cryogel (PAA) and Me2+-N,N,N'-tris (carboxymethyl) ethylendiamine (TED)-PAA]. Enzyme preparation with 50% purity was obtained by direct chromatography of nonclarified cell homogenate, whereas the combination of addition of 10 mM imidazole to buffers for cell sonication and sample loading, the use of precolumn with IDA-PAA matrix noncharged with metal ions, and the application of high flow rate provided the 99% purity of enzyme isolated directly from crude cell homogenate. Co2+-IDA-PAA provided the highest level of selectivity for His6-OPH. Comparative analysis of purification using Co2+-IDA-PAA and Ni-nitrilotriacetic acid-agarose showed obvious advantages of the former in process time, specific activity of purified enzyme, and simplicity of adsorbent regeneration.

Acrylic Resins↗

PubMed2005

Poly(beta-hydroxybutyrate) production by a moderate halophile, Halomonas boliviensis LC1 using starch hydrolysate as substrate.

AIM: The objective of the present work was to enable the use of starch hydrolysate, generated by the action of a recombinant maltooligosaccharide forming amylase from Bacillus halodurans LBK 34, as the carbon source for the production of poly-beta-hydroxybutyrate (PHB) by Halomonas boliviensis LC1. METHODS AND RESULTS: In this work, different amounts of the alpha-amylase (Amy 34) were utilized for starch hydrolysis, resulting in the production of mixtures of maltooligosaccharides (G1-G6) at varying ratios. The highest PHB accumulation (56 wt%) by H. boliviensis cultivated in shake flasks (with agitation at 160 rev min(-1)) was obtained when 6.4 U ml(-1) of the amylase was used for starch hydrolysis. When H. boliviensis cells were grown in a fermentor with no oxygen limitation the accumulation of PHB was decreased to 35 wt%. Although some improvements in PHB accumulation and cell mass concentration were reached by the addition of peptone and phosphate, respectively, major enhancements were attained when oxygen limitation was induced in the fermentor. CONCLUSIONS: Halomonas boliviensis uses preferentially maltose for PHB formation from starch hydrolysate. It is also able to hydrolyse higher sugars if no other simpler carbon source is available but with a significantly lower polymer yield. Furthermore, H. boliviensis is able to adjust its metabolism to oxygen limitation, most probably by directing the excess NAD(P)H to PHB accumulation. SIGNIFICANCE AND IMPACT OF THE STUDY: There have been no reports related to PHB production amongst the members of the genus Halomonas. The use of a maltooligosaccharide forming alpha-amylase, which is active at a temperature and pH close to that required for growth of H. boliviensis, and the versatility of this bacterium in the selection of the carbon source may provide an attractive alternative for the utilization of starch-derived raw materials.

3-Hydroxybutyric Acid↗

PubMed2005

Photosynthetically oxygenated acetonitrile biodegradation by an algal-bacterial microcosm: a pilot-scale study.

A 43-L column photobioreactor was tested for the treatment of acetonitrile using a symbiotic consortium consisting of a Chlorella sorokiniana strain and a Comamonas strain. Complete biodegradation of 1 g acetonitrile/l was achieved in 79 hours under continuous illumination at 500 microE/m(2)s and 26 degrees C. When the photobioreactor was operated at 26 degrees C under a 14/10 hours light/dark illumination regime at 500 microE/m(2)s, complete mineralization of 1 g acetonitrile/l was achieved in 111 hours. However, when acetonitrile was supplied at 2 g/l, the biodegradation process was severely inhibited by the increase of pH and NH4+ concentration during cultivation. In addition to saving energy for aeration, the microalgae assimilated 33% of the NH4+ released during acetonitrile biodegradation, which significantly reduces the need for subsequent nitrogen removal.

Acetonitriles↗

PubMed2005

Aerobic phenanthrene biodegradation in a two-phase partitioning bioreactor.

The aerobic degradation of phenanthrene by a Pseudomonas migulae strain under classical mechanical aeration and under photosynthetic oxygenation (using a Chlorella sorokiniana strain) in a two-phase partitioning bioreactor (TPPB) constructed with silicone oil as organic phase was investigated. When traditional mechanical aeration was used, an increase in the aeration and/or in the agitation rate enhanced phenanthrene biodegradation. Thus, phenanthrene removal rates (based on the total liquid volume of cultivation) ranged from 22 +/- 1 to 36 +/- 2 mg/l h at 100 rpm and 1 vvm and 400 rpm and 3 vvm, respectively. On the other hand, during phenanthrene biodegradation using the algal-bacterial microcosm a maximum rate of 8.1 +/- 1.2 mg/l h at 200 rpm and 8000 lux of illuminance was achieved.

Analysis of Variance↗

PubMed2004

Polycyclic aromatic hydrocarbon biodegradation in extracellular fluids and static batch cultures of selected sub-tropical white rot fungi.

Four sub-tropical white rot fungi, Trametes versicolor, Trametes pocas, Trametes cingulata and isolate DSPM95 were studied alongside the well studied white rot fungus, Phanerochaete chrysosporium, for their ability to remove polycyclic aromatic hydrocarbons (PAHs) from culture media. Both static shallow cultures and extracellular fluids were studied using media contaminated with a defined mixture of the PAHs; fluorene, phenanthrene, anthracene, pyrene and benzo(a)anthracene. With all isolates, the total loss of the parent compound in 31 days was high for fluorene, at +60%, phenanthrene at +40% and anthracene at +42%. Biotransformation of pyrene and benzo(a)anthracene by all the isolates was low, with the highest reduction of pyrene of 15.2% and benzo(a)anthracene of 15.8% being achieved with P. chrysosporium. Disappearance of the more condensed PAHs, pyrene and benzo(a)anthracene, increased in shallow static cultures with the addition of glucose and glucose oxidase as a source of additional H2O2. The addition of Mn2+ and ABTS (2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid)) to culture supernatants was associated with higher levels of biotransformation. Comparison of the isolates T. versicolor, T. pocas, T. cingulata and isolate DSPM95 with P. chrysosporium showed that these strains were competitive in the reduction of the PAHs, reducing the PAHs by more or less the same magnitude. Also these sub-tropical isolates did not accumulate a lot of HPLC detectable metabolites as much as P. chrysosporium.

Basidiomycota↗

PubMed2004

Degradation of toxaphene in water during anaerobic and aerobic conditions.

The degradation of technical toxaphene in water with two kinds of bioreactors operating in sequence was studied. One packed bed reactor was filled with Poraver (foam glass particles) running at anaerobic conditions and one suspended carrier biofilm reactor working aerobically. Chemical oxygen demand (COD), chloride, sulphate, pH, dissolved oxygen, total toxaphene and specific toxaphene isomers were measured. After 6 weeks approx. 87% of the total toxaphene was degraded reaching 98% by week 39. The majority of the conversion took place in the anaerobic reactor. The concentrations of toxaphene isomers with more chlorine substituents decreased more rapidly than for isomers with less chlorine substituents.

Aerobiosis↗

PubMed2004

Impact of food industrial waste on anaerobic co-digestion of sewage sludge and pig manure.

The performance of an anaerobic digestion process is much dependent on the type and the composition of the material to be digested. The effects on the degradation process of co-digesting different types of waste were examined in two laboratory-scale studies. In the first investigation, sewage sludge was co-digested with industrial waste from potato processing. The co-digestion resulted in a low buffered system and when the fraction of starch-rich waste was increased, the result was a more sensitive process, with process overload occurring at a lower organic loading rate (OLR). In the second investigation, pig manure, slaughterhouse waste, vegetable waste and various kinds of industrial waste were digested. This resulted in a highly buffered system as the manure contributed to high amounts of ammonia. However, it is important to note that ammonia might be toxic to the micro-organisms. Although the conversion of volatile fatty acids was incomplete the processes worked well with high gas yields, 0.8-1.0 m3 kg(-1) VS.

Animals↗

PubMed2004

Influence of recirculation flow rate on the performance of anaerobic packed-bed bioreactors treating potato-waste leachate.

The performance of anaerobic, packed-bed bioreactors treating leachate from potato waste was evaluated in terms of organic loading rate (OLR) as well as the recirculation flow rate. Two 1 litre bioreactors, filled with porous glass beads as biofilm carriers and with continuous recirculation flow rates of 10 ml min(-1) and 20 ml min(-1) respectively, were used in the experiment. The OLR applied to each bioreactor was increased stepwise from 4 to 12 kg chemical oxygen demand (COD) m(-3)d(-1) by increasing feed flow rate. The methane yields decreased with increasing OLR in both bioreactors. The methane yield for the bioreactor with the lower recirculation flow rate ranged between 0.10 and 0.14 m3 CH4 kg COD(-1) removed, while for the other bioreactor it was 0.14-0.20 m3 CH4 kg COD(-1) removed. Both bioreactors demonstrated stable COD removal which was around 95% for the bioreactor with lower flow of recirculation while for the other it was 92%, over a range of OLRs of 4-8 kg COD m(-3)d(-1). The bioreactor with the lower recirculation flow rate showed operational stability when a high OLR, namely 12 kg COD m(-3)d(-1), was applied, while the other one became overloaded. There was an accumulation of volatile fatty acids which gave a corresponding drop in pH because the system had a low buffering capacity and this thus ultimately led to process failure. This study demonstrated the suitability of a packed bed bioreactor operated at lower recirculation flow rate for treating leachate from potato waste.

Agriculture↗

PubMed2004

A probe for capture and Fe3+-induced conformational change of lactoferrin selected from phage displayed peptide libraries.

Linear pentadecamer and cyclic hexamer peptide phage libraries were used to isolate phage clones with binding affinity toward lactoferrins purified from human and bovine milk. Phage clones with high specificity toward lactoferrin were selected with different binding strengths depending on the sequence of the peptide displayed by the phage. Phages coated to a microtiterplate were able to capture lactoferrin from crude milk samples without prior treatment. One of the selected sequences, EGKQRR, failed to bind to lactoferrin. In contrast, a branched tree-peptide bearing 4 EGKQRR sequences did bind to lactoferrin (Kd approximately 29 microM) and was also capable of inhibiting the binding of the phage to lactoferrin (IC(50) approximately 17 microM), indicating that avidity was important. Unexpectedly, the affinity of the phage for lactoferrin was influenced by the amount of bound Fe(3+), with a much lower affinity when lactoferrin was saturated with Fe(3+) as compared with the iron-depleted or partially saturated (natural) lactoferrin. As the phage does not bind to the Fe(3+)-binding site, the difference in binding affinity is due to differences in conformation of lactoferrin induced by Fe(3+). These results demonstrate that avidity or multipoint attachment and Fe(3+)-induced conformational changes play an important role in the binding of the selected phage to lactoferrin. Thus, we could demonstrate that, by the use of selected phage clones, we are able not only to detect lactoferrin, but also to capture lactoferrin from crude milk samples. Furthermore, the extent of phage binding provides additional information about the iron content and the concomitant conformation of lactoferrin.

Amino Acid Sequence↗

PubMed2004

Control of an anaerobic reactor towards maximum biogas production.

A new control strategy is introduced for operating anaerobic digestion processes efficiently at high load. The control system includes a cascade controller embedded into a rule-based supervisory system based on extremum-seeking control. The control system measures pH and biogas production rate and varies the organic load by manipulating the influent flow. Good control performances were achieved during the start-up and steady-state running operations and during rejection of disturbances. The control system can run the process under a high load condition and efficiently reject disturbances without explicit measurement of the influent characteristics.

Algorithms↗

PubMed2003

Phenanthrene biodegradation by an algal-bacterial consortium in two-phase partitioning bioreactors.

An algal-bacterial consortium formed by Chlorella sorokiniana and a phenanthrene-degrading Pseudomonas migulae strain was able to biodegrade 200-500 mg/l of phenanthrene dissolved in silicone oil or tetradecane under photosynthetic conditions and without any external supply of oxygen. Phenanthrene was only removed when provided in organic solvent, which confirms the potential of two-phase systems for toxicity reduction. Phenanthrene was degraded at highest rates when provided in silicone oil rather than in tetradecane since this solvent probably sequestered the PAH, reducing its mass transfer to the aqueous phase. The influence of phenanthrene concentration, amount of inoculum and light intensity on pollutant removal was also investigated and, under the best conditions, phenanthrene was degraded at 24.2 g m(-3).h(-1). In addition to being cost-effective and mitigating the release of greenhouse gases into the atmosphere, photosynthetic oxygenation was especially beneficial to the use of two-phase partitioning bioreactors since it prevented solvent emulsification and/or volatilization and evidence was found that the microalgae release biosurfactants that could further enhance phenanthrene degradation.

Aerobiosis↗

PubMed2003

Denitrification at low temperatures using a suspended carrier biofilm process.

The denitrification process was studied in a stirred lab-scale suspended carrier biofilm reactor at low temperatures (3-20 degrees C). The reactor was filled to 50% with Kaldnes K1 carriers. The denitrification rate showed only a rather weak dependence on the temperature, the rate at 3 degrees C being approximately 55% of that at 15 degrees C. The maximum denitrification rate obtained at 15 degrees C was 2.7 g NO(x)(-)-Nm(-2)carrier d (-1). The maximum denitrification rate at 3 degrees C during an 8-day period was found to be constant. During the 8 days, the hydraulic retention time was approximately 1.5h and the inlet NO(3)(-)-N concentration was 30 mg x l(-1).

Biofilms↗

PubMed2003

Separation of coal-tar constituents from soil particles in a two-liquid-phase slurry system.

An evaluation has been made of the capability of rapeseed oil to dissolve polycyclic aromatic hydrocarbon (PAH) crystals in a biphasic system and of its capability to extract PAHs from polluted soil in a two-liquid-phase (TLP) slurry system. Up to 220 g l(-1) of the crystalline hydrocarbons could be dissolved in the organic phase, indicating oil/water-partitioning coefficients of 10(5). When soil from a former gasworks site was treated in a TLP slurry system, it was found that a certain critical amount of vegetable oil had to be added in order to form a free oil phase. Single and multiple extractions gave similar results for multiple short-term and single long-term treatments, with a maximum of 87% for pyrene release. Following a 30-day bioslurry treatment, the total concentration of the 16 EPA PAHs in the soil decreased from 2740 mg kg(-1) to 1366 mg kg(-1). This was followed by one of three different 12-day post-bioslurry treatments. Further bioslurry treatment reduced the final concentration to 1002 mg kg(-1). Abiotic treatment with a surfactant (Brij 30) achieved a reduction to 797 mg kg(-1). Treatment with rapeseed oil gave the best reduction to 343 mg kg(-1).

Coal↗