| 1. |
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| 2. |
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| 3. |
- FazeliNejad, Somayeh, et al.
(författare)
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Inhibitor Tolerance : A Comparison between Rhizopus sp. and Saccharomyces cerevisiae
- 2013
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Ingår i: BioResources. - : North Carolina State University. - 1930-2126. ; 8:4, s. 5524-5535
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Tidskriftsartikel (refereegranskat)abstract
- Zygomycetes fungi are able to produce ethanol, and their biomass may hold a high market value, making them interesting microorganisms from a biorefinery perspective. In the present study, the inhibitor tolerance of the Zygomycetes fungus Rhizopus sp. was evaluated and compared with a flocculating strain of Saccharomyces cerevisiae. The inhibitors furfural, 5-hydroxymethylfurfural [HMF], acetic acid, and levulinic acid and the phenolic compounds catechol, guaiacol, and vanillin were applied in different combinations in a semi-synthetic medium. Glucose uptake and conversion of HMF in the presence of inhibitors were analyzed for the two organisms, and it appeared that the inhibitor resistances of Rhizopus sp. and S. cerevisiae were comparable. However, in the presence of catechol (0.165 g L-1), guaiacol (0.186 g L-1), and vanillin (0.30 g L-1), the glucose uptake by S. cerevisiae was only 3.5% of its uptake in a medium without inhibitors, while under equal conditions, Rhizopus sp. maintained 43% of its uninhibited glucose uptake.
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| 4. |
- Ferreira, Jorge A., et al.
(författare)
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Production of Ethanol and Biomass from Thin Stillage Using Food-Grade Zygomycetes and Ascomycetes Filamentous Fungi
- 2014
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Ingår i: Energies. - : MDPI. - 1996-1073. ; 7:6, s. 3872-3885
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Tidskriftsartikel (refereegranskat)abstract
- A starch-based ethanol facility producing 200,000 m3 ethanol/year also produces ca. 2 million m3 thin stillage, which can be used to improve the entire process. In this work, five food-grade filamentous fungi, including a Zygomycete and four Ascomycetes were successfully grown in thin stillage containing 9% solids. Cultivation with Neurospora intermedia led to the production of ca. 16 g·L−1 biomass containing 56% (w/w) crude protein, a reduction of 34% of the total solids, and 5 g·L−1 additional ethanol. In an industrial ethanol production process (200,000 m3 ethanol/year), this can potentially lead to the production of 11,000 m3 extra ethanol per year. Cultivation with Aspergillus oryzae resulted in 19 g·L−1 biomass containing 48% (w/w) crude protein and the highest reduction of the thin stillage glycerol (54%) among the Ascomycetes. Cultivation with Rhizopus sp. produced up to 15 g·L−1 biomass containing 55% (w/w) crude protein. The spent thin stillage had been reduced up to 85%, 68% and 21% regarding lactic acid, glycerol and total solids, respectively. Therefore, N. intermedia, in particular, has a high potential to improve the ethanol process via production of additional ethanol and high-quality biomass, which can be considered for animal feed applications such as for fish feed.
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| 5. |
- Ferreira, Jorge A., et al.
(författare)
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Spent sulphite liquor for cultivation of an edible Rhizopus sp.
- 2012
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Ingår i: BioResources. - : North Carolina State University: College of Natural Resources. - 1930-2126. ; 7:1, s. 173-188
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Tidskriftsartikel (refereegranskat)abstract
- Spent sulphite liquor, the major byproduct from the sulphite pulp production process, was diluted to 50% and used for production of an edible zygomycete Rhizopus sp. The focus was on production, yield, and composition of the fungal biomass composition. The fungus grew well at 20 to 40°C, but 32°C was found to be preferable compared to 20 and 40°C in terms of biomass production and yield (maximum of 0.16 g/g sugars), protein content (0.50-0.60 g/g), alkali-insoluble material (AIM) (ca 0.15 g/g), and glucosamine content (up to 0.30 g/g of AIM). During cultivation in a pilot airlift bioreactor, the yield increased as aeration was raised from 0.15 to 1.0 vvm, indicating a high demand for oxygen. After cultivation at 1.0 vvm for 84 h, high yield and production of biomass (up to 0.34 g/g sugars), protein (0.30-0.50 g/g), lipids (0.02-0.07 g/g), AIM (0.16-0.28 g/g), and glucosamine (0.22-0.32 g/g AIM) were obtained. The fungal biomass produced from spent sulphite liquor is presently being tested as a replacement for fishmeal in feed for fish aquaculture and seems to be a potential source of nutrients and for production of glucosamine.
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| 6. |
- Ferreira, Jorge A., et al.
(författare)
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Zygomycetes-based biorefinery: Present status and future prospects
- 2013
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 135, s. 523-532
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Tidskriftsartikel (refereegranskat)abstract
- Fungi of the phylum Zygomycetes fulfil all requirements for being utilized as core catalysts in biorefineries, and would be useful in creating new sustainable products. Apart from the extended use of Zygomycetes in preparing fermented foods, industrial metabolites such as lactic acid, fumaric acid, and ethanol are produced from a vast array of feedstocks with the aid of Zygomycetes. These fungi produce enzymes that facilitate their assimilation of various complex substrates, e.g., starch, cellulose, phytic acid, and proteins, which is relevant from an industrial point of view. The enzymes produced are capable of catalyzing various reactions involved in biodiesel production, preparation of corticosteroid drugs, etc. Biomass produced with the aid of Zygomycetes consists of proteins with superior amino acid composition, but also lipids and chitosan. The biomass is presently being tested for animal feed purposes, such as fish feed, as well as for lipid extraction and chitosan production. Complete or partial employment of Zygomycetes in biorefining procedures is consequently attractive, and is expected to be implemented within a near future.
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| 7. |
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| 8. |
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| 9. |
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| 10. |
- Ky, Q. M. H., et al.
(författare)
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Dimorphism of Mucor indicus: different gene expressions between yeast-like and filamentous growth
- 2013
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Ingår i: Minerva Biotecnologica. - : Edizioni Minerva Medica. - 1120-4826 .- 1827-160X. ; 25:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Aim. Mucor indicus is a zygomycetes fungus with several advantages. Its ethanol yield from hexoses rivals that of Saccharomyces cerevisiae and it is capable of producing ethanol from xylose in limited aerobic conditions. It is also able to ferment dilute acid hydrolysate and is known to be dimorphic; able to grow in both filamentous and yeast-like modes.Methods. In this study, the difference between yeast-like and filamentous cells of M. indicus was investigated using modern polymerase chain reaction (PCR) techniques. Four mRNA sequences were detected with a higher expression in the filamentous growth form than in the yeast-like, by a factor of 1.3-4.2. One of the sequences was novel and three have been detected in another species of Mucor, M. circinelloides, coding for a chitin synthase, a proteasome and a sigma 70 factor.Results and conclusion. The novel sequence exhibited the largest difference in expression and was subjected to knock-down. However, it proved to be best suited for detection of emerging growth patterns, since the knock-down had little effect on the developing growth form. With the results of this study, an important step towards understanding the difference in the dimorphic behaviour exhibited by M. indicus, as well as other members of the genus Mucor, has been taken. Potentially it could also be used as one of the tools for the control of the dimorphic behaviour of M. indicus, and other species of the Mucor genus.
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| 11. |
- Lennartsson, Patrik, et al.
(författare)
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A pilot study on lignocelluloses to ethanol and fish feed using NMMO pretreatment and cultivation with Zygomycetes in an airlift reactor
- 2011
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 102:6, s. 4425-4432
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Tidskriftsartikel (refereegranskat)abstract
- A complete process for the production of bioethanol and fungal biomass from spruce and birch was investigated. The process included milling, pretreatment with N-methylmorpholine-N-oxide (NMMO), washing of the pretreated wood, enzymatic hydrolysis, and cultivation of the zygomycetes fungi Mucor indicus. Investigated factors included wood chip size (0.5-16 mm), pretreatment time (1-5 h), and scale of the process from bench-scale to 2 m high airlift reactor. Best hydrolysis yields were achieved from wood chips below 2 mm after 5 h of pretreatment. Ethanol yields (mg/g wood) of 195 and 128 for spruce, and 175 and 136 for birch were achieved from bench-scale and airlift, respectively. Fungal biomass yields (mg/g wood) of 103 and 70 for spruce, and 86 and 66 for birch from bench scale and airlift respectively were simultaneously achieved. NMMO pretreatment and cultivation with M. indicus appear to be a good alternative for ethanol production from birch and spruce.
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| 12. |
- Lennartsson, Patrik, et al.
(författare)
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Growth tolerance of Zygomycetes Mucor indicus in orange peel hydrolysate without detoxification
- 2012
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Ingår i: Process Biochemistry. - : Elsevier Ltd. - 1359-5113 .- 1873-3298. ; 47:5, s. 836-842
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Tidskriftsartikel (refereegranskat)abstract
- The capability of two zygomycetes strains, Mucor indicus and an isolate from tempeh (Rhizopus sp.), to grow on orange peel hydrolysate and their tolerance to its antimicrobial activity, was investigated. Both fungi, in particular M. indicus, tolerated up to 2% d-limonene in semi-synthetic media during cultivation in shake flasks, under aerobic as well as anaerobic conditions. The tolerance of M. indicus was also tested in a bioreactor, giving rise to varying results in the presence of 2% limonene. Furthermore, both strains were capable of consuming galacturonic acid, the main monomer of pectin, under aerobic conditions when no other carbon source was present. The orange peel hydrolysate was based on 12% (dry w/v) orange peels, containing d-limonene at a concentration of 0.6% (v/v), which no other microorganism has been reported to be able to ferment. However, the hydrolysate was utilised by M. indicus under aerobic conditions, resulting in production of 410 and 400 mg ethanol/g hexoses and 57 and 75 mg fungal biomass/g sugars from cultivations in shake flasks and a bioreactor, respectively. Rhizopus sp., however, was slow to germinate aerobically, and neither of the zygomycetes was able to consistently germinate in orange peel hydrolysate, under anaerobic conditions. The zygomycetes strains used in the present study demonstrated a relatively high resistance to the antimicrobial compounds present in orange peel hydrolysate, and they were capable of producing ethanol and biomass in the presence of limonene, particularly when cultivated with air supply.
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| 13. |
- Lennartsson, Patrik, et al.
(författare)
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Integration of the first and second generation bioethanol processes and the importance of by-products
- 2014
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Ingår i: Bioresource Technology. - : Elsevier. - 0960-8524 .- 1873-2976. ; 165, s. 3-8
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Tidskriftsartikel (refereegranskat)abstract
- Lignocellulosic ethanol has obstacles in the investment costs and uncertainties in the process. One solution is to integrate it with the running dry mills of ethanol from grains. However, the economy of these mills, which dominate the world market, are dependent on their by-products DDGS (Distiller’s Dried Grains and Solubles), sold as animal feed. The quality of DDGS therefore must not be negatively influenced by the integration. This puts restraints on the choice of pretreatment of lignocelluloses and utilizing the pentose sugars by food-grade microorganisms. The proposed solution is to use food related filamentous Zygomycetes and Ascomycetes fungi, and to produce fungal biomass as a high-grade animal feed from the residues after the distillation (stillage). This also has the potential to improve the first generation process by increasing the amount of the thin stillage directly sent back into the process, and by decreasing the evaporator based problems.
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| 14. |
- Lennartsson, Patrik R, 1983, et al.
(författare)
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Rhizopus
- 2014
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Ingår i: Encyclopedia of Food Microbiology. - : Academic Press, Elsevier. - 9780123847300 ; , s. 284-290
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Bokkapitel (refereegranskat)
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| 15. |
- Lennartsson, Patrik R, 1983, et al.
(författare)
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Rhizopus
- 2014
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Ingår i: Encyclopedia of Food Microbiology. - 9780123847300 ; , s. 284-290
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 16. |
- Lennartsson, Patrik, et al.
(författare)
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Rhizopus
- 2014
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Ingår i: Encyclopedia of Food Microbiology. - : Elsevier. - 9780123847300 ; , s. 284-290
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Bokkapitel (refereegranskat)
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| 17. |
- Lennartsson, Patrik
(författare)
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Zygomycetes and cellulose residuals : hydrolysis, cultivation and applications
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Zygomycetes is a class of fungi living worldwide as saprobes, as part of mycorrhizae, and as parasites. Humans have used some zygomycetes for centuries in the production of traditional foods, e.g. Indonesian tempe. In the present thesis, the experimental focus was on two zygomycetes strains, Mucor indicus CCUG 22424 and Rhizopus sp. IT. One of the distinguishing features of M. indicus is its dimorphism. The different cell forms were influenced by the culturing conditions. After inoculation, when the initial spore concentration was high (6-8×106 spores/ml), yeast-like growth dominated under anaerobic conditions. With a smaller inoculum, yielding 1-2×105 spores/ml, and access to oxygen, filamentous forms dominated. Only negligible differences in ethanol yield (390-420 mg/g hexoses), productivity (3-5 g/l/h), and inhibitor tolerance were observed. Differential expressions of probably four genes were observed between the yeast-like and filamentous growth forms. Lignocelluloses are a suitable substrate for cultivating zygomycetes, as they occur in abundance, particularly since zygomycetes, unlike Saccharomyces cerevisiae, can utilise pentoses. Lignocelluloses require pretreatment to achieve efficient hydrolysis of the cellulose. N-methylmorpholine-N-oxide (NMMO) was tested for pretreatment of spruce and birch. Reducing wood chip size and/or prolonged pretreatment, promoted hydrolysis yield. Best yields were achieved from <2 mm chips and 5 h pretreatment. The hydrolysate was used for fermentation with M. indicus, resulting in 195 and 175 mg ethanol/g wood, and 103 and 86 mg fungal biomass/g wood, from spruce and birch respectively. Orange peel is another potential substrate. However, the hydrolysate contained 0.6 % (v/v) D-limonene, ten times higher than the concentration inhibiting S. cerevisiae. M. indicus was more resistant and successfully fermented the hydrolysate, producing 400 mg ethanol/g hexoses and 75 mg fungal biomass/g sugars. Both M. indicus and Rhizopus sp. grew in 1.0 % and 2.0 % D-limonene, although the latter was unable to grow in the hydrolysate. A third substrate was also used, spent sulphite liquor (SSL), which is a by-product from sulphite paper pulp mills. The SSL was diluted to 50 % and used for airlift cultivations of Rhizopus sp. In 1.0 vvm aeration, up to 340 mg biomass/g sugars was produced. Prolonged cultivations generally decreased the protein (from 500 to 300 mg/g) and lipid (from 70 to 20 mg/g) contents. In contrast, the cell wall fraction, measured as alkali-insoluble material (AIM), increased (160-280 mg/g), as did the glucosamine (GlcN) content (220-320 mg GlcN/g AIM). The produced fungal biomass could serve as animal feed, e.g. for fish.
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| 18. |
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| 19. |
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| 20. |
- Nyman, Jonas, et al.
(författare)
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Pellet formation of zygomycetes and immobilization of yeast
- 2013
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Ingår i: New Biotechnology. - : Elsevier BV. - 1871-6784 .- 1876-4347. ; 30:5, s. 516-522
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Tidskriftsartikel (refereegranskat)abstract
- Pelleted growth provides many advantages for filamentous fungi, including decreased broth viscosity, improved aeration, stirring, and heat transfer. Thus, the factors influencing the probability of pellet formation of Rhizopus sp. in a defined medium was investigated using a multifactorial experimental design. Temperature, agitation intensity, Ca2+-concentration, pH, and solid cellulose particles, each had a significant effect on pelletization. Tween 80, spore concentration, and liquid volume were not found to have a significant effect. All of the effects were additive; no interactions were significant. The results were used to create a simple defined medium inducing pelletization, which was used for immobilization of a flocculating strain of Saccharomyces cerevisiae in the zygomycetes pellets. A flor-forming S. cerevisiae strain was also immobilized, while a non-flocculating strain colonized the pellets but was not immobilized. No adverse effects were detected as a result of the close proximity between the filamentous fungus and the yeast, which potentially allows for co-fermentation with S. cerevisiae immobilized in pellets of zygomycetes
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| 21. |
- Osadolor, Osagie A., et al.
(författare)
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Introducing Textiles as Material of Construction of Ethanol Bioreactors
- 2014
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Ingår i: Energies. - : MDPIAG. - 1996-1073. ; 7:11, s. 7555-7567
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Tidskriftsartikel (refereegranskat)abstract
- The conventional materials for constructing bioreactors for ethanol production are stainless and cladded carbon steel because of the corrosive behaviour of the fermenting media. As an alternative and cheaper material of construction, a novel textile bioreactor was developed and examined. The textile, coated with several layers to withstand the pressure, resist the chemicals inside the reactor and to be gas-proof was welded to form a 30 L lab reactor. The reactor had excellent performance for fermentative production of bioethanol from sugar using baker’s yeast. Experiments with temperature and mixing as process parameters were performed. No bacterial contamination was observed. Bioethanol was produced for all conditions considered with the optimum fermentation time of 15 h and ethanol yield of 0.48 g/g sucrose. The need for mixing and temperature control can be eliminated. Using a textile bioreactor at room temperature of 22 °C without mixing required 2.5 times longer retention time to produce bioethanol than at 30 °C with mixing. This will reduce the fermentation investment cost by 26% for an ethanol plant with capacity of 100,000 m3 ethanol/y. Also, replacing one 1300 m3 stainless steel reactor with 1300 m3 of the textile bioreactor in this plant will reduce the fermentation investment cost by 19%.
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| 22. |
- Taherzadeh, Mohammad J., et al.
(författare)
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Bioethanol Production Processes
- 2013
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Ingår i: Biofuels Production. - : Wiley. - 9781118634509 - 9781118835913 ; , s. 211-253
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Bokkapitel (refereegranskat)abstract
- Ethanol, with more than 86 billion liters production in 2011, is the dominant biofuel in the global fuel market. Nowadays, ethanol is produced from starch- and sugar sources, so-called 1st generation ethanol, while lignocellulosic ethanol (2nd generation) is not yet applied for industrial applications. In general, the production includes pretreatment, eventual hydrolysis of sugar polymers by enzymes or acids, fermentation by baker’s yeast, for example, and downstream processes such as distillation, dehydration, and evaporation. Furthermore, the global production and consumption of ethanol has also raised ethical and social concerns about, for example, food vs. fuel. This chapter covers the details of processes for this biofuel production.
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| 23. |
- Wu, Xuping, et al.
(författare)
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Expression of EGFR and LRIG proteins in oesophageal carcinoma with emphasis on patient survival and cellular chemosensitivity.
- 2012
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Ingår i: Acta Oncologica. - : Informa Healthcare. - 0284-186X .- 1651-226X. ; 51:1, s. 69-76
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Background. Leucine-rich and immunoglobulin-like domains 1-3 (LRIG1-3) proteins have been implicated in the regulation of EGFR signalling. In the present study, we investigated the clinical implications of the expression of EGFR and LRIG1-3 in oesophageal carcinoma, as well as the correlation between their expression levels and the chemosensitivity of oesophageal carcinoma cell lines. Patients and methods. Tumours from 80 patients with oesophageal carcinoma were investigated for the expression of EGFR and LRIG proteins by immunohistochemistry. Oesophageal carcinoma cell lines were investigated for their expression of EGFR and LRIG1, 2, and 3 by quantitative real time RT-PCR and for their sensitivity to commonly used chemotherapeutics by a cytotoxicity assay. Results and discussion: Based on a total score of intensity and expression rates, a trend towards survival difference was found for EGFR (p = 0.09) and LRIG2 (p = 0.18) whereas for LRIG1 and -3 there was no trend towards any association with survival. Correlation analysis revealed a correlation with the clinical expression of EGFR and LRIG3 (p = 0.0007). Significant correlations were found between LRIG1 expression levels and sensitivity to cisplatin (r = -0.74), docetaxel (r = -0.69), and vinorelbine (r = -0.82) in oesophageal carcinoma cell lines. EGFR and the LRIG proteins may be functionally involved in oesophageal carcinoma, but larger materials are needed to fully elucidate the clinical implication.
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