Breeding cats is my hobby, I also have a professional life
1.1 Maria Christiernin, PhD
1.2 Present position:
Scientific Advisor, Process Analytical Chemistry, Sweden Operations, AstraZeneca since 20070601
1.3 Previous positions:
Project leader at National Board of Health and Welfare, “enheten för uppföljning och utredning, Nationella Planeringsstödet (NPS)”. 20060918-20070228
PhD position in the field of wood chemistry at the department of fiber- and polymer technology. Royal Institute of Technology
PhD position in the field of wood biotechnology at the department of Biotechnology. Royal Institute of Technology
Presently President of a pedigree cat organisation, “AbySomaliringen” with 208 Scandinavian members. Activities include research projects in breed specific heritable genetic diseases, seminars, quarterly magazine, sponsor contacts, etc.
Sports: Passionate climber, surf when we stay at hour house in Morrocco, commute to work on my bycicle. Latest achievement: Vasaloppet 2010, Uppsala-Stockholm 2011, 80 km ice-skating
Formerly President of a parent’s organisation at the school my son was studying in at the time (Johan Skytteskolan, Älvsjö)
Worked as a cook and baker in various restaurants in Stockholm, New York, San Fransisco, Boston, New Dehli and Mumbai. Studied Italian, History and Literature one year at University per Stranieri in Perugia, Italy.
1.5 Language Skills
English: fluent in speech and writing
French: fluent in speech
Italian: fluent in speech
Doctor of Philosophy (PhD), KTH June 15, 2006
Thesis entitled: Composition of Lignin in Outer Cell-Wall Layers
Fulltext on internet:
Licentiate of Engineering (Lic), KTH October 25, 2002
Thesis entitled: Biological Role and Technical Application of Xyloglucan endotansglycosylase and Xyloglucan
Fulltext on internet:
Master of Science in Chemical Engineering, KTH August 13, 1999
Thesis on the subject of biochemistry entitled: Enantioselectivity of the active site tunnel in Candida rugosa lipase: Studies by rational substrate engineering
3 Scientific merits
During PhD: Isolation of the aromatic polymer lignin from selected trees for NMR analysis as well as degradation of wood meal and extensive work-up procedures for chemical analysis of carbohydrates and lignin. Techniques used for degradation products were: GC-FID, GC-MS and GPC. Wood tissue samples were also examined with AFM and light microscopy as well as CLSM, when confocal microscopy was used a variety of methods for sample preparation were applied.
During Licentiate: Isolation and purification of native protein from plants and development of enzyme activity assays for the protein including synthesis of fluorescent and radioactive artificial substrates. Production and purification of heterologously expressed protein was also carried out. Improvement of paper quality by addition of hemicellulose to kraft pulp. In addition to the techniques already mentioned spectrophotometry, TLC, HPLC, MPLC, SDS-PAGE and Western blotting were used.
Presently my research at AstraZeneca is mainly in the areas of particle characterisation and dissolution. Particle shape and size have a major impact on processability during drug manufacturing as well as the dissolution profile. For particle characterisation I have used laser diffraction and image analysis, both automated analysis with Malvern Morphologi G3 instrument and Camsizer as well as other microscopic/spectroscopic techniques (light microscopy, CLSM, SEM, RAMAN). Products analysed are generally granulates, tablets, pellets comprising microcrystalline cellulose, hemicelluloses, glucose and active pharmaceutical ingredients.
Regarding dissolution kinetics I have worked mainly with method development for a new automated dissolution instrument developed by AstraZeneca and Midroc that will be implemented in the AstraZeneca tablet production line before the end of 2010.
AstraZeneca is a global pharmaceutical company, which means extensive collaborations between regional and global sites on a weekly basis. This, together with my 7 years of working and studying outside of Scandinavia before starting my undergraduate studies have given my extensive international experience.
I have taught undergraduate courses during my PhD studies. I do not teach abundantly now, but I am involved in instructing AstraZeneca employees in how to run experiments and develop methods for automated image analysis and automated dissolution analysis.
Christiernin, M., S. M. Notley, L. Zhang, T. Nilsson and G. Henriksson (2009). "Comparison between 10,000-year old and contemporary spruce lignin." Wood Sci. Technol.43(1-2): 23-41.
Wood from white spruce Picea glauca that had been preserved by rapid burial in lake sediments 10,000 years ago, was investigated and compared to a contemporary ref. white spruce wood. The 10,000-yr old sample appeared to have an intact primary cell wall and middle lamella, whereas the carbohydrate monomer distribution, and microscopic images showed that the secondary wall was at least partially removed, indicating that this structure had been selectively attacked by bacteria. The Klason lignin amt. in the aged spruce was found to be 60%. The relative lignin monomer content in the aged spruce was 9% lower than that of the ref. wood, showing that there were fewer b-O-4' linkages in the aged sample. This finding was supported by SEC anal. of the thioacidolyzed samples as a larger proportion of lignin oligomers were obsd. in the aged spruce than in the ref. material. This indicates a somewhat greater no. of condensed bonds in the aged spruce than in the ref. spruce sample. Quant. 13C NMR anal. and HSQC techniques applied on milled wood lignins (MWL) revealed no significant structural differences between the aged spruce and the ref. [on SciFinder (R)]
Christiernin, M. (2007). Årsrapport NPS 2007 En analys av barnmorskors, sjuksköterskors, läkares, tandhygienisters och tandläkares arbetsmarknad” Socialstyrelsen.
Christiernin, M. (2006). Tillgång på: specialistsjuksköterskor och legitimerade röntgensjuksköterskor 2006, Socialstyrelsen.
Christiernin, M. (2006). "Structure of lignins in developing xylem of Norway spruce." Plant Physiol. Biochem. (Amsterdam, Neth.)44(11-12): 693-699.
The developing xylem in a Norway spruce (Picea abies) clone was investigated during a growth season and compared to lignin from sapwood of the same tree clone. Klason and acid-sol. lignin contents were detd. as well as the carbohydrate monomer distribution and protein content. By analyzing lignin thioacidolysis products, it was shown that only guaiacyl units could be detected in the materials, and the relative amt. of b-O-4' bonds was assessed. Monomeric and selected dimeric lignin products were identified by mass spectrometry. The specimens were embedded and thin sections examd. by microscopy to det. the state of cell differentiation in the samples. In the spring and early summer, growth was very rapid and the intention was to collect tissue in which exclusively the middle lamella/primary cell wall had begun to lignify. Combining data regarding Klason lignin, protein content and carbohydrate monomer distribution with microscopy, it was found that the developing xylem sample from mid-June contained lignin from exclusively middle lamella/primary wall. The Klason lignin content in the developing xylem during the growth season was 20%, 5% and 10% in Apr., June and August, resp. Thioacidolysis showed that the lignin had more condensed structures than lignin from the ref. Norway spruce clone wood. Mass spectrometry showed that the developing xylem specimens from June and August contained more lignin structures with end-groups than the ref. sample. These results suggest that lignification in the cambial layer and early developing xylem may take place more in a bulk fashion during the summer. [on SciFinder (R)]
Christiernin, M. (2006). "Lignin composition in cambial tissues of poplar." Plant Physiol. Biochem. (Amsterdam, Neth.)44(11-12): 700-706.
The cambial tissues of a Populus balsamifera, Balsam poplar clone were studied during a growth season. The Klason and acid-sol. lignin contents were detd. as well as the carbohydrate monomer distribution and the protein content. Both the phloem and the xylem sides of the cambial region were examd. The samples were analyzed by thioacidolysis and structures of dimeric products were detd. by mass spectrometry after desulfuration. Chem. anal. of samples during the growth season was combined with microscopy of embedded specimens that showed the state of cell differentiation at the time of sampling. In spring and early summer, growth is very rapid and the intention was to collect tissue in which exclusively the middle lamella/primary cell wall had begun to lignify. The Klason lignin, protein content and carbohydrate monomer distribution showed that all the specimens from the cambial tissues sampled during a growth season contained predominantly middle lamella and primary walls; except for the developing xylem sampled in August where the carbohydrate compn. showed that secondary walls were present. Thioacidolysis showed that the lignin from the cambial tissues had more condensed structures than the lignin from the ref. balsam poplar clone wood. More guaiacyl than syringyl units were detected and mass spectrometry showed that the cambial tissues contained more lignin structures with end-groups than the ref. sample. These results suggest that lignification in the cambial layer and early developing xylem may take place predominantly in a bulk fashion during the summer. [on SciFinder (R)]
Yan, H., T. Lindstroem and M. Christiernin (2006). "Some ways to decrease fibre suspension flocculation and improve sheet formation." Nord. Pulp Pap. Res. J.21(1): 36-43.
Fiber suspension flocculation was studied in a flow loop system, simulating the flow conditions in a modern paper machine headbox. Fiber suspensions were studied using an optical detection method. Images were taken by a high speed video camera with transmitted infra-red laser light pulse illumination after the headbox nozzle. Fiber flocculation was evaluated by power spectrum anal. using the concepts of mean floc size and flocculation index. A refined unbleached softwood kraft pulp suspension was used in this investigation. The effect of a formation aid, anionic polyacrylamide, A-PAM, was studied with different addn. levels in the fiber suspensions, showing the effects on decreasing the fiber flocculation and improving the sheet formation. Fiber suspensions were also studied at different medium temps. and at different fiber concns. It was found that a decrease of medium temp. decreases the fiber suspension flocculation. These mechanisms of fiber flocculation redn. were discussed in the paper. The refined unbleached softwood kraft pulp was also used for studying the effect of a non-ionic polymer, xyloglucan, on fiber suspension flocculation. Xyloglucan is strongly adsorbed on fiber surface decreasing the friction between fibers, therefore, reducing the fiber flocculation in suspensions. The flocculation redn. increased with an increased addn. of xyloglucan. The effect of xyloglucan on fiber flocculation was also compared with the effects of cationic polyacrylamide, C-PAM, and anionic polyacrylamide, A-PAM, in the same pulp suspension. A refined ECF (Elemental Chlorine Free) bleached softwood kraft pulp was grafted with CM-cellulose, CMC, for studying the effects of surface modification in different ionic forms on fiber suspension flocculation. CMC-grafting on fiber surfaces reduced the fiber flocculation in suspensions by decreasing the friction between fibers, and the flocculation redn. was in the order of Na-form > H-form > Ca-form. Hence, charged groups provide an electrosteric barrier, decreasing the friction between fibers, resulting an improved fiber dispersion. [on SciFinder (R)]
Christiernin, M., A. B. Ohlsson, T. Berglund and G. Henriksson (2005). "Lignin isolated from primary walls of hybrid aspen cell cultures indicates significant differences in lignin structure between primary and secondary cell wall." Plant Physiol. Biochem. (Amsterdam, Neth.)43(8): 777-785.
Hybrid aspen (Populus tremula x tremuloides) cell cultures were grown for 7, 14 and 21 days. The cell cultures formed primary cell walls but no secondary cell wall according to carbohydrate anal. and microscopic characterization. The primary walls were lignified, increasingly with age, according to Klason lignin anal. Presence of lignin in the primary walls, with a higher content in 21-day old cells than in 7-day old cells, was further supported by phloroglucinol/HCl reagent test and confocal microscopy after both immunolocalization and staining with acriflavin. Both laccase and peroxidase activity were found in the cultures and the activity increased during lignin formation. The lignin from the cell culture material was compared to lignin from mature aspen wood, where most of the lignin originates in the secondary cell wall, and which served as our secondary cell wall control. Lignin from the cell walls was isolated and characterized by thioacidolysis followed by gas chromatog. and mass spectrometry. The lignin in the cell cultures differed from lignin of mature aspen wood in that it consisted exclusively of guaiacyl units, and had a more condensed structure. Five lignin structures were identified by mass spectrometry in the cell suspension cultures. Thus, hybrid aspen cell culture used in this investigation may be a convenient exptl. system for studies of primary cell wall lignin. [on SciFinder (R)]
Henriksson, G., M. Christiernin and R. Agnemo (2005). "Monocomponent endoglucanase treatment increases the reactivity of softwood sulphite dissolving pulp." J. Ind. Microbiol. Biotechnol.32(5): 211-214.
Softwood dissolving pulp was treated with a com. monocomponent fungal endocellulase. The reactivity of the pulp for the prodn. of rayon and cellulose derivs. as detd. with the Fock method increased drastically with relatively low amts. of enzyme, and the yield loss and decrease of viscosity were moderate. The mechanism behind the increased reactivity is discussed. [on SciFinder (R)]
Christiernin, M., G. Henriksson, M. E. Lindstroem, H. Brumer, T. T. Teeri, T. Lindstroem and J. Laine (2003). "The effects of xyloglucan on the properties of paper made from bleached kraft pulp." Nord. Pulp Pap. Res. J.18(2): 182-187.
Xyloglucan was adsorbed onto bleached softwood kraft pulp followed by prepn. and anal. of handsheets with respect to sheet formation as well as sheet mech. and optical properties. Adsorption of xyloglucan was found to be slow. After more than 20 h adsorption, equil. had not been reached. The amt. of xyloglucan adsorbed increased with beating, but neither the rate of adsorption nor the quantity adsorbed was significantly affected by temp. Xyloglucan was found to be practically irreversibly adsorbed onto the fibers and the effects of xyloglucan on paper sheet properties were investigated after thorough washing of the pulp. The adsorption characteristics of xyloglucan confirm observations by other authors on other cellulose substrates. Tensile index values for handsheets formed with the xyloglucan-contg. pulps were higher than those measured for control pulps with a comparable beating degree. The light scattering coeff. was, however, not affected by xyloglucan adsorption. Hence, the increase in tensile strength is attributed to an increased relative bond strength between the fibers. Tensile strength vs. tear strength relationship was similar for pulps with and without xyloglucan, but water retention value and dewatering resistance were lower for the xyloglucan treated pulps than for the ref. pulps at the same tensile strength. In addn., formation was improved for pulps with adsorbed xyloglucan. The conclusion is that xyloglucan is a promising wet end additive that decreases the necessity for beating of the pulp and improves the formation of paper. [on SciFinder (R)]
Bourquin, V., N. Nishikubo, H. Abe, H. Brumer, S. Denman, M. Eklund, M. Christiernin, T. T. Teeri, B. Sundberg and E. J. Mellerowicz (2002). "Xyloglucan endotransglycosylases have a function during the formation of secondary cell walls of vascular tissues." Plant Cell14(12): 3073-3088.
Xyloglucan transglycosylases (XETs) have been implicated in many aspects of cell wall biosynthesis, but their function in vascular tissues, in general, and in the formation of secondary walls, in particular, is less well understood. Using an in situ XET activity assay in poplar stems, we have demonstrated XET activity in xylem and phloem fibers at the stage of secondary wall formation. Immunolocalization of fucosylated xylogucan with CCRC-M1 antibodies showed that levels of this species increased at the border between the primary and secondary wall layers at the time of secondary wall deposition. Furthermore, one of the most abundant XET isoforms in secondary vascular tissues (PttXET16A) was cloned and immunolocalized to fibers at the stage of secondary wall formation. Together, these data strongly suggest that XET has a previously unreported role in restructuring primary walls at the time when secondary wall layers are deposited, probably creating and reinforcing the connections between the primary and secondary wall layers. We also obsd. that xylogucan is incorporated at a high level in the inner layer of nacreous walls of mature sieve tube elements. [on SciFinder (R)]
Berglund, P., M. Christiernin and E. Hedenstrom (2001). "Enantiorecognition of chiral acids by Candida rugosa lipase: two substrate binding modes evidenced in an organic medium." ACS Symp. Ser.776(Applied Biocatalysis in Specialty Chemicals and Pharmaceuticals): 263-273.
We have identified the existence of different modes of binding the enantiomers of 2-methyl-branched carboxylic acids to a lipase active site by rational substrate engineering. Similar to hydrolysis, previously investigated, we have now evidence for differential binding modes in the Candida rugosa lipase-catalyzed esterifications in cyclohexane. The relevance of considering two different binding modes to understand lipase enantiorecognition is demonstrated by introducing bulky substituents on a chiral carboxylic acid which impose a different orientation of the substrate acyl chain in the active site of Candida rugosa lipase. With this substrate engineering approach based on mol. modeling it is thus possible to markedly alter the enantioselectivity of the lipase. Examples from hydrolysis and new results from esterifications in an org. solvent are presented and discussed. [on SciFinder (R)]