An Exploratory Study of Hydrochar as a Matrix for Biotechnological Applications.

This paper explores the potentialities of hydrochar in protein separation and enzyme immobilization for non-energy biorefinery applications of hydrothermal carbonization. An innovative experimental procedure monitors soluble protein-hydrochar interactions and enzymatic reactions in a continuously stirred tank reactor. The hydrochar comes from hydrothermal carbonization of silver fir (200 °C, 30 min, 1/7 solid/water ratio) and standard activation (KOH, oven, 600 °C). Bovine serum albumin, a non-active, globular protein, was adsorbed at ≤3300 mg/g. Sip's isotherms fitted data well (R2 = 0.99999). The immobilization used a commercial ß-glucosidase, which catalyzes the hydrolysis of cellobiose to glucose, a bottleneck of the cellulose to fermentable sugar bioconversion network due to the fast enzyme deactivation. The hydrochar adsorbed ≤26 w/w% of enzyme. The heterogeneous biocatalyst operational stability was 24 times that of the soluble one. The results encourage further investigations and foreshadow process schemes coupling hydrothermal carbonization and industrial bioconversions.

Effect of inhibitors released during steam-explosion treatment of poplar wood on subsequent enzymatic hydrolysis and SSF.

Steam-exploded (SE) poplar wood biomass was hydrolyzed by means of a blend of Celluclast and Novozym cellulase complexes in the presence of the inhibiting compounds produced during the preceding steam-explosion pretreatment process. The SE temperature and time conditions were 214 degrees C and 6 min, resulting in a log R(0) of 4.13. In enzymatic hydrolysis tests at 45 degrees C, the biomass loading in the bioreactor was 100 g(DW)/L (dry weight) and the enzyme-to-biomass ratio 0.06 g/g(DW). The enzyme activities for endo-glucanase, exo-glucanase, and beta-glucosidase were 5.76, 0.55, and 5.98 U/mg, respectively. The inhibiting effects of components released during SE (formic, acetic, and levulinic acids, furfural, 5-hydroxymethyl furfural (5-HMF), syringaldehyde, 4-hydroxy benzaldehyde, and vanillin) were studied at different concentrations in hydrolysis runs performed with rinsed SE biomass as model substrate. Acetic acid (2 g/L), furfural, 5-HMF, syringaldehyde, 4-hydroxybenzaldehyde, and vanillin (0.5 g/L) did not significantly effect the enzyme activity, whereas formic acid (11.5 g/L) inactivated the enzymes and levulinic acid (29.0 g/L) partially affected the cellulase. Synergism and cumulative concentration effects of these compounds were not detected. SSF experiments show that untreated SE biomass during the enzymatic attack gives rise to a nonfermentable hydrolysate, which becomes fermentable when rinsed SE biomass is used. The presence of acetic acid, vanillin, and 5-HMF (0.5 g/L) in SSF of 100 g(DW) /L biomass gave rise to ethanol yields of 84.0%, 73.5%, and 91.0% respectively, with respective lag phases of 42, 39, and 58 h.

Nitrile, amide and temperature effects on amidase-kinetics during acrylonitrile bioconversion by nitrile-hydratase/amidase in situ cascade system.

In this study the amidase kinetics of an in situ NHase/AMase cascade system was explored as a function of operational parameters such as temperature, substrate concentration and product formation. The results indicated that controlling amidase inactivation, during acrylonitrile bioconversion, makes it possible to recover the intermediate product of the two-step reaction in almost a pure form, without using purified enzyme. It has been demonstrated, in long-term experiments performed in continuous stirred UF-membrane bioreactors, that amidase is kinetically controlled by its proper substrate, depending on the structure, and by acrylonitrile. Using acrylamide, AMase-stability is temperature dependent (5°C, kd=0.008 h(-1); 30°C kd=0.023 h(-1)). Using benzamide, amidase is thermally stable up to 50°C and no substrate inhibition/inactivation occurs. With acrylonitrile, AMase-activity and -stability remain unchanged at concentrations <200 mM but at 200 mM, 35°C, after 70 h process, 90% irreversible inactivation occurs as no AMase-activity on benzamide revives.

[The analysis of psychological and social problems, the physical development in young people with congenital adrenal hyperplasia - owner experience]. / Analiza problemów psychologiczno-spolecznych i ocena rozwoju mlodego pacjenta leczonego z powodu wrodzonego przerostu kory nadnerczy w oparciu o material wlasny.

INTRODUCTION: Congenital adrenal hyperplasia (CAH) is an inherited metabolic disorder affecting physical and psychosexual development connected with endocrine disturbances. THIS STUDY AIMED: to assess the physical development of children treated for CAH and to analyze their psychological and social problems in their parents' opinion. MATERIAL AND METHODS: The subjects were 20 children with CAH (aged 4.5-19 years, 7 girls and 13 boys) and their parents. The research was based on a retrospective analysis of subjects' development and a questionnaire for parents asking about their emotional reactions to diagnosis, concerns and expectations, knowledge about CAH as well as gender assignment of their children. RESULTS: The parents asked about their emotional reaction to diagnosis of CAH reported anxiety (60%) and helplessness (40%). About 40% of the parents were worried about further sexual life of their children. Most of the parents were satisfied with the way they were informed about CAH, nevertheless about 15% didn't fully understand the matter of this disorder. Over 60% of the parents searched for additional information about CAH. CAH-affected children aged <12 years were higher than healthy children, but they didn't exceed 50th percentile of height after 12th year of life. During the developmental period, the difference between the height of healthy children and those with CAH increased, children with CAH were smaller. Their BMI was between the 90th and 97th percentile both in girls and boys. Questioned parents noticed that CAH-affected girls preferred boy's toys, sports and plays. Occupational plans of girls with CAH correlated more with a group of healthy and CAH-affected boys than with healthy girls. The parents emphasized the importance of support groups for children with CAH and complained of lack of satisfying psychological support. CONCLUSIONS: Physical development of children with CAH is characterized by specific problems. Quick confirmation of final diagnosis and complex genetic counseling allow to introduce proper pharmacological treatment and social and psychological support, The essential issue is to improve parents' education about CAH and provide support groups for families of CAH-affected children.