| Title |
Heteropolisacharidus skaidančių fermentų atranka, charakterizavimas ir funkcinės svarbos analizė / |
| Translation of Title |
Screening, characterization and functionality analysis of heteropolysaccharide degrading enzymes. |
| Authors |
Petkauskaitė, Raimonda |
| Full Text |
|
| Pages |
228 |
| Keywords [eng] |
heteropolysaccahride ; oligosaccharide ; pectin ; pullulan ; enzymes |
| Abstract [eng] |
Starch and pectin are among of the most important heteropolysaccharides for biosphere. Nature and biotechnology directly relies on possibilities to exploit these biopolymers. Full exploitation of starch and pectin would be impossible without possibility to disrupt these polymers enzymatically. The available variety of amylases and pectinases remains not satisfactory in context of biotechnology challenges. Novel amylases and pectinases were screened using soil metaproteomic and enrichment culture methods. Enzymes were detected by zymography from soil microorganisms. Sequences of detected enzymes were identified by mass spectrometry. Thermostable and thermoactive pullulanase AmyA1 and pectate lyase PL47 from geobacilli were characterized in vitro. Intracellular type I pullulanase AmyA1 hydrolyses pullulan, glycogen and soluble starch. Constitutively secreted endopolygalacturonate transeliminase PL47 was active against polygalacturonic acid, pectin and pectin from apple pomace. Under suboptimal reaction conditions AmyA1 and PL47 were able to generate long-chain oligosaccharides which are valuable for biotechnology. Immobilization of AmyA1 and PL47 increased thermostability. AmyA1 activity was increased by immobilization, but immobilized PL47 was less active. Isolation of Geobacillus thermodenitrificans DSM 101594 strain from soil and genome sequencing ensured in silico characterization of AmyA1 and PL47 operonic organization and characterization of enzymes functional importance. AmyA1 is important for basic nutritional strategy of strain ability to utilize starch. PL47 obtained by horizontal gene transfer ensures ability to utilize pectin, what reflects strain adaptation to econiche. |
| Dissertation Institution |
Vilniaus universitetas. |
| Type |
Doctoral thesis |
| Language |
Lithuanian |
| Publication date |
2020 |
