Proizvodnja D- i L-mliječne kiseline s pomoću čiste i združene kulture bakterija iz roda Lactobacillus sp
| Autor: | Antonija Trontel, Ana Batušić, Ivana Gusić, Anita Slavica, Božidar Šantek, Srđan Novak |
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| Jazyk: | angličtina |
| Rok vydání: | 2011 |
| Předmět: | |
| Zdroj: | Food Technology and Biotechnology Volume 49 Issue 1 |
| ISSN: | 1334-2606 1330-9862 |
| Popis: | Batch cultivation of monoculture of Lactobacillus sp. and two–strain mixed culture of Lactobacillus sp. and Lactobacillus amylovorus DSM 20531T was carried out with the aim of producing L-(+)- and D-(–)/L-(+)-lactic acid to be implemented in poly(lactic acid) polymer production. Metabolic capacity of two Lactobacillus strains to ferment different carbon sources (glucose, sucrose or soluble starch) during cultivation in MRS medium at 40 °C, in a laboratory-scale stirred tank bioreactor was defined. Lactobacillus sp. showed similar affinity towards mono- and disaccharide substrates, which were homofermentatively converted mostly to L-(+)-lactic acid. L. amylovorus DSM 20531T has been characterized as a D/L-lactate producer and it is capable of conducting simultaneous saccharification and fermentation. Due to the interaction of Lactobacillus sp. with L. amylovorus DSM 20531T, starch was hydrolysed and fermented to the mixture of L-(+)- and D-(–)-lactic acid. Modified Luedeking-Piret kinetics used for the description of substrate utilization, growth of mono- and mixed cultures and production of lactic acid stereoisomers showed good agreement with experimental data. Proveden je šaržni uzgoj čiste kulture Lactobacillus sp. i združene kulture bakterija Lactobacillus sp. i Lactobacillus amylovorus DSM 20531T radi proizvodnje L-(+)- i D-(-)/L-(+)-mliječne kiseline i njihove primjene u proizvodnji polilaktida. Definirana je metabolička aktivnost dvaju sojeva iz roda Lactobacillus koji mogu fermentirati različite izvore ugljika (glukozu, saharozu ili topljivi škrob) tijekom uzgoja u MRS podlozi pri 40 °C u laboratorijskom bioreaktoru s miješalom. Bakterija Lactobacillus sp. sličnom brzinom homofermentativno konvertira monosaharide i disaharide do L-(+)-mliječne kiseline (od 89 do 93 %). Bakterija L. amylovorus DSM 20531T okarakterizirana je kao proizvođač D/L-mliječne kiseline i može provoditi simultanu saharifikaciju i fermentaciju. S pomoću združene kulture Lactobacillus sp. i L. amylovorus DSM 20531T škrob je hidroliziran i fermentiran do L-(+)- i D-(-)-mliječne kiseline. Potrošnja supstrata, rast čiste i združene kulture te proizvodnja stereoizomera mliječne kiseline opisani su prilagođenom Luedeking-Piret kinetikom, a dobiveni su rezultati u skladu s eksperimentalnim podacima. |
| Databáze: | OpenAIRE |
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