Piena permeāta izmantošanas iespējas 2-feniletanola biosintēzei ar raugu Kluyveromyces marxianus
Date
2017
Authors
Žorža, Laura
Journal Title
Journal ISSN
Volume Title
Publisher
Latvijas Universitāte
Abstract
Bakalaura darba mērķis bija izvērtēt industriāla substrāta – laktozi saturoša piena permeāta- izmantošanas iespējas 2-feniletanola biosintēzei ar rauga Kluyveromyces marxianus diviem celmiem- DSM 5422 un DSM 5418- un noskaidrot barotnes sastāva (pussintētiskā laktozes barotne, piena permeāta laktozes barotne, slāpekļa avota (amonija sulfāta), L-fenilalanīna koncentrācija) ietekmi uz 2-feniletanola producēšanu. Tika pierādīta piena permeāta kā oglekļa avota izmantošanas iespēja 2-feniletanola biosintēzei. Pētījumu gaitā tika noskaidrots, ka labākus 2-feniletanola biosintēzes rādītājus uzrādīja K.marxianus DSM 5418 celms, kurš tika audzēts piena permeāta barotnē bez papildus pievienotā amonija sulfāta. Tika novērots, ka DSM 5418 celmam ir raksturīga augsta tolerance pret inhibīciju ar 2-feniletanolu. Izmantojot vairākfaktoru eksperimentālo modelēšanu, tika pētīta laktozes koncentrācijas un L-fenilalanīna ietekme uz Kluyveromyces marxianus 2-feniletanola producēšanu un šo abu faktoru mijiedarbība. Tika konstatēts, ka laktozes koncentrācija 100 g/L piena permeāta barotnē ļauj sasniegt augstāko 2-feniletanola koncentrāciju, un, L-fenilalanīna koncentrācijai palielinoties diapazonā no 5 līdz 15 g/L, 2-feniletanola iznākums no L-fenilalanīna samazinās. Šī bakalaura darba izstrādē tika apgūtas nepieciešamās metodes: raugu kultivēšanas metodes, biomasas noteikšanas metode ar spektrofotometru, fermentācijas parametru noteikšana un HPLC- hromatogrāfa metode. Pētījumi tika veikti LU MBI, Ogļhidrātu biokonversijas laboratorijā.
The aim of this work was to determine industrial substrate - lactose containing milk permeate- capabilities of use for 2-phenylethanol biosynthesis by yeast Kluyveromyces marxianus two strains- DSM 5422 and DSM 5418- and to determine effects of medium composition (semisynthetic lactose medium, milk permeate lactose medium, nitrogen source (ammonium sulfate), L-phenylalanine) on the production of 2-phenylethanol. It was determined that milk permeate can be used as a carbon source for the production of 2-phenylethanol. In this research it was found that the best 2-phenylethanol yield rates showed DSM 5418 strain on milk permeate medium without nitrogen source added. It was observed that DSM 5418 strain have high tolerance against inhibition with 2-phenylethanol. The effects of lactose concentration and L-phenylalanine and interaction of both factors on Kluyveromyces marxianus 2-phenylethanol production was studied using multifactorial experimental design. It was determined that lactose concentration 100 g/L allows to achieve higher 2-phenylethanol concentration and 2-phenylethanol yield from L-phenylalanine decreases at increasing concentration of L-phenylalanine in the range of 5-15 g/L. During the research essential experimental methods were mastered: yeasts cultivation methods, biomass determination with spectrophotometer, fermentation characteristics calculations, HPLC chromatograph method. The research was carried out at the University of Latvia, Microbiology and Biotechnology Institute, Laboratory of Carbohydrates Bioconversion.
The aim of this work was to determine industrial substrate - lactose containing milk permeate- capabilities of use for 2-phenylethanol biosynthesis by yeast Kluyveromyces marxianus two strains- DSM 5422 and DSM 5418- and to determine effects of medium composition (semisynthetic lactose medium, milk permeate lactose medium, nitrogen source (ammonium sulfate), L-phenylalanine) on the production of 2-phenylethanol. It was determined that milk permeate can be used as a carbon source for the production of 2-phenylethanol. In this research it was found that the best 2-phenylethanol yield rates showed DSM 5418 strain on milk permeate medium without nitrogen source added. It was observed that DSM 5418 strain have high tolerance against inhibition with 2-phenylethanol. The effects of lactose concentration and L-phenylalanine and interaction of both factors on Kluyveromyces marxianus 2-phenylethanol production was studied using multifactorial experimental design. It was determined that lactose concentration 100 g/L allows to achieve higher 2-phenylethanol concentration and 2-phenylethanol yield from L-phenylalanine decreases at increasing concentration of L-phenylalanine in the range of 5-15 g/L. During the research essential experimental methods were mastered: yeasts cultivation methods, biomass determination with spectrophotometer, fermentation characteristics calculations, HPLC chromatograph method. The research was carried out at the University of Latvia, Microbiology and Biotechnology Institute, Laboratory of Carbohydrates Bioconversion.
Description
Keywords
Bioloģija , Kluyveromyces marxianus , piena permeāts , 2-feniletanols , fermentācija , laktoze