Production, Purification and Characterization of Antimicrobial Biomolecules from Potential Probiotic Lactic Acid Bacteria

Sahar Deraz

Research output: ThesisDoctoral Thesis (compilation)

Abstract

Development and optimization of the production of lactic acid bacteria (LAB) and their attendant 'natural' inhibitors as biopreservatives to control undesirable bacteria currently remains a primary focus of several laboratories involved in research concerning food safety and quality. Strategies utilized to study incorporation of biopreservatives into food include either direct use of LAB-strains or use of a biopreservative preparation in the form of previously fermented product or use of semipurified, purified, or chemically synthesized bacteriocins. Modern concepts or perspectives of the application of LAB include the following selections: i) the best adapted and safely performing LAB strains, ii) strains with probiotic effects and/or health-promoting effects and finally iii) strains with food protective activities. In the study presented in this thesis, three different strains, Lactobacillus acidophilus DSM 20079, Pediococcus damnosus 2.6 and Lactobacillus sakei CCUG 42685, have been chosen to study their biotechnological properties according to one or several of the previously mentioned concepts. Structural and functional characterization of a novel antimicrobial peptide (acidocin 20079) from an LAB with interesting characteristics as producer strain (Lactobacillus acidophilus DSM 20079), has been made, showing that the isolated bacteriocin has a potential for industrial application. Furthermore, the functional properties of selected bacteriocin producing strains (L. acidophilus DSM 20079 and Pediococcus damnosus 2.6) as probiotic have been studied. The strains showed a high tolerance to the main obstacles of the GI-tract in experiments simulating native conditions at 37 °C. Finally, improvements within the field of purification of bacteriocins from non-clarified crude homogenate are needed as the currently published protocols are often cumbersome. An economically reliable process hence has to be developed for bacteriocin purification. A chromatographic matrix based on continuous supermacroporous cryogel was successfully used for the purification of sakacin P (produced by L. sakei CCUG 42685) directly from non-clarified crude. The bound bacteriocin was eluted with 81-87 % recovery in particulate free eluate with more than 60%purity after one purification step.
Original languageEnglish
QualificationDoctor
Awarding Institution
  • Biotechnology
Supervisors/Advisors
  • [unknown], [unknown], Supervisor, External person
Award date2005 Dec 19
Publisher
ISBN (Print)91-89627-44-X
Publication statusPublished - 2005

Bibliographical note

Defence details

Date: 2005-12-19
Time: 10:30
Place: The lecture hall C, at the centre for chemistry and chemical engineering, Lund Institute of Technology

External reviewer(s)

Name: Axelsson, Lars
Title: PhD
Affiliation: Matforsk AS, Norwegian Food Research Institute Osloveien 1N-1430 Ås, Norway

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<div class="article_info">Sahar Deraz, Eva Nordberg Karlsson, Martin Hedstr¨om, Maria M Andersson and Bo Mattiasson. <span class="article_issue_date">2005</span>. <span class="article_title">Purification and characterisation of acidocin D20079, a bacteriocin produced by Lactobacillus acidophilus DSM 20079</span> <span class="journal_series_title">Journal of Biotechnology</span>, <span class="journal_volume">vol 117</span> <span class="journal_pages">pp 343-354</span>. <span class="journal_distributor">Biotechnology Department</span></div>
<div class="article_info">Sahar Deraz, Martin Hedström, Eva Nordberg Karlsson, Sara Linse and Bo Mattiasson. <span class="article_issue_date"></span>. <span class="article_title">Production and physicochemical characterization of acidocin D20079, a bacteriocin produced by the potential probiotic strain Lactobacillus acidophilus DSM 20079</span> <span class="journal_distributor">Biotechnology Department</span> (manuscript)</div>
<div class="article_info">Tina Immerstrand, Sahar Deraz, Olof Mårtensson, Åsa Ljungh, Rickard Öste, Eva Karlsson and Olle Holst. <span class="article_issue_date"></span>. <span class="article_title">The probiotic potential of Pediococcus damnosus 2.6</span> <span class="journal_distributor">Biotechnology Department</span> (submitted)</div>
<div class="article_info">Fatima Plieva, Irina Savina, Sahar Deraz, Jonatan Andersson, Igor Yu Galaev and Bo Mattiasson. <span class="article_issue_date">2004</span>. <span class="article_title">Characterization of supermacroporous monolithic polyacrylamide based matrices designed for chromatography of bioparticles</span> <span class="journal_series_title">Journal of Chromatography B</span>, <span class="journal_volume">vol 807</span> <span class="journal_pages">pp 129-137</span>. <span class="journal_distributor">Biotechnology Department</span></div>
<div class="article_info">Sahar Deraz, Fatima Plieva, Igor Yu Galaev, Eva Nordberg Karlsson and Bo Mattiasson. <span class="article_issue_date"></span>. <span class="article_title">Capture of bacteriocins directly from non-clarified fermentation broth using macroporous monolithic cryogels with phenyl ligands</span> <span class="journal_distributor">Biotechnology Department</span> (submitted)</div>

Subject classification (UKÄ)

  • Industrial Biotechnology

Keywords

  • Lactobacillus
  • Bioteknik
  • Biotechnology
  • Livsmedelsteknik
  • Food and drink technology
  • bacteriocin purification.
  • inhibitory activity
  • Bacteriocin
  • antimicrobial protein

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