Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Characterization of bacteriocins produced by lactic acid bacteria from fermented beverages and optimization of starter cultures
Thesis (MSc (Microbiology))--Stellenbosch University, 2008.
Saved in:
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Thesis |
| Language: | English |
| Published: |
Stellenbosch : Stellenbosch University
2008
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613955546939392 |
|---|---|
| access_status_str | Open Access |
| author | Von Mollendorff, Johan Wilhelm |
| author2 | Dicks, Leon Milner Theodore |
| author_browse | Dicks, Leon Milner Theodore Von Mollendorff, Johan Wilhelm |
| author_facet | Dicks, Leon Milner Theodore Von Mollendorff, Johan Wilhelm |
| author_sort | Von Mollendorff, Johan Wilhelm |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MSc (Microbiology))--Stellenbosch University, 2008. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/2174 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:44:21.913Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2008 |
| publishDateRange | 2008 |
| publishDateSort | 2008 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/2174 Characterization of bacteriocins produced by lactic acid bacteria from fermented beverages and optimization of starter cultures Von Mollendorff, Johan Wilhelm Dicks, Leon Milner Theodore Stellenbosch University. Faculty of Science. Dept. of Microbiology. Lactobacillus plantarum Lactobacillus fermentum Probiotics Theses -- Microbiology Dissertations -- Microbiology Microbiology Thesis (MSc (Microbiology))--Stellenbosch University, 2008. Lactobacillus plantarum JW3BZ and Lactobacillus fermentum JW15BZ isolated from boza, a Bulgarian cereal based fermented beverage, produce bacteriocins JW3BZ and JW15BZ active against a wide range of food spoilage and pathogenic bacteria. Strains JW3BZ and JW15BZ are resistant to low pH (pH 2.0–4.0). Both strains grow well in MRS broth with an initial pH ranging from 5.0 to 10.0. Strain JW3BZ displayed intrinsic resistance to bile salts. Strain JW15BZ, on the other hand, is sensitive to bile salts exceeding concentrations of 0.3% (w/v). Both strains are weakly hydrophobic and are resistant to a wide range of antibiotics, antiinflammatory drugs and painkillers. Strains JW3BZ and JW15BZ adhered at 4% to Caco-2 cells and they did not compete with Listeria monocytogenes Scott A for adhesion. A homologue of MapA, a gene known to play a role in adhesion, was detected in L. plantarum JW3BZ. Both strains have high auto- and co-aggregation properties. Bacteriocin JW15BZ was partially purified with ammonium sulfate, followed by separation on Sep-Pak C18 and reverse phase High Pressure Liquid Chromatography (HPLC). Two separate peaks with antimicrobial activity were recorded for bacteriocin JW15BZ, suggesting that it consists of at least two antimicrobial peptides. Lactobacillus plantarum JW3BZ contains genes homologous to plnE, plnF and plnI of the plnEFI operon that encode for two small cationic bacteriocin-like peptides with double-glycine-type leader peptides and its respective immunity proteins. The antimicrobial activity displayed by strain JW3BZ may thus be ascribed to the production of plantaricins E and F. Bacteriocin JW3BZ and JW15BZ displayed activity against herpes simplex virus (HSV-1) (EC50=200 μg/ml). Both strains were identified in boza after 7 days at storage at 4 oC and repressed the growth of Lactobacillus sakei DSM 20017, indicating that the bacteriocins are produced in situ. The sensory attributes of boza prepared with different starter cultures did not vary considerably, although statistical differences were observed for acidity and yeasty aroma. Encapsulation of strain JW3BZ and JW15BZ in 2% sodium alginate protected the cells from low pH (1.6) and 2.0% (w/v) bile. The rate at which cells were released from the matrix varied, depending on the conditions. Better survival of strains JW3BZ and JW15BZ encapsulated in 2% (w/v) alginate was observed during 9 h in a gastro-intestinal model. Highest release of cells was observed at conditions simulating colonic pH (pH 7.4), starting from 56-65% during the first 30 min, followed by 87%. Complete (100%) release was recorded after 2.5 h at these conditions. Strains JW3BZ and JW15BZ could be used as starter cultures in boza. The broad spectrum of antimicrobial activity of bacteriocins JW3BZ and JW15BZ is an added advantage, rendering the cells additional probiotic properties. Encapsulation of the cells in alginate gel increased their resistance to harsh environmental conditions and may be the ideal method to deliver viable cells in vivo. 2008-06-24T11:54:04Z 2010-06-01T08:42:09Z 2008-06-24T11:54:04Z 2010-06-01T08:42:09Z 2008-03 Thesis http://hdl.handle.net/10019.1/2174 en Stellenbosch University application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Lactobacillus plantarum Lactobacillus fermentum Probiotics Theses -- Microbiology Dissertations -- Microbiology Microbiology Von Mollendorff, Johan Wilhelm Characterization of bacteriocins produced by lactic acid bacteria from fermented beverages and optimization of starter cultures |
| title | Characterization of bacteriocins produced by lactic acid bacteria from fermented beverages and optimization of starter cultures |
| title_full | Characterization of bacteriocins produced by lactic acid bacteria from fermented beverages and optimization of starter cultures |
| title_fullStr | Characterization of bacteriocins produced by lactic acid bacteria from fermented beverages and optimization of starter cultures |
| title_full_unstemmed | Characterization of bacteriocins produced by lactic acid bacteria from fermented beverages and optimization of starter cultures |
| title_short | Characterization of bacteriocins produced by lactic acid bacteria from fermented beverages and optimization of starter cultures |
| title_sort | characterization of bacteriocins produced by lactic acid bacteria from fermented beverages and optimization of starter cultures |
| topic | Lactobacillus plantarum Lactobacillus fermentum Probiotics Theses -- Microbiology Dissertations -- Microbiology Microbiology |
| url | http://hdl.handle.net/10019.1/2174 |
| work_keys_str_mv | AT vonmollendorffjohanwilhelm characterizationofbacteriocinsproducedbylacticacidbacteriafromfermentedbeveragesandoptimizationofstartercultures |