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Friedrich Gotz - One of the best experts on this subject based on the ideXlab platform.

  • Staphylococcus carnosus: from Starter Culture to protein engineering platform
    Applied Microbiology and Biotechnology, 2017
    Co-Authors: John Lofblom, Minh Thu Nguyen, Ralf Rosenstein, Stefan Stahl, Friedrich Gotz
    Abstract:

    Since the 1950s, Staphylococcus carnosus is used as a Starter Culture for sausage fermentation where it contributes to food safety, flavor, and a controlled fermentation process. The long experience with S. carnosus has shown that it is a harmless and “food grade” species. This was confirmed by the genome sequence of S. carnosus TM300 that lacks genes involved in pathogenicity. Since the development of a cloning system in TM300, numerous genes have been cloned, expressed, and characterized and in particular, virulence genes that could be functionally validated in this non-pathogenic strain. A secretion system was developed for production and secretion of industrially important proteins and later modified to also enable display of heterologous proteins on the surface. The display system has been employed for various purposes, such as development of live bacterial delivery vehicles as well as microbial biocatalysts or bioadsorbents for potential environmental or biosensor applications. Recently, this surface display system has been utilized for display of peptide and protein libraries for profiling of protease substrates and for generation of various affinity proteins, e.g., Affibody molecules and scFv antibodies. In addition, by display of fragmented antigen-encoding genes, the surface expression system has been successfully used for epitope mapping of antibodies. Reviews on specific applications of S. carnosus have been published earlier, but here we provide a more extensive overview, covering a broad range of areas from food fermentation to sophisticated methods for protein-based drug discovery, which are all based on S. carnosus .

  • genome analysis of the meat Starter Culture bacterium staphylococcus carnosus tm300
    Applied and Environmental Microbiology, 2009
    Co-Authors: Ralf Rosenstein, Christiane Nerz, Lalitha Biswas, Alexandra Resch, Guenter Raddatz, Stephan C Schuster, Friedrich Gotz
    Abstract:

    The Staphylococcus carnosus genome has the highest GC content of all sequenced staphylococcal genomes, with 34.6%, and therefore represents a species that is set apart from S. aureus, S. epidermidis, S. saprophyticus, and S. haemolyticus. With only 2.56 Mbp, the genome belongs to a family of smaller staphylococcal genomes, and the ori and ter regions are asymmetrically arranged with the replichores I (1.05 Mbp) and II (1.5 Mbp). The events leading up to this asymmetry probably occurred not that long ago in evolution, as there was not enough time to approach the natural tendency of a physical balance. Unlike the genomes of pathogenic species, the TM300 genome does not contain mobile elements such as plasmids, insertion sequences, transposons, or STAR elements; also, the number of repeat sequences is markedly decreased, suggesting a comparatively high stability of the genome. While most S. aureus genomes contain several prophages and genomic islands, the TM300 genome contains only one prophage, ΦTM300, and one genomic island, νSCA1, which is characterized by a mosaic structure mainly composed of species-specific genes. Most of the metabolic core pathways are present in the genome. Some open reading frames are truncated, which reflects the nutrient-rich environment of the meat Starter Culture, making some functions dispensable. The genome is well equipped with all functions necessary for the Starter Culture, such as nitrate/nitrite reduction, various sugar degradation pathways, two catalases, and nine osmoprotection systems. The genome lacks most of the toxins typical of S. aureus as well as genes involved in biofilm formation, underscoring the nonpathogenic status.

Guleren Alsancak Ozkan - One of the best experts on this subject based on the ideXlab platform.

  • the effects of a Starter Culture on the formation of biogenic amines in turkish soudjoucks
    Meat Science, 1999
    Co-Authors: Kamuran Ayhan, Nuray Kolsarici, Guleren Alsancak Ozkan
    Abstract:

    The effects of Starter Culture containing Lactobacillus sake, Pediococcus pentosaceus, Staphylococcus carnosus plus Staphylococcus xylosus on the formation of biogenic amines during ripening of Turkish soudjoucks were investigated. Determination of eight different biogenic amines was carried out by reverse-phase high performance liquid chromatography (HPLC) using diode array detection. It was found that aerobic plate counts (APC) decreased in the samples with added Starter Culture. Lactic acid bacteria counts increased in both the controls and samples with added Starter during ripening. Total Enterobacteriaceae (ENT) counts decreased on the 30th day for vacuum packed and Starter added samples. Yeast counts decreased only in vacuum packed and Starter added samples on the 30th day. No biogenic amines were found in ground meat samples. Putrescine (PU) and tyramine (TYR) were determined in all control samples during the storage at 4°C. Starter addition inhibited formation of PU but not TYR.

Kingsley E Nwachukwu - One of the best experts on this subject based on the ideXlab platform.

  • Soya‐yoghurt Starter Culture development from fermented tropical vegetables
    Journal of the Science of Food and Agriculture, 1992
    Co-Authors: Leslie M Nsofor, Obianuju N Nsofor, Kingsley E Nwachukwu
    Abstract:

    The development of soya-yoghurt Starter Culture from fermented tropical vegetables was initiated. Soya milk fortified with 10 g litre−1 sucrose was sterilised (121°C for 15 min) and inoculated with the exudate of fermented tropical vegetables. Acid production in the soya milk medium during incubation at 42°C for 5 h was evaluated and compared with cows' milk based Cultures. Aroma of the soya milk based and cows' milk based Cultures was also compared. Cultures derived from fermented cassava and corn separately reduced soya milk pH from 6′8 to 43 and 45, and significantly greater Culture activity was observed in soya milk than in cows' milk. The Culture from corn produced the most acceptable yoghurt-like aroma in soya milk while that from African oil bean seed produced the least acceptable aroma. The consumer-acceptable mild buttermilk-like aroma of yoghurt was not produced in soya milk or cows' milk by the Cultures evaluated.

  • soya yoghurt Starter Culture development from fermented tropical vegetables
    Journal of the Science of Food and Agriculture, 1992
    Co-Authors: Leslie M Nsofor, Obianuju N Nsofor, Kingsley E Nwachukwu
    Abstract:

    The development of soya-yoghurt Starter Culture from fermented tropical vegetables was initiated. Soya milk fortified with 10 g litre−1 sucrose was sterilised (121°C for 15 min) and inoculated with the exudate of fermented tropical vegetables. Acid production in the soya milk medium during incubation at 42°C for 5 h was evaluated and compared with cows' milk based Cultures. Aroma of the soya milk based and cows' milk based Cultures was also compared. Cultures derived from fermented cassava and corn separately reduced soya milk pH from 6′8 to 43 and 45, and significantly greater Culture activity was observed in soya milk than in cows' milk. The Culture from corn produced the most acceptable yoghurt-like aroma in soya milk while that from African oil bean seed produced the least acceptable aroma. The consumer-acceptable mild buttermilk-like aroma of yoghurt was not produced in soya milk or cows' milk by the Cultures evaluated.

Gianluigi Mauriello - One of the best experts on this subject based on the ideXlab platform.

  • microencapsulated Starter Culture during yoghurt manufacturing effect on technological features
    Food and Bioprocess Technology, 2017
    Co-Authors: Annachiara De Prisco, Hein J F Van Valenberg, Vincenzo Fogliano, Gianluigi Mauriello
    Abstract:

    The potential of living cell microencapsulation in sustaining cells’ viability, functionality and targeted release in gastrointestinal tract is relatively well documented. Differently, the effects exerted by the capsules on cell metabolic activities during fermentation of a food matrix as well as on cell physiology are poorly addressed. This paper aimed at studying the effects of chitosan-alginate capsules (matrix and core-shell) on metabolic activities of Streptococcus thermophilus and probiotic Lactobacillus delbrueckii during milk fermentation for yoghurt production. This food system has been used to monitor growth, acidification kinetics and strain proteolytic activity. Bacterial viability has been monitored during yoghurt storage at 4 °C for 28 days and an in vitro digestion to evaluate the protective effect exerted by the capsules. Furthermore, production of volatile metabolites associated with Starter Culture activity was monitored by headspace solid-phase microextraction-GC/MS to explore possible influence of microenvironment on cell metabolism. Results indicate that both kinds of capsules influenced at different extent cell functionalities (growth, acidification and proteolysis), while they improve cell viability during yoghurt storage and simulated gastrointestinal passage. The volatile pattern revealed that capsules influenced their production in yoghurt: 12 out of 28 volatiles recovered in yoghurt fermented by free and encapsulated Starters had significantly different concentration. However, concentration of the main aroma constituents (e.g. acetaldehyde, diacetyl, acetoin) was not significantly affected. Due to the leakage of bacteria from microcapsules during fermentation, the final product resulted in co-existing of free and still encapsulated cells, with the main advantage of an increased viability during yoghurt storage and simulated digestion of the encapsulated counterpart.

V Diez - One of the best experts on this subject based on the ideXlab platform.