Microorganisms in Food Production: Enzymes and Culture Maintenance

Culture Maintenance and Preparation Food Fermentations Enzymes 01 Principles of Culture Maintenance and Preparation Maintenance of Activity of Cultures Attained by periodic transfer of the culture into the proper culture medium, incubation until the culture reaches the maximal stationary phase of growth & then storage at temperatures low enough to prevent further growth. Preparation of stock cultures for a long storage time through lyophilization and freezing in liquid nitrogen (-196°C) and agar slants with 1% NaCl (Erkmen & Bozoglu, 2016) Maintenance of Purity of Cultures They should be obtained periodically from a culture laboratory or be checked regularly for purity. Microscopic examination Plate the culture Presence of substances not produced by the desired organism (Erkmen & Bozoglu, 2016) Preparation of Cultures Mother Culture Usually prepared daily from a previous mother culture and originally from the stock culture Can be used to inoculate larger quantity of culture medium to produce the bulk culture to be used in the fermentation process (Erkmen & Bozoglu, 2016) Preparation of Cultures Culture makers attempt to produce and maintain a culture that: Contains only the desired microorganism(s) Uniform in microbial numbers, proportions (if mixed culture) and activity from day to day Active in producing the products desired Has adequate resistance to unfavourable conditions, if needed (Erkmen & Bozoglu, 2016) Activity of Cultures Activity of a culture is judged by its rate of growth and production of products Mother or the intermediate culture must be satisfactory and culture medium, incubation time, and temperature must be optimal.

The ______ of Cultures Attained by periodic transfer of the culture into the proper culture medium, incubation until the culture reaches the maximal stationary phase of growth & then storage at temperatures low enough to prevent further growth.

______ of stock cultures for a long storage time through lyophilization and freezing in liquid nitrogen (-196°C) and agar slants with 1% NaCl (Erkmen & Bozoglu, 2016) Maintenance of Purity of Cultures They should be obtained periodically from a culture laboratory or be checked regularly for purity. Microscopic examination Plate the culture Presence of substances not produced by the desired organism (Erkmen & Bozoglu, 2016) ______ of Cultures Mother Culture Usually prepared daily from a previous mother culture and originally from the stock culture Can be used to inoculate larger quantity of culture medium to produce the bulk culture to be used in the fermentation process (Erkmen & Bozoglu, 2016) ______ of Cultures Culture makers attempt to produce and maintain a culture that: Contains only the desired microorganism(s) Uniform in microbial numbers, proportions (if mixed culture) and activity from day to day Active in producing the products desired Has adequate resistance to unfavourable conditions, if needed (Erkmen & Bozoglu, 2016) Activity of Cultures Activity of a culture is judged by its rate of growth and production of products Mother or the intermediate culture must be satisfactory and culture medium, incubation time, and temperature must be optimal.

Mother or the intermediate culture must be satisfactory and culture medium, incubation time, and temperature must be optimal.

______ makers attempt to produce and maintain a culture that: Contains only the desired microorganism(s) Uniform in microbial numbers, proportions (if mixed culture) and activity from day to day Active in producing the products desired Has adequate resistance to unfavourable conditions, if needed (Erkmen & Bozoglu, 2016)