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Abstract majority of food fermentation. Preservation of lactic acid bacteria is a common problem in all research laboratories, while the best method depends upon both the organisms and the particular characteristics being conside:red. This work was carried out to study the possibilities of preserving some strains from Lactic acid bacteria belonging to the genus Lactobacillus. The experimentad methode were drying in gelatin discs ar~ Lyophilization. The strains used in these exper~~ents were: Lactobacillus acidophilus CAIM l055.Laeto.lactis CAIM 1091, Lacto.fermentum CAlli lJJB, Lacto.casei aubsp. casei CAlM 1093, Lacto.casei subsp rharonoaus CAIM 1094 and Lacto. bulp;aricus CAD: 1322. Factors affecting the preservation of Lactobacilli strains using abovementioned methods were studied. The factors were focused on suspending media, storage temperature and gaseous conditions. To study the effect of temperature and atmospheric conditions during the storage period, two systems were applied. The first system in 1vhich the containers were kept under atmospheric conditions using storage temperature either 4°C or -20°C, The secondsystem was the same as in the first system except containers were kept under vacuum. Viable count, Lactic acid and diacetyl production were determined before and after drying and during storage period. The lyophilizid ampoule were stored at 4”C and the same characters were determined. Also the efficiency of some of the preserved strains were experimented ·.in: (a) Production of table green olives using Lactobacillus casei subsp casei as starter • (b) Production of new yoghurt type. The results obtained could be summarized as fellows:- 1. The best mediu!n for the drying process of Lacto.acidophilus CAIM 1055 was nutrient gelatin+ 10% honey and for the storage cond:i tion was -20 °C under vacuum. 2. The best medium for the drying process of Lacto.laotis CAIM 1091 was nutrient gelatin+ 0.5% sodium glutamate and the storage condition was -20°0J. The best medium fort drying process of Laeto.fermentum CAIM 1)38 was nutrient gelatin+ 0,5% sodium glutamate and the storage condition was 4°C under vacuum, 4. The best medium for preserving of Lacto. casei subsp.casei CAIM 1093 was nutrient gelatin T glucose and the storage condition was -20°C under vacuum. 5. The best medium ofof the drying process of Lacto.casei subsp.rhamnosus CAIM 1094 was nutrient gelatin and the storage condition was -20°C under vacuum, 6. Recovery of Lacto. bul,garious CAIM 1322 has been lost in all suspending media during the drying process. 7. The lyophilized lactobacilli have been survived during the lyophilization proce~s, but the drying in gelatin discs was a better system than the lyophilization. 8. The utilisation of Lacto.casei subsp,casei as starters for green olive fermentation was recommended. The Lactobacilli medium was also reconmended as cult.ivation and rehydration medium for these starters.9. The utilisation of Lacto, easei subsp. rhamnoaus aa starter for yoghurt to increase its dietetic value was recommended. |