الفهرس 
storage in distilled waterOnly 14 pages are availabe for public view
 |  | from | 181 |  |  |
| | | from | 181 | | |
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.