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Abstract
V- SUMMARY
Sugar is a carbohydrate that occurs naturally in fruits and vegetables. Of all known plants, sugar is the most highly concentrated in sugar beets and sugarcane. The sucrose from sugar beet and sugarcane is identical, and the same as the sucrose found in fruits and vegetables. Sugar considered one of the most important merchandise which represents 30% of global sugar production from the beet, so we have to reduce the loss in sugar by all means. The microbial loss of sucrose in sugar industries considers one of the important losses in sugar inside and outside the factory. So the main goal of this study is finding away to overcome or inhibition the growth of bacterial inside the factory which caused sucrose degradation in extraction tower by natural technique. This technique is alternative treatment instead of chemical agents against bacterial activity. The control of bacterial infections in sugar factories is complex and so it is difficult to achieve optimum results. There are many different types of bacteria, which can vary from one factory to another, also different, more resilient strains, can develop during a campaign. Furthermore different conditions within the factory (pH, temperature, aerobic/anaerobic), enables particular strains. The present work was designed to control microbial losses of sucrose in DAKAHALIA SUGAR COMPANY, caused by Bacillus stearothermophilus.
Two means were used:
1- Control using essential oils. 2- Control by plants extract.
So natural products are very effective alternatives to standard biocides and should be considered for bacterial control.
During study period the different strains of bacterial were isolated from sugar beet extraction juice through 2006, 2007 seasons and the results of isolation appeared that Bacillus stearothermophilis is the only isolated bacteria.
Identification of the bacteria in the laboratory achieved by morphological shape and biochemical reactions. The results proved that the bacteria isolates are Bacillus stearothermophilus which are typically found in the hot areas of the system.
Twenty nine plant extracts and thirteen essential oils were screened to evaluate their inhibitory activity against Bacillus stearothermophilus under laboratory conditions by using an agar diffusion technique.
Among plants and oil extracts used in this investigation we found that Ocimum basilicum, Mentha spicata, and Eugenia caryophyllus oils & Ocimum basilicum, Mentha spicata, Geranium gruinum, Datura stramonium, Mentha, Citrus limon, Eucalyptus rostrata, Silybum marianum, Humulus lupulus and Zingiber officinale extracts have high effect against bacteria, while Majorana hortensis, Pimpeniella anisum, Olea europaea, Cinnamomum zeylanicum, and Citrus Limon oils & Cinnamomum zeylanicum, Cuminum cyminum, Lantana camara, Nicotiana tabacum Graham, Schinus terebenthifolius , Chrysanthemum morifolium, Caltrops procera, and Curcuma domestic extracts have intermediate effect against bacteria. On the other hand Apium graveolens and Lactuca Sativa oil & Alcea rosea, Nerium olender and Mentha longifolia extracts have very rare or missing effect against bacteria.
The best essential oil and extracts were used to evaluate the resistance of thermophilus bacteria is: Ocimum basilicum and Mentha spicata oils & Geranium gruinum extract.
In the present study, it was revealed that essential oil of mint was the best oil against the bacterial growth, where it reduced significantly the radial growth of bacteria. Mint oil can reduced the bacteria growth in lab under the required condition nearly to 100% and this give speculate that there is no any appearance of bacteria. Mint essential oil completely inhibited the growth of bacteria. While that basil oil was the second effect against tested bacteria after mint oil and the third effect was recorded by geranium extract.
The studied oils were applied on the juice to study the change of pH, polarization and purity for the treated juice, as a good indication for sugar degradation by the bacteria. The results show that DMSO is the solvent to dissolve the extracted plant, since DMSO has no effect towards bacteria.
It can be concluded that Mentha spicata, Ocimum basilicum oils and Geranium gruinum extract can be used for controlling Bacillus stearothermophilus in sugar manufacture. These products were extracted from natural plants cultivated in Egypt and it’s very safely, cheapest and available as compared to chemical agents which used currently in the DAQAHLIA SUGAR COMPANY.