Melle Nassima Didouh is a PHd scholar in Microbial Development. She has done the Doctoral research on “Characterization and treatment of the process of bioﬁ lm formation by Bacillus cereus in the dairy ﬁ eld optimization of cleaning and disinfection procedures” from University of Tlemcen and she had completed her Master’s Degree in Nature and Life Science.
Bacillus cereus is an endospore-forming bacterium frequently found in dairy products and dairy environment. In fact their spores have great ability to adhere to surfaces, in particular to hydrophobic surfaces and produce many toxins. Th e most B. cereus spores studied has been shown to be generally strongly hydrophobic. Many studies have shown a relationship between the bacterial spore characteristics and its ability to adhere to surfaces. In this study, molecular identifi cation (M13 RAPD, Rep PCR, PFGE), toxicogenic and physicochemical characterization of 14 Bacillus cereus strains isolated from a dairy plant located in north-western Algeria were studied using Microbial Adhesion To Hydrocarbon (MATH) method, and zeta potential measurements, respectively. Twelve (12) strains belong to Bacillus cereus group III and the two other to Bacillus cereus group IV. Spores of 11 strains presented a hydrophilic character and three a hydrophobic one. Th e spore zeta potential values for all strains were between 12.28 and -44, 51 mV. Four spore morphologies were investigated by Transmission Electron Microscopy (TEM) aft er negative staining. Th is allowed the clear observation of an exosporium surrounding all B. cereus spores. Th e ability of spores to adhere to stainless steel was also studied and varied among strains. Th e presence of an exosporium was not suffi cient to explain the ability of spores to adhere to stainless steel surfaces. When physicochemical surface characters of B. cereus spores were compared the hydrophobicity, the appendages length, the surface of spore and exosporium were found as the signifi cant adhesion parameters.
Manal Abdulaziz Saleh AlGhsyar has completed her master’s degree in Food Science and Dairy Technology. She has worked as the Principal of Manarat Al-Qassim School and hosted educational exhibitions.
Increasing world population, increasing demand for and cost of protein-rich foods, and the continuing need to improve the nutritional and functional properties of protein ingredients have contributed to a greater research into blends or composites as food ingredients. Proteins co-precipitates have a range of biological, physical, chemical, functional, sensory and nutritional properties giving the potential application as product ingredients in the food industry, though relatively little published information is available on this subject. Camels serve as a major source of milk and meat in the Middle East, where there are is a great number of camels in Saudi Arabia, which is the second largest country in the production of camel milk aft er Somalia; camel milk is considered a highly consumed food in the Arab Gulf states. Also, proteins from camels’ and goats’ milks are characterized with diff erent properties than cow proteins, and they are an important source for milk in the desert areas. Th e aim of this study was to obtained the co-precipitates proteins of camels’ and goats’ milk using diff erent methods such as heat treatment with or without addition of Calcium Chloride (CaCl2) or Hydrochloric Acid (HCl) as well as precipitation aft er the concentration of proteins by ultra-fi ltration and then study their physical and functional characteristics to recommend their use in the food industry.