Cairo University, Egypt
Dr Hoda Elzeini has completed her PhD in Michigan State University, USA. She is a professor in Cairo University, Dairy Sci., Department. She has published more than 20 papers in different journals and has been serving as an editorial board member of Bioinfo Publications Journals.
Lactic Acid Bacteria (LAB) widely distributed in nature and play an important role in many food fermentations. Bacterial cell morphology is useful and valuable characteristics used in identification and are one of the easiest and greatest important tools for classification of bacteria. Therefore, cell morphological shape and size of six strains of cocci LAB grown in M17 broth and RSM were studied using scanning electron microscope (SEM) and image analysis technique. Results indicated that, Pediococcus acidilactici EMCC1690 was the smallest strain in size and Streptococcus thermophilus 779N was smaller than Enterococcus and Lactococcus strains. Excloding Pediococcus acidilactici, cells of other strains were generally smaller in size when grown in RSM than in M17 broth. Cells of cocci LAB were not perfectly spherical. In conclusion, cell shape and size parameters can be used for identification and classification of cocci LAB with determination of defined standard conditions for growth. It could be useful for identification of novel strains used to produce dairy food products.