Halophilic microorganisms Haliphilic microorganisms are those organisms which require certain minimal concentrations of salt (NACl) for growth. Slight halophiles grow optimally in media containing 2.5%. Most of the slight halophilic bacteria originate from marine environments Marine psychrophilic bacteria of the genera pseudomonas, Moraxella. Acinetobacter, and Flavobacterium contribute to the spoilage of marine fish and shelfish Moderate halophiles grow optimally in media containing 5.20% salt and most of the moderately halophilic bacteria involved in the spoilage of salted foods are gram positive species of the Bacillaceae and Micrococcaceae The extreme halophiles grow optimally in media containing 20-30% salt The extreme hamophiles are principally species of the genera Halobacterium and Halococcus which produce bright red or pink pigments, grow very slowly. They have been incriminated in spoilage of fish, and hides preserved in sea salts.
Halotolerant organisms Are those organisms capable of growth in salt concentrations exceeding 5%. Some halotolerant microorganisms are involved in food spoilage while some others such as staphylococcus aureus and cl.perfringens are pathogenic.