Growth of Entamoeba invadens in sediments with metabolically repressed bacteria leads to multicellularity and redefinition of the amoebic cell system.

Growth of Entamoeba invadens in sediments with metabolically repressed bacteria leads to multicellularity and redefinition of the amoebic cell system. Roum Arch Microbiol Immunol. 2013 Jan-Mar;72(1):25-48 Authors: Niculescu VF Abstract Extracellular signaling and mechanisms of cell differentiation in Entamoeba are misunderstood. The main reason is the popular use of axenic media, which do not correspond to the natural habitats of Entamoeba. The axenic environment lacks the exogenous activators and repressors provided by natural habitats. Absent bacterial commensals understanding of the development of the amoebic cell system remains deficient. The present Aa(Sm) culture method using mixed sediments of antibiotically repressed Aerobacter aerogens and amoebae was developed to model in vitro extracellular signaling that induce multicellularity in cultures of E. invadens. Repressed oxygen consuming sediment bacteria supply E. invadens the hypoxic environment needed for differentiation and development. The amoebae themselves alter the environment by consuming the bacteria by phagocytosis thus reversing hypoxia. Exogenous activators are in this manner down regulated and suppressed. This feedback effect controls amoebic development and differentiation. Co-existing cell types and cell fractions with different life spans and cell cycle length could be identified. Aa(Sm) long term cultures contain continuous and non-continuous self renewing cel...
Source: Roumanian Archives of Microbiology and Immunology - Category: Microbiology Tags: Roum Arch Microbiol Immunol Source Type: research