The haloarchaeon Haloferax volcanii grows on acetate as sole carbon and energy source. The genes and proteins involved in uptake and activation of acetate and in gluconeogenesis were identified and analyzed by characterization of enzymes and by growth experiments with the respective deletion mutants. (i) An acetate transporter of the sodium: solute-symporter family (SSF) was characterized by kinetic analyses of acetate uptake into H. volcanii cells. The functional involvement of the transporter was proven with a Δssf mutant. (ii) Four paralogous AMP-forming acetyl-CoA synthetases that belong to different phylogenetic clades were shown to be functionally involved in acetate activation. (iii) The essential involvement of the glyoxylate cycle as an anaplerotic sequence was concluded from growth experiments with an isocitrate lyase knock-out mutant excluding the operation of the methylaspartate cycle reported for Haloarcula species. (iv) Enzymes involved in phosphoenolpyruvate synthesis from acetate, namely two malic enzymes and a phosphoenolpyruvate synthetase, were identified and characterized. Phylogenetic analyses of haloarchaeal malic enzymes indicate a separate evolutionary line distinct from other archaeal homologs. The exclusive function of phosphoenolpyruvate synthetase in gluconeogenesis was proven by the respective knock-out mutant. Together, this is a comprehensive study of acetate metabolism in archaea.

盐古菌 火山嗜盐杆菌以醋酸盐作为唯一碳和能源生长。通过酶的表征和通过具有各自缺失突变体的生长实验，鉴定和分析了参与乙酸盐吸收和活化以及糖异生的基因和蛋白质。（i）钠：溶质符号家族（SSF）的乙酸盐转运蛋白的特征在于动力学分析了乙酸盐摄入火山嗜血杆菌细胞。Δ证明了转运蛋白的功能参与自卫队突变体。（ii）属于不同系统进化进化枝的四个同源AMP形成的乙酰辅酶A合成酶显示在功能上与乙酸酯激活有关。（iii）乙醛酸循环作为无花果酸序列的必要参与是通过异柠檬酸裂合酶敲除突变体的生长实验得出的结论，其中不包括报道的天冬氨酸甲酯循环的操作。盐藻种类。（iv）鉴定和表征了由乙酸盐合成磷酸烯醇丙酮酸的酶，即两种苹果酸酶和磷酸烯醇丙酮酸的合成酶。盐生古苹果酸酶的系统发育分析表明，有一条不同于其他古生同源物的独立进化系。磷酸烯醇丙酮酸合成酶在糖异生中的排他性功能已由各自的敲除突变体证明。总之，这是古细菌中乙酸代谢的综合研究。