Rhodospirillum rubrum is a gram-negative bacterium that naturally takes advantage of CO and which, in the presence of acetate, accumulates carbon and energy units as polyhydroxybutyrate (PHB). Since the conversion of CO depends on a large protein membrane complex that is expressed after the exposure to carbon monoxide, this study presents the effects of a CO-based acclimation in R. rubrum on the growth trend and on the production of PHB. The strain was cultured in two consecutive fermentation cycles on 15% of CO, and the behaviour of this species, in the presence of acetate or a reducing sugar, such as fructose, was compared. The exposure of R. rubrum to CO during the first adaptation phase led to the development of a metabolically active population characterised by a greater biomass growth. The supply of fructose ensured a shorter lag-phase and a higher biomass titre, but it also determined a decrease in the biopolymer accumulation. However, R. rubrum showed the best carbon utilisation in the absence of fructose, with a growth molar yield of 48 mg mol⁻¹, compared to the 12 mg mol⁻¹ obtained for fructose feeding.

红螺螺旋藻是一种革兰氏阴性细菌，自然会利用一氧化碳，并且在存在乙酸盐的情况下，会以聚羟基丁酸酯（PHB）的形式积累碳和能量单元。由于CO的转化取决于所暴露于一氧化碳后表达的大蛋白质复合物膜，本研究呈现在基于CO-驯化的影响深红红螺菌的生长的趋势，对生产PHB的。该菌株在15％的CO中连续两个发酵周期进行培养，并且比较了该物种在乙酸盐或还原糖（例如果糖）存在下的行为。R. rubrum的暴露在第一个适应阶段从一氧化碳转化为一氧化碳导致了新陈代谢活跃的群体的发展，其特征是生物量的增长更大。果糖的供应确保了较短的滞后阶段和较高的生物量效价，但也确定了生物聚合物积累的减少。然而，深红红螺菌显示出在不存在果糖的最佳碳利用率，具有的48毫克摩尔生长摩尔收率^-1，相对于12毫克摩尔^-1果糖馈送获得。