Accumulation of poly-β-hydroxybutyrate byRhodobacter sphaeroideson various carbon and nitrogen substrates

Abstract

Combinations of various carbon and nitrogen substrates were used to study poly‐β‐hydroxybutyrate accumulation and H2 evolution by Rhodobacter sphaeroides strain RV. The cells evolved hydrogen on lactate, pyruvate, or succinate under nitrogen‐deprived conditions and on lactate‐glutamate and pyruvate‐glutamate media. Poly‐β‐hydroxybutyrate content under nitrogen‐sufficient and nitrogen‐deprived conditions was highest on acetate (up to ∼40% of cell dry weight). Transfer of the cells from ammonium to ammonium‐free medium resulted in increases in the poly‐β‐hydroxybutyrate content on lactate and pyruvate of up to ∼15% and ∼20%, respectively. An increase in pH caused a decrease in H2 production and an increase in poly‐β‐hydroxybutyrate accumulation on lactate under nitrogen‐deprived conditions.

The effect of methane and odd-chain fatty acids on 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) synthesis by a Methylosinus-dominated mixed culture

“…For example, Caulobacter (OTU4), Brevundimonas (OTU14), Hyphomicrobium (OTU13, 16, and 25), Pseudomonas (OTU22), Rhodanobacter (OTU6), Comamonas (OTU3), Burkholderia (OTU19), and Terrimonas (OTU21) (Additional file 1: Table S1) were all present, and these have capacity to accumulate PHA (Urakami and Komagata 1987;Zhao et al 1993;Khatipov et al 1998;Silva et al 2000;Qi and Rehm 2001;Thakor et al 2003;Keenan et al 2004;Solaiman and Swingle 2010;Zhu et al 2010;Li et al 2011;Tripathi et al 2012;Wang and Liu 2014). Further, according to previous studies, Pseudomonas (Li et al 2011;Tripathi et al 2012), Comamonas (Thakor et al 2003), Rhodanobacter (Khatipov et al 1998) and Burkholderia (Silva et al 2000;Keenan et al 2004;Zhu et al 2010) can accumulate copolyesters from propionate or valerate under unbalanced growth conditions. However, the population of these genera presented less than 5% of the total community when the nitrogen starvation experiment was conducted (Additional file 1: Table S1).…”

Pathways and Mechanisms of Single-Cell Protein Production: Carbon and Nutrient Transformation

“…Unlike carbon mineralization by heterotrophic microbes, PPB remove organics from wastewater through carbon assimilation . PPB’s biomass yields on simple substrates can reach 1.0 g of COD/g of COD removed .…”

Photofermentative Poly-3-Hydroxybutyrate Production by <em>Rhodopseudomonas</em> Sp. S16-VOGS3 in a Novel Outdoor L-Shaped Row Photobioreactor

“…This last family of proteobacteria (Rhodospirillaceae) can produce PHA through the photo-fermentation process. The PNSB show a high potential to accumulate intracellular PHB granules as energy and carbon reserves and are active H2 producers when they are grown under stress conditions [11,12]. Combined production of PHB and bio-hydrogen through photoautotrophic metabolism could lead to a further advantage for the environment by converting solar energy into alternative sources of energy and bioplastics [12].…”

“…The PNSB show a high potential to accumulate intracellular PHB granules as energy and carbon reserves and are active H2 producers when they are grown under stress conditions [11,12]. Combined production of PHB and bio-hydrogen through photoautotrophic metabolism could lead to a further advantage for the environment by converting solar energy into alternative sources of energy and bioplastics [12]. The bacterial genera more able to accumulate a substantial quantity of PHB are Rhodobacter sphaeroides RV and Rhodospirillum rubrum, suggesting that the efficiency of the biochemical pathway depends on the particular species and growth conditions (e.g.…”

“…Knowledge of the mechanism of the aforementioned relationships may provide a clue to an alternative approach of controlling cultivation to achieve the preferred product, PHB or H2. Khatipov et al [12] achieved high PHB content (40 % of dry cell weight) into the cells of Rhodobacter sphaeroides RV on lactate media increasing the initial pH of the ammonium-free medium to 10 or higher.…”