Engineering self-flocculating Halomonas campaniensis for wastewaterless open and continuous fermentation.

Halomonas has been developed as a platform for the next generation industrial biotechnology allowing open and nonsterile growth without microbial contamination under a high-salt concentration and alkali pH. To reduce downstream cost associated with continuous centrifugation and salt containing wastewater treatment, Halomonas campaniensis strain LS21 was engineered to become self-flocculating by knocking out an etf operon encoding two subunits of an electron transferring flavoprotein in the predicted electron transfer chain. Self-flocculation could be attributed to the decrease of the surface charge and increase of the cellular hydrophobicity resulted from deleted etf.

Engineering NADH/NAD ratio in Halomonas bluephagenesis for enhanced production of polyhydroxyalkanoates (PHA).

Halomonas bluephagenesis has been developed as a platform strain for the next generation industrial biotechnology (NGIB) with advantages of resistances to microbial contamination and high cell density growth (HCD), especially for production of polyhydroxyalkanoates (PHA) including poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). However, little is known about the mechanism behind PHA accumulation under oxygen limitation. This study for the first time found that H.

Microbial Synthesis of 5-Aminolevulinic Acid and Its Coproduction with Polyhydroxybutyrate.

5-Aminolevulinic acid (ALA), an important cell metabolic intermediate useful for cancer treatments or plant growth regulator, was produced by recombinant Escherichia coli expressing the codon optimized mitochondrial 5-aminolevulinic acid synthase (EC: 2.3.1.