Halomonasas a chassis

Abstract

With the rapid development of systems and synthetic biology, the non-model bacteria, Halomonas spp., have been developed recently to become a cost-competitive platform for producing a variety of products including polyesters, chemicals and proteins owing to their contamination resistance and ability of high cell density growth at alkaline pH and high salt concentration. These salt-loving microbes can partially solve the challenges of current industrial biotechnology (CIB) which requires high energy-consuming sterilization to prevent contamination as CIB is based on traditional chassis, typically, Escherichia coli, Bacillus subtilis, Pseudomonas putida and Corynebacterium glutamicum. The advantages and current status of Halomonas spp. including their molecular biology and metabolic engineering approaches as well as their applications are reviewed here. Moreover, a systematic strain engineering streamline, including product-based host development, genetic parts mining, static and dynamic optimization of modularized pathways and bioprocess-inspired cell engineering are summarized. All of these developments result in the term called next-generation industrial biotechnology (NGIB). Increasing efforts are made to develop their versatile cell factories powered by synthetic biology to demonstrate a new biomanufacturing strategy under open and continuous processes with significant cost-reduction on process complexity, energy, substrates and fresh water consumption.

Metabolic engineering ofZymomonas mobilisfor continuous co-production of bioethanol and poly-3-hydroxybutyrate (PHB)

“…1,3 Halomonas bluephagenesis, one of the well-studied halophilic microorganisms for PHB accumulation, has been reprogrammed to be a low-cost chassis for various biosynthesis under seawater-based unsterile open fermentation conditions with a cell density of 80 g L −1 and PHB accumulated to 80% (DCW). [13][14][15] Pilot and industrial scale PHB productions have also been deployed using those strains. 13 The PHB biosynthesis pathway in C. necator H16 includes the genes of phaA encoding a 3-ketothiolase enzyme for the condensation of two molecules of acetyl-CoA to form acetoacetyl-CoA, phaB encoding NADPH-dependent acetoacetyl-CoA reductase to catalyze 3-hydroxybutyryl-CoA synthesis, and phaC encoding a PHA synthase for PHB polymerization.…”

“…[13][14][15] Pilot and industrial scale PHB productions have also been deployed using those strains. 13 The PHB biosynthesis pathway in C. necator H16 includes the genes of phaA encoding a 3-ketothiolase enzyme for the condensation of two molecules of acetyl-CoA to form acetoacetyl-CoA, phaB encoding NADPH-dependent acetoacetyl-CoA reductase to catalyze 3-hydroxybutyryl-CoA synthesis, and phaC encoding a PHA synthase for PHB polymerization. It is crucial to increase the availability of precursor acetyl-CoA and cofactor NADPH for the intracellular accumulation of PHB.…”

Advances and trends in microbial production of polyhydroxyalkanoates and their building blocks

“…Halomonas bluephagenesis TD01 ( H. bluephagenesis ), a natural PHB producer isolated from salt lake ( Tan et al, 2011 ), has been recently developed as a versatile chassis for PHA productions and value added chemicals, which exemplifies a cost-effective biomanufacturing paradigm based on next generation industrial biotechnology (NGIB) enabling non-sterile open fermentation process under high salt and high pH condition ( Ye and Chen, 2021 ). Currently, the genetically reprogrammed H. bluephagenesis can produce various PHA polymers, including PHB ( Tan et al, 2011 ), PHBV ( Fu X.…”

“…( Li M. et al, 2021 ). To date, many building blocks, including rational designed enzymes ( Chek et al, 2019 ; Lim et al, 2021 ), fine-tuned metabolic pathways towards monomer synthesis ( Pacholak et al, 2021 ) and genetically engineered chassis of predominant PHA accumulation performance ( Liang et al, 2020 ; Ye and Chen, 2021 ), have been developed for sufficient PHA synthesis using a variate of substrates.…”

Baseline proteomics characterisation of the emerging host biomanufacturing organism Halomonas bluephagenesis

“…Understanding potential interactions between inserted and native proteins including competitive side reactions of both precursor and product molecules will support attainment of desirable outcomes in biomanufacturing projects. Shared proteomics resources will provide the biomanufacturing community with ready access to such modern systems biology tools and support innovation and accelerate industrial application of these organisms to next-generation industrial biotechnology 13 .…”