Synthesis of High-Molecular-Weight Polyhydroxyalkanoates by Marine Photosynthetic Purple Bacteria

Higuchi-Takeuchi, Mieko; Morisaki, Kumiko; Toyooka, Kiminori; Numata, Keiji

doi:10.1371/journal.pone.0160981

Cited by 78 publications

(75 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The M w of PHA is dependent on the frequency of the chain transfer reaction, in which the PHA polymer chain is transferred from the PHA synthase after polymerization to a chain transfer reagent such as water or alcohol (Tomizawa et al, 2010;Higuchi-Takeuchi et al, 2016). The presence of mixed components of sugars, glycerol, and water in sweetwater could have contributed to the lower chain transfer reaction frequency, thus resulting in high M w .…”

Section: Molecular Weights Of P(3hb) Produced By B Megaterium Umtkb-mentioning

confidence: 99%

Bioconversion of novel and renewable agro-industry by-products into a biodegradable poly(3-hydroxybutyrate) by marine Bacillus megaterium UMTKB-1 strain

Yatim¹,

Syafiq²,

Huong³

et al. 2017

bta

View full text Add to dashboard Cite

Agro-industry by-products are abundant in various valuable compounds. Some of these raw materials are considered as a cheaper carbon source for polyhydroxyalkanoate (PHA) production when compared with pure substrates. It is however often a costly affair for industries to recover the residual carbon components. In this study, poly(3-hydroxybutyrate) [P(3HB)] was produced using a marine Bacillus megaterium UMTKB-1 strain from sweetwater, a by-product from cane sugar refining process. The bioconversion was initiated in shaken-flasks and fermenter experiments. Applications of seawater and sweetwater mixture as well as sweetwater only as PHA culture media were investigated. The produced polymer was characterized using Gas Chromatography (GC) and Gel Permeation Chromatography (GPC). P(3HB) accumulation from tested carbon sources ranged from 3 to 49 wt%. The strain could accumulate P(3HB) in saline conditions when minimal salts medium was replaced with seawater and sweetwater. The P(3HB) content was between 7 and 27 wt%. This strain was also able to grow and accumulate up to 14 wt% P(3HB) when sweetwater was the sole PHA biosynthesis medium. The weights of P(3HB) produced was in the range 3-12 × 10 5 with polydispersity index values ranging from 2.7 to 3.8. The agroindustry by-products have proven to be potential carbon feedstocks for P(3HB) production. The tested strain was able to grow and accumulate P(3HB) in a novel carbon substrate medium, the sweetwater. This by-product could be used as a raw material for P(3HB) production without any pretreatment.

show abstract

Section: Molecular Weights Of P(3hb) Produced By B Megaterium Umtkb-mentioning

confidence: 99%

Bioconversion of novel and renewable agro-industry by-products into a biodegradable poly(3-hydroxybutyrate) by marine Bacillus megaterium UMTKB-1 strain

Yatim¹,

Syafiq²,

Huong³

et al. 2017

bta

View full text Add to dashboard Cite

show abstract

“…Additionally, PHA producers derived from marine bacteria and halophiles could also reduce production costs and lower contamination risk by using seawater as culture media [16–18]. A few research groups have been focusing on marine photosynthetic purple bacteria, which have the additional advantage of the ability to grow and biosynthesize PHA under microaerobic conditions [19, 20].…”

Section: Introductionmentioning

confidence: 99%

“…The presence of PHAs in this bacterium was first observed using Sudan Black B staining [23]. It has been previously determined that sodium chloride, vitamins, ammonium chloride, phosphate and carbon sources could affect PHA accumulation and cell growth of R. sulfidophilum [19, 20].…”

Section: Introductionmentioning

confidence: 99%

Optimal iron concentrations for growth-associated polyhydroxyalkanoate biosynthesis in the marine photosynthetic purple bacteriumRhodovulum sulfidophilum

Foong

Higuchi-Takeuchi

Numata

2019

Preprint

Self Cite

View full text Add to dashboard Cite

26 Polyhydroxyalkanoates (PHAs) are a group of natural biopolyesters that resemble petroleum-27 derived plastics in terms of physical properties but are less harmful biologically to the 28 environment and humans. Most of the current PHA producers are heterotrophs, which require 29 expensive feeding materials and thus contribute to the high price of PHAs. Marine 30 photosynthetic bacteria are promising alternative microbial cell factories for cost-effective, 31 carbon neutral and sustainable production of PHAs. In this study, Rhodovulum sulfidophilum, 32 a marine photosynthetic purple nonsulfur bacterium with a high metabolic versatility, was 33 evaluated for cell growth and PHA production under the influence of various media 34 components found in previous studies. We evaluated iron, using ferric citrate, as another 35 essential factor for cell growth and efficient PHA production and confirmed that PHA 36 production in R. sulfidophilum was growth-associated under microaerobic and 37 photoheterotrophic conditions. In fact, a subtle amount of iron (1 to 2 µM) was sufficient to 38 promote rapid cell growth and biomass accumulation, as well as a high PHA yield during the 39 logarithmic phase. However, an excess amount of iron did not enhance the growth rate or 40 PHA productivity. Thus, we successfully confirmed that an optimum concentration of iron, 41 an essential nutrient, promotes cell growth in R. sulfidophilum and also enhances PHA 42 utilization. 43 44 Introduction 45 Polyhydroxyalkanoates (PHAs) are a family of biopolyesters that are produced by a wide 46 variety of microorganisms for the purpose of surviving in unfavorable growth and stress 47 conditions; these molecules act as carbon and energy storage, redox regulators and 48 cryoprotectants [1-3]. PHA is one of the well-known bioplastics (biobased and 49 biodegradable) that has been extensively developed with the aims to overcome problems such 3 50 as plastic solid wastes, harmful chemical substance leaching and dependence on 51 nonrenewable fossil fuels. These are the main disadvantages of petroleum-derived synthetic 52 plastics [4, 5]. 53 54 However, the high price of PHAs has made them less competitive compared to conventional 55 synthetic plastics due to the high cost of raw materials used in fermentation and downstream 56 purification steps [6-8]. Heterotroph bacteria such as wild-type or engineered strains of 57 Cupriavidus necator H16, Alcaligenes latus, Pseudomonas putida and Escherichia coli are 58 the main workhorses for large-scale production of PHAs [9-11]. These heterotroph bacteria 59 lack photosynthesis ability and thus require expensive carbon supplies to sustain their growth 60 and PHA biosynthesis. On the other hand, photosynthetic microorganisms could produce 61 their own foods by utilizing inexpensive and abundantly available resources such as sunlight,62 carbon dioxide and nitrogen and are thus potential next-generation microbial cell factories 63 [12, 13]. Several studies have reported successful PHA production by photosynthetic bact...

show abstract

“…For PHA extraction, seedlings were grown on 0.5×MS with or without 1% sucrose for 10 days. The method for extracting PHA was modified from a previous study (Higuchi-Takeuchi et al 2016). Approximately 100 mg dw of 10-day-old seedlings were ground into fine powder with a mortar and pestle and mixed with 9 ml of hexane.…”

mentioning

confidence: 99%

“…To measure ethyl-3-hydroxybutyrate (ethyl-3HB) as a monomer unit of PHA, 100 µl of the dehydrated sample was assessed by GC/MS (QP2010 Plus, Shimadzu, Kyoto, Japan) with an HP-5MS column and He gas. GC/MS analysis was performed according to previous work and purified 3HB was used as a standard (Higuchi-Takeuchi et al 2016).…”

mentioning

confidence: 99%

Sucrose supplementation suppressed the growth inhibition in polyhydroxyalkanoate-producing plants

Yoshizumi

Yamada

Higuchi-Takeuchi

et al. 2017

Plant Biotechnology

Self Cite

View full text Add to dashboard Cite

Polyhydroxyalkanoate (PHA) is a thermoplastic polymer with several advantageous properties, including biomass origin, biocompatibility, and biodegradability. PHA is synthesized in transgenic plants harboring 3 enzymatic genes: phaA, phaB, and phaC (collectively referred to as phaABC). PHA-producing plants exhibit severe growth inhibition that leads to extremely low PHA accumulation when these enzymes are localized in the cytosol. This growth inhibition could be attributed to the deleterious effects of the PHA biosynthetic pathway on endogenous essential metabolites or to PHA cytotoxicity itself. We performed precise morphological observations of phaABC-overexpressing Arabidopsis (ABC-ox), which displayed typical growth inhibition. On growth medium without sucrose, ABC-ox exhibited a pale green phenotype, dwarfism, including small cotyledons and true leaves, and short roots. ABC-ox partially recovered from this growth inhibition when the growth medium was supplemented with 1% sucrose. This recovery was reversed after ABC-ox grown on 1% sucrose medium was transferred to soil. ABC-ox grown on 1% sucrose medium not only demonstrated recovery from growth inhibition but were also the only examined plants with PHA accumulation, suggesting that growth inhibition was not caused by PHA cytotoxicity but rather by a lack of essential metabolites.

show abstract

Synthesis of High-Molecular-Weight Polyhydroxyalkanoates by Marine Photosynthetic Purple Bacteria

Cited by 78 publications

References 50 publications

Bioconversion of novel and renewable agro-industry by-products into a biodegradable poly(3-hydroxybutyrate) by marine Bacillus megaterium UMTKB-1 strain

Bioconversion of novel and renewable agro-industry by-products into a biodegradable poly(3-hydroxybutyrate) by marine Bacillus megaterium UMTKB-1 strain

Optimal iron concentrations for growth-associated polyhydroxyalkanoate biosynthesis in the marine photosynthetic purple bacteriumRhodovulum sulfidophilum

Sucrose supplementation suppressed the growth inhibition in polyhydroxyalkanoate-producing plants

Contact Info

Product

Resources

About