• Title/Summary/Keyword: polyhydroxyalkanoates

Search Result 59, Processing Time 0.072 seconds

Valorization of Pineapple Peel Waste for Sustainable Polyhydroxyalkanoates Production

  • Kannika Bunkaew;Kittiya Khongkool;Monthon Lertworapreecha;Kamontam Umsakul;Kumar Sudesh;Wankuson Chanasit
    • Microbiology and Biotechnology Letters
    • /
    • v.51 no.3
    • /
    • pp.257-267
    • /
    • 2023
  • The potential polyhydroxyalkanoates (PHA)-producing bacteria, Bacillus megaterium PP-10, was successfully isolated and studied its feasibility for utilization of pineapple peel waste (PPW) as a cheap carbon substrate. The PPW was pretreated with 1% (v/v) H2SO4 under steam sterilization and about 26.4 g/l of total reducing sugar (TRS) in pineapple peel hydrolysate (PPH) was generated and main fermentable sugars were glucose and fructose. A maximum cell growth and PHA concentration of 3.63 ± 0.07 g/l and 1.98 ± 0.09 g/l (about 54.58 ± 2.39%DCW) were received in only 12 h when grown in PPH. Interestingly, PHA productivity and biomass yield (Yx/s) in PPH was about 4 times and 1.5 times higher than in glucose. To achieve the highest DCW and PHA production, the optimal culture conditions e.g. carbon to nitrogen ratios of 40 mole/mole, incubation temperature at 35℃ and shaking speed of 200 rpm were performed and a maximum DCW up to 4.24 ± 0.04 g/l and PHA concentration of 2.68 ± 0.02 g/l (61% DCW) were obtained. The produced PHA was further examined its monomer composition and found to contain only 3-hydroxybutyrate (3HB). This finding corresponded with the presence of class IV PHA synthase gene. Finally, certain thermal properties of the produced PHA i.e. the melting temperature (Tm) and the glass transition temperature (Tg) were about 176℃ and -4℃, respectively whereas the Mw was about 1.07 KDa ; therefore, the newly isolated B. megaterium PP-10 is a promising bacterial candidate for the efficient conversion of low-cost PPH to PHA.

Recent Trends in The Production of Polyhydroxyalkanoates Using Marine Microorganisms (해양 미생물에 의한 폴리하이드록시알카노에이트 생산의 최근 동향)

  • Seon Min Kim;Hye In Lee;Hae Su Jeong;Young Jae Jeon
    • Journal of Life Science
    • /
    • v.33 no.8
    • /
    • pp.680-691
    • /
    • 2023
  • Peak oil, climate change, and microplastics caused by the production and usage of petroleum-based plastics have threatened the sustainability of our daily life, and this has emerged as a recent global issue. To solve this global issue, the production and usage of biodegradable eco-friendly bioplastics such as polyhydroxyalkanoates (PHAs) has been suggested as an alternative. Therefore, in this review, the present status of global PHA manufacturers, the advantages of the production of PHAs using marine-origin microorganisms (with their productivity potential) and further required research and development strategies for cost-competitive production of PHAs using marine-based microorganisms were investigated. In this review, PHAs produced from marine microorganisms were found to have similar physical properties to petroleum-based plastics but with several advantages that can reduce the costs of PHA production. Those advantages include, seawater used in the medium preparation step, and osmotic-based cell lysis technology used in the separation and purification steps. However, the PHA productivities from marine microorganisms showed somewhat lower efficiencies than those from the commercial strains isolated from terrestrial environments. In order to solve the problem, further research strategies using synthetic microbiology-based technology, the development of long-term continuous culture technology, and solutions to improve PHA efficiency are required to meet future market demands for alternative bioplastics.

Pseudomonas oleovorans의 유가식 배양에 의한 medium chain length Polyhydroxyalkanoates (MCL-PHA) 생산

  • Kim, Beom-Su;Im, Hui-Yeon
    • 한국생물공학회:학술대회논문집
    • /
    • 2000.04a
    • /
    • pp.207-210
    • /
    • 2000
  • Pseudomonas oleovorans was cultivated to produce medium chain length polyhydroxyalkanoates (MCL-PHA) fram octanoic acid and ammonium nitrate as carbon and nitrogen source, respectively, by a pH-stat fed-batch culture technique. The octanoate concentration of the culture broth was maintained below 4 g/L by feeding the mixture of octanoic acid and ammonium nitrate when the culture pH rose above high limit. The effect of the ratio of octanoic acid to ammonium nitrate (C/N ratio) in the feed on the PHA production was examined. The final cell concentrations of 62.5, 54.7, and 9.5 g/L, PHA contents of 62.9, 75.1, and 67.6% of dry cell weight, and productivities of 1.03, 0.632, and 0.161 g/L/h were obtained when the C/N ratio in the feed were 10, 20, and 100 g octanoic acid/g ammonium nitrate, respectively.

  • PDF

Production of Polyhydroxyalkanoates from Sludge Palm Oil Using Pseudomonas putida S12

  • Kang, Du-Kyeong;Lee, Cho-Ryong;Lee, Sun Hee;Bae, Jung-Hoon;Park, Young-Kwon;Rhee, Young Ha;Sung, Bong Hyun;Sohn, Jung-Hoon
    • Journal of Microbiology and Biotechnology
    • /
    • v.27 no.5
    • /
    • pp.990-994
    • /
    • 2017
  • Polyhydroxyalkanoates (PHAs) are biodegradable plastics produced by bacteria, but their use in diverse applications is prohibited by high production costs. To reduce these costs, the conversion by Pseudomonas strains of PHAs from crude sludge palm oil (SPO) as an inexpensive renewable raw material was tested. Pseudomonas putida S12 was found to produce the highest yield (~41%) of elastomeric medium-chain-length (MCL)-PHAs from SPO. The MCL-PHA characteristics were analyzed by gas-chromatography/mass spectrometry, gel permeation chromatography, and differential scanning calorimetry. These findings may contribute to more widespread use of PHAs by reducing PHA production costs.

Short-Chain-Length Polyhydroxyalkanoates: Synthesis in Metabolically Engineered Escherichia coli and Medical Applications

  • PARK, SI-JAE;CHOI, JONG-IL;LEE, SANG-YUP
    • Journal of Microbiology and Biotechnology
    • /
    • v.15 no.1
    • /
    • pp.206-215
    • /
    • 2005
  • Polyhydroxyalkanoates (PHAs) are homo or hetero polyesters of (R)-hydroxyalkanoates accumulated in various microorganisms under growth-limiting condition in the presence of excess carbon source. They have been suggested as biodegradable substitutes for chemically synthesized polymers. Recombinant Escherichia coli is one of the promising host strains for the economical production of PHAs, and has been extensively investigated for the process development. The heterologous PHA biosynthetic pathways have been established through the metabolic engineering and inherent metabolic pathways of E. coli have been redirected to supply PHA precursors. Fermentation strategies for cultivating these recombinant E. coli strains have also been developed for the efficient production of PHAs. Nowadays, short-chain-length (SCL) PHAs are being re-invited due to its improved mechanical properties and possible applications in the biomedical area. In this article, recent advances in the development of metabolically engineered E. coli strains for the enhanced production of SCL-PHAs are reviewed. Also, medical applications of SCL-PHAs are discussed.