: Twenty-six different bacterial strains were isolated from samples taken from different locations Dammam, Saudi Arabia, for screening of their polyhydroxyalkanoate (PHA) production capability. The initial screening was conducted by staining with Sudan Black B and Nile Red, followed by examination under fluorescence and electron microscopes to characterize PHA granule formation. The PHA-producing bacterial isolates were identified using 16S rRNA gene analyses; the most potent bacterial strain was identified as Pseudomonas sp. strain-P(16). The PHA production capability of this strain in the presence of different low-cost carbon sources, such as rice bran, dates, and soy molasses, was analyzed. PHA production in the presence of rice bran, dates, and soy molasses was 90.9%, 82.6%, and 91.6%, respectively.
Biosynthesis of polyhydroxyalkanoates (PHA) has been studied since the 1920s. The biosynthesis pathways have been well understood and various attempts have been made to improve the PHA biosynthesis efficiency. Recent progresses have been focused on systematic improvements on PHA biosynthesis including changing growth pattern for rapid proliferation, engineering to enlarge cell sizes for more PHA accumulation space, reprogramming the PHA synthesis pathways using optimized RBS and promoter, redire...
#2Cristiano Varrone(DTU: Technical University of Denmark)H-Index: 19
Last. Hariklia N. Gavala(DTU: Technical University of Denmark)H-Index: 29
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Abstract Crude glycerol is an important by-product of the biodiesel industry, which can be converted into volatile fatty acids (VFA) and/or 1,3-propanediol (1,3-PDO) by fermentation. In this study, a selective conversion of VFA to polyhydroxyalkanoates (PHA) was attained while leaving 1,3-PDO in the supernatant by means of mixed microbial consortia selection strategies. The process showed highly reproducible results in terms of PHA yield, 0.99 ± 0.07 C mol PHA/C mol S (0.84 g COD PHA/g COD S), P...
Last. Guo-Qiang Chen(THU: Tsinghua University)H-Index: 1
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Abstract As intracellular carbon and energy storage materials, polyhydroxyalkanoates (PHA) are a diverse biopolyesters synthesized by many bacteria. PHA have been produced in large quantity for various application research including medical implants for approximately 30 years. Many studies demonstrated that PHA are promising implant materials due to their diverse and ascendant mechanical, biodegradable and tissue compatible properties. Importantly, common PHA biodegradation products including ol...
Last. Robbert Kleerebezem(TU Delft: Delft University of Technology)H-Index: 73
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Abstract To enrich polyhydroxyalkanoate (PHA) producing microbial communities, generally, a feast-famine regime is applied. Here we investigated the impact of continuous substrate feeding on the enrichment of PHA-producing bacteria in two sequencing batch reactors (SBRs). In the first reactor, the substrate (acetate) was dosed continuously and Zoogloea sp. was enriched. The culture accumulated PHA upon exposure to excess carbon, but the PHA production rate and storage capacity (53 wt.%) were one...
#1Long Huang(HIT: Harbin Institute of Technology)H-Index: 9
#2Zhiqiang Chen(HIT: Harbin Institute of Technology)H-Index: 23
Last. Yao Wang(HIT: Harbin Institute of Technology)H-Index: 4
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Abstract The Feast-Famine (FF) process has been frequently used to select polyhydroxyalkanoate (PHA)-accumulating mixed cultures (MCs), but there has been little insight into the ecophysiology of the microbial community during the selection process. In three FF systems with well-defined conditions, synchronized variations in higher-order properties of MCs and complicate microbial community succession mainly including enrichment and elimination of non-top competitors and unexpected turnover of to...
Polyhydroxyalkanoates (PHA) are bio-based microbial biopolyesters; their stiffness, elasticity, crystallinity and degradability are tunable by the monomeric composition, selection of microbial production strain, substrates, process parameters during production, and post-synthetic processing; they display biological alternatives for diverse technomers of petrochemical origin. This, together with the fact that their monomeric and oligomeric in vivo degradation products do not exert any toxic or el...
#1Cristian Peptu(SAV: Slovak Academy of Sciences)H-Index: 9
#2Marek Kowalczuk(PAN: Polish Academy of Sciences)H-Index: 33
Abstract There is an increased need for polymer materials with low ecological impact and the use of renewable resources for polymer biosynthesis represents an attractive solution. In this context, the biosynthesis of polyhydroxyalkanoates (PHAs) represents perhaps one of the most solid responses offered by the researchers. This chapter covers the relevant and recent literature concerning the biosynthesis of PHAs and their physicochemical properties. The raw materials used in the fermentative pro...
Abstract Polyhydroxyalkanoates (PHAs) are biopolyesters, stored within cells as energy storage materials by various microorganisms. Due to their biocompatibility and biodegradability, PHAs have a wide range of applications in various industries such as biomedical sector including tissue engineering, bio-implant patches, drug delivery, surgery and wound dressing. PHAs are green plastics and they have positive social and environmental impact when compared with conventional plastics in terms of pro...
The search for new materials that replace fossil fuel-based plastics has been focused on biopolymers with similar physicochemical properties to fossil fuel-based plastics, such as Polyhydroxyalkanoates (PHA). The present paper reviews the challenges of scaling-up PHA production from waste streams during the period from 2014 to 2016, focusing on the feasibility of the alternatives and the most promising alternatives to its scaling-up. The reviewed research studies mainly focus on reducing costs o...
The polyhydroxyalkanoate was discovered almost around a century ago. Still, all the efforts to replace the traditional non-biodegradable plastic with much more environmentally friendly alternative are not enough. While the petroleum-based plastic is like a parasite, taking over the planet rapidly and without any feasible cure, its perennial presence has made the ocean a floating island of life-threatening debris and has flooded the landfills with toxic towering mountains. It demands for an immed...
Abstract null null Replacement of substrate by utilizing renewable, sustainable, abundance, and low-costs carbon sources derived from agricultural waste enables the reduction of wastes in industry and simultaneously capacitate the production of value-added products. The total amount of sugar in the banana frond extract (BFE) was 42.7 g/L, which in part consist of 10.5 g/L fructose. The effect of various BFE concentration on the PHB production was determined by conducting the fermentation utilizi...
Bioplastics have been an interesting area of research and development in the last few decades. Normal plastics are made out of petroleum products, which is a non-renewable resource. Apart from that, its non-biodegradable nature makes it a serious threat to the environment, and hence a better alternative is needed. Bioplastics are synthesized by microorganisms and are biodegradable; this property makes them a promising alternative to normal plastic. However, the major drawback related to bioplast...
Bacteria are considered as the major cell factories, which can effectively convert nitrogen and carbon sources to a wide variety of extracellular and intracellular biopolymers like polyamides, polysaccharides, polyphosphates, polyesters, proteinaceous compounds, and extracellular DNA. Bacterial biopolymers find applications in pathogenicity, and their diverse materialistic and chemical properties make them suitable to be used in medicinal industries. When these biopolymer compounds are obtained ...
Last. José González-Valdez(Tec: Monterrey Institute of Technology and Higher Education)H-Index: 14
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Abstract This work aims to study the bio-interfacial properties of poly(ester-urethane) composite scaffolds based on poly (3-hydroxybutyrate) [PHB] and modified by surface plasma-radiation-induced graft polymerization of N-isopropylacrylamide (NIPAAm). The delivering power of the Argon radio-frequency plasma was increased from 5−20 W. The yields over the polyurethane surface, grafting density, topographical dimensions, architecture, surface energy, and wettability were surveyed in the establishe...
In recent years, biopolymers have been attracting the attention of researchers and specialists from different fields, including biotechnology, material science, engineering, and medicine. The reason is the possibility of combining sustainability with scientific and technological progress. This is an extremely broad research topic, and a distinction has to be made among different classes and types of biopolymers. Polyhydroxyalkanoate (PHA) is a particular family of polyesters, synthetized by micr...
Microbial polyhydroxyalkanoates (PHAs) are biopolyesters produced by microorganisms as intracellular granules under nutrient stress. Due to non-toxic and biodegradable behavior these polyesters are a sustainable source of wide range of biomaterials such as bioplastics. As a result of excellent polymeric properties such as melting temperatures (Tm), glass transition temperature (Tg), crystallinity, Young’s modulus and stress to break ratio these polyesters are capable of replacing the synthetic p...