Figure - available from: Applied Microbiology and Biotechnology
This content is subject to copyright. Terms and conditions apply.
Source publication
Polyhydroxyalkanoate (PHA) is a family of microbial polyesters that is completely biodegradable and possesses the mechanical and thermal properties of some commonly used petrochemical-based plastics. Therefore, PHA is attractive as a biodegradable thermoplastic. It has always been a challenge to commercialize PHA due to the high cost involved in th...
Similar publications
The population growth in the present era and the great advances made in life has made the human beings inclined towards various industries and materials as a result of which the production and the accumulation of the waste materials in the environment are inevitable. Plastic industries are among the most important and most frequently applied indust...
Polyhydroxyalkanoates (PHAs) are polyesters synthesized by bacteria as a carbon and energy storage material. PHAs are characterized by thermoplasticity, biodegradability, and biocompatibility, and thus have attracted considerable attention for use in medical, agricultural, and marine applications. The properties of PHAs depend on the monomer compos...
Citations
... The indigestible P(3HB) was subsequently excreted by the mealworms in the form of faecal pellets. After the biological recovery process, the P(3HB) was extracted from the faecal pellets and purified using distilled water and NaOH [50,51]. ...
The expanding urbanization of coastal areas has led to increased ocean sprawl, which has had both physical and chemical adverse effects on marine and coastal ecosystems. To maintain the health and functionality of these ecosystems, it is imperative to develop effective solutions. One such solution involves the use of biodegradable polymers as bioactive coatings to enhance the bioreceptivity of marine and coastal infrastructures. Our study aimed to explore two main objectives: (1) investigate PHA-degrading bacteria on polymer-coated surfaces and in surrounding seawater, and (2) comparing biofilm colonization between surfaces with and without the polymer coating. We applied poly(3-hydroxybutyrate) [P(3HB)) coatings on concrete surfaces at concentrations of 1% and 6% w/v, with varying numbers of coating cycles (1, 3, and 6). Our findings revealed that the addition of P(3HB) indeed promoted accelerated biofilm growth on the coated surfaces, resulting in an occupied area approximately 50% to 100% larger than that observed in the negative control. This indicates a remarkable enhancement, with the biofilm expanding at a rate roughly 1.5 to 2 times faster than the untreated surfaces. We observed noteworthy distinctions in biofilm growth patterns based on varying concentration and number of coating cycles. Interestingly, treatments with low concentration and high coating cycles exhibited comparable biofilm enhancements to those with high concentrations and low coating cycles. Further investigation into the bacterial communities responsible for the degradation of P(3HB) coatings identified mostly common and widespread strains but found no relation between the concentration and coating cycles. Nevertheless, this microbial degradation process was found to be highly efficient, manifesting noticeable effects within a single month. While these initial findings are promising, it’s essential to conduct tests under natural conditions to validate the applicability of this approach. Nonetheless, our study represents a novel and bio-based ecological engineering strategy for enhancing the bioreceptivity of marine and coastal structures.
... The final stage is the adult stage, during which they acquire the ability to reproduce (Zhang et al., 2019;Selaledi et al., 2020) (Figure 1). (Ong et al., 2018;Dreyer et al., 2021). ...
... Gambar 1.7. Siklus Hidup Ulat Hongkong (Ong et al., 2018) Ulat hongkong hidup di tempat yang gelap dan lembap seperti di dalam tanah, bawah kayu mati, atau dalam tempat yang terbuat dari bahan organik. Mereka makan berbagai jenis makanan seperti gandum, tepung roti, sayuran, dan buah-buahan yang membusuk. ...
... Pupa ini berwarna putih dan berbentuk seperti kumbang yang belum berkembang. Selama 12 hingga 20 hari, pupa akan mengalami perkembangan dan berubah menjadi kumbang dewasa (Ong et al., 2018). ...
Plastik adalah salah satu bahan yang sangat umum digunakan dalam kehidupan modern kita. Plastik dianggap sebagai bahan yang murah dan praktis, namun memberikan permasalahan pada lingkungan yaitu sampah. Sampah plastik juga menjadi permasalahan lingkungan di Indonesia, dimana plastik menjadi salah satu penyumbang timbulan sampah nasional. Hal ini diperlukan solusi yang efektif dan efisien dalam pengelolaan sampah plastik. Pengelolaan sampah plastik dapat dilakukan seperti pembuatan biji plastik maupun penggunaan agen biodegradasi yang lebih ramah lingkungan. Namun, biaya yang digunakan dalam pengelolaan sampah yaitu pembuatan biji plastik serta menggunakan agen biologis tersebut juga cukup tinggi. Penggunaan larva bisa menjadi solusi alternatif dalam degradasi sampah plastik. Larva tersebut seperti ulat jerman, ulat hongkong maupun ulat lilin.
... The production cost of PHA is significantly impacted by the energy consumption required for cell crushing and the cost of solvents used for extraction [101,102]. This energyintensive and environmentally unfriendly production process poses a major challenge for PHA production. ...
The extensive utilization of traditional petroleum-based plastics has resulted in significant damage to the natural environment and ecological systems, highlighting the urgent need for sustainable alternatives. Polyhydroxyalkanoates (PHAs) have emerged as promising bioplastics that can compete with petroleum-based plastics. However, their production technology currently faces several challenges, primarily focused on high costs. Cell-free biotechnologies have shown significant potential for PHA production; however, despite recent progress, several challenges still need to be overcome. In this review, we focus on the status of cell-free PHA synthesis and compare it with microbial cell-based PHA synthesis in terms of advantages and drawbacks. Finally, we present prospects for the development of cell-free PHA synthesis.
... That's why, PHA cost more than synthetic petroleum-based plastics, which limits their industrial applications (Lee et al. 2021a). PHA is currently being produced commercially at the cost of €2.2-5.0 kg −1 , whereas only polypropylene plastic is available for €1.0 kg −1 (Berwig et al. 2016;Ong et al. 2018). PHA production is cost-effective if the suitable substrate is used as it influences up to one-half of the total price (Choi and Lee 1997;Bhatia et al. 2017;Liu et al. 2021). ...
Bioplastics replace synthetic plastics of petrochemical origin, which contributes challenge to both polymer quality and
economics. Novel polyhydroxyalkanoates (PHA)-composite materials, with desirable product quality, could be developed,
thus targeting the global plastics market, in the coming years. It is possible that PHA can be a greener substitute for their
petroleum-based competitors since they are simply decomposed, which may lessen the pressure on municipal and industrial
waste management systems. PHA production has proven to be the bottleneck in industrial application and commercialization
because of the high price of carbon substrates and downstream processes required to achieve reliability. Bacterial PHA
production by these municipal and industrial wastes, which act as a cheap, renewable carbon substrate, eliminates waste
management hassles and acts as an efficient substitute for synthetic plastics. In the present review, challenges and opportunities
related to the commercialization of polyhydroxyalkanoates are discussed and presented. Moreover, it discusses critical steps
of their production process, feedstock evaluation, optimization strategies, and downstream processes. This information may
provide us the complete utilization of bacterial PHA during possible applications in packaging, nutrition, medicine, and
pharmaceuticals.
... Valorisation of aged PLA could be achieved through its conversion, using mild operating conditions and a selective organic catalyst, into ethyl lactate as bio-based industrial solvent [35]. Biological recycling has been assessed for polyhydroxyalkanoates (PHAs) conversion into animal feed supplements [36,37]. Combined chemicalebiological poly(3-hydroxybutyrate) (PHB) recycling has been assessed through thermolytic distillation for crotonic acid production followed by bacterial fermentation of crotonic acid for new PHB production [38]. ...
Sustainability assessment should be considered as a decision-making framework for the development of circular processes. Techno-economic, environmental and social metrics should be integrated and interrelated (e.g., through life-cycle costing) to achieve sustainable and circular processes. Industrial symbiosis is a key strategy that promotes the physical exchange of resources, energy and/or by-products among different industries in an effort to achieve competitive and sustainable production. By-products and waste streams from conventional linear value chains can be considered as feedstock for the future sustainable chemical industry. This review elaborates on the state-of-the-art sustainability and circularity assessment methodology and indicators focusing on the life-cycle of biopolymer production, including end-of-life alternatives for their post-consumer valorization.
... The production of PHA at large scale still faces problems due to the high production cost of PHA compared to synthetic plastics. Recently, the commercial price of PHA and polypropylene plastic is about €2.2-5.0/kg and €1.0/kg, respectively (Ong et al., 2018). Substrates such as fatty acids and sugars play a significant role in the production of biopolymer, making up around 50% of the final cost. ...
... Non-conventional methods which bypass some of the complicated processes of extracting and purifying the PHA granules from the bacterial cells are undergone in which they have termed it as biological recovery. In recent years, biological disruption methods included mealworms, bacterial predators, rats [251][252][253]. Martínez et al. [106] proposed using the obligate predatory bacterium Bdellovibrio bacteriovorus as a unique cell lytic agent capable of recovering intracellular bioproducts such as PHA. ...
... The NPCM was digested selectively without altering the molecular weight of the PHA [254,255]. Without the use of solvents, amounts of PHA in kilograms with purities surpassing 90% may be extracted in the laboratory using this approach [253]. Biological recovery, on the other hand, takes longer than any other recovery method and necessitates biomass pre-treatment. ...
Exponential increase in the use and disposal of synthetic plastics has raised an alarming concern related to their adverse effect on the environment due to their recalcitrant nature and non biodegradability. Nevertheless, the depletion in the petrochemical sources made it imperative to search for other sustainable alternatives to synthetic plastics. This triggered the attention on biodegradable plastics produced from plants, animals and microbial sources that have excellent material properties like their synthetic counterparts. Polyhydroxyalkanoates (PHAs) are ineluctably promising microbial polyesters that have the competence to supersede traditional oil-based synthetic polymers which causes major disposal issues worldwide. The compostable nature, biocompatibility, thermostability, and resilience of these bio-based polymers make them an acceptable replacement in the global market. Their versatile material properties made them a propitious candidate in packaging, biomedicine, tissue engineering, biofuel production, nanocomposite formation, and other industrial applications. Despite their potential advantages, the commercialization of PHA is hindered majorly due to the high cost associated with their production and extraction. This review work majorly focuses on the production, extraction, applications and fermentation strategies for enhancing PHA production. The review also addresses the production of PHA from extremophiles, challenges associated with PHA production and sustainable substrates for PHA production using various agroindustrial wastes.
... The preference for insects over animals for the biological recovery of PHA was due to their worldwide distribution, ease of rearing, their requirement for less space, water, and simple management to transform low-value substrates/organic matter into body biomass and value-added products 14,15 . In addition to mealworms, a trial experiment with other insects showed that cricket, cockroach, and superworm can readily consume the freezedried bacterial cells and excreted the white faecal pellets 16 . Mealworms were chosen for their ease of cultivation under dry conditions and longer larval periods (2-3 months). ...
... During the larval stage, mealworms can absorb a substantial amount of nutrients from the bacterial cells and recover a large quantity of PHA granules. The biological method of PHA recovery using mealworms 16,17 fits the concept of industrial symbiosis whereby the bioplastic industry provides the freeze-dried cells to the mealworm farm at little or no cost and the farm returns the faecal pellets containing the PHA to the bioplastic industry. The mealworm farm saves on the cost of feed at this stage and can reduce the selling price of mealworms. ...
Polyhydroxyalkanoates (PHAs) are bio-based polymers produced in bacterial cells to replace some petrochemical plastics. It has always been a challenge to commercialise PHA due in part to the costly recovery processes of the PHA granules from the bacterial cells. The biological approach of using mealworms, Tenebrio molitor, for the recovery of PHA from the bacterial cells is a newly established method that is at the scale-up stage. On the other hand, the aquaculture feed industry needs a low-cost mealworm meal as a protein source. We aimed at studying the nutritional value of the mealworms (which are by-products) used for the poly(3-hydroxybutyrate) (PHB) (the most common type of PHA) recovery from the bacterial and examining the effect of the mealworms on the growth performance, and feed utilization efficiency of red hybrid tilapia ( Oreochromis sp.). The cells were fed to the mealworms to digest the proteinaceous cellular materials and excrete the PHB granules in the form of fecal pellets. The resulting mealworms were used as fishmeal replacement to formulate five isonitrogenous (35% crude protein) and isolipidic (8% lipid) diets at mealworm meal (MwM) inclusion levels of 0% (MwM0/control diet), 25% (MwM25), 50% (MwM50), 75% (MwM75) or 100% (MwM100). The results showed good nutritive value mealworms [high protein (75%), low-lipid (10%)] and up to 75% MwM inclusion diet was good in supplying satisfactory nutrients and energy to the red hybrid tilapia. This approach is beneficial in a way that minimal cost was involved in recovering kilograms of PHB and the proteins, lipids, and minerals from the bacterial cells do not end up as wastes but in turn, are used as nutrition by the larvae.
... The extraction of PHA from intracellular inclusion bodies is a crucial process. Various reactive chemicals are used to extract PHA from bacterial cells [35]. The sodium hypochlorite digestion method [36,37] and solvent extraction by chloroform method [38] are usually used separately for PHA extraction but in this study, both methods were used in combination to extract PHA biopolymer from bacterial cells. ...
Polyhydroxyalkanoates (PHA) are the biomaterials isolated naturally from bacterial strains. These are present in granules and accumulated intracellularly for storage and energy uptake in stressed conditions. This work was based on the extraction of polyhydroxyalkanoates from haloarchaeal strains isolated from samples of a salt mine and Halocin activity screening of these isolates. For the screening of polyhydroxyalkanoates, Nile Blue and Sudan Black Staining were performed. After confirmation and theoretical determination, polyhydroxyalkanoates extraction was done by sodium hypochlorite digestion and solvent extraction by chloroform method in combination. Polyhydroxyalkanoates production was calculated along with the determination of biomass. Halocin activity of these strains was also screened at different intervals. Isolated strains were identified by 16S RNA gene sequencing. Polyhydroxyalkanoates polymer was produced in form of biofilms and brittle crystals. Halocin activity was exhibited by four strains, among which confirmed halocin activity was shown by strain K7. The remarkable results showed that polyhydroxyalkanoates can replace synthetic plastics which are not environment friendly as they cause environmental pollution – a major threat to Earth rising gradually. Therefore, by switching to the use of biodegradable bioplastics from the use of synthetic plastics, it would be beneficial to the ecosphere.
