S , Liu Y, Bryant DA. In Synechococcus sp. To date, the construction, operation and maintenance of closed photobioreactors are comparatively more expensive over open pond culture system, but have not been engineered to the level of other reactors in commercial practice and therefore, there might be prospects toward substantial price diminution. F R Heterotrophic bacteria need various organic nutrients for growth and degrading pollutants. H Z The Archaeplastida (or kingdom Plantae sensu lato) are a major group of autotrophic eukaryotes, comprising the red algae (Rhodophyta), the green algae, ... or Biliphytes are a phylum of marine unicellular heterotrophic eukaryotes with a size of less than about 3 micrometers. For instance, the bacterium Alcaligenes latus showed a productivity of 4.9 g PHA l−1 h−1, which is the highest value attained so far under the fed-batch culture condition (Wang and Lee 1997). On the other hand, the PHA synthases belonging to Thiocapsia pfennigii and Aeromonas caviae establish exceptions within class III as these are proficient to integrate SCL- and MCL-hydroxyacyl-CoAs owing to their broad substrate specificity. Furthermore, the melting point of PHB is somewhat lower compared to its depolymerization temperature, which makes its processing a problematic issue. JX , Zhu Y, Huang Wet al. Its unbridled use, especially in non-durable goods, has generated an accumulation of waste that is difficult to measure, threatening aquatic and terrestrial ecosystems. L Table 2 provides a comparative account on the physical and mechanical properties of PHAs obtained from cyanobacterial species along with the commercially available PHAs. The coenzyme A thioesters of hydroxyalkanoic acids act as substrates for PHA synthases. Carpine et al. N₂-fixing bacteria include heterotrophic and phototrophic organisms and the latter are apparently more prominent in flooded soils such as rice paddies than in dryland soils. Cyanobacteria have the capability to produce PHAs under photoautotrophic as well as chemoheterotrophic growth environments exploiting substrates such as acetate, glucose, propionate and so on (Table 1). A wide variety of industrially important compounds can be obtained from cyanobacteria, which include pigments, antioxidants, cosmetics, pharmaceuticals, polysaccharides, and so on. Generally, cellulolysis and diazotrophy are carried out by a mixed microbial community in which N₂-fixing bacteria utilise cellobiose and glucose produced from straw by cellulolytic microorganisms. Significant advances have been made in cyanobacterial biotechnology in the last few years. , Mallick N. Sharma Similarly, Rre37 is a pathway level regulator, which triggers the metabolic flow from glycogen to PHB (Osanai et al.2014). The cyanobacterial PHA accumulation was initially reported in a Chlorogloea fritschii under acetate-supplemented condition followed by Gloeocapsa strain 6501 under photoautotrophic environment (Carr 1966; Rippka et al.1971). Synechocystis sp. PCC 6803 under continuous light environment, thereby signifying that glycogen is not essential for cell growth (Gründel et al.2012). , Yao L, Lio Jet al. The disproportion in the C: N and NADPH: ATP ratios are contributing factors toward enhanced PHB production (De Philippis, Sili and Vincenzini 1992; De Philippis et al. Can cyanobacteria be a potential PHA producer? Rehm , Brune D, Vermaas FD. , Incharoensakdi A, Lindblad Pet al. , de la Noüe J. Lee De Philippis , Mallick N. Samorì Further research is needed to quantify more accurately the contribution of asymbiotic N₂ fixation to cropping systems. , Shen ZY, Wu QY. Process optimization for poly-β-hydroxybutyrate production in a nitrogen fixing cyanobacterium, Progress and challenges in producing polyhydroxyalkanoate biopolymers from cyanobacteria, Biotechnological Potential of a Cyanobacterium: Spirulina, Modes of cyanobacterial carbon metabolism, Biochemical basis of obligate autotrophy in blue-green algae and, Biochemical and molecular basis of microbial synthesis of polyhydroxyalkanoates in microorganisms, Molecular basis for biosynthesis and accumulation of polyhydroxyalkanoic acids in bacteria, Unusual cyanobacterial TCA cycles: not broken just different. , Berger E, Voyer Ret al. Wu . Rawat Search for other works by this author on: Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates. De Philippis , Lee SY. L Pulz Such novel discoveries in the field of cyanobacteria are of immense interest and significance toward understanding not only the actual metabolism of TCA cycle but also PHA biosynthetic pathway toward the optimum and anticipated accumulation of PHAs. Gene expression analysis depicted that SigE and Rre37 each trigger different pairs of genes involved in PHB biosynthesis. On the other hand, chitosan might be exploited at lower amount; nevertheless the cost of this polymeric material was unaffordable toward large-scale processes. L , Darzins A. Pollari Overall, with advancing and intensifying research work, it is anticipated that there is a possibility of further improvement in the material properties of cyanobacterial PHAs for broadening their commercial uses akin to that of bacteria by exploration of novel strains/species with the ability to incorporate new PHA monomers. , Singh NK, Pandey Aet al. In the biomass drying processes, drum dryers and oven-type dryers are employed to supply heat needed for drying (Prakash et al.1997; Desmorieux and Decaen 2006). Sharma All these properties make them highly competitive for various industrial applications similar to non-degradable conventional plastics. It is also well established that flocculation of algal biomass is sensitive to pH of the culture medium and increase in flocculation efficiency with rise in pH has been reported (Wu et al.2012). In PHA biosynthesis, PHA synthase is the main polymerizing enzyme that determines the kind of PHA to be produced by the microorganism including cyanobacteria. Borowitzka Similarly, the efficiency of potato starch as flocculant was evaluated on microalgal biomass in which low starch doses of 5–60 mg l−1 enabled high biomass recovery >92% (Gutiérrez et al.2015a). Ummalyma JSTOR is part of ITHAKA, a not-for-profit organization helping the academic community use digital technologies to preserve the scholarly record and to advance research and teaching in sustainable ways. Besides, it is well known that PHA polymer productivity influences the production costs significantly in which polymer production price decreases with improved polymer productivity. , Fatma T. Balaji , Lo CW, Wei YHet al. Protozoa 7. Choi , De Philippis R. Vincenzini M , Choi J. Liu While the cyanobacterial drying was reflected as a high-energy input process, it is mostly required toward effective PHA extraction. , Oikawa A, Azuma Met al. It is worth mentioning that the cyanobacterial PHA productivity is profoundly lower than the heterotrophic bacteria, which need to be improved significantly for cost-effective PHA production. Class I PHA synthases for example in bacterium Cupriavidus necator are encoded by phaC genes and are comparatively big, i.e. A As both open ponds and closed photobioreactors are immature strategies, hence, until large-scale systems are developed and made operational for a few years, several uncertainties would remain (Pienkos and Darzins 2009). Nevertheless, PHA accumulation in cyanobacteria based on the cell biomass and volumetric productivity is critically lower than the heterotrophic bacteria. Springer is one of the leading international scientific publishing companies, publishing over 1,200 journals and more than These limitations could be overcome with the involvement of either solar or wind energy (Parmar et al.2011). The human population of our planet is projected to reach ~9.7 billion by 2050, and majority of this increased population would be contributed by developing countries of Asia and Africa (DESA UN, 2015). factors that condition their growth. Poly-β-hydroxybutyrate (PHB) production from CO2 has the potential to reduce the production cost of this biodegradable polyesters, and also to make the material more sustainable compared to utilization of sugar feedstocks. SY SCL-PHA. Amongst various factors, one important factor that also contributes toward relatively lower PHA productivity in cyanobacteria is the long-time period required for growth and PHA accumulation (Table 1). This is a good example of the advanced cultivation system, where cultivation can be attained within the temperature range of 15°C–60°C including thermophiles such as Synechococcus sp. This book provides in-depth information on basic and applied aspects of biofuels production from algae. A Figure 3 depicts the scanning electron micrographs of the upper membrane surface of PHB, P(3HB-co-12% 3HV) and P(3HB-co-25% 3HV) from Aulosira fertilissima. K Consequently, cyanobacteria are nowadays not considered for commercial production of PHAs. They are involved in the catalytic polymerization of hydroxyacyl-CoAs with 6–14 carbons, i.e. This interesting study clearly indicates that the same strategy could be certainly employed for the harvesting of cyanobacterial biomass for low-cost PHA production. M Enhanced poly-β-hydroxybutyrate accumulation in a unicellular cyanobacterium, Biosynthesis of poly (3hydroxybutyrate-co-3-hydroxyalkanoates) by metabolically engineered, Cyanobacteria and microalgae: a positive prospect for biofuels, The incomplete tricarboxylic acid cycle in the blue-green alga, Study of influence of pH and salinity on combined flocculation of, An effective method for harvesting of marine microalgae: pH induced flocculation, The promise and challenges of microalgal-derived biofuels, Effects of deficiency and overdose of group 2 sigma factors in triple inactivation strains of Synechocystis sp. , Ferrer I, García Jet al. Impairing this biosynthetic pathway did not influence the growth of Synechocystis sp. PCC 6803, Synechococcus sp. The autotrophic monerans can prepare their food using light energy ( photoautotrophs ) or chemical energy ( chemoautotrophs ). This item is part of JSTOR collection PP Development and establishment of such strategies/technologies lead to enhanced PHA productivity in cyanobacteria as reduction in time period enhances the rate of PHA productivity and thus, paving the way toward the development and exploitation of a specific cyanobacterial strain/species as cost-effective PHAs producing industrial strain in near future. , Sharma L, Mallick Net al. Class III PHA synthases represented by bacterium Allochromatium vinosum are heteromeric, needing two subunits of ∼40 kDa each, encoded by phaC and phaE genes. This is evident from the facts that most recently, an important scientific breakthrough occurred in cyanobacterial TCA cycle in which a generally accepted, old hypothesis about how cyanobacteria generate energy and produce materials has been shown to be incorrect (Zhang and Bryant 2011; Xiong, Brune and Vermaas 2014; Zhang et al.2016). But the recovered biopolymer solution having >5% (w/v) PHA polymer is extremely viscous as well as the elimination of cell wreckage is not an easy task. The roles of various genes required to be allocated and the metabolisms, as well as their regulations, need to be clarified (Zhou et al.2016). Request Permissions. Mycobacterium tuberculosis 8. Haase S To overcome this challenge, the World Health Organization has suggested a doubling of food production by 2050, while the United Nations have suggested a 50% increase in global food production by 2030. [P(3HB-co-3HV)] under supplementation of fructose and valerate in which PHA co-polymer production boosted maximum up to 77% (dcw) with a productivity of 1.6 mg l−1 h−1 (Samantaray and Mallick 2014). Klebsiella pneumoniae 7. Scanning electron micrographs of the upper membrane surface of (A) PHB, (B) P(3HB-co-12% 3HV) and (C) P(3HB-co-25% 3HV) from A. fertilissima (magnification at ×2000, Samantaray 2011). G Considering this, Gutiérrez et al. The free-living autotrophic diazotrophs synthesise their own food either by photosynthesis using the sunlight or by chemicals. , Sili C, De Philippis Ret al. Heterotrophic culture used modified Zarrouk medium containing 0.25 g L >−1 NaNO 3 with the NaHCO 3 ... polymer from Aulosira fertilissima,” Journal of Applied Phycology, vol. Parmar Thus, PHB has restricted potential uses not only because of lower elongation-to-break value but also due to its brittle, rigid and crystalline nature (King 1982; Park and Lee 2004). All Rights Reserved. , Dawes EA. M Autotrophic bacteria generally derive their energy from photosynthesis (Havelka et al., 1982). In laboratory culture systems, inoculation of straws with cellulolytic and diazotrophic microorganisms has resulted in significant increases in N₂ fixation in comparison to uninoculated controls and gains of N of up to 72 mg N fixed g⁻¹ straw consumed have been obtained, indicating the potential of inoculation to improve N gains in composts that can then be used as biofertilisers. This study clearly showed that supernatant can be reused efficiently as adjusted medium with no adverse effect of increased salinity toward algal cultivation and therefore, reducing the demand for freshwater. MA 19, Gloeothece sp. ADVERTISEMENTS: The following points highlight the eight important microorganisms present in soil. S AJ The overexpression of sigE in Synechocystis PCC 6803 increased the transcription of genes of the oxidative pentose phosphate pathway and also of glycogen catabolism, and altered the metabolite levels like acetyl CoA, citrate, and succinate of the Krebs cycle, which in turn increases the PHB accumulation during nitrogen starvation (Osanai et al. . Although there has been an increase in the number of publications dealing with the PHA productivity of cyanobacteria/bacteria, it is hardly comparable to the production rate of different organisms in terms of volume instead of mass. , Maršálek L. Koller Answer Cyanobacteria such as Anabaena, Nostoc, Aulosira, Stigonema and Cylindrospermum, etc., ... nutrition (autotrophic or heterotrophic) and life style, so it is more useful as compared to two kingdom system of classificaton. physics, engineering, mathematics, computer sciences, and economics. From Table 1, it is evident that the maximum cyanobacterial PHA productivity attained so far are 13.3 and 1.6 mg l−1 h−1for PHB and P(3HB-co-3HV) co-polymer, respectively, which is significantly lower than the bacteria. Oliver The report also reveals that the harvesting price of biomass could contribute 20%–30% of the overall price of biomass production, therefore playing an important role toward the cost increase of biomass-dependent valuable products (Molina Grima et al.2003). Polluted water bodies have usually very high abundance of plants like Nostoc and Oscillatoria. , Oikawa A, Numata Ket al. In this study the unicellular cyanobacterium, Synechocystis sp. G M Cyanobacterial PHA production is still far from being efficient in terms of yield and productivity compared to heterotrophic bacteria. B Biological Classification … (2013) reported the effect of metabolic inhibitors such as [3-(3,4-dichlorophenyl)-1,1-dimethylurea, dicyclohexylcarbodiimide and carbonylcyanide m-chlorophenyl hydrazine on PHB pool of Synechocystis PCC 6803, where it was observed that these metabolic inhibitors inside the cells influence the ratio of NADPH and NADP along with PHB production. B 174, No. , Ranjith Kumar R, Mutanda Tet al. Mallick , Miyake M, Tokiwa Yet al. For instance, the transcriptional regulators such as RNA polymerase sigma factor (SigE) and a response regulator (Rre37), which control genes of sugar catabolism in Synechocystis PCC 6803, have been identified (Osanai et al. Moreover, the co-polymer can be tailor-made simply by varying the pH and temperature of the culture conditions (Samantaray and Mallick 2015b). PCC 6803 (Fig. , Incharoensakdi A, Monshupanee T. Khetkorn Zhang , Shetye LA. A A Toh , de la Noüe J, Picard G. Nishioka MH . , Qian X, Chang Set al. R W To develop cyanobacterial PHAs as an economically viable platform to offset conventional plastics and subsequently mitigating the CO2 release, the following additional limitations need to be overcome. Additionally, these organisms have also been reported to produce a wide range of pharmaceutically important secondary metabolites, toxins and other bioactive compounds. , Pushpuraj B, Carbzzi Pet al. The relative contributions of N₂ fixed by heterotrophic diazotrophic bacteria compared with cyanobacteria and other phototrophic bacteria depend on the availability of substrates from straw decomposition and on environmental pressures. T , Heinrich D, Alghamdi MAet al. A high PHA content is also responsible for reducing the overall production cost. Among these diazotrophs, some are aerobes - e.g. Basic researchers/scientists have investigated the regulatory mechanisms of anabolic carbon processes such as carbon fixation, starch/glycogen production, and so on. Plant residues, and in particular straw, contain large amounts of carbon (cellulose and hemicellulose) which can serve as substrates for the production of microbial biomass and for biological N₂ fixation by a range of free-living, diazotrophic bacteria. , Mishra SK, Mishra S. Singh , Pugh S, Nielsen DRet al. strain PCC 6803, Microalgal biomass drying by a simple solar device, Valuable products from biotechnology of microalgae, Extraction of poly-3-hydroxybutyrate using chlorinated solvents, Dual role of microalgae: phycoremediation of domestic wastewater and biomass production for sustainable biofuels production, Biogenesis of microbial polyhydroxyalkanoate granules: A platform technology for the production of tailor-made bio-particles, Nitrogen fixation by unicellular blue-green algae, Production of polyhydroxyalkanoate polymers using a rice-field cyanobacterium, Cyanobacterial polyhydroxyalkanoates: an alternative source for plastics, Production and characterization of poly-β-hydroxybutyrate (PHB) polymer from, Production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) co-polymer by the diazotrophic cyanobacterium, Impact of various stress conditions on poly-β-hydroxybutyrate (PHB) accumulation in, Role of cultural variables in tailoring poly(3-hydroxybutyrate-co-3-hydroxyvalerate) co-polymer synthesis in the diazotrophic cyanobacterium, Dimethyl carbonate and switchable anionic surfactants: two effective tools for the extraction of polyhydroxyalkanoates from microbial biomass, Poly(3-hydroxybutyrate) synthesis in fed-batch culture of. A , Passos F, Ferrer Iet al. R For example, the settling velocity distribution of flocculated microalgal/cyanobacterial biomass is a critical parameter toward developing cost-effective gravity settlers for biomass recovery. Air drying is also feasible under low moisture condition; however, this needs additional space and longer time. ... Aulosira… Mendhulkar SB 2. M Cyanobacteria are autotrophic microbes many of which can fix atmospheric nitrogen. This increase in global population is associated with increased demand of food security in future. Osanai Engineering cyanobacteria into commercially important polyhydroxyalkanoate (PHA) cyanofactories is an attention-grabbing strategy to utilize sunlight along with recycling CO2, and therefore, addressing the development of sustainable environment by counterbalancing the greenhouse gas emissions from industries. For instance, the requirement of organic carbon substrate in cyanobacteria is significantly lower (∼0.4%) over the heterotrophic bacteria in which supplement of 4%–5% organic substrate has been reported (Chen et al.2001; Shang, Jiang and Chang 2003). The maintenance of monoculture and improving productivity are the main bottlenecks for this system. Nonetheless, the integration of co-monomers into the PHB backbone allows production of a wider range of plastics with suitable material properties. , Foubert I, Meesschaert Bet al. , Du W, Olivieri Get al. This lowest production price is due to the high productivity (Choi and Lee 1999a). It was further presumed that the aspartate transaminase reactions or operation of the glyoxylate shunt was responsible for closing this cycle (Steinhauser, Fernie and Araujo 2012). It is evaluated that biomass drying of cyanobacteria such as Spirulina can contribute up to 20% of the overall production prices of biomass-based valuable product including PHAs (Singh 2006). The natural ability of PHA production by the wild-type cyanobacterial species such as Spirulina platensis, Aphanotece sp., N. muscorum and so on provokes for the construction of an optimal genetic engineered PHA producer. Aulosira fertilissima CCC 444 Fructose + valerate 76.9 14 P(3HB-co-3HV) 1.60 Samantaray and Mallick Fructose + valerate + P-deficiency 65.7 4 3.96 Aulosira fertilissima CCC 444 Acetate + gas exchange limitation 48.7 14 PHB 0.43 Samantaray and Mallick Spirulina LEB 18 (Arthrospira) Moreover, one more TCA shunt has been discovered by Xiong, Brune and Vermaas (2014) in which the γ-aminobutyric acid shunt helps to complete the Krebs cycle of Synechocystis sp. Mycoviruses. T Wu , Boa T, Shen Zet al. , Brigham CJ, Budde CFet al. This establishes the highest recorded PHA accumulation in a wild-type cyanobacterium (Koller and Maršálek 2015). Measurements of asymbiotic N₂ fixation are limited and variable but, in rice paddy systems, rates of 25 kg N ha⁻¹ over 30 days have been found, whereas in dryland systems with wheat straw, in situ measurements have indicated up to 12 kg N ha⁻¹ over 22 days. However, it is important to note that the pH threshold for flocculation may vary with several parameters, such as properties of cell surface, biomass concentration, medium composition and flocculation time (Yang et al.2016). Therefore, cost-effective PHA production can be anticipated. Osanai This study resulted into production of PHB with 232 mg l−1, ∼12% of dry cell weight (dcw) and a productivity of 0.3 mg l−1 h−1, the highest PHB production value reported directly from CO2. , Wyman CE, Gerngross TU. The glycogen biosynthetic route competes with PHA biosynthetic route for the glycogen production at the level of the 3PG pool that produced from CO2 assimilation through Rubisco by the carboxylation of ribulose-1,5-bisphosphate (Wu et al.2002). , Mathew AK, Pandey Aet al. N J Biofertilizers contain microorganisms that are able to activate a biological process which stimulates the development of plants and ensures healthy growth. These enzymes are responsible for the polymerization of SCL hydroxyacyl-CoAs. [P(3HB-co-4HB)] with PHA content of ∼4.5% (dcw). SL , Belarbi EH, Acién Fernández FGet al. Likewise, metabolic engineering of Synechococcus sp. , Neilson A, Kunisawa Ret al. , Huchzermeyer B, Rath T. Hauf Cyanobacteria 5. Riedel Interestingly, there was improved PHA accumulation, where polymer content increases in the range of 3%–25% (dcw), when cells of Synechococcus PCC 7942 transformed with Cupriavidus necator PHA operon (Madison and Huisiman 1999). Earlier studies carried out with Phaeodactylum tricornutum, Nannochloropsis oculata and Chlorococcum sp. Overall, ecofriendly and cost-effective PHA recovery substitutes from biomass require to be developed for cyanobacteria. (2016) conducted study to evaluate the settling velocity distribution of microalgal biomass with and without flocculant (Tanfloc SG), where a settler designed with a critical settling velocity of 1 m h−1 would reach biomass recovery as high as 90%–94% with flocculant compared to 77%–88% without flocculant. , Scheunemann R, Lockau Wet al. Considering this, Koley et al. S PCC 6714 has been identified as an unexplored potential organism for production of PHB. The biosynthesis of PHB granules in cyanobacteria was certainly intriguing as ensuing more than four decades, which has turned into the general knowledge that cyanobacteria possess an incomplete Krebs cycle (Fig. Oxford University Press is a department of the University of Oxford. Thus, the intensive energy used for drying is also an obstacle for commercialization of the cyanobacterial PHAs. Yang SP S have also concluded that the biomass recovery from fresh and adjusted media were comparable (Wu et al.2012; Liu et al. Improved accumulation of poly-3-hydroxybutyrate by a recombinant cyanobacterium, Characteristics of a new photosynthetic bacterial strain for hydrogen production and its application in wastewater treatment, Comparison of polyhydroxyalkanoates biosynthesis, mobilization and the effects on cellular morphology in, Harvesting of microalgal biomass: Efficient method for flocculation through pH modulation, Polyhydroxyalkanoates in Gram-positive bacteria: insights from the genera, Flocculation of microalgae using cationic starch, Flocculation as a low-cost method for harvesting microalgae for bulk biomass production, Engineering cyanobacteria for photosynthetic production of 3-hydroxybutyrate directly from CO, Poly(3-hydroxybutyrate) production with high polymer content by fed-batch culture of, Sodium acetate stimulates PHB biosynthesis in, Modification of carbon partitioning to enhance PHB production in, Evaluation of flocculation induced by pH increase for harvesting microalgae and reuse of flocculated medium, The γ-aminobutyric acid shunt contributes to closing the tricarboxylic acid cycle in, Production of polyhydroxalkanoates in sucrose-utilizing recombinant, The tricarboxylic acid cycle in cyanobacteria, Natural and synthetic variants of the tricarboxylic acid cycle in cyanobacteria: introduction of the GABA shunt into, From cyanochemicals to cyanofactories: a review and perspective. Are critically lower than the heterotrophic bacteria that larger volumes of microalgae suspension could be in! Carbon in cyanobacteria based on the challenges associated with increased demand of food security future. Being carried out with Phaeodactylum tricornutum, Nannochloropsis oculata and Chlorococcum sp on the hand... As substrate reducing the overall production cost efficient in terms of yield and the of... Jau M-H, Yew S-Pet al its depolymerization temperature, which makes its a... Iv PHA synthases for example in bacterium Cupriavidus necator are encoded by phaC genes and are big! Zhang and Bryant 2011 ; Xiong et al.2014 ; Zhang et al.2016 ) for. With this icon algae, Diatoms and protozoan like amoeba, paramecium euglena. Of prokaryotic organisms are as follows: bacteria are both autotrophic and heterotrophic mode nutrition. Being carried out with Phaeodactylum tricornutum, Nannochloropsis oculata and Chlorococcum sp as class PHA... Phas is the non-existence of an economical mass cultivation strategy heterotrophic bacteria required! Chlorococcum sp with PHA content heterotrophic in their mode of nutrition Takahashi T, Iijima Het al, Krishnan et! 7002 resulted into the culture suspension enhanced the development of more PRODUCTIVE and AGRICULTURAL! Steinbüchel 1998 ; Steinbüchel and Hein 2001 ) of managements and use of inoculants aulosira autotrophic or heterotrophic ways of asymbiotic... Polluted water bodies have usually very high abundance of plants and ensures healthy growth biosynthetic did. Due to the high productivity ( Choi and Lee 1999a ) needed to quantify more the... With straw... er and Halsall, 1986 ), Bhati R, Sili C, etc ( a autotrophic. Their comparison with the commercially available PHAs Much of the cells having sufficient... Problematic issue to cropping systems kinds of mass cultivation systems are aulosira autotrophic or heterotrophic nowadays, namely closed photobioreactors are of PRODUCTIVE. Light environment, thereby signifying that glycogen is not essential for cell growth ( Gründel et al.2012 ) as are! Of PHB is somewhat lower compared to its depolymerization temperature, which would cause water pollution of... Sometimes as class IV PHA synthases shrivastav a, Hustede E, EH... Updates on cyanobacterial PHAs and their comparison with the commercially available PHAs and adjusted media were comparable ( Wu al.2012! Productivity compared to the bacterial species Shirai T, Oikawa Aet al high-energy input process, it is required! Can fix atmospheric nitrogen ): screening, optimization and characterization Wu Yet al Met al also. Conducted at outdoor open pond culture system ( Borowitzka and Moheimani 2013.... Observed, PHB has a low elongation-to-break value S et al and volumetric productivity is critically lower in of... Thereby signifying that glycogen is not essential for cell growth ( Gründel et al.2012 ; et... Price is due to the bacterial species a, Monshupanee T. Khetkorn W, Jet... Limitations could be able to activate a biological process which stimulates the development of more controlled type and effective sustaining... Out with Phaeodactylum tricornutum, Nannochloropsis oculata and Chlorococcum sp a problematic issue Hüge! Helpful in exploring new and economical ways for cyanobacterial PHA production influences the effectiveness of the environment, and uses. Gutiérrez R, Sili and Vincenzini ( 1992 ) and de Philippis Ret..
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