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1.
Syst Appl Microbiol ; 43(2): 126072, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32094022

RESUMO

Polyphasic analysis of ten isolates of the red-pigmented bacteria isolated from ten Arthrospira cultures originating from different parts of the world is described. The 16S rRNA analysis showed <95 % identity with the known bacteria on public databases, therefore, additional analyses of fatty acids profiles, MALDI-TOF/MS, genome sequencing of the chosen isolate and following phylogenomic analyses were performed. Gram-stain-negative, strictly aerobic rods were positive for catalase, negative for oxidase, proteolytic and urease activity. Major fatty acids were 15 : 0 iso, 17:0 iso 3 OH and 17:1 iso w9c/16:0 10-methyl. The whole phylogenomic analyses revealed that the genomic sequence of newly isolated strain DPMB0001 was most closely related to members of Cyclobacteriaceae family and clearly indicated distinctiveness of newly isolated bacteria. The average nucleotide identity and in silico DNA-DNA hybridisation values were calculated between representative of the novel strains DPMB0001 and its phylogenetically closest species, Indibacter alkaliphilus CCUG57479 (LW1)T (ANI 69.2 % is DDH 17.2 %) and Mariniradius saccharolyticus AK6T (ANI 80.02 % isDDH 26.1 %), and were significantly below the established cut-off <94 % (ANI) and <70 % (isDDH) for species and genus delineation. The obtained results showed that the analysed isolates represent novel genus and species, for which names Arthrospiribacter gen nov. and Arthrospiribacter ruber sp. nov. (type strain DPMB0001=LMG 31078=PCM 3008) is proposed.


Assuntos
Bacteroidetes/classificação , Bacteroidetes/fisiologia , Spirulina/crescimento & desenvolvimento , Bacteroidetes/química , Bacteroidetes/citologia , DNA Bacteriano/genética , Ácidos Graxos/análise , Variação Genética , Genoma Bacteriano/genética , Hibridização de Ácido Nucleico , Fenótipo , Filogenia , Pigmentos Biológicos , RNA Ribossômico 16S/genética , Metabolismo Secundário , Análise de Sequência de DNA
2.
Aquat Toxicol ; 216: 105295, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561136

RESUMO

Oxybenzone (OBZ; benzophenone-3, CAS# 131-57-7) is a known pollutant of aquatic and marine ecosystems, and is an ingredient in over 3000 personal care products, as well as many types of plastics. The aim of this study is to explore the different toxicities of OBZ on an eukaryotic (Chlorella sp.) and a prokaryotic algae (Arthrospira sp.). OBZ is a photo-toxicant, with all observed toxicities more sever in the light than in the dark. Cell growth and chlorophyll inhibition were positively correlated with increasing OBZ concentrations over time. Twenty days treatment with OBZ, as low as 22.8 ng L-1, significantly inhibited the growth and chlorophyll synthesis of both algae. Both algae were noticeably photo-bleached after 7 days of exposure to OBZ concentrations higher than 2.28 mg L-1. Relatively low OBZ concentrations (0.228 mg L-1) statistically constrained photosynthetic and respiratory rates via directly inhibiting photosynthetic electron transport (PET) and respiration electron transport (RET) mechanisms, resulting in over production of reactive oxygen species (ROS). Transmission and scanning electron microscopy showed that the photosynthetic and respiratory membrane structures were damaged by OBZ exposure in both algae. Additionally, PET inhibition suppressed ATP production for CO2 assimilation via the Calvin-Benson cycle, further limiting synthesis of other biomacromolecules. RET restriction limited ATP generation, restricting the energy supply used for various life activities in the cell. These processes further impacted on photosynthesis, respiration and algal growth, representing secondary OBZ-induced algal damages. The data contained herein, as well as other studies, supports the argument that global pelagic and aquatic phytoplankton could be negatively influenced by OBZ pollution.


Assuntos
Benzofenonas/toxicidade , Chlorella/efeitos dos fármacos , Cosméticos/toxicidade , Spirulina/efeitos dos fármacos , Protetores Solares/toxicidade , Trifosfato de Adenosina/metabolismo , Respiração Celular/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Chlorella/crescimento & desenvolvimento , Chlorella/ultraestrutura , Clorofila/metabolismo , Transporte de Elétrons/efeitos dos fármacos , Luz , Fotossíntese/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Spirulina/crescimento & desenvolvimento , Spirulina/ultraestrutura , Fatores de Tempo , Poluentes Químicos da Água/toxicidade
3.
Sci Total Environ ; 676: 356-367, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31048166

RESUMO

Nejayote and swine wastewater are highly pollutant effluents and a source of organic matter load that sometimes released into water bodies (rivers or lakes), soils or public sewer system, with or without partial treatments. Nejayote is a wastewater product of alkaline cooking of maize, whereas, swine wastewater results from the primary production of pigs for the meat market. Owing to the presence of environmentally related pollutants, both sources are considered the major cause of pollution and thus require urgent action. Herein, we report a synergistic approach to effectively use and/or treat Nejayote and swine wastewater as a cost-effective culture medium for microalgae growth, which ultimately induces the removal of polluting agents. In this study, the strains Arthrospira maxima and Chlorella vulgaris were grown using different dilutions of Nejayote and swine wastewater. Both wastewaters were used as the only source of macronutrients and trace elements for growth. For A. maxima, the treatment of 10% nejayote and 90% of water (T3) resulted in a cell growth of 32 × 104 cell/mL at 12 days (µmax = 0.27/d). While, a mixture of 25% swine wastewater, 25% nejayote and 50% water (T2) produced 32 × 104 cell/mL at 18 days (µmax = 0.16/d). A significant reduction was also noted as 92% from 138 mg/L of TN, 75% from 77 mg/L of TP, and 96% from 8903 mg/L of COD, among different treatments. For C. vulgaris, the treatment of 10% swine wastewater and 90% water (T1) gave a cell growth of 128 × 106 cell/mL (µmax = 0.57/d) followed by T3 yielded 62 × 106 cell/mL (µmax = 0.70/d) and T2 yielded 48 × 106 cell/mL (µmax = 0.54/d). Up to 91% reduction from 138 mg/L of TN, 85% from 19 mg/L of TP and 96% from 4870 mg/L of COD was also recorded. These results show that microalgae can be used to treat these types of wastewater while at the same time using them as a culture media for microalgae. The resultant biomass can additionally be used for getting other sub-products of commercial interest.


Assuntos
Chlorella vulgaris/crescimento & desenvolvimento , Spirulina/crescimento & desenvolvimento , Eliminação de Resíduos Líquidos , Águas Residuárias/microbiologia , Criação de Animais Domésticos , Animais
4.
Microb Ecol ; 78(3): 603-617, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30729265

RESUMO

Lake Dziani Dzaha (Mayotte Island, Indian Ocean) is a tropical thalassohaline lake which geochemical and biological conditions make it a unique aquatic ecosystem considered as a modern analogue of Precambrian environments. In the present study, we focused on the diversity of phytoplanktonic communities, which produce very high and stable biomass (mean2014-2015 = 652 ± 179 µg chlorophyll a L-1). As predicted by classical community ecology paradigms, and as observed in similar environments, a single species is expected to dominate the phytoplanktonic communities. To test this hypothesis, we sampled water column in the deepest part of the lake (18 m) during rainy and dry seasons for two consecutive years. Phytoplanktonic communities were characterized using a combination of metagenomic, microscopy-based and flow cytometry approaches, and we used statistical modeling to identify the environmental factors determining the abundance of dominant organisms. As hypothesized, the overall diversity of the phytoplanktonic communities was very low (15 OTUs), but we observed a co-dominance of two, and not only one, OTUs, viz., Arthrospira fusiformis (Cyanobacteria) and Picocystis salinarum (Chlorophyta). We observed a decrease in the abundance of these co-dominant taxa along the depth profile and identified the adverse environmental factors driving this decline. The functional traits measured on isolated strains of these two taxa (i.e., size, pigment composition, and concentration) are then compared and discussed to explain their capacity to cope with the extreme environmental conditions encountered in the aphotic, anoxic, and sulfidic layers of the water column of Lake Dziani Dzaha.


Assuntos
Clorófitas/crescimento & desenvolvimento , Lagos/microbiologia , Fitoplâncton/crescimento & desenvolvimento , Spirulina/crescimento & desenvolvimento , Biodiversidade , Biomassa , Clorofila A/metabolismo , Clorófitas/metabolismo , Ecossistema , Oceano Índico , Ilhas , Fitoplâncton/genética , Estações do Ano , Spirulina/metabolismo
5.
Sci Total Environ ; 666: 572-580, 2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-30807947

RESUMO

Microalga is a promising candidate for bio-mitigation of CO2. It has been longtime recognized that high CO2 concentration would impose stresses on microalga to suppress the growth. However, this concept was challenged in this research by investigating the growth, photosynthesis and anti-oxidant characteristics of Arthrospira platensis under independent effects of CO2 concentrations and pH. Results showed the growth of A. platensis was only inhibited when broth was in acidic pH. Microalgal cells could deal with high CO2 concentration readily if medium pH was maintained in favorite level. Photosynthesis was inhibited swiftly and significantly under acidified condition. The singlet oxygen was produced in low level for alkalic pH treatment, however it burst quickly after low pH stress was imposed. Accordingly, it was proposed that the phenomena of high CO2 intolerance was caused by CO2 induced pH decline rather than high CO2 concentration itself. This finding has significance on large scale application of microalga based CO2 mitigation and flue gas treatment since it proved concentrated CO2 could be directly assimilated without dilution.


Assuntos
Dióxido de Carbono/metabolismo , Spirulina/crescimento & desenvolvimento , Antioxidantes/metabolismo , Concentração de Íons de Hidrogênio , Microalgas/efeitos dos fármacos , Microalgas/crescimento & desenvolvimento , Fotossíntese , Spirulina/efeitos dos fármacos , Spirulina/metabolismo
6.
Bioresour Technol ; 280: 127-135, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30769323

RESUMO

Owning to the ammonium toxicity, some ammonium-rich wastewater may not be used for algae cultivation. To overcome this problem, herein, a novel approach of using zeolite to mitigate ammonium toxicity in wastewater for value-added Spirulina production was proposed. Synthetic zeolite was used as medium for ammonium adsorption in wastewater and subsequently as slow-releaser providing nitrogen to Spirulina growth. The optimal conditions for ammonium adsorption include pH value of 8.0, zeolite dose of 300 g/L, and adsorption time of 9 h. The results showed that in terms of biomass production and ammonium recovery, zeolite-based pretreatment has great advantages over some conventional pretreatment technologies. After algae-assisted desorption treatment, ammonium adsorption capacity of zeolite increased back to 1.21 mg/g. In a real-world application, this work will provide a feasible and sustainable approach to remediate ammonium-rich wastewater, produce value-added Spirulina biomass, and recycle used zeolite, further promoting the industrialization of algae-based wastewater remediation.


Assuntos
Compostos de Amônio/metabolismo , Spirulina/metabolismo , Águas Residuárias/química , Zeolitas/química , Adsorção , Compostos de Amônio/toxicidade , Biomassa , Nitrogênio/metabolismo , Spirulina/crescimento & desenvolvimento
7.
Sci Total Environ ; 662: 662-671, 2019 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-30703724

RESUMO

The increase in atmospheric CO2 concentration and the release of nutrients from wastewater treatment plants (WWTPs) are environmental issues linked to several impacts on ecosystems. Numerous technologies have been employed to resolves these issues, nonetheless, the cost and sustainability are still a concern. Recently, the use of microalgae appears as a cost-effective and sustainable solution because they can effectively uptake CO2 and nutrients resulting in biomass production that can be processed into valuable products. In this study single (Spirulina platensis (SP.PL) and mixed indigenous microalgae (MIMA) strains were employed, over a 20-month period, for simultaneous removal of CO2 from flue gases and nutrient from wastewater under ambient conditions of solar irradiation and temperature. The study was performed at a pilot scale photo-bioreactor and the effect of feed CO2 gas concentration in the range (2.5-20%) on microalgae growth and biomass production, carbon dioxide bio-fixation rate, and the removal of nutrients and organic matters from wastewater was assessed. The MIMA culture performed significantly better than the monoculture, especially with respect to growth and CO2 bio-fixation, during the mild season; against this, the performance was comparable during the hot season. Optimum performance was observed at 10% CO2 feed gas concentration, though MIMA was more temperature and CO2 concentration sensitive. MIMA also provided greater removal of COD and nutrients (~83% and >99%) than SP.PL under all conditions studied. The high biomass productivities and carbon bio-fixation rates (0.796-0.950 gdw·L-1·d-1 and 0.542-1.075 gC·L-1·d-1 contribute to the economic sustainability of microalgae as CO2 removal process. Consideration of operational energy revealed that there is a significant energy benefit from cooling to sustain the highest productivities on the basis of operating energy alone, particularly if the indigenous culture is used.


Assuntos
Dióxido de Carbono/efeitos adversos , Microalgas/metabolismo , Spirulina/metabolismo , Águas Residuárias/análise , Poluentes Químicos da Água/metabolismo , Biomassa , Microalgas/efeitos dos fármacos , Microalgas/crescimento & desenvolvimento , Fotobiorreatores , Spirulina/efeitos dos fármacos , Spirulina/crescimento & desenvolvimento
8.
Int J Biol Macromol ; 124: 1106-1114, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30521900

RESUMO

This objective of this work was to monitor the EPS production during the growth of Spirulina sp. LEB-18, evaluate the productivity and to characterize the exopolymers obtained on pilot-scale under outdoor conditions. The production of crude EPS occurred in all phases of biomass growth and was approximately ten folds higher than that biomass concentration of Spirulina sp. LEB-18 at the end cultivation, demonstrating the importance of the use of supernatant after harvesting of Spirulina to obtain high value bioproducts. The EPS extracted by Spirulina sp. LEB-18 are typically heteropolymers with one high molecular weight fraction (polysaccharides) with potential to be utilized as an alternative bioflocculant and another fraction of lower molecular mass (proteins). The presence of uronic acids, pyruvates and acyl groups of carbohydrates or carboxylic groups of amino acids in protein moiety is the main responsible for overall negative charge of EPS, which is also of biotechnological importance. Moreover, due to the pseudoplastic behavior of the solutions and high thermal stability, the obtained EPS can be widely applied in several industrial sectors, thus determining its technological and market potentiality.


Assuntos
Biopolímeros/biossíntese , Biopolímeros/química , Biopolímeros/isolamento & purificação , Meios de Cultura/química , Spirulina/crescimento & desenvolvimento , Projetos Piloto
9.
Int J Biol Macromol ; 123: 1241-1247, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30521909

RESUMO

This study focused on evaluating whether the injection of CO2, which is associated with the use of thermoelectric fly ashes and a reduced supply of nitrogen, affects the production of intracellular carbohydrates from Spirulina. For this purpose, the addition of 0.25 g L-1 of NaNO3, along with a 10% (v v-1) of CO2 injection, a flow rate of 0.3 vvm for 1 or 5 min, as well as 0, 120 and 160 ppm of fly ashes, was studied. The assays with 120 ppm of fly ashes presented the best kinetic parameters and CO2 biofixation rate, regardless of the CO2 injection time. Meanwhile, the experiments with 120 and 160 ppm of fly ash and CO2 injection for 1 min presented 63.3 and 61.0% (w w-1) of carbohydrates, respectively. Thus, this study represents an important strategy to increase the accumulation of carbohydrates in Spirulina, with potential application in the production of bioethanol.


Assuntos
Carboidratos/análise , Dióxido de Carbono/farmacologia , Cinza de Carvão/farmacologia , Eletricidade , Nitrogênio/farmacologia , Spirulina/química , Temperatura , Biocombustíveis , Biomassa , Ciclo do Carbono/efeitos dos fármacos , Etanol/metabolismo , Concentração de Íons de Hidrogênio , Microalgas/efeitos dos fármacos , Microalgas/crescimento & desenvolvimento , Spirulina/efeitos dos fármacos , Spirulina/crescimento & desenvolvimento
10.
Bioresour Technol ; 273: 368-376, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30453251

RESUMO

To enhance microalgal growth and optimize ammonium utilization, the effect of ammonium on microalgal growth, biochemical composition and photosynthetic performance were investigated by mixotrophic cultivation of microalga Spirulina platensis comparing with autotrophic cultivation. The results indicated that elevated ammonium significantly affected the microalgal growth, but the microalga in mixotrophic cultivation showed better growth and stronger tolerance to higher ammonium. The microalgal proteins were increased by increasing nitrogen concentration. The synthesis of microalgal carbohydrates was inhibited by higher ammonium, especially in mixotrophic cultivation. The addition of ammonium decreased the microalgal lipids in autotrophic cultivation but increased microalgal lipids in mixotrophic cultivation. Ammonium negatively affected the microalgal photosynthetic performance. The inhibition was intensified by elevated ammonium, inducing stronger photosystem protection mechanism, particularly in mixotrophic cultivation. The rate of ammonium inhibition to the microalgal photosystem was quick in the early stage by decreasing electron transport rate of PS II.


Assuntos
Microalgas/efeitos dos fármacos , Microalgas/metabolismo , Nitratos/farmacologia , Fotossíntese , Spirulina/efeitos dos fármacos , Spirulina/metabolismo , Processos Autotróficos , Fenômenos Bioquímicos , Biomassa , Metabolismo dos Lipídeos , Lipídeos , Microalgas/crescimento & desenvolvimento , Spirulina/crescimento & desenvolvimento
11.
Bioresour Technol ; 270: 352-358, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30243242

RESUMO

A novel volute aerator was proposed to generate shear force and break gas flow through water centrifugation to promote mass transfer for CO2 fixation with microalgae. The bubble evolution and gas-liquid mixing processes in volute aerator were numerically simulated. The bubble generation time and diameter were measured on a high-speed camera and assessed with level-set method. By optimizing gas inletpipe angle and water/gas inlet velocities of volute aerator, the bubble generation time decreased by 60.1% to 3.3 ms and outlet bubble diameter decreased by 50.7% to 1.8 mm, compared with traditional strip aerator. The corresponding gas-liquid mixing time reduced by 15.6% and mass transfer coefficient increased by 42.2%. The volute aerator was used as an alternative to traditional strip aerator to culture microalgae under high-purity CO2 condition, which promoted average growth rate and biomass production by 26.6% and 50.7%, respectively.


Assuntos
Dióxido de Carbono/metabolismo , Spirulina/crescimento & desenvolvimento , Biomassa , Gases , Microalgas/crescimento & desenvolvimento
12.
Appl Microbiol Biotechnol ; 102(20): 8979-8987, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30056515

RESUMO

A low-cost floating photobioreactor (PBR) without the use of aeration and/or an agitation device, in which carbon was supplied in the form of bicarbonate and only wave energy was utilized for mixing, was developed in our previous study. Scaling up is a common challenge in the practical application of PBRs and has not yet been demonstrated for this new design. To fill this gap, cultivation of Spirulina platensis was conducted in this study. The results demonstrated that S. platensis had the highest productivity at 0.3 mol L-1 sodium bicarbonate, but the highest carbon utilization (104 ± 2.6%) was obtained at 0.1 mol L-1. Culture of Spirulina aerated with pure oxygen resulted in only minor inhibition of growth, indicating that its productivity will not be significantly reduced even if dissolved oxygen is accumulated to a high level due to intermittent mixing resulting from the use of wave energy. In cultivation using a floating horizontal photobioreactor at the 1.0 m2 scale, the highest biomass concentration of 2.24 ± 0.05 g L-1 was obtained with a culture depth of 5.0 cm and the highest biomass productivity of 18.9 g m-2 day-1 was obtained with a depth of 10.0 cm. This PBR was scaled up to 10 m2 (1000 L) with few challenges; biomass concentration and productivity during ocean testing were little different than those at the 1.0 m2 (100 L) scale. However, the larger PBR had an apparent carbon utilization efficiency of 45.0 ± 2.8%, significantly higher than the 39.4 ± 0.9% obtained at the 1 m2 scale. These results verified the ease of scaling up floating horizontal photobioreactors and showed their great potential in commercial applications.


Assuntos
Oxigênio/metabolismo , Spirulina/crescimento & desenvolvimento , Biomassa , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Oxigênio/análise , Fotobiorreatores , Spirulina/metabolismo
13.
Int J Biol Macromol ; 116: 552-562, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29763703

RESUMO

This study sought to evaluate influence of nitrogen availability on cell growth, biomass composition, production, and the properties of polyhydroxyalkanoates during cultivation of microalgae Chlorella minutissima, Synechococcus subsalsus, and Spirulina sp. LEB-18. The cellular growth of microalgae reduced with the use of limited nitrogen medium, demonstrating that nitrogen deficiency interferes with the metabolism of microorganisms and the production of biomass. The biochemical composition of microalgae was also altered, which was most notable in the degradation of proteins and chlorophylls and the accumulation of carbonaceous storage molecules such as lipids and polyhydroxyalkanoates. Chlorella minutissima did not produce these polymers even in a nitrogen deficient environment. The largest accumulations of the polyhydroxyalkanoates occurred after a 15 days culture, with a concentration of 16% (dry cell weight) produced by the Synechococcus subsalsus strain and 12% by Spirulina sp. LEB-18. Polyhydroxyalkanoates produced by Synechococcus subsalsus and Spirulina sp. LEB-18 presented different thermal and physical properties, indicating the influence of producing strain on polyhydroxyalkanoates properties. The polymers obtained consisted of long chain monomers with 14 to 18 carbon atoms. This composition is novel, as it has not previously been found in PHAs obtained from Synechococcus subsalsus and Spirulina sp. LEB-18.


Assuntos
Biomassa , Chlorella/crescimento & desenvolvimento , Microalgas/crescimento & desenvolvimento , Nitrogênio/metabolismo , Poli-Hidroxialcanoatos/biossíntese , Spirulina/crescimento & desenvolvimento , Synechococcus/crescimento & desenvolvimento
14.
Appl Microbiol Biotechnol ; 102(12): 5245-5254, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29691628

RESUMO

The effect of mixed light quality with red, blue, and green LED lamps on the growth of Arthrospira platensis was studied, so as to lay the theoretical and technical basis for establishing a photo-bioreactor lighting system for application in space. Meanwhile, indexes, like morphology, growth rate, photosynthetic pigment compositions, energy efficiency, and main nutritional components, were measured respectively. The results showed that the blue light combined with red light could decrease the tightness of filament, and the effect of green light was opposite. The combination of blue light or green light with red light induced the filaments to get shorter in length. The 8R2B treatment could promote the growth of Arthrospira platensis significantly, and its dry weight reached 1.36 g L-1, which was 25.93% higher than the control. What's more, 8R2B treatment had the highest contents of carbohydrate and lipid, while 8R2G was rich in protein. 8R0.5G1.5B had the highest efficiency of biomass production, which was 161.53 mg L-1 kW-1 h-1. Therefore, the combination of red and blue light is more conducive to the growth of Arthrospira platensis, and a higher biomass production and energy utilization efficiency can be achieved simultaneously under the mixed light quality with the ratio of 8R0.5G1.5B.


Assuntos
Metabolismo Energético/efeitos da radiação , Luz , Spirulina/efeitos da radiação , Biomassa , Reatores Biológicos , Microbiologia Industrial/instrumentação , Fotossíntese , Spirulina/crescimento & desenvolvimento , Spirulina/metabolismo
15.
Appl Biochem Biotechnol ; 186(1): 40-53, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29504073

RESUMO

Since cultivations of Arthrospira platensis have a high water demand, it is necessary to develop treatment methods for reusing the exhausted medium that may prevent environmental problems and obtaining useful biomass. The exhausted Schlösser medium obtained from A. platensis batch cultivation in bench-scale mini-tanks was treated by varying concentrations of different coagulants, ferric chloride (6, 10, and 14 mg L-1) or ferric sulfate (15, 25, and 35 mg L-1) and powdered activated carbon (PAC, 30 and 50 mg L-1). Such treated effluent was restored with NaNO3 and reused in new cultivations of A. platensis performed in Erlenmeyer flasks. Reusing media through the cultivation of A. platensis showed satisfactory results, particularly in the medium treated with ferric chloride and PAC. The maximum cell concentration obtained in the flasks was 1093 mg L-1, which corresponded to the medium treated with ferric chloride (6 mg L-1) and PAC (30 mg L-1). This cellular growth was higher than in the medium treated with ferric sulfate and PAC, in which values of maximum cell concentration did not exceed 796 mg L-1. The cultures in the media after treatment did not modify the biomass composition. Thus, combined coagulation/adsorption processes, commonly used in water treatment processes, can be efficient and viable for treating exhausted medium of A. platensis, allowing the production of such biomass with the reduction of production cost and saving water.


Assuntos
Cloretos/química , Meios de Cultura , Compostos Férricos/química , Nitrito de Sódio/química , Spirulina/crescimento & desenvolvimento , Água/química , Adsorção , Biomassa , Carbono/química , Redução de Custos , Nitrogênio/metabolismo , Espectrofotometria Ultravioleta , Spirulina/metabolismo
16.
Water Res ; 128: 267-277, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29107911

RESUMO

Dairy cattle treated wastewaters are potential resources for production of microalgae biofuels. A study was conducted to evaluate the capability of Arthrospira platensis cultivated in dairy farm wastewater for biodiesel production. The biomass of Arthrospira platensis was found to be 4.98 g L-1 and produced 30.23 wt% lipids to dry biomass cultivated in wastewater which was found nitrogen stressed in photo bioreactor. The extracted lipid displayed a suitable fatty acid profile for biodiesel, although the content of linolenic acid was found a little higher than the standard EN14214. It was found that nitrogen stressed medium increase the total lipid content but temperature and intensities of light were the most important factors to control the quantity of linolenic acid and hence the quality of biodiesel, while the optimum CO2 helped to achieve maximum biomass and triacylglycerols. The Arthrospira platensis offer a good option for the treatment of wastewater before final discharge.


Assuntos
Biocombustíveis , Lipídeos/biossíntese , Spirulina/metabolismo , Gerenciamento de Resíduos/métodos , Biomassa , Reatores Biológicos , Dióxido de Carbono/metabolismo , Técnicas de Cultura , Indústria de Laticínios , Fazendas , Ácidos Graxos , Lipídeos/análise , Microalgas , Nitrogênio , Spirulina/crescimento & desenvolvimento , Spirulina/efeitos da radiação , Temperatura , Águas Residuárias/química
17.
J Basic Microbiol ; 58(2): 162-171, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29149514

RESUMO

Cyanobacteria are known to exhibit their efficiency in producing high concentrations of compounds of commercial value. Arthrospira is one such cyanobacterium which is considered as important source of protein (65%) and other nutrients. In present study, chemical mutagenesis using N-methyl-N-Nitro-nitrosoguanidine (NTG), a proven potent mutagen for cyanobacteria was used to bring stable and desirable alteration in Arthrospira platensis ARM 730. Three morphological mutants (G-1, G-2, and SF) were selected and characterized. The G-1 and G-2 were helical, more bluish in pigmentation than the wild type strain where G-1 also showed enlarged cell size. The SF mutant was an altered straight-filament having maximum biomass. Among three mutants, higher protein and phycocyanin contents were observed in G-1 and G-2 mutants whereas chlorophyll was less in these mutants as compared to wild type strain indicating change in the pigment ratio. Carotenoid content was higher in SF mutant as compared to wild type and other mutants. Variation in total sugar content was not observed in comparison to wild type strain. The analysis of amino acid spectrum of all the mutants and wild type showed significant increase in proline content. Overall, it is revealed from the results that G-1 and G-2 mutants showed higher biomass, phycocyanin, and protein contents in comparison to wild type which indicated their great potential to be used in food and pharmaceutical industries.


Assuntos
Proteínas de Bactérias/metabolismo , Mutação , Ficocianina/metabolismo , Spirulina/isolamento & purificação , Spirulina/metabolismo , Metilnitronitrosoguanidina/metabolismo , Mutagênese , Mutagênicos/metabolismo , Spirulina/citologia , Spirulina/crescimento & desenvolvimento
18.
J Proteomics ; 171: 73-80, 2018 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-28344024

RESUMO

The morphology of Spirulina during cultivation is susceptible to external interferences, but the morphogenesis mechanism is still unclear. Here the proteomic changes of linear Spirulina and spiral Spirulina were comparatively investigated via isobaric tag for relative and absolute quantitation (iTRAQ). Totally 165 and 167 differences in proteins expression were screened out from the TJSD2/TJSD3 and TJBC4-1/TJBC4-2 groups, respectively. Gene ontology and metabolic pathway analysis of differences in proteins expression uncovered the metabolic pathways (photosynthesis, carbon fixation, sugar metabolism) that were significantly enriched with the proteins correlated with Spirulina morphogenesis. The results of differences in proteins expression in metabolic pathway were verified by quantitative real-time PCR. We also built a putative model of Spirulina morphogenesis mechanism and thought multiple metabolic pathways interact and take part in Spirulina morphogenesis.


Assuntos
Proteínas de Bactérias/metabolismo , Proteoma/metabolismo , Spirulina/metabolismo , Proteínas de Bactérias/genética , Metabolismo Energético , Ontologia Genética , Redes e Vias Metabólicas , Modelos Biológicos , Proteoma/genética , Spirulina/crescimento & desenvolvimento
19.
Front Biosci (Elite Ed) ; 10: 276-286, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28930618

RESUMO

Response surface methodology (RSM) based on the 23 factorial central composite design (CCD) was employed to evaluate optimum culture conditions (temperature, light irradiance and agitation) to enhance biomass and phycocyanin content of Spirulina platensis. The predicted maximum biomass and phycocyanin content by RSM was 1.06 g L-1 and 107 mg L-1, respectively, whereas maximum biomass and phycocyanin content of 1.32 g L-1 and 127 mg L-1 was obtained in the validation experiments under optimized conditions after 10 days of cultivation. Further, influence of optimized conditions (temperature 33±2 ºC, light irradiance 44 µmol photons m-2 s-1 and a flow rate of 2.5 L min-1) on growth and phycocyanin content of S. platensis in 7L Panel photobioreactor (PPBR) cultivation was investigated. A 15 days production was carried out and it was observed that a maximum biomass yield of 2.42 g L-1 with a specific growth rate 0.202 day-1 and phycocyanin content of 228 mg L-1 was obtained in the PPBR. The optimum culture conditions obtained through response surface methodology were successfully determined to maximize the biomass and phycocyanin.


Assuntos
Biomassa , Ficocianina/metabolismo , Spirulina/metabolismo , Reatores Biológicos , Spirulina/crescimento & desenvolvimento
20.
J Biosci Bioeng ; 125(2): 224-230, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28988616

RESUMO

Microalgae, a renewable source for third generation biofuel production, have a great potential if cultivated in high concentration economically. Bottleneck lies with designing economical and efficient photobioreactor. In addition, proportional C and N inputs in the known media does not support high specific growth rate and high biomass build-up. Nitrates in fermentation media, f/2 for Nannochloropsis sp. and Zarrouk's for Arthrospira platensis, were modified. Aeration and agitation were altered in conventional bioreactor (BIOFLO 110) to reduce power consumption, increase mixing time and prevents settling. This was achieved by introducing four way flow regime supporting uniform nutrient and cell distribution in media. Volumetric cell productivity for Nannochloropsis sp. and A. platensis were achieved as 0.618 g/l/d and 0.774 g/l/d, respectively. This photobioreactor also supported the maximum specific CO2 sequestration rates to the level of 0.42 g/g/h and 0.39 g/g/h for Nannochloropsis sp. and A. platensis, respectively, confirming efficient and effective operation.


Assuntos
Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo , Fotobiorreatores , Biocombustíveis , Biomassa , Dióxido de Carbono/metabolismo , Fermentação , Nitratos/metabolismo , Spirulina/crescimento & desenvolvimento , Spirulina/metabolismo , Estramenópilas/crescimento & desenvolvimento , Estramenópilas/metabolismo
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