scholarly journals Symbiotic Co-Culture of Scenedesmus sp. and Azospirillum brasilense on N-Deficient Media with Biomass Production for Biofuels

2019 ◽  
Vol 11 (3) ◽  
pp. 707 ◽  
Author(s):  
Jose Contreras-Angulo ◽  
Teresa Mata ◽  
Sara Cuellar-Bermudez ◽  
Nidia Caetano ◽  
Rashmi Chandra ◽  
...  

The treatment of nitrogen-deficient agriculture wastewater, arising from the vegetable and fruit processing, is a significant problem that limits the efficiency of its biological treatment. This study evaluates the effectiveness of the symbiotic co-culture of Azospirillum brasilense and Scenedesmus sp., under two nitrogen levels (8.23 mg L−1 and 41.17 mg L−1) and mixing systems (aeration and magnetic stirring), aiming to simultaneously use the N-deficient media for their growth while producing biomass for biofuels. Microalgae growth and biomass composition, in terms of protein, carbohydrate and fatty acid contents, were evaluated at the end of the exponential growth phase (15 days after inoculation). Results show that the symbiotic co-culture of microalgae-bacteria can be effectively performed on nitrogen-deficient media and has the potential to enhance microalgae colony size and the fatty acid content of biomass for biofuels. The highest biomass concentration (103 ± 2 mg·L−1) was obtained under aeration, with low nitrogen concentration, in the presence of A. brasilense. In particular, aeration contributed to, on average, a higher fatty acid content (48 ± 7% dry weight (DW)) and higher colony size (164 ± 21 µm2) than mechanical stirring (with 39 ± 2% DW and 134 ± 21 µm2, respectively) because aeration contribute to better mass transfer of gases in the culture. Also, co-culturing contributed in average, to higher colony size (155 ± 21 µm2) than without A. brasilense (143 ± 21 µm2). Moreover, using nitrogen deficient wastewater as the culture media can contribute to decrease nitrogen and energy inputs. Additionally, A. brasilense is approved and already extensively used in agriculture and wastewater treatment, without known environmental or health issues, simplifying the biomass processing for the desired application.

2020 ◽  
Vol 10 (12) ◽  
pp. 4398
Author(s):  
Sofoklis Bouras ◽  
Nikolaos Katsoulas ◽  
Dimitrios Antoniadis ◽  
Ioannis T. Karapanagiotidis

The simultaneous use of crude glycerol and effluent from anaerobic digestate, both wastes derived from the biofuel industry, were tested in the frame of circular economy concept, as potential low-cost nutrient sources for the cultivation of rich in docosahexaenoic acid (DHA) oil microalgae strain Schizochytrium limacinum SR21. Initially, the optimal carbon and nitrogen concentration levels for high S. limacinum biomass and lipids production were determined, in a culture media containing conventional, high cost, organic nitrogen sources (yeast extract and peptone), micronutrients and crude glycerol at varying concentrations. Then, the effect of a culture media composed of crude glycerol (as carbon source) and effluent digestate at varying proportions on biomass productivity, lipid accumulation, proximate composition, carbon assimilation and fatty acid content were determined. It was shown that the biomass and total lipid content increased considerably with varying effluent concentrations reaching 49.2 g L−1 at 48% (v/v) of effluent concentration, while the lipid yield at the same effluent concentration reached 10.15 g L−1, compared to 17.0 g L−1 dry biomass and 10.2 g L−1 lipid yield when yeast extract and peptone medium with micronutrients was used. Compared to the control treatment, the above production was obtained with 48% less inorganic salts, which are needed for the preparation of the artificial sea water. It was shown that Schizochytrium limacinum SR21 was able to remediate 40% of the total organic carbon content of the biofuel wastes, while DHA productivity remained at low levels with saturated fatty acids comprising the main fraction of total fatty acid content. The results of the present study suggest that the simultaneous use of two waste streams from the biofuel industry can serve as potential nutrient sources for the growth of Schizochytrium limacinum SR21, replacing the high cost organic nutrients and up to one half the required artificial sea water salts, but upregulation of DHA productivity through optimization of the abiotic environment is necessary for industrial application, including aqua feed production.


1993 ◽  
Vol 28 (5) ◽  
pp. 289-296 ◽  
Author(s):  
Sebastián Sánchez ◽  
Ma Eugenia Martínez ◽  
Emilio Molina ◽  
José A. de la Casa ◽  
Francisco García

Author(s):  
C. S. Bricker ◽  
S. R. Barnum ◽  
B. Huang ◽  
J. G. Jaworskl

Cyanobacteria are Gram negative prokaryotes that are capable of oxygenic photosynthesis. Although there are many similarities between eukaryotes and cyanobacteria in electron transfer and phosphorylation during photosynthesis, there are two features of the photosynthetic apparatus in cyanobacteria which distinguishes them from plants. Cyanobacteria contain phycobiliproteins organized in phycobilisomes on the surface of photosynthetic membrane. Another difference is in the organization of the photosynthetic membranes. Instead of stacked thylakolds within a chloroplast envelope membrane, as seen In eukaryotes, IntracytopIasmlc membranes generally are arranged in three to six concentric layers. Environmental factors such as temperature, nutrition and light fluency can significantly affect the physiology and morphology of cells. The effect of light Intensity shifts on the ultrastructure of Internal membrane in Anabaena variabilis grown under controlled environmental conditions was examined. Since a major constituent of cyanobacterial thylakolds are lipids, the fatty acid content also was measured and correlated with uItrastructural changes. The regulation of fatty acid synthesis in cyanobacteria ultimately can be studied if the fatty acid content can be manipulated.


2016 ◽  
Vol 2 (1) ◽  
pp. 37-42 ◽  
Author(s):  
J.M. Pino Moreno ◽  
A. Ganguly

In the present paper we have determined the fatty acid content of some edible insects of Mexico. A comparative analysis of the insect species studied in this research showed that caproic acid was present in a minimal proportion which ranged between 0.01 for Periplaneta americana (nymphs) and 0.06 (g/100 g, dry basis) for Euschistus strenuus. The highest proportion of caprilic acid (0.09) was found in Tenebrio molitor (adults). Atta sp. had the highest amount of capric acid (0.26). Polistes sp. was found to be rich in lauric acid (0.77) and for myristic acid it had the highest content (5.64). Dactylopius sp. and E. strenuus were rich in palmitic acid (14.89). Euschistus taxcoensis had the highest quantity of palmitoleic acid (12.06). Llaveia axin exhibited the highest quantity of stearic acid (22.75). Polistes sp. was found to be rich in oleic acid (38.28). The highest quantity of linoleic acid was observed in T. molitor (larvae) (10.89), and in L. axin the highest content of linolenic acid (7.82) was obtained. A comparison between the species under the present investigation revealed that, in general, the insects are poor in caproic, caprilic, capric, lauric, myristic, palmitoleic and linolenic acids, because the quantities were either minimal or could not be detected at all. They had moderate quantities of stearic, palmitic and linoleic acids and had high quantities of oleic acid. Finally it was concluded that although a particular insect species is unable to fulfil the total fatty acid need for a human, if consumed in combination they could definitely be able to supply a good amount of this highly valued nutrient.


Diversity ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 105
Author(s):  
Amirah Yuslan ◽  
Sharifah Najuwa ◽  
Atsushi Hagiwara ◽  
Mazlan A. Ghaffar ◽  
Hidayu Suhaimi ◽  
...  

Salinity is a known factor in shaping population dynamics and community structure through direct and indirect effects on aquatic ecosystems. Salinity changes further influence food webs through competition and predation. The responses of Moina macrocopa (Cladocera) collected from Setiu Wetland lagoon (Terengganu) was evaluated through manipulative laboratory experiments to understand the ability of M. macrocopa to tolerate high salinity stress. Specifically, the fatty acid composition, growth, survival, and reproduction of this cladocerans species was examined. Sodium chloride (NaCl) as used in the treatments water with the concentration 0, 4, 6, 8, 12, and 15 salinity. Fatty acid levels were determined using Gas Chromatography and Mass Spectrophotometry (GC-MS). The results indicated that optimal conditions produced the highest fatty acid content, especially the polyunsaturated fatty acid content, such as EPA (eicosapentaenoic acid), ALA (alpha-linoleic acid), ARA (arachidonic acid), and DHA (docosahexaenoic acid). Furthermore, M. macrocopa survival was best at salinity 0, with a percentage of 98%, whereas the opposite occurred at salinity 15, with approximately 20% of viable animals surviving. Besides, M. macrocopa also showed the highest reproduction rate at salinity 0 (e.g., average initial age of reproduction, 4.33 ± 0.58 days) compared with other salinities level. Interestingly, the difference in growth at different salinities was not evident, an unusual finding when considering adverse effects such as osmoregulation pressure on the organism. Based on the results, we conclude that M. macrocopa can only tolerate salinity below salinity 8 and cannot withstand stressful environmental conditions associated with salinities above 8.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Roel M. Maas ◽  
Yale Deng ◽  
Yueming Dersjant-Li ◽  
Jules Petit ◽  
Marc C. J. Verdegem ◽  
...  

AbstractSustainable aquafeed production requires fishmeal replacement, leading to an increasing use of plant-derived ingredients. As a consequence, higher levels of antinutritional substances, such as non-starch polysaccharides and phytate, are present in aquafeeds, with negative effects on fish performance, nutrient digestibility and overall gut health. To alleviate these negative effects, providing exogenous digestive enzymes and/or probiotics can be an effective solution. In this study, we tested the effect of dietary supplementation of enzymes (phytase and xylanase) and probiotics (three strains of Bacillus amyloliquefaciens) on nutrient digestion kinetics and volatile fatty acid content along the gut, and the distal gut microbiome diversity in Nile tilapia. Chyme volatile fatty content was increased with probiotic supplementation in the proximal gut, while lactate content, measured for the first time in vivo in fish, decreased with enzymes along the gut. Enzyme supplementation enhanced crude protein, Ca and P digestibility in proximal and middle gut. Enzymes and probiotics supplementation enhanced microbial interactions as shown by network analysis, while increased the abundance of lactic acid bacteria and Bacillus species. Such results suggest that supplementation with exogenous enzymes and probiotics increases nutrient availability, while at the same time benefits gut health and contributes to a more stable microbiome environment.


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