Enhanced Production of Photosynthetic Pigments and Various Metabolites and Lipids in the Cyanobacteria Synechocystis sp. PCC 7338 Culture in the Presence of Exogenous Glucose (original) (raw)
Related papers
Renewable Energy, 2019
The aim of this study was to investigate the effects of sodium nitrate (NaNO 3) limitation on cyanobacterium Synechocystis PCC 6803 growth in order to increase its lipid content. The results revealed that the nitrate limitation conditions increase the volumetric biomass productivity, reaching the maximum content at 0.75 g/L NaNO 3 (0.043 g/L$day). The maximum chlorophyll a and b concentrations were 6.42 mg/mL (0.75 g/L NaNO 3) and 0.63 mg/mL (1.25 g/L NaNO 3), respectively for Synechocystis PCC 6803, cultured in week 9. Also, Synechocystis PCC 6803 exhibited a decrease of protein content and an increase of lipid content with the decrease of NaNO 3 concentration. The obtained results suggested that a concentration of 0.75 g/L NaNO 3 in the Synechocystis PCC 680 growth medium resulted in the highest lipid content (21.3%), making it a potential feedstock for biodiesel production.
Microbiology, 1994
The biosynthetic pathway of glucosylglycerol (GG), the osmoprotective compound of Synechocystis sp. PCC 6803, was found to proceed from ADPglucose and glycerol 3-phosphate via glucosylglycerol phosphate in a two-step reaction. Using an in vitro assay it was shown that the GG-forming enzyme system required activation, which could be initiated in vivo by hypertonic salt concentrations and osmotic shock, or in vitro by NaCl addition at the stage of enzyme extraction or assay.
Algal Research, 2014
Biodiesel Cyanobacteria Lipid feedstock Synechococcus sp. PCC7942 Enzymatic catalysis Cyanobacteria have several advantages as lipid feedstock for biodiesel production compared to microalgae. These benefits include the ability to increase lipid content via genetic manipulation, a high growth rate, nitrogenfixation and a simpler cell wall, which aids in lipid extraction. Moreover, these bacteria have the capability to convert solar energy into biomass that is two times greater than microalgae and ten times greater than corn and sugar cane. The aim of this study was to optimize the cultivation conditions of Synechococcus sp. PCC7942 and to evaluate the lipid feedstock to generate biodiesel via an enzymatic route. For this purpose, the effect of light intensity (50-150 μmol m −2 s −1 ) and the concentration of Na 2 CO 3 (0.5-1.5 g L −1 ) were studied according to a 2 2 full-factorial design. Under optimized conditions, the biomass productivity (Q P ) of 124.0 ± 3.2 mg L −1 day −1 , lipid content of 29.0 ± 2.1% and lipid productivity of 35.9 ± 0.5 mg L −1 day −1 were obtained. The fatty acid profile indicated differences when the medium was enriched with Na 2 CO 3 and cultured in high light intensity, resulting in an increase in unsaturated fatty acids, particularly linoleic acid, which accounts for 40% of the fatty acids in Synechococcus sp. PCC7942. The lipid feedstock was characterized and used as feedstock for biodiesel synthesis using Novozym® 435 as a catalyst and ethanol as an acyl acceptor. The biocatalyst was able to form ethyl esters from all of the fatty acids present in the lipid feedstock, attaining a conversion of 97.1%. Analysis of Synechococcus sp. PCC7942 lipids indicated the potential of this cyanobacterium as a biodiesel feedstock. The primary fatty acids of this cyanobacterium were C16-C18, which is suitable for the production of good-quality biodiesel.
SYNTHESIS OF NEUTRAL LIPIDS IN Chlorella sp. UNDER DIFFERENT LIGHT AND CARBONATE CONDITIONS
Lipids are biomolecules of great scientific and biotechnological interest due to their extensive applications. Microalgae are potential biological systems used in the synthesis of lipids, particularly Chlorella sp., which is characterized by its high lipid content and for having the right profile for the obtainment of biofuel. Lipid production in microalgae is influenced by several physical and chemical factors. Any modification thereof can cause a stress response represented by changes in synthesized lipid composition, varying from one species to another. This paper evaluates the effect of different light wavelengths, photoperiods and calcium carbonate (CaCO3) supply in lipid synthesis in Chlorella sp. In order to do so,the microalgae was grown in Bold's Basal Medium (BBM) at 20ºC with constant aeration and subject to low blue (470 nm) and red (700 nm) light wavelengths, 0,5 g.L-1 and 1,5 g.L-1 concentrations of CaCO3 and 6-hour light, 18-hour darkness (6:18) and 18-hour light, 6-hour darkness (18:6) photoperiods. The results indicate a higher growth rate for microalgae under red light, 0,5 g.L-1 of CaCO3 and a photoperiod of 6:18. On the other hand, lipid production is higher under blue light, 1,5 g.L-1 of CaCO3 and an18:6 photoperiod. Analysis by gas chromatography indicate that the fatty acids in the samples are oleic, linoleic and palmitoleic, which are of recognized importance in the biodiesel industry. This suggests that neutral lipid synthesis can be optimized in two stages: first, by promoting growth and subsequently, by inducing lipid production.
Assessment of different carbohydrates as exogenous carbon source in cultivation of cyanobacteria
Bioprocess and Biosystems Engineering, 2014
Glucose is the substrate most widely used as exogenous carbon source for heterotrophic cultivation of cyanobacteria. Due to limited information about the use of different carbohydrates as carbon sources to support cyanobacterial heterotrophic metabolism, the objective of this work was to evaluate different monosaccharides (arabinose, fructose, galactose, glucose, mannose and xylose), disaccharides (lactose, maltose, sucrose and trehalose) and polysaccharides (carboxymethylcellulose, cassava starch, Hi-maize Ò , maltodextrin Corn Globe 1805 Ò and xylan) as exogenous carbon source for heterotrophic culture of cyanobacterium Phormidium sp. The batch cultivation using fructose as organic carbon source resulted in the highest (p \ 0.05) cell biomass (5,540 mg/ L) in parallel with the highest (p \ 0.05) substrate yield coefficient (0.67 mg biomass /mg fructose ). Mannose was the carbon source with the highest (p \ 0.05) substrate consumption rate (3,185.7 mg/L/day) and maltodextrin was the carbohydrate with major potential to produce biomass (1,072.8 mg biomass /L/day) and lipids (160.8 mg lipids /L/day). Qualitatively, the fatty acid profiles of the lipid extract from Phormidium sp. showed predominance of saturated chains for the cultures grown with most of the carbon sources, with the exception of the ones grown with xylose and maltodextrin.
JOURNAL OF PURE AND APPLIED MICROBIOLOGY, 2016
The present study is a trial to cultivate three different cyanobacterial strains (Anabaena laxa, Anabaena fertilissima and Nostoc muscorum) under four different growth conditions using BG11 0 growth medium. These conditions were represented by static glucose medium with glucose (1%, w/v), aerated medium (aerated by bubbling technique depending on atmospheric CO 2 normally existed in air with a concentration of 0.03%), growth medium enriched with molasses of sugar cane (0.7%, v/v) and aerated growth medium enriched with glucose (1%, w/v). A. laxa, A. fertilissima and N. muscorum exhibited high biomass production under mixotrophic growth condition rather than aerated autotrophic condition. Whereas, static glucose medium enhanced the growth of A. laxa, A. fertilissima and N. muscorum significantly with dry weight yield of 3.6, 3.1 and 5.2 g L-1 , respectively. Moreover, glucose enhanced lipid content for both A. laxa and N. muscorum to produce 293.9 and 253.5 ìg g-1 fresh wt., respectively. While A. fertilissima exhibited the highest lipid content under aerated enriched glucose medium (307.6 ìg g-1 fresh wt.). Static glucose medium supported the lipid synthesis rate of N. muscorum to record 6.3 folds, as compared to the control, after 10 days of treatment. While A. fertilissima exhibited its highest lipid synthesis rate under aerated enriched glucose condition after 2 days. Ten fatty acids were detected for all the investigated cyanobacterial strains with different percentages, under static glucose medium (1%, w/v) during the stationary phase. Half of them were saturated fatty acids and the others were two mono-unsaturated and three poly-unsaturated fatty acids. Myristic, palmitoleic and arachidonic acids were the most abundant among all the tested isolates.
Enhancing Photosynthetic Production of Glycogen-Rich Biomass for Use as a Fermentation Feedstock
Frontiers in Energy Research, 2020
Current sources of fermentation feedstocks, i.e., corn, sugar cane, or plant biomass, fall short of demand for liquid transportation fuels and commodity chemicals in the United States. Aquatic phototrophs including cyanobacteria have the potential to supplement the supply of current fermentable feedstocks. In this strategy, cells are engineered to accumulate storage molecules including glycogen, cellulose, and/or lipid oils that can be extracted from harvested biomass and fed to heterotrophic organisms engineered to produce desired chemical products. In this manuscript, we examine the production of glycogen in the model cyanobacteria, Synechococcus sp. strain PCC 7002, and subsequent conversion of cyanobacterial biomass by an engineered Escherichia coli to octanoic acid as a model product. In effort to maximize glycogen production, we explored the deletion of catabolic enzymes and overexpression of GlgC, an enzyme that catalyzes the first committed step toward glycogen synthesis. We found that deletion of glgP increased final glycogen titers when cells were grown in diurnal light. Overexpression of GlgC led to a temporal increase in glycogen content but not in an overall increase in final titer or content. The best strains were grown, harvested, and used to formulate media for growth of E. coli. The cyanobacterial media was able to support the growth of an engineered E. coli and produce octanoic acid at the same titer as common laboratory media.
Cyanobacteria : A neglected potent candidate for biodiesel production
2017
Department of Chemistry, Department of Earth and Environmental Studies, Department of Chemical Engineering, National Institute of Technology Durgapur, Durgapur-713 209, West Bengal, India <em>E-mail</em> : jitamanyu.chakrabarty@ch.nitdgp.ac.in <em>Manuscript received 01 August 2017, accepted 03 September 2017</em> Algae have emerged as a potent biofuel resource due to the presence of triacylglycerol. Fatty acids esters of appropriate chain length are used as biodiesels. Cyanobacteria are devoid of triacylglycerol, consequently are not considered as biodiesel resource. However, emphasis is not given on other fatty acid containing lipids like phospholipid, glycolipid, and steryl esters of cyanobacteria. In the present study two cyanobacteria i.e. <em>Anabaena anomala, Oscillatoria subbrevis</em> and one macroalga <em>Rhizoclonium</em> <em>hieroglyphicum</em> respectively were lysed and lipid was extracted separately. The maxi...
The objective of the current study was to investigate the effect of using glucose as a sole carbon source as well as in combination with glycerol as a complex carbon substrate in BG-11 media, to produce microalgal biomass (gL -1 ), lipid (dcw%) and biochemical components, such as total soluble carbohydrates (mgmL -1 ) and proteins (mgmL -1 ) by Chlorella pyrenoidosa, over a cultivation period of 12 days. The present study revealed that using glucose as sole carbon source at various concentrations ranging from 1 to 20 (gL -1 ), total lipid, total biomass, total protein and total carbohydrates increased. In comparison to control showed increased biomass gL -1 (0.29±0.021 to 0.53±0.012), while Lipid content (DCW %) enhanced from (4.87± 0.021 to 14.09±0.016). But it has no stimulatory effects found on photosynthetic pigment i.e. total chlorophyll (µgmL -1 )
2012
The objective of this research is to study of microbial lipid production by locally photosynthetic microalgae and oleaginous yeast via integrated cultivation technique using CO2 emissions from yeast fermentation. A maximum specific growth rate of Chlorella sp. KKU-S2 of 0.284 (1/d) was obtained under an integrated cultivation and a maximum lipid yield of 1.339g/L was found after cultivation for 5 days, while 0.969g/L of lipid yield was obtained after day 6 of cultivation time by using CO2 from air. A high value of volumetric lipid production rate (QP, 0.223 g/L/d), specific product yield (YP/X, 0.194), volumetric cell mass production rate (QX, 1.153 g/L/d) were found by using ambient air CO2 coupled with CO2 emissions from yeast fermentation. Overall lipid yield of 8.33 g/L was obtained (1.339 g/L of Chlorella sp. KKU-S2 and 7.06g/L of T. maleeae Y30) while low lipid yield of 0.969g/L was found using non-integrated cultivation technique. To our knowledge this is the unique report ab...