Cyanobacterium Aponinum Research Articles

Effects of salinity and nitrogen source on growth and lipid production for a wild algal polyculture in produced water media

An algae polyculture (discovered in oil and gas produced water (PW) originating from a production facility in the Permian Basin of southwestern New Mexico) was composed primarily of Cyanobacterium aponinum, Parachlorella kessleri, with the remaining populations consisting of several species of halotolerant bacteria. The polyculture was tested in PW based media at a variety of different salinities and initial nutrient concentrations to determine the effects of these environmental conditions upon growth and lipid production. The polyculture exhibited growth rates of 46–51 mg ash free dry weight (AFDW)/L/D in PW over a salinity range from 15 to 60 g total dissolved solids (TDS)/L in PW containing nitrate as a nitrogen source. Growth was reduced at higher salinity. Biomass productivity in 60 g TDS/L PW was higher with ammonium as the nitrogen source (47.2–57 mg AFDW/L/D) than nitrate, with the highest growth observed using initial concentrations of 13 mg NH4-N and 1.7 PO4-P/L (single day growth of 99 mg AFDW/L/D). Of the conditions tested lipid productivity was greatest (around 12 mg lipids/L/D) at a salinity of 60 g TDS/L after phosphorus depletion (ammonium still present), and the maximum lipid content (48% of AFDW) after ammonium depletion (phosphate still present). Higher salinity, initial ammonium, and phosphate levels enriched for P. kessleri over C. aponinum, which also resulted in increased lipid content and productivity. Conversion of lipids to fatty acid methyl ester (FAME) created a profile dominated by palmitic (C16:0) and stearic (C18:0) acid and would produce a usable biodiesel. The results indicated that a mixed culture of C. aponinum, P. kessleri, and other micro fauna is a potential candidate for cultivation in brackish to hypersaline PW based media for the production of biomass and/or biofuels.

A Comparative study of cyanobacteria and microalgae for biofuel production

The use of algae for producing biofuel is expected to play a critical role as an alternative energy source in the near future, particularly in light of depleting fossil fuel reserves and the adverse environmental impact on fossil fuels.This study discusses the production of biofuel from cyanobacteria and microalgae by various processes. Microalgae and cyanobacteria can produce high amount of lipids and that is the sole reason for they being identified as a potential biodiesel feedstock. They also have the ability to fix CO2 and have rapid growth rates. It is observed that algae can be converted to oily substances that grows in Carbon-dioxide enriched air. It also can contribute to solve major problems of air pollution resulting from CO2 evolution This experiment is undertaken to know the proper trans-esterification, amount of biodiesel production (ester) from cyanobacteria and microalgae species. In this experiment, common species such as Cyanobacterium aponinum and Spirogyra sp. are used to compare the amount of biodiesel production. It is observed that C.aponinum can produce high amount of algal oil and biodiesel (ester) than Spirogyra sp. However, biomass when calculated was found to be higher in C.aponinum compared to Spirogyra sp. The paper indicates that biodiesel can be produced from both the species with C.aponinum being a better one.

High diversity of thermophilic cyanobacteria in Rupite hot spring identified by microscopy, cultivation, single-cell PCR and amplicon sequencing.

Genotypic and morphological diversity of cyanobacteria in the Rupite hot spring (Bulgaria) was investigated by means of optical microscopy, cultivation, single-cell PCR, and 16S rRNA gene amplicon sequencing. Altogether, 34 sites were investigated along the 71-39°C temperature gradient. Analysis of samples from eight representative sites shown that Illumina, optical microscopy, and Roche 454 identified 72, 45 and 19% respective occurrences of all cumulatively present taxa. Optical microscopy failed to detect species of minor occurrence; whereas, amplicon sequencing technologies suffered from failed primer annealing and the presence of species with extensive extracellular polysaccharides production. Amplicon sequencing of the 16S rRNA gene V5-V6 region performed by Illumina identified the cyanobacteria most reliably to the generic level. Nevertheless, only the combined use of optical microscopy, cultivation and sequencing methods allowed for reliable estimate of the cyanobacterial diversity. Here, we show that Rupite hot-spring system hosts one of the richest cyanobacterial flora reported from a single site above 50°C. Chlorogloeopsis sp. was the most abundant at the highest temperature (68°C), followed by Leptolyngbya boryana, Thermoleptolyngbya albertanoae, Synechococcus bigranulatus, Oculatella sp., and Desertifilum sp. thriving above 60°C, while Leptolyngbya geysericola, Geitlerinema splendidum, and Cyanobacterium aponinum were found above 50°C.

The potential of foodwaste leachate as a phycoremediation substrate for microalgal CO2 fixation and biodiesel production.

Foodwaste leachate (FWL) is often generated during foodwaste treatment processes. Owing to its high nutrient content, FWL has high potential for phycoremediation, a microalgal technology application for water treatment while acting as CO2 fixation tank. Additionally, the end product of microalgal from phycoremediation can be potentially used for biodiesel production. Therefore, the phycoremediation has drawn a lot of attention in recent decades. This study evaluates the performance of microalgal foodwaste leachate treatment and the potential of utilizing FWL as medium for microalgal biodiesel production. Two microalgal species, Dunaliella tertiolecta and Cyanobacterium aponinum, were selected. For each species, two experimental levels of diluted FWL were used: 5 and 10% FWL. The partial inhibition growth model indicates that some inhibit factors such as ammonia; total suspended solids and oil and grease (O&G) content suppress the microalgal growth. Most of the nutrient such as nitrogen and phosphorus (> 80%) can be removed in the last day of phycoremediation by D. tertiolecta. C. aponinum also show considerable removal rate on total nitrogen ammonia and nitrate (> 60%). Biomass (0.4-0.5g/L/day) of D. tertiolecta and C. aponinum can be produced though cultivated in diluted FWL. The bio-CO2 fixation rates of the two species were 610.7 and 578.3mg/L/day of D. tertiolecta and C. aponinum. The strains contain high content of saturated fatty acid such as C16 and C18 making them having potential for producing good quality biodiesel.

Responses of a new isolated Cyanobacterium aponinum strain to temperature, pH, CO2 and light quality

A new strain of cyanobacteria was isolated from seawater samples collected near Jimo hot springs, Qingdao, China, and was identified as Cyanobacterium aponinum by 16S rDNA analysis. This study examined the effects of temperature, pH, light quality and high CO2 concentration on the growth of the cyanobacteria. Results showed that the strain exhibited a higher growth rate (about 168.4 mg L−1 day−1) at 35 °C than other temperatures (surviving at up to 50 °C) and a wide growth tolerance to acidic stress (pH 3.0 to 4.0) resulting from either H2SO4 or HNO3. The four light qualities, ranked by greatest to least biomass effect, were as follows: LED white light (LW) > LED red light (LR) > fluorescent white light (FW) > LED blue light (LB), achieving a higher lighting effect at a LW light intensity (60 μmol photons m−2 s−1) lower than other light qualities, which implied less energy consumption therewith. This strain demonstrates excellent CO2 tolerance at least 10% CO2 with the highest productivity in biomass (about 337.8 mg L−1 day−1) measured at 1% CO2 level. Results indicate that this strain is a promising candidate for use in biofixation of CO2 from flue gases emitted by thermoelectric plants.

Biodiversity analysis of the unique geothermal microbial ecosystem of the Blue Lagoon (Iceland) using next-generation sequencing (NGS)

The Blue Lagoon is a shallow geothermal lake which contains sea- and freshwater and is extremely high in silica content. This study has provided the first in-depth molecular survey of its planktic microbial inhabitants and laid the groundwork for future environmental and physiological work. Most MiSeq sequences obtained were affiliated with Alphaproteobacteria (36%), Cyanobacteria (26%), and Gammaproteobacteria (24%). Cyanobacteria were found to be the principal primary producers with 99.8% of the cyanobacterial sequences belonging to the unicellular Cyanobacterium aponinum. Filamentous genera: Halomicronema and Phormidium were very minor and present only outside the bathing area. The calculated diversity was typical of samples from extreme environments. Elevated salinity and high concentration of silicium attract extremophiles that are either highly adapted specialists for certain conditions or generalists with wide tolerance ranges. Relatively few abundant phyla were represented; 95% of observed OTUs consisted of less than ten sequences and only 0.5% had more than 1000 sequences. All rarefaction curves were far from saturation and a higher number of sequences is apparently required to cover the whole community diversity. Although, the diversity of the abundant taxa was limited, the rare biosphere, detectable only with next generation sequencing, increased significantly the diversity.

Bacterial diversity of the outflows of a Polichnitos (Lesvos, Greece) hot spring, laboratory studies of a Cyanobacterium sp. strain and potential medical applications

The bacterial diversity of the outflows of Polichnitos (Lesvos, Greece) hot spring has been investigated. Cyanobacteria showing high sequence homologies with Phormidium sp. and Cyanobacterium aponinum were found. Members of the Alphaproteobacteria closely related to Rhodobium sp. Albidovulum sp., Rhodobacter sp., Microvigra sp., Nitratireductor sp. and Phaeobacter sp. Gammaproteobacteria, Betaproteobacteria and Firmicutes were represented by members of Idiomarina sp., Marinobacter sp., Shinella sp., Bacillus sp. and Clostridium sp. with sequence homologies ranging from 92% to 100%. Members of the Bacteroidetes and Planctomycetes were represented by sequences of novel phylogenetic linkages exhibiting 87–90% sequence homology with type strains. When the hot spring consortium was cultivated in bioreactor repeated batch culture under photo-autotrophic growth conditions at temperature < 30 °C, Cyanobacterium sp. dominated over Phormidium sp. Cyanobacterium sp. seems to have biotechnological potential since its extracellular broth exhibited a strong insecticidal activity against larvae of Aedes aegypti (a vector of important human diseases) and significant anti-cancer activity against the PC3 human prostate cancer cell line, while its toxicity against human endothelial cells was relatively low.

Carbon dioxide from geothermal gas converted to biomass by cultivating coccoid cyanobacteria

ABSTRACTThe Blue Lagoon is a geothermal aquifer with a diverse ecosystem located within the Reykjanes UNESCO Global Geopark on Iceland’s Reykjanes Peninsula. Blue Lagoon Ltd., which exploits the aquifer, isolated a strain of coccoid cyanobacteria Cyanobacterium aponinum (C. aponinum) from the geothermal fluid of the Blue Lagoon more than two decades ago. Since then Blue Lagoon Ltd. has cultivated it in a photobioreactor, for use as an active ingredient in its skin care products. Until recently, the cultivation of C. aponinum was achieved by feeding it on 99.99% (4N) bottled carbon dioxide (CO2). In this investigation, C. aponinum was cultivated using unmodified, non-condensable geothermal gas (geogas) emitted from a nearby geothermal powerplant as the feed-gas instead of the 4N-gas. The geogas contains roughly 90% vol CO2 and 2% vol hydrogen sulfide (H2S). A comparison of both CO2 sources was made. It was observed that the use of geogas did enhance the conversion efficiency. A 13 weeks’ average CO2 conversion efficiency of C. aponinum was 43% and 31% when fed on geogas and 4N-gas, respectively. Despite the high H2S concentration in the geogas, sulfur accumulation in the cultivated biomass was similar for both gas sources. Our results provide a model of a CO2 sequestration by photosynthetic conversion of otherwise unused geothermal emission gas into biomass.

Influence of light and temperature on growth and high-value molecules productivity from Cyanobacterium aponinum

Cyanobacterium aponinum is a thermotolerant cyanobacterium species isolated from different thermal springs and showing potential therapeutic application thanks to the synthesis and release of exopolysaccharides with anti-inflammatory and immunomodulating properties. This work investigates the effects of temperature and light on growth rate, biomass yield, and released polysaccharides (RPS) synthesis in C. aponinum cultures. The highest biomass productivity was obtained at 40 °C (about 92 mg L−1 d−1), while the highest RPS synthesis rate (about 10 mg L−1 d−1) was detected at 35 °C. At this temperature, the influence of light intensities, between 15 and 650 μmol photons m−2 s−1, was also evaluated. C. aponinum showed the highest productivity in biomass (about 280 mg L−1 d−1) and RPS (about 20 mg L−1 d−1) at 500 μmol photons m−2 s−1. Interestingly, this strain also had the ability to accumulate other high-value compounds such as phycocyanin, zeaxanthin, and β-carotene suggesting that C. aponinum can be used for the industrial production of multiple molecules of biotechnological interest.

Detection of weed algae in open pond cultures of Cyanobacterium aponinum using PAM

The potential use of non-arable land in the al-Wusta region of the Sultanate of Oman for the production of algae biomass was examined. Brackish cleaned production water from oil production supplemented with commercial fertilizer was used as growth medium. The indigenous isolate Cyanobacterium aponinum WP7(1) was grown in open ponds using batch or semi-continuous cultivation. Biomass production rates of 15–24 g/m2/day were achieved. The change of salinity due to evaporation, which was thought to be a major challenge, did not exceed 35 ppt. All cultures showed contaminations with weed algae. Contaminations with green algae or diatoms were detectable using fluorescence pattern excited by four different wavelengths using a pulse-amplitude-modulation chlorophyll fluorometer (PAM). It is possible to estimate the health level and the mayor groups of which a culture is composed using the PAM method. Therefore, the fluorescence of the photosynthetically inactive sample is compared with the fluorescence after all copies of photosystem II were closed by exposing the sample to a high-intensity light beam. A detection limit of one weed algae cell in a hundred cells was achieved.

Exopolysaccharides from Cyanobacterium aponinum from the Blue Lagoon in Iceland increase IL-10 secretion by human dendritic cells and their ability to reduce the IL-17+RORγt+/IL-10+FoxP3+ ratio in CD4+ T cells

Regular bathing in the Blue Lagoon in Iceland has beneficial effects on psoriasis. Cyanobacterium aponinum is a dominating member of the Blue Lagoon's microbial ecosystem. The aim of the study was to determine whether exopolysaccharides (EPSs) secreted by C. aponinum (EPS-Ca) had immunomodulatory effects in vitro. Human monocyte-derived dendritic cells (DCs) were matured in the absence or presence of EPS-Ca and the effects were determined by measuring the secretion of cytokines by ELISA and the expression of surface molecules by flow cytometry. DCs matured with EPS-Ca at 100μg/ml secreted higher levels of IL-10 than untreated DCs. Subsequently, DCs matured in the presence or absence of EPS-Ca were co-cultured with allogeneic CD4+ T cells and their effects on T cell activation analysed by measuring expression of intracellular and surface molecules and cytokine secretion. Supernatant from allogeneic T cells co-cultured with EPS-Ca-exposed DCs had raised levels of IL-10 compared with control. A reduced frequency of IL-17+RORγt+ T cells was observed when co-cultured with EPS-Ca-exposed DCs and a tendency towards increased frequency of FoxP3+IL-10+ T cells, resulting in a lower IL-17+RORγt+/FoxP3+IL-10+ ratio. The study shows that EPSs secreted by C. aponinum stimulate DCs to produce vast amounts of the immunosuppressive cytokine IL-10. These DCs induce differentiation of allogeneic CD4+ T cells with an increased Treg but decreased Th17 phenotype. These data suggest that EPSs from C. aponinum may play a role in the beneficial clinical effect on psoriasis following bathing in the Blue Lagoon.

Growth of Cyanobacterium aponinum influenced by increasing salt concentrations and temperature.

The increasing requirement of food neutral biofuels demands the detection of alternative sources. The use of non-arable land and waste water streams is widely discussed in this regard. A Cyanobacterium was isolated on the area of a possible algae production side near a water treatment plant in the arid desert region al-Wusta. It was identified as Cyanobacterium aponinum PB1 and is a possible lipid source. To determine its suitability of a production process using this organism, a set of laboratory experiments were performed. Its growth behavior was examined in regard to high temperatures and increasing NaCl concentrations. A productivity of 0.1 g L−1 per day was measured at an alga density below 0.75 g L−1. C. aponinum PB1 showed no sign of altered growth behavior in media containing 70 g L−1 NaCl or less. Detection of a negative effect of NaCl on the growth using Pulse-Amplitude-Modulation chlorophyll fluorescence analysis was not more sensitive than optical density measurement.

Microbial oil production from thermophile cyanobacteria for biodiesel production

Compared to lipid extraction from algae, little work has been performed for cyanobacteria. In this article it is aimed to show high lipid accumulation potential of Synechococcus sp., Cyanobacterium aponinum and Phormidium sp. cells in BG-11 medium. Four different pH values (6–9) and NaNO 3 (0.25, 0.5, 1.0, 1.5 g/L) concentrations were examined at different incubation days to discover the highest lipid accumulation. The maximum lipid content could be achieved in the medium containing 0.25 g/L NaNO 3 at pH 7 for Synechococcus sp., pH 8 for C. aponinum and pH 9 for Phormidium sp. after 15 days. The maximum lipid contents and C16 and C18 methyl ester yields were measured as 42.8% and 46.9% for Synechococcus sp., 45.0% and 67.7% for C. aponinum, 38.2% and 90.6% for Phormidium sp. The saturated compounds were 74.5%, 77.9%, 84.7% for Synechococcus sp., C. aponinum and Phormidium sp., respectively. These crude lipids could be promising feedstock for biodiesel production.