Thermosynechococcus Sp Research Articles

Coaggregation Occurs between a Piliated Unicellular Cyanobacterium, Thermosynechococcus, and a Filamentous Bacterium, Chloroflexus aggregans.

Cyanobacteria are widely distributed in natural environments including geothermal areas. A unicellular cyanobacterium, Thermosynechococcus, in a deeply branching lineage, develops thick microbial mats with other bacteria, such as filamentous anoxygenic photosynthetic bacteria in the genus Chloroflexus, in slightly alkaline hot-spring water at ~55 °C. However, Thermosynechococcus strains do not form cell aggregates under axenic conditions, and the cells are dispersed well in the culture. In this study, Thermosynechococcus sp. NK55a and Chloroflexus aggregans NBF, isolated from Nakabusa Hot Springs (Nagano, Japan), were mixed in an inorganic medium and incubated at 50 °C under incandescent light. Small cell aggregates were detected after 4 h incubation, the size of cell aggregates increased, and densely packed cell aggregates (100-200 µm in diameter) developed. Scanning electron microscopy analysis of cell aggregates found that C. aggregans filaments were connected with Thermosynechococcus sp. cells via pili-like fibers. Co-cultivation of C. aggregans with a pili-less mutant of Thermosynechococcus sp. did not form tight cell aggregates. Cell aggregate formation was observed under illumination with 740 nm LED, which was utilized only by C. aggregans. These results suggested that Chloroflexus filaments gather together via gliding motility, and piliated cyanobacterial cells cross-link filamentous cells to form densely packed cell aggregates.

Thermosynechococcus sp. CL-1 (TCL-1) as an efficient cyanobacterium in CO2 fixation, C-phycocyanin production, and removal of Cd and Pb

Photosynthetic microorganisms achieve a tremendous CO2 fixation rate and heavy metal removal. This study assessed the performance of Thermosynechococcus sp. CL-1 for CO2 fixation, heavy metals (Cd and Pb) removal, and C-phycocyanin production. The tests were conducted under various light intensities (500–2,000 µE/m2/s) and the concentration of additional Cd and Pb. Cultivation was carried out in a flat-panel photobioreactor at a temperature of 50 oC for 12 h for examination of CO2 fixation rate, heavy metal removal, and phycocyanin production. Increasing light intensity promoted TCL-1 growth performance and only a slight decline was caused by the heavy metals. Supply of 2,000 µE/m2/s light intensity with 5 MF, 2.5 mg-Cd/L, and 0.5 mg-Pb/L achieved CO2 fixation rates of 118.1±12.5, 106.9±30.1, and 114.1±26.9 mg/L/h, respectively. Total Cd removal was presented under 2,000 µE/m2/s light intensity, but only 36–67% Pb removal was achieved. Removal of heavy metals was dominated by the bio-adsorption process by the functional groups on the surface of the cells. Besides, heavy metals also reduced C-phycocyanin production by TCL-1. Thus, TCL-1 can be a potential candidate for simultaneous CO2 fixation and heavy metal removal.

Importance of lighting color and period for CO2 fixation and C-phycocyanin production during Thermosynechococcus sp. CL-1 growth

Lighting arrangement is a critical factor in cultivation of photosynthetic microorganisms such as a cyanobacterium, Thermosynechococcus sp. CL-1 (TCL-1). This study observed the impact of various light intensities, light colors, and lighting periods on TCL-1 CO2 fixation rate and C-phycocyanin production. TCL-1 growth and CO2 fixation rate were not affected by the light color during continuous illumination. The best CO2 fixation rate of 2.29 ± 0.54 and 2.26 ± 0.14 g-CO2/L/d were achieved under white and red lighting, respectively. However, application of 12/12 h light-dark illumination diminished TCL-1 performance especially under red light and it might be caused by the reduction of accumulated chlorophyll-a. Furthermore, extended studies were also conducted for the efficient C-phycocyanin extraction and purification strategies, along with accumulated cyanotoxins analysis. Purification using ion-exchange chromatography elevated C-phycocyanin purity index to 3.34. Besides, treatment using distilled water and freeze dryer could remove the accumulated cylindrospermopsin and saxitoxin from TCL-1.

Removal of endocrine disruptor compounds, CO2 fixation, and macromolecules accumulation in Thermosynechococcus sp. CL-1 cultivation.

Recently, concern on several environmental issues including the pollutant discharge and high concentration of CO2 have gained high interest due to its impact on ecosystem and global warming effect, respectively. Implementation of photosynthetic microorganism carries out numerous advantages including high efficiency of CO2 fixation, the great endurance under extreme conditions and generation of valuable bioproducts. Thermosynechococcus sp. CL-1 (TCL-1), a cyanobacterium, has the ability to perform CO2 fixation and accumulation of various byproducts under extreme conditions like high temperature and alkalinity, presence of estrogen, or even using swine wastewater. This study aimed to assess TCL-1 performance under various endocrine disruptor compounds (bisphenol-A, 17-β-estradiol/E2, and 17-α-ethynilestradiol/EE2), concentrations (0-10mg/L), light intensities (500-2000 µE/m2/s), and dissolved inorganic carbon/DIC levels (0-113.2mM). Addition of E2 content even until 10mg/L carried out insignificant biomass growth interruption along with the improvement in CO2 fixation rate (79.8±0.1mg/L/h). Besides the influence of E2, application of higher DIC level and light intensity also enhanced the CO2 fixation rate and biomass growth. The highest biodegradation of E2 at 71% was achieved by TCL-1 in the end of 12h cultivation period. TCL-1 dominantly produced protein (46.7%±0.2%), however, production of lipid and carbohydrate (39.5±1.5 and 23.3±0.9%, respectively) also could be considered as the potential source for biofuel production. Thus, this study can provide an efficient strategy in simultaneously dealing with environmental issues with side advantage in production of macromolecules.

Multifunctional Thermosynechococcus sp. CL-1 cultivation in swine wastewater for nutrients utilization, CO2 fixation, and C-phycocyanin production

BackgroundCombination of the CO2 fixation and wastewater treatment process can be simultaneously and efficiently conducted using cultivation of photosynthetic microorganisms along with generation of byproducts as the alternative benefit. MethodIn this study, a cyanobacterium, Thermosynechococcus sp. CL-1 (TCL-1), has been cultivated in unsterilized swine wastewater for assessment on nutrients (N and P) removal, CO2 fixation rate, and accumulation of C-phycocyanin. Experiment was conducted using a flat panel photobioreactor and under supply of various light intensities of 500-2,000 µE/m2/s. Significant findingsThe presence of ammonium and phosphate in the swine wastewater were favorable to support the growth of TCL-1. TCL-1 eliminated almost all the ammonium during 8 h of experimental test under illumination of higher light intensity (1,000 or 2,000 µE/m2/s). Similarly, compared to other tested light intensities, 2,000 µE/m2/s resulted in greater phosphate utilization. However, 500 µE/m2/s light intensity indicated a higher total phosphorus utilization. Besides, addition of dissolved inorganic carbon (DIC) in the swine wastewater resulted the highest CO2 fixation rate of 145.1±12.1 mg/L/h. C-phycocyanin as a valuable pigment compound was accumulated by TCL-1 with concentration of 4.9 %dwc, productivity of 6.46±0.7 mg/L/h, and in the purity index range of 0.79-0.86.

Thermosynechococcus sp. CL-1 cultivation for Zn removal in swine wastewater with simultaneous CO2 fixation and macromolecules accumulation

Treatment of swine wastewater via cultivation of photosynthetic microorganism is highly promising due to the benefits in nutrient utilization, cost reduction, high efficiency, and production of various bioproducts. Besides, photosynthetic microorganisms are also acknowledged for their high tolerance toward extreme growth conditions, including the presence of heavy metals. This study assessed the tolerance of Thermosynechococcus sp. CL-1 (TCL-1) in the cultivation using swine wastewater for CO2 fixation, Zn removal, and production of lipid, protein, and carbohydrate. Addition of 113.2 mM dissolved inorganic carbon was also set for simulation of almost saturated CO2 content in a chemical scrubbing wastewater after CO2 absorption process. Experiment was conducted in a 1 L flat panel photobioreactor for 12 h periods, under illumination of various light intensities, and compared with the performance in modified Fitzgerald medium. TCL-1 cultivation under 1000 μE/m2/s light intensity provided the optimum growth condition in swine wastewater which led to high biomass productivity (55.69 mg/L/h) and CO2 fixation rate (91.8 mg/L/h). TCL-1 in this cultivation also removed 62.5 % Zn content from swine wastewater and bioadsorption route was detected as the major elimination process. The rapid utilization of nitrogen compounds in swine wastewater resulted in the dominant production of protein reached to 59.5 ± 3.1%dwc.

Combined strategy for 17-α-ethynilestradiol removal, CO2 fixation, and carotenoid accumulation using Thermosynechococcus sp. CL-1 cultivation

An isolated cyanobacterium, Thermosynechococcus sp. CL-1 (TCL-1), is a potential CO2 fixation, estrogen removal, and pigments production agent even under extreme conditions. In this study, TCL-1 was cultivated under various 17-α-ethinylestradiol/EE2 contents and growth conditions (light intensities and dissolved inorganic nitrogen/DIN). Under low EE2 concentration (1 mg/L), TCL-1 presented hormesis phenomenon with promotion of biomass productivity (68.2 ± 0.6 mg/L/h) and β-carotene productivity (0.47 ± 0.12 mg/L/h) compared to control cultivation without EE2. Strong endurance of TCL-1 was indicated by insignificant biomass growth reduction, even under 10 mg/L EE2. Moreover, compared to the variety of DIN levels, light intensity presented a greater influence on growth, CO2 fixation, and carotenoid accumulation of TCL-1. Total EE2 removal by TCL-1 reached the range of 66.4–82.3 % and the process was initiated by adsorption on cells’ surfaces prior to accumulation.

CO2 fixation and cultivation of Thermosynechococcus sp. CL-1 for the production of phycocyanin

Cultivation of Cyanobacteria is preferable for CO2 fixation process due to its efficiency and production of beneficial byproducts like phycocyanin. In this study, Thermosynechococcus sp. CL-1 (TCL-1) was cultivated in a 30 L flat panel photobioreactor using a 3-fold-modified Fitzgerald medium with 113.2 mM dissolved inorganic carbon. The highest CO2 fixation rate of 21.98 ± 1.52 mg/L/h was followed by higher lipid content (49.91 % dry weight content or %dwc) than the generated carbohydrate (24.22 %dwc). TCL-1 also potentially produced phycocyanin that was dominated by C-phycocyanin (98.10 ± 6.67 mg/g) along with a lower amount of allophycocyanin and phycoerythrin under extraction using various types of solvent. Stability of phycocyanin extract was further examined during storage under various temperatures and light illuminations. Extraction with 36 % glucose solvent presented a protective effect to phycocyanin from heat and photo-damage which was proven by the kinetics study of phycocyanin degradation in this study.

Comparative analysis reveals distinctive genomic features of Taiwan hot-spring cyanobacterium Thermosynechococcus sp. TA-1.

Thermosynechococcus is a genus of thermophilic unicellular cyanobacteria that dominates microbial mats in Asian non-acidic hot springs. These cyanobacteria are the major primary producers in their ecological niches and are promising sources of thermostable enzymes for biotechnology applications. To improve our understanding of these organisms, we conducted whole-genome sequencing of a novel strain for comparative analysis with other representatives in the same genus. This newly characterized strain, Thermosynechococcus sp. TA-1, was isolated from the Taian hot springs in Taiwan. Analyses based on average nucleotide identity (ANI) and genome-scale phylogeny suggested that TA-1 and another Taiwanese strain CL-1 belong to a novel species-level taxon. Two metagenome-assembled genomes (MAGs) originated from India represent the sister group, and Thermosynechococcus elongatus PKUAC-SCTE542 from China is the next closest lineage. All cultivated strains and MAGs from Japan form a separate monophyletic clade and could be classified into two species-level taxa. Intriguingly, although TA-1 and CL-1 share 97.0% ANI, the genome alignment identified at least 16 synteny breakpoints that are mostly associated with transposase genes, which illustrates the dynamic nature of their chromosomal evolution. Gene content comparisons identified multiple features distinct at species- or strain-level among these Thermosynechococcus representatives. Examples include genes involved in bicarbonate transportation, nitric oxide protection, urea utilization, kanamycin resistance, restriction-modification system, and chemotaxis. Moreover, we observed the insertion of type II inteins in multiple genes of the two Taiwanese strains and inferred putative horizontal transfer of an asparagine synthase gene (asnB) associated with exopolysaccharides gene cluster. Taken together, while previous work suggested that strains in this genus share a highly conserved genomic core and no clear genetic differentiation could be linked to environmental factors, we found that the overall pattern of gene content divergence is largely congruent with core genome phylogeny. However, it is difficult to distinguish between the roles of phylogenetic relatedness and geographic proximity in shaping the genetic differentiation. In conclusion, knowledge of the genomic differentiation among these strains provides valuable resources for future functional characterization.

Simultaneous 17β-estradiol degradation, carbon dioxide fixation, and carotenoid accumulation by Thermosynechococcus sp. CL-1

Thermosynechococcus sp. CL-1 (TCL-1) has a high potency to utilize CO2 under extreme conditions including high temperature, alkaline condition, and the occurrence of 17β-estradiol (E2). In this study, TCL-1 cultivation with E2 addition in the range of 0–20 mg/L was combined with various growth arrangements (light intensity and dissolved inorganic nitrogen/DIN level). After 120 h cultivation, the 1.0 mg/L E2, 200 µmol photons/m2/s light intensity, and 5.8 mM available nitrogen performed the best growth with 4.58 ± 0.18 mg/L/h biomass productivity, 94.9 ± 3.3% total estrogen removal, and 11.41 ± 0.11 mg/L/h CO2 fixation rate. Estrogen degradation was mainly carried out by biodegradation route which started from E2 conversion into estrone/E1 and with only 4–6% influence from the abiotic factors. Compared with the accumulated zeaxanthin, β-carotene was dominantly generated with a productivity of 0.043 ± 0.019 mg/L/h. Therefore, TCL-1 cultivation is an efficient strategy for simultaneous CO2 fixation, estrogen removal, and carotenoid accumulation as valuable byproducts.

Combination of iron-silicate adsorption and Thermosynechococcus sp. CL-1 cultivation for swine wastewater treatment, CO2 fixation, phycobiliproteins generation

Implementation of photosynthetic microorganism, like Thermosynechococcus sp. CL-1 (TCL-1), is considered as an eco-friendly strategy for carbon dioxide fixation and nutrient utilization in wastewater. However, high level of ammoniacal nitrogen carries out toxicity to TCL-1 cell and adsorption can be applied as a pre-treatment stage. This study observed application of iron-silicate on ammoniacal nitrogen adsorption in non-sterilized and undiluted swine wastewater as pre-treatment for TCL-1 cultivation for CO2 fixation, NH4+-N degradation, and phycobiliprotein generation. The utilization of 100 g/L iron-silicate performed efficient adsorption with the quantity of 4.05 mg-N/g-Fe/Si and fitted the pseudo-first-order adsorption with R2 value of 0.993. The adsorption pre-treated swine wastewater was implemented as TCL-1 growth medium under the 1000 μE/m2/s light intensity for 12 h. The TCL-1 biomass growth, CO2 fixation, and NH4+-N removal rate during cultivation period reached to 31.67 ± 1.25; 57.54 ± 6.09; and 6.05 ± 0.20 mg/L/h respectively. Phycobiliprotein as a byproduct was generated with the productivity of 13.9 mg/g/h. Thus, coupling iron-silicate for pre-treatment step of TCL-1 cultivation in swine wastewater is eco-friendly strategy to reduce water demand for dilution, ignite phycobiliprotein accumulation during the CO2 fixation and nutrient utilization process.

Chemoenzymatic synthesis of fucosylated oligosaccharides using Thermosynechococcus α1–2-fucosyltransferase and their application in the regulation of intestinal microbiota

A novel bacterial α 1–2-fucosyltransferase (α 2FT) from Thermosynechococcus sp. NK55a (Ts2FT) has been discovered and characterized. It shares 28–62% protein sequence homology to α 2FTs reported previously. The Ts2FT was cloned as an N-terminal His6-tagged recombinant protein (His6-Ts2FT) and expressed in E. coli BL21 (DE3). It was expressed at a level of 6.2 mg/L culture after induction with 0.05 mM of isopropylβ-d-1-thiogalactoside (IPTG) at 16 °C for 20 h. It showed the optimal activity at a reaction temperature of 40 °C and pH of 7.0. The presence of a Mg2+ improved its catalytic efficiency. Ts2FT displayed a strict acceptor specificity and could recognize only β1–3-galatoside acceptors. It was used efficiently for one-pot multienzyme synthesis of fucosylated oligosaccharides. One of the products, lacto-N-fucopentaose I was shown to promote the growth of intestinal probiotics including those belonging to Acidobacteria, Actinobacteria, Proteobacteria, Planctomycetes, and Chloroflexi.

Elimination of inorganic carbon and nitrogen resided in swine wastewater using Thermosynechococcus sp. CL-1 enriched culture

Nutrient pollution released from highly accumulated swine wastewater is getting concerned due to global warming and waterbody harmful. Traditional combination of nitrification and denitrification is commonly applied to remove carbon and nitrogen compounds resided in various wastewater with disadvantages of high cost and energy requirements. This study applied the thermophilic flat panel photobioreactor (tFPBR) with high growth rate of TCL-1 culture to evaluate the efficiency of inorganic carbon and nitrogen transformation.This 12-h operation resulted that TCL-1 enriched batch, grown in 50 °C and alkaline environment with 1,000 µE/m2/s light intensity, had high potential for CO2 fixation rate of 122.29 ± 9.93 mg/L/h and nitrogen removal rate of 7.76 mg-N/L/h treating swine wastewater, in comparison with comprehensive community involved in carbon and nitrogen cycles in the field-scale anoxic tank. This study provided the Rapid-growing photosynthetic cyanobacteria in place of slow-growing autotrophic microbes for of carbon and nitrogen transformation in the wastewater system.

Nitrogen and 17β-Estradiol level regulate Thermosynechococcus sp. CL-1 carbon dioxide fixation, monosaccharide production, and estrogen degradation

Thermosynechococcus sp. CL-1 (TCL-1), a thermophilic cyanobacterium from a hot spring in Taiwan, has been known of its efficiency in CO2 fixation, byproducts production (pigments, macromolecules). This study observed the performance of TCL-1 in CO2 fixation, estrogen degradation, and monosaccharide production under various levels of Dissolved Inorganic Nitrogen (DIN) and 17β-estradiol (E2) as nitrogen supply and estrogen addition. Under nitrogen starvation, TCL-1 performed similar results on CO2 fixation rate and biomass production but enhanced the monosaccharide production compared to the cases of high nitrogen supply. The highest CO2 fixation rate and glucose productivity reached to 151.8 ± 6.6 and 38.1 ± 0.9 mg/L/h, under DIN level of 0.58 mM and 0.5 mg/L E2. Adding E2 in the system did not inhibit the performance of TCL-1. During the cultivation, TCL-1 converted E2 into E1 and the biodegradation was the main path for estrogen degradation. Total E2 degradation reached to 69.4 ± 2.0%.

Light factors and nitrogen availability to enhance biomass and C-phycocyanin productivity of Thermosynechococcus sp. CL-1

In this study, the light factors and nitrogen availability effect on Thermosynechococcus sp. CL-1 (TCL-1) productivity of biomass and C-phycocyanin were observed. The variation of light factors (intensity, color and arrangement) and concentration of dissolved inorganic nitrogen (DIN) from 2.9 to 116.7 mM were applied in the TCL-1 cultivation with 3 g/L initial biomass concentration. Moreover, extended cultivation using two DIN concentrations with better results and various lighting arrangements were conducted. Additionally, the malondialdehyde (MDA) content in the biomass was also measured as the indicator of oxidative stress. The double-side lighting arrangement with the intensity of 500 and 1000 μmole m−2 s-1 reach better biomass productivity while the mixed lighting with red LED enhances C-phycocyanin productivity. Outstanding C-phycocyanin productivity of 281.4 ± 10 mg L-1 day-1 is achieved by the application of double side mixed color lighting and the intensity of 250 μmole m−2 s-1 on each side. Application of 2.9 mM DIN in the TCL-1 culture gains the highest biomass productivity recorded as 2022 ± 162 mg L-1day-1. Otherwise, highest C-phycocyanin productivity is 201.6 ± 40.4 mg L-1day-1 with 14.6 mM DIN. The higher concentration of MDA, which indicates the larger amount of free radical in the FPBR, is produced in the cultivation using 2.9 mM DIN.

Growth factors arrangement enhances Thermosynechococcus sp. CL-1 carotenoid productivity during CO2 fixation

CO2 bio-fixation by photosynthetic microorganisms not only offer high efficiency on its process, but also produce valuable byproducts. Carotenoids are one of the interesting byproducts of the photosynthetic microorganism cultivation due to its wide application in industries. Isolated cyanobacterium, Thermosynechococcus sp. CL-1 (TCL-1), was assessed for its theoretical feasibility of performance on biomass productivity, carotenoid (zeaxanthin, β-carotene) productivity and CO2 fixation rate. The cultivation carried out under various growth factors including light intensity, concentration of nitrogen supply and salinity.Cultivation with the addition of 5.8 mM nitrogen supply under light intensity of 1000 μE/m2/s and 0.14 M salinity gained the best results on biomass productivity (90.3 mg/L/h) and CO2 fixation rate (129.1 ± 5.5 mg/L/h) at the 8th hour of cultivation. This results related with the highest zeaxanthin productivity which reached 0.074 ± 0.004 mg/L/h and β-carotene productivity of 0.39 ± 0.03 mg/L/h. The results indicated that TCL-1 is the potential source to efficiently produce carotenoid compounds.

Production of phycobiliprotein and carotenoid by efficient extraction from Thermosynechococcus sp. CL-1 cultivation in swine wastewater

In this study, the performance of TCL-1 cultivation in swine wastewater was observed under various light intensity, treatment type of swine wastewater, and initial biomass concentration. Furthermore, pigments production (phycobiliprotein and carotenoid), was the main target in this study along with optimum extraction method. Under the cultivation in the anoxic treated swine wastewater (ATSW), highest biomass increment (1.001 ± 0.104 g/L) was achieved with 2 g/L initial biomass concentration and 1,000 µE/m2/s light intensity whereas cultivation in the anoxic and aerobic treated swine wastewater (AATSW) presented better performance on pigments production with the highest production in allophycocyanin which reached 12.07 ± 0.3% dwc. Extraction time and ultrasonication have significant influence on the phycobiliprotein extraction, yet different temperature and incubation time give similar extraction result for β-carotene. Carotenoids production with AATSW cultivation were two times higher than the cultivation in ATSW. However, ammonium-N degradation was performed better in the ATSW cultivation.

Improvement of Thermosynechococcus sp. CL-1 performance on biomass productivity and CO2 fixation via growth factors arrangement

The enormous attraction on CO2 biofixation using photosynthetic microorganisms such as cyanobacteria has been risen due to its promising efficiency and valuable by-products production. In this study, an isolated cyanobacterium from hot spring in Taiwan, Thermosynechococcus sp. CL-1 (TCL-1) was evaluated for its growth factors arrangement effect on the biomass productivity and CO2 biofixation. The initial biomass concentration, and nutrient supply level variation influenced TCL-1 biomass productivity and CO2 biofixation rate while the adjusted and controlled pH value gave an insignificant difference on its performance. The initial biomass concentration of 3 g L−1 gave the best result on biomass productivity and CO2 fixation which reached 143.4 mg L−1 h−1 and 224 mg L−1 h−1 respectively. Regarding to the result of this study, controlled pH value by the CO2 supply inside the reactor, produced an insignificant difference in TCL-1 performance compared to those with the uncontrolled pH value. The variation of nutrient supply level was achieved by the variation of macronutrient and micronutrient supply inside the medium. The G-solution contains metals and other micronutrient elements which are necessary for the growth of TCL-1. The combination between 5–folds MF medium as the macronutrient, and 3-folds G-solution as the micronutrient supply, present the best TCL-1 performance on biomass productivity and CO2 fixation rate.

Comparative Genomic Analysis of a Novel Strain of Taiwan Hot-Spring Cyanobacterium Thermosynechococcus sp. CL-1.

Thermosynechococcus is a genus of thermophilic unicellular cyanobacteria that are dominant in microbial mats at about 50–65°C in alkaline hot springs of eastern Asia. We used PacBio SMRT Sequencing to sequence the complete genome of a novel strain of thermophilic cyanobacterium, Thermosynechococcus sp. CL-1, isolated from the Chin-Lun hot spring (pH 9.3, 62°C) in Taiwan. Genome-scale phylogenetic analysis and average nucleotide identity (ANI) results suggested that CL-1 is a new species in the genus Thermosynechococcus. Comparative genome analysis revealed divergent genome structures of Thermosynechococcus strains. In addition, the distinct genetic differences between CL-1 and the other Thermosynechococcus strains are related to photosynthesis, transporters, signal transduction, the chaperone/usher system, nitric oxide protection, antibiotic resistance, prokaryotic immunity systems, and other physiological processes. This study suggests that Thermosynechococcus strains have actively acquired many putative horizontally transferred genes from other bacteria that enabled them to adapt to different ecological niches and stressful conditions in hot springs.

Cloning of a C-phycocyanin Alpha Subunit from Thermosynechococcus sp. TUBT-T01 and Prediction of Its Properties

C-Phycocyanin, a blue-colored and water soluble protein, is a class of phycobiliproteins that are the major light-harvesting pigments of a photosynthetic system in cyanobacteria. C-phycocyanins are utilized in many industries, including as natural colorants in food and cosmetics and as antioxidant compounds. However, the uses of C-phycocyanins have been limited due to their vulnerability to high temperatures. Therefore, the objective of this study was to identify and analyze the C-phycocyanin gene isolated from Thermosynechococcus sp. TUBT-T01, living in a hot spring in Surat Thani province, in the hope that this C-phycocyanin exhibited thermostable properties and that their applications could be expanded over a wide range of industries. In the present study, the polymerase chain reaction of the gene encoding alpha subunits of C-phycocyanin (cpcA) was performed, using primers designed based upon the sequence alignments of cpcA from Thermosynechococcus sp. available in the GenBank database. The putative cpcA, with an approximate size of 500 base pairs, was detected on an agarose gel. The DNA sequencing analysis indicated that the cpcA was 489 base pairs in length, and its nucleotide sequence was 94 % identical to those of thermophilic Thermosynechococcus sp. NK55, T. elongatus BP-1, and Synechococcus vulcanus. The deduced amino acid sequence was very similar to those of Thermosynechococcus sp. NK55, T. elongatus BP-1, and S. vulcanus. The data derived from the homologous model revealed that the presence of Asp28, Lys32, and Ser72 in the alpha subunit of C-phycocyanin from Thermosynechococcus sp. TUBT-T01 could provide the high thermostability property of this protein.