Species Composition of Cyanidiales Assemblages in Pisciarelli (Campi Flegrei, Italy) and Description...

The biodata of Gabriele Pinto is printed adjacent to his contribution in this book.Biodata of the authors C. Ciniglia, C. Cascone and A. Pollio (with the authorGabriele Pinto) of the chapter “Species Composition of Cyanidiales Assemblagesin Pisciarelli (Campi Flegrei, Italy) and Occurrence of Galdieria phlegrea sp. nov.”

Claudia Ciniglia works at University “Federico II” of Naples as a researcher. Herresearch interest is focused on thermoacidophilic algal community, basically onbiodiversity of Cyanidiales, their population structure and their phylogeneticrelationships. Another research area of interest is in the application of new meth-ods for assessing the geno- and cytotoxicity of xenobiotics on unicellular algae.

E-mail: [email protected]

Carmela Cascone is a researcher at APAT – Environmental Protection Agencyand Technical Services. Her research field deals with Sustainable Use of NaturalResources and particularly with the development of Decoupling and Eco-effi-ciency Indicators. She took her degree in natural sciences working on “HabitatRelationship Model for Roe Deer (Capreolus capreolus) in the AbruzzoAppennines”. Then she got a PhD in Modelling Environmental System produc-ing Population Dispersion Models in Multi-Patch Environment using TemporalSimulation and GIS Software.


J. Seckbach (ed.), Algae and Cyanobacteria in Extreme Environments, 487–502.© 2007 Springer.

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Antonino Pollio is a professor of botany at the University “Federico II” of Naples.His scientific interests are in the area of extremophilic phototrophic organisms,particularly their ecophysiological and taxonomic characterization, as well astheir potential economical applications. Another area of interest is in the use ofunicellular algae for the risk assessment of xenobiotics in water environments.



SPECIES COMPOSITION OF CYANIDIALES ASSEMBLAGES INPISCIARELLI (CAMPI FLEGREI, ITALY) AND DESCRIPTIONOF GALDIERIA PHLEGREA SP. NOV.

G. PINTO1, C. CINIGLIA1, C. CASCONE2 AND A. POLLIO1

1Dipartimento delle Scienze Biologiche, Sezione Biologia vegetale,via Foria 223, Università Federico II, 80139 Napoli, Italy.2APAT – Agenzia per la Protezione dell’Ambiente e per i ServiziTecnici, via Curtatone, 3 – 00185 Roma, Italy

1. Introduction

In his landmarking “Thermophilic organisms and life at high temperature,”Brock (1978) wrote about the biogeography of Cyanidium that virtually everyacidic hot springs in the world had been colonized by this organism. This was theend-point of a series of geographical expeditions which had been carried outsince the mid 1920s of the past century, when Molisch (1926) visited numerousJapanese thermal springs, recording the ubiquitous presence in sulphuric acid richwaters of a microalga initially identified as a Chroococcus species. In the sameyears a team of German scientists was studying the algal flora of Java, Bali andSumatra (Deutsche Sunda expedition 1928–1929), isolating from different vol-canic sites a microalga quite similar to that observed by Molisch (1926). Geitlerand Ruttner (1936) classified this species as Cyanidium caldarium and placed itwithin the Cyanophyceae.

During the 1930s the occurrence of C. caldarium in Japanese hot springs wasextensively recorded by Negoro, who later (1944) published a detailed account ofhis field studies. Further Japanese thermal springs were visited approximately inthe same years by Schwabe (1944), who confirmed the ubiquitous presence ofC. caldarium in these habitats. Schwabe in the same paper also described theresults of his explorations in Chile, presenting a description of another organism,C. caldarium forma chilense previously classified as C. caldarium var. chilensis(1936). The main diacritical character of this organism was its occurrence in non-thermal and non-acidic habitats (caves located along the shores of Central andSouth Chile).

The modern exploration of Cyanidium begins with T.D. Brock, who carriedout a broad survey of more than 200 thermal areas in North and CentralAmerica, Europe (Iceland and Italy), Japan, Hawaii and New Zealand (Brock,1978). The exploration covered aquatic and terrestrial stations of each thermalspring, documenting the presence of Cyanidium in both kinds of habitat and inall the thermal sites. According to Doemel and Brock (1971) the occurrence ofC. caldarium was recorded in aquatic habitats between 20°C and 55°C, whereas

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on soils the temperature range was between 10°C and 55–57°C. In both habitatsC. caldarium was always found at pH values below 5.0.

During the 1970s two other extensive explorations on the algae living inacidic habitats were performed in Europe. Hargreaves and Whitton (1976) carriedout a comprehensive survey of the algal flora of highly acidic streams ofEngland, which later was extended to the rest of UK and to several sites inBelgium and in the USA (Whitton and Diaz, 1981). The selected sites were mainlyassociated to mine drainage, and to a minor extent, with the cooler part of geot-hermal springs and with several industrial effluents. According to the authorsC. caldarium occurred in some of these non-thermal habitats, even though the sitein which it was found was not indicated.

In the same years Pinto and Taddei (1978) visited up to 120 acidic sites ofItaly, reporting the presence of C. caldarium not only in acidic hot springs, butalso in acidic non-thermal sites, such as the sulphur mines. The authors docu-mented for the first time that almost all the sites investigated were characterizedby the presence of mixed populations in which not only C. caldarium was foundbut also two other very similar unicellular algae, which were subsequently classi-fied as Cyanidioschyzon merolae and Galdieria sulphuraria (De Luca et al., 1978;Merola et al., 1981). Pinto and Taddei (1978) did not give an account of the rel-ative abundance of these three microalgae in natural assemblages, but stressedthat Cy. merolae was less frequent than the other two species, and scarcely pres-ent in all the samples in which it had been found.

The coexistence of up to three thermo-acidophilic unicellular algae was sub-sequently confirmed in American thermal sites (De Luca et al., 1979;Gambardella et al., 1980) and in Asia (De Luca et al., 1981). In more recent timesa similar situation was also found in the Kamchatka peninsula (Russia) and onKunashir Island, where in addition to the three Cyanidiales species worldwidedistributed, three new Galdieria species were for the first time observed (Sentsova,1994).

All the data so far collected suggest that thermoacidic environmentsthroughout the world are inhabited by mixed populations of Cyanidiales, butcomposition and patterns of distribution of each single species in these naturalassemblages remain unknown.

To shed light on the influence that physical and chemical variations exert onCyanidiales assemblages we have examined the distribution and variability oftheir natural assemblages at Pisciarelli, a hydrothermal system located on theeastern edge of the Solfatara crater in the central part of the Campi FlegreiCaldera (Napoli, Italy) (Fig. 1). Pisciarelli is a liquid-dominant system, withspring water temperatures of up to 92°C (Valentino and Stanzione, 2003).Thermal pools are fed by meteoric waters intersected by fumarolic gases risingfrom a deep boiling aquifer. The gaseous sulphur in the fumarolic fluids is totallyrepresented by H2S.

The microbial community is composed of different groups of prokaryotes,such as Archaea (Kvist et al., 2005), chemotrophic sulphur bacteria, anoxygenic

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phototrophic bacteria and eukaryotic algae (Brock, 1978); these latter are mainlyrepresented by Cyanidiales assemblages, growing diffusely over the entire site, andother acid-tolerant belonging to Chlorophyceae and Bacillariophyceae (Husset al., 2002; Ciniglia et al., 2005; Pollio et al., 2005).

The coexistence of several ecological conditions (hot springs, streams, mud,rock walls), characterized by different pH, temperature values, water potentialand mineralogical parageneses makes Pisciarelli as an ideal site for analysing theCyanidiales assemblages and their relationships with the different microhabitatsoccurring in the site.

2. Description of the Site

For the purposes of this study, the site of Pisciarelli, whose dimensions areapproximately 40 × 20 m, has been divided into five stations characterized by dif-ferent environmental conditions:

Station A: This area is delimited by a rock wall of irregular outline, 1.50 mwide × 6 m long; surrounding a hot sulphur spring where strong fumarolic emis-sions continuously blow against the rocks. The temperature of the rock wallsranges from 33°C to 45°C. Cyanidiales form a soft-green mat which completelycovers the wall surface (Fig. 2, station A).

Station B: It corresponds to the soils covering a large part of the site,starting 10 m from the hot pools. Station B is covered by sandy soils, irregu-larly covered by opal and/or alunite layers generated by the hydrothermalactivity. Here, Cyanidiales assemblages lie superficially as a thin stratum

SPECIES COMPOSITION OF CYANIDIALES ASSEMBLAGES 491

Figure 1. The site of Pisciarelli, Campi Flegrei (Naples, Italy).


between the crushed stones, forming clearly identifiable emerald-green patches.The temperature variation depends on the presence of numerous small frac-tures in the soil, scattered all over this station, from which hot vapours areliberated. Soil temperature is 37–45°C across a round area of about 20–30 cmin diametre encircling each fracture. In some spots of station B, where frac-tures are absent, temperature ranges from 18°C to 30°C from winter to spring.Cyanidiales assemblages are largely present, forming deep-green patchesdiffused all over the station, and particularly in the vicinity of small fractures(Fig. 2, station B).

Station C: This station is a fissure of approximately 2 × 1.2 m, enveloped insulphur emissions, and covered by a thin and crumbly sulphate crystal layer. It isan interlithic site in which the Cyanidiales grow at temperature ranging fromabout 35°C to 43°C (Fig. 2, station C).

Station D: Two rivulets rise respectively from the main pool and from a sec-ondary hot spring, and flow across a slope of siliceous sinter into channels about10 cm deep, for a length of 10 m (Fig. 2 station D1), after which they become asingle stream, running for 10 m and opening out at the end into a small pond,which dries up during summer. The temperature of the two bubbling rivuletsranges from 60°C to 65°C, both in winter and in spring, because of fumarolicemissions. Downstream, when the rivulets flow together, gaseous emissions werenever observed and temperatures ranged from 32°C to 45°C (Fig. 2, station D2).Cyanidiales assemblages occur along the border of the streamlets, often inter-mingled with dense local aggregations of diatoms, which could bemacroscopically recognized by their green-brown colour.

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Figure 2. Map of Pisciarelli, with locations of five sampling stations: (A) rocks around hot boilingpools; (B) altered soil surrounding hot pools; (C) fissure in the rock wall; (D1 and D2) muddy soil andborder of the rivulet; (E) endolithic community.


Station E: A rock wall situated in the south-western part of the area ofPisciarelli. It is a dry, crypto-endolithic site, in which the Cyanidiales occurbeneath the superficial layers of alunite. Temperature ranges from 18°C to 22°Cin winter and from 24°C to 30°C in summer, due to the scarce influence of thegaseous emissions (Fig. 2, station E).

3. Results

3.1. CHEMICAL ANALYSES OF ROCKS AND MINERALS

Al, Si, P, S and K are the main chemical elements constituting rocks in Pisciarelli;Cl and Ti are scarcely represented, and Mg is totally absent. Sulphates are verywidespread in this environment, as are sulphur, alunite and other soluble sulphateminerals. The main product of the alteration of the volcanic cover produced byacidic fluids is opal, spread on the surface of the trachitic rocks and among frac-tures. Alunite is the predominant supergenic sulphate phase at Pisciarelli, mainlyrepresented by the potassic term KAl3(OH)6(SO4)2. The sulphate mineral parage-nesis includes Al-sulphate hydrate minerals, letovicite, alunogen, as well as termsof the alum group like tschermigite; native sulphur also occurs.

In station A the sulphur fumes are extremely powerful, providing constantlyhigh temperatures and high humidity rates; here, rocks around the pool aremainly composed by Si; all the other chemical elements (P, K, Ti, Al, S, Cl) arescarcely represented.

Chemical analyses of mats collected in the altered soil of station B revealeda high content of Si (65%), K (30.8%) and S (8.04%), likely to be related to thepresence of opal and scarce microcrystalline alunite. No significant mineralogicaldifferences have been detected between stations B and C.

The altered soil surrounding rivulets and stream (station D) results from tra-chytic rock alteration by hot acid fluids. It is rich in opal, while sulphate mineralsrepresent only a minor component. The muddy bed of the rivulets was made upof silica deriving from volcanic rocks.

The rock walls of the endolithic sites at Pisciarelli (station E, Fig. 2) arestrongly leached and appear white due to the presence of alunite; here gases andvapours come from surrounding fumaroles and pools with minor flow.

4. Algal Distribution

4.1. STATION A – ROCKS AROUND HOT BOILING POOLS:THE CYANIDIALES COMMUNITY

The sulphur fumes in station A (Fig. 2) are extremely powerful, favoring thedevelopment of a large, thick algal mat characterized by algal communities inwhich only members of the Cyanidiales were observed; green patches, formed



exclusively by Cyanidiales, were distributed along the station at temperaturesranging from 33°C to 45°C and at very low pH values (0.5–1.5).

The population density of Cyanidiales assemblages at the five sample pointsof this station ranged from 11 to 65 × 106 cells/g of sample (fresh weight). The rel-ative abundance of G. sulphuraria varied from about 20% to 50%, whereas C.caldarium was the dominant species, occurring at a relative percentage of 48–67%.Finally Cy. merolae was the least represented species in the Cyanidiales assem-blages: its abundance did not exceed 15% (Table 2).

4.2. STATION B – ALTERED SOIL SURROUNDING HOT POOLS:THE CYANIDIALES–PINNULARIA–CHLAMYDOMONASCOMMUNITY

At station B sites pH values ranged from 1.0 to 1.8 and temperature was 37–43°C.The algal communities were composed of Cyanidiales, Chlamydomonaspitschmannii and Pinnularia sp. Cyanidiales accounted for about 60% of theassemblages, whereas Ch. pitschmannii and Pinnularia sp. amounted to 40% ofthe population. The total cell number of Cyanidiales in the sampling sites was inthe range between 34 and 59 × 106 cells/mg of fresh weight (Table 2). The relativeabundance of C. caldarium in the Cyanidiales assemblages was between 38% and84%, whereas G. sulphuraria was present at 9–60% and Cy. merolae representednot more than 7% of the total Cyanidiales population.

4.3. STATION C – FISSURE IN THE ROCK WALL

This station is characterized by the presence of a fracture in the rock wall, 2 mhigh and 1.5 m wide. Here the temperature is constantly high, ranging from 35°Cto 55°C, and the pH is between 0.5 and 1.5 (Table 1). The algal communitydetected in station C was dominated by Cyanidiales. The total cell number ofCyanidiales in the algal assemblages of station C was in the range between 3.9and 79 × 106 cells/g fresh weight (Table 2). In station C G. sulphuraria numericallypredominant (60–95%), whereas C. caldarium in one sampling point reached 40%of relative abundance in the Cyanidiales assemblages, being limited in the othersampling points at 30% or less. Cy. merolae was not present in this station.

4.4. STATIONS D1 AND D2 – MUDDY SOIL AND BORDER OF THE RIVULET

In station D1 (two rivulets flowing separately) temperature was higher than 60°Cand no algal mat was found along the border of rivulets.

In station D2, a single rivulet flows that originated from the confluence ofthe two rivulets, a photosynthetic community composed of Cyanidiales and

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Table 1. Main chemical elements detected for each station. Lowest and highest pH and temperaturevalues during the samples collection are also reported.

pH T

Station Chemical elements Min Max Min Max

A – rocks surrounding Al 0.89%, Si 73.26%, P 5.05%, 0.5 1.5 33 45hot pools S 0.61%, Cl 0.65%, K 3.52%,

Ti 1.32%, Fe 0.00%B – altered soil Al 10.02%, Si 65.0%, P 10.32%, 1.0 1.8 37 43surrounding hot pools S 8.04%, Cl 0.50%, K 25.08%,

Ti 0.05%, Fe 3.84%C – fissure in the rock Al 9.89%, Si 67.08%, P 9.48%, 0.5 1.5 35 55wall S 9.81%, Cl 0.00%, K 20.72%,

Ti 0.9%, Fe 2.78%D – muddy soil of the rivuletD1 Al 5.63%, Si 57.5, P 4.5%, 1.0 3.0 60 65

S 18.05%, Cl 0.00%, K 15.5%,Ti 0.50%, Fe 0.5%

D2 Al 5.63%, Si 57.5, P 4.5%, 2.0 3.0 32 42S 18.05%, Cl 0.00%, K 15.5%,Ti 0.50%, Fe 0.5%

E – altered rock walls Al 10.64%, Si 20.02, P 2.03%, 0.5 1.0 18 30S 43.45%, Cl 0.00%, K 2.09%,Ti 0.00%, Fe 0.2%

Pinnularia sp. was detected underneath a thin slimy layer (1–3 mm), only on theborders and on the muddy bed of the single stream (Fig. 2, D2) formed bythe confluence of the two rivulets. Here temperature and pH were respectively inthe range 32–42°C and 2.0–3.0 (Table 1). Cyanidiales and Pinnularia sp. werepresent and the diatom was the dominant species. Cyanidiales in this assemblagesrepresented less than 20% of total cell number. C. caldarium was also in this sta-tion the dominant species, amounting to 43–92% of the total cell number,whereas G. sulphuraria occurred in a range between 5%and 55%, and Cy. merolaewas always below 11% (Table 2).

4.5. STATION E – ENDOLITHIC COMMUNITY

The endolithic algal population had a density ranging from 23 to 30 × 106 cells/gof fresh soil (Table 2) and was exclusively represented by Galdieria at 0.5 mmdepth, under a more external sulphur–sulphate layer exposed to the air, in a lowaltered rock matrix lying on opal resulting from rock alteration. Temperature wasnot high (Tmax = 30°C), and pH very low (0.5–1.5) (Table 1). The algal layer wasaround 0.2 mm thick. In one case, an endolithic population of Galdieria cells wasfound at 10 cm depth inside the white and crumbly wall.


The data so far presented represent the results of two field campaignscarried out in late winter and spring of 2005. Cyanidiales assemblages present acomposition of species which can be highly different in the stations considered:as a general rule, Cy. merolae is always a minor component of these assemblages,being limited to about 10% of the Cyanidiales populations, whereas C. caldariumor G. sulphuraria alternatively dominate in the different stations. To explore dif-ferences in abundance of these two species between pH or temperature classes,data on the numerical composition of natural assemblages were examined withone-way ANOVA, when they met the assumption of normality or homogeneityof variance, and with ANOVA Kruskall–Wallis when groups were not homoge-neous. Statistical analyses have revealed that the relative abundance ofC. caldarium and G. sulphuraria in the assemblages is not significantly differentbetween pH or temperature classes (not shown).

Doemel and Brock (1971) suggested that soil water content is one of themajor forces driving the composition of Cyanidiales assemblages. As can be seenin Fig. 3, laboratory experiments indicate that there is a clear difference in desiccation

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Table 2. Total cells number and % of each genera of Cyanidiales in the investigated stations. The val-ues are the average of three counts. The standard error was never higher than 5%.

Station Total cell number % Galdieria % Cyanidium % Cyanidioschyzon

A1 118,000,000 42 53 5A2 33,300,000 35 50 15A3 31,200,000 20 67 13A4 56,300,000 38 58 4A5 65,400,000 50 48 2B1 58,400,000 9 84 7B2 59,500,000 39 59 2B3 57,600,000 32 65 3B4 46,500,000 35 61 4B5 34,300,000 60 38 2C1 14,300,000 69 31 0C2 3,900,000 80 20 0C3 31,400,000 60 40 0C4 13,800,000 95 5 0C5 79,000,000 85 15 0D2.1 25,400,000 5 92 3D2.2 6,900,000 55 43 2D2.3 4,000 22 67 11D2.4 8,000 50 45 5D2.5 20,000 18 78 4E1 25,000,000 100 0 0E2 23,000,000 100 0 0E3 27,000,000 100 0 0E4 30,000,000 100 0 0E5 28,000,000 100 0 0


tolerance between C. caldarium and G. sulphuraria, this latter species being muchmore resistant to loss of water. From these results it could be possible to predictthat in humid stations the dominant species of Cyanidiales assemblages could beC. caldarium, whereas in relatively dry habitats G. sulphuraria should prevail.

The population structure of the Cyanidiales assemblages sampled in the fivestation of Pisciarelli was also investigated by analysing a three-gene data set ofplastid sequences: psaA, psb A and rbcL. Molecular analyses of environmentalsamples were performed by extracting DNA from each natural sample, and sub-sequently by amplifying the rbcL gene using PCR. The results have confirmed therelative composition of Cyanidiales assemblages, as obtained from the countswith the optical microscope. Moreover, two phylogenetic analyses were per-formed: in the first one were partial sequences of the three concatenated plastidgenes psaA (1,395 nt), psbA (957 nt) and rbcL (1,215 nt) found in 17 Cyanidiales,15 non-Cyanidiales red algae and two green algae and a glaucophyte as the out-group (Fig. 4). In the second analyses rbcL data-sets representative of Cyanidialesstrains from different geographical locations were compared: four Asian, threeRussian, three American and 17 local populations from Italy (Fig. 5). Both treesdocumented that the Galdieria lineage is divided in two subgroups, defined asGaldieria A and Galdieria B. The former includes strains with a worldwide distri-bution, whereas members of Galdieria B lineage are restricted to Italy. All thesamples from the endolithic station (E) of Pisciarelli belong to the Galdieria B lineage,


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Figure 3. Desiccation tolerance between C. caldarium and G. sulphuraria. The algae, collected in theexponential phase of growth (500,000 cells/mL), were dehydrated by mild heating in a convection ovenat 40°C for 1–4 days. A sample of each strain was stained daily with the vital stain neutral red to esti-mate the number of dead cells.


which was also found in few other natural samples of station C, where light inten-sity was much reduced.

The differences between the two Galdieria lineages have also been confirmedby ecophysiological experiments. Two strains respectively belonging to G. sulphu-raria A and G. sulphuraria B have been isolated from Pisciarelli natural samples.G. sulphuraria A cultivated at 25 and 38°C exhibited higher growth rates thanG. sulphuraria B. Moreover this latter strain showed the best growth at 25°C(Fig. 6). The photosynthetic rates versus light intensity of G. sulphuraria A and Bare shown in Fig. 7. G. sulphuraria B has documented a very low Pmax, confirm-ing that it is a shape-adapted strain.

The G. sulphuraria strains so far isolated from Pisciarelli revealed no mor-phological traits that could be used to distinguish between them, but molecular

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Figure 4. Phylogeny of the Cyanidiales inferred from minimum evolution (ME) analysis using thelogDet transformation of the combined plastid DNA sequences of psaA, psbA and rbcL. Results ofa ME-logDet bootstrap analysis are shown above the branches, whereas the bootstrap values from aprotein maximum likelihood analysis using the JTT evolutionary model are shown below thebranches. Only bootstrap values >60% are shown. The thick nodes represent >95% Bayesian poste-rior probability for clades using the site-specific GTR model (from Ciniglia et al., 2004).


analyses have shown that the endolithic strain is clearly distinct from the G. sulphuraria typical species. Similar situations have already been described forunicellular green algae: Suda et al. (2002) proposed the species Nannochloropsisoceanica on the basis of rbcL sequence differences, and Krienitz et al. (2004) haveinstituted the new genus Parachlorella, based on molecular data, such as the com-plete sequences of both the 18S rRNA gene and the ITS2 region.


Figure 5. Phylogeny of the Cyanidiales inferred from a minimum evolution (ME) analysis using theLogDet transformation of the rbcL sequences: Results of a ME-LogDet bootstrap analysis are shownabove the branches, whereas the bootstrap values fro a protein maximum likelihood analysis using theJTT evolutionary model are shown below the branches. Only bootstrap values >60% are shown. Thethick nodes represent >95% Bayesian posterior probability for clades using the site-specific GTRmodel. Sequences from the environmental survey are represented by Pisciarelli [followed by] collectionsite and are marked with asterisks (from Ciniglia et al., 2004).


500 G. PINTO ET AL.

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Figure 6. Growth rates of G. sulphuraria A and G. sulphuraria B at 38°C and 25°C. The two strainswere grown on liquid medium (Allen) and the growth was followed for 15 days by colorimeter read-ings at 550 nm.

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Figure 7. Photosynthetic rates of G. sulphuraria A and G. sulphuraria B as a function of light inten-sity. The experimental temperature was 25°C.

In our opinion, the molecular differences observed between the strain G. sulphuraria A and G. sulphuraria B support the institution of a new Galdieriaspecies, which has been named as G. phlegrea and includes the Galdieria B lineage.Further tests should be performed on other isolates of the same lineage to confirm


that also ecophysiological traits, such as the best growth at relatively low tempera-ture (25°C), and the low Pmax value, can be considered as diagnostic characters ofthis species.

Galdieria phlegrea G. Pinto, C. Ciniglia, C. Cascone, A. Pollio sp. nov.Etymology from the latin plegreus = volcanic. The specific epithet refers to CampiFlegrei (Naples, Italy), the site where the alga was found.

Proprietas morphologicae et propagatio similis sed haec species ordine nucleotido-rum in rbcL cetera specie generis differt. In Campi Phlegrei, Neapoli segregata.

Morphological characters and reproduction are the same, but this speciesdiffers from the other species of the genus by the order of nucleotides in rbcL.Isolated from Campi Flegrei, Naples, Italy.

Authentic strain: deposited in the Algal Collection of Dipartimento delleScienze Biologiche, Section of Plant Biology, University “Federico II” of Naples,Italy with strain number 291.

Type Locality: Pisciarelli, a branch of Campi Flegrei Caldera, Naples, Italy.

5. Acknowledgements

The authors gratefully acknowledge the anonymous reviewers who revised themanuscript.

6. References

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Ciniglia C., Yoon H.S., Pollio A., Pinto G., Bhattacharya D. (2004) Hidden biodiversity of theextremophilic Cyanidiales red algae. Mol. Ecol. 13 (7): 1827–1838.

Ciniglia C., Valentino G.M., Cennamo P., De Stefano M., Stanzione D., Pinto G., Pollio A. (2005)Influences of geochemical and mineralogical constraints on algal distribution in acidichydrothermal environments: Pisciarelli (Naples, Italy) as a model site. Arch. Hydrobiol. 162 (1):121–142.

De Luca P., Taddei R., Varano L. (1978) Cyanidioschyzon merolae: a new alga of thermal acidic envi-ronments. Webbia 33 (1): 37–44.

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De Luca P., Musacchio A., Taddei R. (1981) Acidophilic algae from the fumaroles of Mount Lawu(Java) locus classicus of Cyanidium caldarium Geitler. Giorn. Bot. Ital. 115: 1–9.

Doemel W.N., Brock T.D. (1971) The physiological ecology of Cyanidium caldarium. J. Gen.Microbiol. 67: 17–32.

Gambardella R., Moretti A., Musacchio A. (1980) Autoecologia ed ultrastruttura di alghe ter-moacidofile del nord e centro America. Delpinoa 21: 35–45.

Geitler L., Ruttner F. (1936) Die Cyanophyceen der Deutschen limnologische Sunda-Expedition, ihreMorphologie, Systematik und Ökologie. C. Ökologischer Teil. Arch. Hydrobiol. (Stuttgart) Suppl.Bd XIV (Tropische Binnengenwässer VI): 553–715.



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Species Composition of Cyanidiales Assemblages in Pisciarelli (Campi Flegrei, Italy) and Description...

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