Volker A R Huss

Friedrich-Alexander-University of Erlangen-Nürnberg | FAU · Department of Biology

The genus Coccomyxa comprises green microalgae, which can be found worldwide in remarkably versatile aquatic and terrestrial ecosystems including symbiotic associations with a number of different hosts. In this study, we describe a new species, Coccomyxa onubensis, based on 18S and ITS ribosomal DNA (rDNA) sequence data. Coccomyxa onubensis was iso...

The genus Coccomyxa comprises green microalgae, which can be found worldwide in remarkably versatile aquatic and terrestrial ecosystems including symbiotic associations with a number of different hosts. In this study, we describe a new species, Coccomyxa onubensis, based on 18S and ITS ribosomal DNA (rDNA) sequence data. Coccomyxa onubensis was iso...

Open rooftop incubators may provide a cost-effective way for producing microalgal biomass for biodiesel production without requiring large land areas. While cultivating a Chlorella vulgaris strain with high oil content in a rooftop incubator, we identified an invading thermo-resistant green alga, which replaced the original culture. The isolated st...

Molecular analyses employing sequencing of the complete ribosomal RNA cistron (18S rDNA, ITS1, 5.8S rDNA, ITS2, and 28S rDNA) and transcriptome analysis of the RuBisCO gene (rbcL) were done on Chlorella vulgaris UTEX 2714. The constructed phylogenetic trees showed that C. vulgaris UTEX 2714 is Chlorella sorokiniana. Growth analysis and production o...

The increasing incidence of rare mastitis-causing pathogens has urged the implementation of fast and efficient diagnostic and control measures. Prototheca algae are known to be associated with diseases in humans and animals. In the latter, the most prevalent form of protothecosis is bovine mastitis with Prototheca zopfii and Prototheca blaschkeae r...

Chlorella, the archetype of uniforme green algae, is a high-performance primary producer in aquatic and terrestrial ecosystems. Under the simple spherical morphology of Chlorella, many other “green balls” unfolded independent phylogenetic lineages as a result of convergent evolution. By contrast, green algae with strikingly different phenotypes wer...

Roystonea regia is a popular landscape palm famous for its smoothly sculpted white trunk, but sometimes it is spoiled by epiphytic green algae inhabiting the bark. We identified a trebouxiophycean green alga as the single dominant species growing on the trunk of a royal palm in Hainan, China. Light and transmission electron microscopy showed adult...

The processes of CO2 acquisition were characterized for the acid-tolerant, free-living chlorophyte alga, CPCC 508. rDNA data indicate an affiliation to the genus Coccomyxa, but distinct from other known members of the genus. The alga grows over a wide range of pH from 3.0 to 9.0. External carbonic anhydrase (CA) was detected in cells grown above pH...

In the summer of 2003, a microalga strain was isolated from a massive green microalgae bloom in wastewater stabilization ponds at the treatment facility of La Paz, B.C.S., Mexico. Prevailing environmental conditions were air temperatures over 40 degrees C, water temperature of 37 degrees C, and insolation of up to 2400 micromol m2 s(-1) at midday f...

Bovine mastitis is an important and complex disease responsible for economic losses in the dairy industry. Biotype II strains of the green alga Prototheca zopfii can be involved, most often resulting in chronic mastitis of difficult treatment associated with reduced milk production. This type of infection is rare, but the number of reported cases i...

A novel unicellular Chlorella-like green alga was isolated from the rubber tree (Hevea brasiliensis). The cultured cells were described by light and electron microscopy. Most adult cells were spherical with a single cup-shaped parietal chloroplast, although a few cells contained 2 to 4 chloroplasts. Chloroplasts contained many small pyrenoids with...

Informational genes such as those encoding rRNAs are related to transcription and translation, and are thus considered to be rarely subject to lateral gene transfer (LGT) between different organisms, compared to operational genes having metabolic functions. However, several lines of evidence have suggested or confirmed the occurrence of LGT of DNA...

Intracellular symbioses involving eukaryotic microalgae and a variety of heterotrophic protists and invertebrates are widespread, but are unknown in higher plants. Recently, we reported the isolation and molecular identification of a Coccomyxa-like green alga from in vitro cell cultures of Ginkgo biloba L. This alga resides intracellularly in an im...

Three Chlamydomonas strains were isolated from the soils of a hot spring located in the Campi Flegrei Caldera (Naples, Italy). Ecophysiological, morpho-cytological and molecular features were used to characterize these isolates and to compare them with chlamydomonax acidophila strains from algal culture collections. The strains were collected from...

Chlorella is one of the archetypical forms of coccoid green algae and one of the best-studied phototrophic eukaryotes. However, its systematics remains enigmatic due to conflicts between morphological and molecular phylogenetic approaches. The sequences of the 18S ribosomal RNA gene of nine strains of Chlorella and related taxa, and the ITS2 region...

Little is known about phytoplankton communities inhabiting low pH environments such as volcanic and geothermal sites or acidic waters. Only specialised organisms are able to tolerate such extreme conditions. There is, thus, low species diversity. We have characterised the previously isolated acid tolerant Chlorella-like microalgae Viridiella frider...

Although intracellular associations with mycorrhizal fungi are known for Ginkgo biloba, no other endosymbiotic relationships have ever been reported for this "living fossil." A protoplast culture derived from haploid explants has now revealed the existence of a green alga in vitro, whose eukaryotic status was confirmed by transmission electron micr...

We have sequenced the mitochondrial DNA (mtDNA) of Hyaloraphidium curvatum, an organism previously classified as a colorless green alga but now recognized as a lower fungus based on molecular data. The 29.97-kbp mitochondrial chromosome is maintained as a monomeric, linear molecule with identical, inverted repeats (1.43 kbp) at both ends, a rare ge...

Complete nuclear 18S rRNA and chloroplast 16S rRNA coding sequences of the fusiform green alga Closteriopsis acicularis (G. M. Smith) Belcher et Swale (Chlorophyta) were used to determine its phylogenetic position within the Chlorophyta. Phylogenetic trees inferred from both genes show that C. acicularis is most closely related to Chlorella kessler...

Coccoid green algae of the Selenastraceae were investigated by means of light microscopy, TEM, and 18S rRNA analyses to evaluate the generic concept in this family. Phylogenetic trees inferred from the 18S rRNA gene sequences showed that the studied species of autosporic Selenastraceae formed a well-resolved monophyletic clade within the DO group o...

We have studied the plastid genome of Ochrosphaera neapolitana (Hymenomonadaceae, Prymnesiophyta), a member of the chlorophyll a + c-containing algae. Total DNA from ). neapolitana was fractionated in a CsCl density gradient, and the 'lighter' upper band (which is typically of plastid origin) was unusually abundant relative to the 'heavier' nuclear...

The unicellular heterotrophic protist Hyaloraphidium is classified with a family of green algae, the Ankistrodesmaceae. The only species that exists in pure culture and that is available for taxonomic studies is H. curvatum. Comparative18S ribosomal RNA sequence analyses showed that H. curvatum belongs to the fungi rather than to the algae. Within...

ABSTRACT This paper describes the expression analyses of the AtSTP3 gene of Arabidopsis thaliana, the functional characterization of the encoded protein as a new monosaccharide transporter, and introduces the AtSTP gene family. The kinetic properties of the AtSTP3 protein (for sugar transport protein 3) were studied in a hexose transport deficient...

The green alga Scenedesmus pupukensis and the red alga Porphyra spiralis contain large group-IC1 introns in their nuclear small subunit ribosomal RNA genes due to the presence of open reading frames at the 5' end of the introns. The putative 555 amino-acid Scenedesmus-encoded protein harbors a sequence motif resembling the bacterial S9 ribosomal pr...

A multimethod approach was used to characterize unicellular green algae that were traditionally assigned to the genus Chlorella Beijerinck and to resolve their phylogenetic relationships within the Chlorophyta. Biochemical, physiological, and ultrastructural characters, together with molecular data such as DNA base composition and DNA hybridization...

A wide range of aquatic protists and invertebrates harbour endosymbiotic microalgae within their cells. Regardless of the nature of the algae, phycobionts in marine habitats, mostly dinoflagellates or diatoms, are traditionally called “zooxanthellae”, while algae involved in freshwater endosymbiotic associations are referred to as “zoochlorellae”....

The prasinophytes comprise a morphologically heterogeneous assembly of mostly marine flagellates and coccoid taxa, which represent an important component of the nano- and picoplankton, and have previously figured prominently in discussions about the origin and phylogeny of the green plants. To evaluate their putative basal position in the Viridipla...

Four genera of the Phacotaceae (Phacotus, Pteromonas, Wislouchiella, Dysmorphococcus), a family of loricated green algal flagellates within the Volvocales, were investigated by means of transmission electron microscopy and analysis of the nuclear encoded small-subunit ribosomal RNA (18S rRNA) genes and the plastid-encoded rbcL genes. Additionally,...

Ranging from unicells to complex “plantlike” organisms that are adapted to habitats from subaerial or terrestrial to freshwater or marine, the green algae represent a diversity of life forms that offer a daunting challenge in the search for shared morphological characters. The ultrastuctural techniques that fueled the 1970s and early 1980s revoluti...

Biochemical and physiological properties of 16 Scene-desmus species representing the three subgenera Scenedesmus. Acutodesmus. and Desmodesmus are not suitable for species differentiation. All Scenedesmus species studied thus far produce secondary carotenoids, e.g. astaxanthin and canthaxanthin, under nitrogen-deficient conditions. In addition, wit...

Morphological, biochemical, and molecular data strongly suggest a common ancestry of land plants and Charophyceae sensu MATTOX & STEWART. Although it is now widely accepted that the Charophyceae are a sister group to the land plants, there is considerable disagreement over the systematics of different charophycean taxa and whether a Chara- or Coleo...

Morphological, biochemical, and molecular data strongly suggest a common ancestry of land plants and Charophyceae sensu MATTOX & STEWART. Although it is now widely accepted that the Charophyceae are a sister group to the land plants, there is considerable disagreement over the systematics of different charophycean taxa and whether a Chara- or Coleo...

The morphology, ultrastructure, and 185 rRNA gene sequences of two strains of picoplanktonic chlorophytes isolated from the same lake were compared with a culture of Choricystis minor (Skuja) Felt (Chlorococcales, Chlorophyta) from the culture collection in Gottingen, BRD. It was concluded that the isolated strains were attributable to this species...

Complete 18S ribosomal RNA sequence data from representatives of all extant pteridophyte lineages together with RNA sequences from different seed plants were used to infer a molecular phylogeny of vascular plants that included all major land plant lineages. The molecular data indicate that lycopsids are monophyletic and are the earliest diverging g...

Complete nuclear-encoded small-subunit 18S rRNA (= SSU rRNA) gene sequences were determined for the prasinophyte green alga Mantoniella squamata; the charophycean green algae Chara foetida, Coleochaete scutata, Klebsormidium flaccidum, and Mougeotia scalaris; the bryophytes Marchantia polymorpha, Fossombronia pusilla, and Funaria hygrometrica; and...

The nuclear DNA base composition of 26 strains of green algae belonging to the Chlorococcales was analysed by reversed-phase high-performance liquid chromatography (HPLC). 5-Methyldeoxycytidine was the only modified nucleoside detected in addition to the standard nucleosides deoxyadenosine, deoxycytidine, deoxyguanosine and deoxythymidine. The amou...

The Hydra/Chlorella symbiosis is an important model system for examining host/symbiont specificity in alga/invertebrate systems. The capability of free-living Chlorella to establish symbioses correlates with tolerance of growth to low pH. This agrees with preliminary evidence that pH levels in perialgal vacuoles in aposymbiotic hydra drop to values...

The species of the genus Chlorella exhibit considerable biochemical and physiological differences. Therefore, it is important to select for and utilize in research or biotechnology correctly identified strains of the species having the most favorable properties for the respective project. We examined the Chlorella strains of the University of Texas...

The evolution of oxygenic photosynthesis stands apart as the most significant event in the biogeochemical history of our earth. It would be difficult to imagine a more far-reaching occurrence — the planetary atmosphere was modified forever towards an opposite end of the chemical spectrum. The early atmosphere was reducing, could support the abiotic...

The nuclear small subunit ribosomal RNA gene of the unicellular green alga Ankistrodesmus stipitatus contains a group I intron, the first of its kind to be found in the nucleus of a member of the plant kingdom. The intron RNA closely resembles the group I intron found in the large subunit rRNA precursor of Tetrahymena thermophila, differing by only...

Complete small-subunit rRNA (16S-like rRNA) coding region sequences were determined for eight species of the Chlorococcales (Chlorophyceae). The genera investigated include Prototheca, Ankistrodesmus, Scenedesmus, and five Chlorella species. Distance matrix methods were used to infer a phylogenetic tree that describes evolutionary relationships bet...

Biochemical and physiological characters of 5 symbiotic Chlorella strains, 4 of them from Paramecium (Ciliata) and one from Acanthocystis (Rhizopoda, Heliozoa), were studied. Four strains (3 from Paramecium and one from Acanthocystis) belong to the same species. This is characterized by the presence of hydrogenase, no formation of secondary caroten...

Strains of 12 different species of the genus Chlorella were analyzed for amount, reiteration frequency and kinetic complexity of chromosomal DNA components by C0t analysis. The resulting C0t curves reveal at least two different DNA components consisting of single copy DNA (up to 95%) and of repetitive DNA with complexities of 4.1 x 10(3) base pairs...

Relationship among symbiotic dinoflagellates of the genusSymbiodinium derived from seven different host species has been studied by means of DNA/DNA hybridization. DNA homologies range from about 70 to 30%D. Highest homology is regarded as subspecific level. Based on the characteristics of DNA and phenotypes,Symbiodinium microadriaticum subsp.micro...

Phylogenetic relationships within the genusChlorella were studied by means of DNA/DNA hybridization under both optimal and relaxed reassociation conditions as well as by determination of the thermal stability of hybrid DNA duplexes. The results indicate a relationship betweenC. fusca var.fusca, C. fusca var.rubescens, C. fusca var.vacuolata, and th...

Four species of the unicellular green alga Chlorella, C. vulgaris, C. luteoviridis, C. minutissima, and C. zofingiensis, were characterized with respect to DNA similarities as determined by quantitative DNA hybridization procedures. In contrast to previous DNA hybridization procedures. In contrast to previous results, C. vulgaris turned out to be a...

DNA homologies of 14 strains of Chlorella protothecoides were determined. All strains are related by a high degree of DNA similarity (96–102% D) with the exception of strain 211-11 a which proved to belong to C. kessleri. There is, however, no detectable DNA homology with strains of the genus Prototheca which is supposed to have evolved from C. pro...

46 strains ofChlorella, identified by physiological and biochemical characters, were examined for their ability to form stable symbioses with aposymbioticHydra viridis. It was found to be a species-specific characteristic. Among the 15 taxa studied, onlyC. saccharophila var.ellipsoidea, C. saccharophila var.saccharophila, C. fusca var.vacuolata, C....

DNA of eight endosymbiotic dinoflagellates (zooxanthellae) from seven different host species has been analyzed as to its thermal characteristics and base composition by means of spectrophotometry and high performance liquid chromatography. All algae under investigation contain both methylcytosine and hydroxymethyluracil in addition to the bases typ...

DNA hybridization techniques showed Chlorella fusca var. vacuolata and C. kessleri to be homogeneous species with DNA homologies of 90–100% C. fusca var. fusca and var. rubescens, however, have only about 15% DNA homology with C. fusca var. vacuolata and should no longer be regarded as varieties. A good correlation was found so far between biochemi...

We propose the transfer of Pseudomonas perfectomarina to the species Pseudomonas stutzeri as strain ZoBell. The proposal is based on 60% deoxyribonucleic acid (DNA)-DNA homology with P. stutzeri ATCC 1758ST, a similar guanine-plus-cytosine content, and the conformity of more than 100 nutritional and general characteristics.

Three strains of symbiotic Chlorella (NC64A, CE/76, UTEX-130) could be assigned to C. vulgaris by physiological and DNA-hybridization studies and a fourth symbiotic strain, 3N8/13-1, exhibited characteristics intermediate between C. vulgaris and C. sorokiniana. None of the strains contained detectable sporopollenin or was nutritionally fastidious b...

Two different DNA hybridization methods were used to study the genetic relationships among strains of Chlorella sorokiniana. Closely related strains could be easily detected by comparison of DNA renaturation rates as determined spectrophotometrically, whereas the degree of relationship of more remotely related strains could be determined by means o...