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Lothar Krienitz - One of the best experts on this subject based on the ideXlab platform.
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mass developments of the cyanobacteria Anabaenopsis and cyanospira nostocales in the soda lakes of kenya ecological and systematic implications
Hydrobiologia, 2013Co-Authors: Lothar Krienitz, Pawan K Dadheech, Kiplagat KotutAbstract:The food web of the saline–alkaline lakes of East Africa is characterised by a unique interaction between the Lesser Flamingos as consumer birds and the cyanobacterium Arthrospira fusiformis as the primary producer. However, this interaction is disturbed frequently by alterations of the phytoplankton community. During the period 2001–2012, species of the cyanobacteria Anabaenopsis and Cyanospira were observed in four soda lakes of the African Rift Valley and compared to the entire phytoplankton biomass and composition. Their morphology was highly variable. Each species preferred a distinct range of salinity: C. capsulata 30–40 ppt, C. rippkae 25–35 ppt, A. arnoldii and A. abijatae 10–30 ppt, and A. elenkinii 0–15 ppt. Occasional dominance of Anabaenopsis and Cyanospira in the lakes investigated shows that members of these genera are serious competitors of A. fusiformis, the main food for Lesser Flamingos. Furthermore, mass developments of C. capsulata adversely affected food uptake by the flamingos at Lake Bogoria because they formed mucilaginous colonies that clogged the food filter system. From field samples of the three lakes, uncultured Anabaenopsis and Cyanospira spp. clones were obtained and subjected to phylogenetic analyses. The 16S rRNA gene sequencing data put into doubt the differentiation of Anabaenopsis and Cyanospira into separate genera as recently suggested.
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Does the potentially toxic cyanobacterium Microcystis exist in the soda lakes of East Africa
Hydrobiologia, 2011Co-Authors: Kiplagat Kotut, Lothar KrienitzAbstract:Presently, the food chains of the famous saline alkaline flamingo-lakes of East Africa are the focus of intense scientific discussion as the lakes host toxic cyanobacteria, which when consumed by Lesser Flamingos, weaken the birds and therefore make them susceptible to attacks by infective diseases. The distribution, genetic and toxicological aspects of Microcystis in Kenya has been studied extensively. Although there are reports on the occurrence of Microcystis in Kenya’s hypersaline alkaline lakes, they have not been confirmed. Our investigations carried out over a 10-year period in about 50 inland waters showed that Microcystis occurs exclusively in freshwaters, but never in the hypersaline alkaline lakes. Microscopic examinations of the phytoplankton of these lakes revealed the presence of Anabaenopsis abijatae (Nostococales) whose lumpy structure makes it roughly similar to Microcystis when viewed under an inverted microscope. We conclude that the possible occurrence of Microcystis in hypersaline alkaline lakes is doubtful and, as such, confirmatory studies including microphotographic documentation of findings should be carried out.
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Fluctuating algal food populations and the occurrence of lesser flamingos (Phoeniconaias minor) in three Kenyan rift valley lakes.
Journal of Phycology, 2010Co-Authors: Lothar Krienitz, Kiplagat KotutAbstract:The last two decades have witnessed increasing epi- sodes of lesser flamingo die-offs in East Africa. Based on data on phytoplankton composition, biomass, and flamingo population density in three alkaline-saline lakes of Kenya (Bogoria, Nakuru, and Oloidien) in 2001-2010, this study explored the link between sud- den flamingo deaths and fluctuations in algal food quantity and quality. The phytoplankton biomass ran- ged from 13 to 768 mg AE L )1 . Similarly, flamingo numbers varied widely from 500,000 indi- viduals in the study lakes. The dominance of the cya- nobacterium Arthrospira fusiformis (Woron.) Komarek et J. W. G. Lund was interrupted at irregular intervals in each lake and replaced partly by populations of dif- ferent species of the nostocalean Anabaenopsis or by the picoplanktonic chlorophyte Picocystis salinarum Lewin. The populations of Anabaenopsis have the potential of blocking the flamingo food filtration sys- tem with their large and slimy colonies; moreover, they are able to produce cyanotoxins. Estimates of fla- mingo populations suggest that low flamingo num- bers coincided with periods of low algal food quantity and ⁄or poor quality. A food deficit can be theorized to have two effects on the flamingos: (i) it weakens them to the point of being susceptible to attacks of infective diseases, such as the ones caused by Mycobacterium avium and Pseudomonas aeruginosa, and (ii) it predisposes them to poisoning by cyanotox- ins and pollutants, by reducing their capacity to han- dle toxic substances. This study therefore concludes that the challenges facing the flamingos are associ- ated with changes in their environment, which affect food and water supply.
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Changes of phytoplankton communities in Lakes Naivasha and Oloidien, examples of degradation and salinization of lakes in the Kenyan Rift Valley
Hydrobiologia, 2009Co-Authors: Andreas Ballot, Eberto Novelo, Kiplagat Kotut, Lothar KrienitzAbstract:Increasing degradation of the water quality, caused by overuse and salinization, leads to considerable changes of the phytoplankton composition in Kenyan Rift Valley lakes. Exemplarily, the phytoplankton communities and biomasses of deteriorating freshwater Lake Naivasha and salinizing Lake Oloidien were studied between 2001 and 2005, accompanied by physico-chemical measurements (pH, total phosphorus and nitrogen, alkalinity, conductivity). Over the last three decades, the ecology of these two water basins has been subjected to dramatic changes, caused by excessive use of water and catchment area by man. In L. Naivasha a shift in the dominance of coccoid cyanobacteria towards dominance of Chlorophyceae (Botryococcus terribilis) was observed. Lake Oloidien exhibited a shift in the dominance of coccoid Chlorophyceae towards dominance of cyanobacteria (Arthrospira fusiformis, Anabaenopsis elenkinii). Phytoplankton findings and chemical data demonstrate that L. Naivasha has developed towards a eutrophic freshwater lake while L. Oloidien has progressed towards a hypereutrophic alkaline-saline lake.
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morphological and phylogenetic analysis of Anabaenopsis abijatae and Anabaenopsis elenkinii nostocales cyanobacteria from tropical inland water bodies
Microbial Ecology, 2008Co-Authors: Andreas Ballot, Pawan K Dadheech, Sigrid Haande, Lothar KrienitzAbstract:Anabaenopsis spp. are heterocytous cyanobacteria commonly found in tropical, subtropical, and temperate water bodies. So far, the knowledge about the phylogeny of this genus is poor. Therefore, we have isolated 15 Anabaenopsis spp. strains from Kenyan and Mexican alkaline and saline water bodies and from a Ugandan freshwater body and studied the morphology and phylogeny in a polyphasic approach. Morphologically, the investigated strains could be discriminated in two groups. One group was containing six Anabaenopsis abijatae and A. cf. abijatae strains with up to more than 500 vegetative cells in one filament, mostly single intercalary heterocyte formation, and the ability to branch out. The other group comprised nine strains of Anabaenopsis elenkinii with short filaments with up to 38 vegetative cells, intercalary heterocytes in pairs, and no ability to branch out. The morphological differences were reflected in the two distinct clusters, which were found in the phylogenetic trees of 16S rDNA and PC-IGS. While the high 16S rDNA similarity values >97.5% found between all investigated A. abijatae and A. elenkinii strains support the assignment of these two species to one single genus, the morphological differences and the low similarity values (<87.3) found in PC-IGS sequences between the two clusters indicate two separate genera. A close morphological and phylogenetic relationship was found for A. abijatae and Anabaenopsis (Cyanospira) rippkae.
Andreas Ballot - One of the best experts on this subject based on the ideXlab platform.
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Polyphasic characterization of newly isolated Anabaenopsis (Cyanobacteria) strains from tropical Brazil and Mexico
Phytotaxa, 2018Co-Authors: Kleber Renan De Souza Santos, Marli Fátima Fiore, Ana Paula Dini Andreote, Guilherme Scotta Hentschke, Haywood Dail Laughinghouse, Andreas Ballot, Eberto Novelo, Célia Leite Sant'annaAbstract:The taxonomy of four isolated strains of Anabaenopis elenkinii and A. arnoldii from North and South America were investigated using a polyphasic approach. The studied populations were collected from seven alkaline lakes of the Brazilian Pantanal and Nabor Carrillo Lake, Texcoco region (Mexico), between 2004 and 2012, where they frequently formed blooms during the dry season. The morphological plasticity of the populations, from natural and culture conditions, was described based on 200 individuals of each species. The 16S rRNA and the cpc-BA-IGS phylogenetic analyses show Anabaenopsis as a sister-taxon of Cyanospira . The Anabaenopsis clade has three strongly supported subclusters related to the origin of strains: Pantanal+Mexico, Kenya+Australia and one European clade. Although these data indicate that the currently known Anabaenopsis strains belong to more than one species, we are being conservative and not describing them as new species due to the lack of more molecular data. We highlight the need of a revision of the genus, considering also that Anabaenopsis sp. PCC 9215, the current reference strain used for the genus, is not identified as A. elenkinii and it is phylogenetically grouped with Anabaenopsis strains identified as A. circularis , A. arnoldii , A. nadsonii and A. elenkinii .
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first report of anatoxin a producing cyanobacterium aphanizomenon issatschenkoi in northeastern germany
Toxicon, 2010Co-Authors: Andreas Ballot, Jutta Fastner, Maren Lentz, Claudia WiednerAbstract:Abstract The neurotoxin anatoxin-a (ATX), has been detected in several northeast German lakes during the last two decades, but no ATX producers have been identified in German water bodies so far. In 2007 and 2008, we analyzed phytoplankton composition and ATX concentration in Lake Stolpsee (NE Germany) in order to identify ATX producers. Sixty-one Aphanizomenon spp. strains were isolated, morphologically and phylogenetically characterized, and tested for ATX production potential by liquid chromatography–tandem mass spectrometry (LC–MS/MS). New primers were specifically designed to identify a fragment of a polyketide synthase gene putatively involved in ATX synthesis and tested on all 61 Aphanizomenon spp. strains from L. Stolpsee and 92 non-ATX-producing Aphanizomenon spp., Anabaena spp. and Anabaenopsis spp. strains from German lakes Langersee, Melangsee and Scharmutzelsee. As demonstrated by LC–MS/MS, ATX concentrations in L. Stolpsee were undetectable in 2007 and ranged from 0.01 to 0.12 μg l−1 in 2008. Fifty-nine of the 61 strains isolated were classified as Aphanizomenon gracile and two as Aphanizomenon issatschenkoi. One A. issatschenkoi strain was found to produce ATX at concentrations of 2354 ± 273 μg g−1 fresh weight, whereas the other A. issatschenkoi strain and A. gracile strains tested negative. The polyketide synthase gene putatively involved in ATX biosynthesis was found in the ATX-producing A. issatschenkoi strain from L. Stolpsee but not in the non-ATX-producing Aphanizomenon spp., Anabaena spp. and Anabaenopsis spp. strains from lakes Stolpsee, Langersee, Melangsee, and Scharmutzelsee. This study is the first confirming A. issatschenkoi as an ATX producer in German water bodies.
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paralytic shellfish poisoning toxin producing cyanobacterium aphanizomenon gracile in northeast germany
Applied and Environmental Microbiology, 2010Co-Authors: Andreas Ballot, Jutta Fastner, Claudia WiednerAbstract:Neurotoxic paralytic shellfish poisoning (PSP) toxins, anatoxin-a (ATX), and hepatotoxic cylindrospermopsin (CYN) have been detected in several lakes in northeast Germany during the last 2 decades. They are produced worldwide by members of the nostocalean genera Anabaena, Cylindrospermopsis, and Aphanizomenon. Although no additional sources of PSP toxins and ATX have been identified in German water bodies to date, the observed CYN concentrations cannot be produced solely by Aphanizomenon flos-aquae, the only known CYN producer in Germany. Therefore, we attempted to identify PSP toxin, ATX, and CYN producers by isolating and characterizing 92 Anabaena, Aphanizomenon, and Anabaenopsis strains from five lakes in northeast Germany. In a polyphasic approach, all strains were morphologically and phylogenetically classified and then tested for PSP toxins, ATX, and CYN by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA) and screened for the presence of PSP toxin- and CYN-encoding gene fragments. As demonstrated by ELISA and LC-MS, 14 Aphanizomenon gracile strains from Lakes Melang and Scharmutzel produced four PSP toxin variants (gonyautoxin 5 [GTX5], decarbamoylsaxitoxin [dcSTX], saxitoxin [STX], and neosaxitoxin [NEO]). GTX5 was the most prevalent PSP toxin variant among the seven strains from Lake Scharmutzel, and NEO was the most prevalent among the seven strains from Lake Melang. The sxtA gene, which is part of the saxitoxin gene cluster, was found in the 14 PSP toxin-producing A. gracile strains and in 11 non-PSP toxin-producing Aphanizomenon issatschenkoi, A. flos-aquae, Anabaena planktonica, and Anabaenopsis elenkinii strains. ATX and CYN were not detected in any of the isolated strains. This study is the first confirming the role of A. gracile as a PSP toxin producer in German water bodies.
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Changes of phytoplankton communities in Lakes Naivasha and Oloidien, examples of degradation and salinization of lakes in the Kenyan Rift Valley
Hydrobiologia, 2009Co-Authors: Andreas Ballot, Eberto Novelo, Kiplagat Kotut, Lothar KrienitzAbstract:Increasing degradation of the water quality, caused by overuse and salinization, leads to considerable changes of the phytoplankton composition in Kenyan Rift Valley lakes. Exemplarily, the phytoplankton communities and biomasses of deteriorating freshwater Lake Naivasha and salinizing Lake Oloidien were studied between 2001 and 2005, accompanied by physico-chemical measurements (pH, total phosphorus and nitrogen, alkalinity, conductivity). Over the last three decades, the ecology of these two water basins has been subjected to dramatic changes, caused by excessive use of water and catchment area by man. In L. Naivasha a shift in the dominance of coccoid cyanobacteria towards dominance of Chlorophyceae (Botryococcus terribilis) was observed. Lake Oloidien exhibited a shift in the dominance of coccoid Chlorophyceae towards dominance of cyanobacteria (Arthrospira fusiformis, Anabaenopsis elenkinii). Phytoplankton findings and chemical data demonstrate that L. Naivasha has developed towards a eutrophic freshwater lake while L. Oloidien has progressed towards a hypereutrophic alkaline-saline lake.
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morphological and phylogenetic analysis of Anabaenopsis abijatae and Anabaenopsis elenkinii nostocales cyanobacteria from tropical inland water bodies
Microbial Ecology, 2008Co-Authors: Andreas Ballot, Pawan K Dadheech, Sigrid Haande, Lothar KrienitzAbstract:Anabaenopsis spp. are heterocytous cyanobacteria commonly found in tropical, subtropical, and temperate water bodies. So far, the knowledge about the phylogeny of this genus is poor. Therefore, we have isolated 15 Anabaenopsis spp. strains from Kenyan and Mexican alkaline and saline water bodies and from a Ugandan freshwater body and studied the morphology and phylogeny in a polyphasic approach. Morphologically, the investigated strains could be discriminated in two groups. One group was containing six Anabaenopsis abijatae and A. cf. abijatae strains with up to more than 500 vegetative cells in one filament, mostly single intercalary heterocyte formation, and the ability to branch out. The other group comprised nine strains of Anabaenopsis elenkinii with short filaments with up to 38 vegetative cells, intercalary heterocytes in pairs, and no ability to branch out. The morphological differences were reflected in the two distinct clusters, which were found in the phylogenetic trees of 16S rDNA and PC-IGS. While the high 16S rDNA similarity values >97.5% found between all investigated A. abijatae and A. elenkinii strains support the assignment of these two species to one single genus, the morphological differences and the low similarity values (<87.3) found in PC-IGS sequences between the two clusters indicate two separate genera. A close morphological and phylogenetic relationship was found for A. abijatae and Anabaenopsis (Cyanospira) rippkae.
Kiplagat Kotut - One of the best experts on this subject based on the ideXlab platform.
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mass developments of the cyanobacteria Anabaenopsis and cyanospira nostocales in the soda lakes of kenya ecological and systematic implications
Hydrobiologia, 2013Co-Authors: Lothar Krienitz, Pawan K Dadheech, Kiplagat KotutAbstract:The food web of the saline–alkaline lakes of East Africa is characterised by a unique interaction between the Lesser Flamingos as consumer birds and the cyanobacterium Arthrospira fusiformis as the primary producer. However, this interaction is disturbed frequently by alterations of the phytoplankton community. During the period 2001–2012, species of the cyanobacteria Anabaenopsis and Cyanospira were observed in four soda lakes of the African Rift Valley and compared to the entire phytoplankton biomass and composition. Their morphology was highly variable. Each species preferred a distinct range of salinity: C. capsulata 30–40 ppt, C. rippkae 25–35 ppt, A. arnoldii and A. abijatae 10–30 ppt, and A. elenkinii 0–15 ppt. Occasional dominance of Anabaenopsis and Cyanospira in the lakes investigated shows that members of these genera are serious competitors of A. fusiformis, the main food for Lesser Flamingos. Furthermore, mass developments of C. capsulata adversely affected food uptake by the flamingos at Lake Bogoria because they formed mucilaginous colonies that clogged the food filter system. From field samples of the three lakes, uncultured Anabaenopsis and Cyanospira spp. clones were obtained and subjected to phylogenetic analyses. The 16S rRNA gene sequencing data put into doubt the differentiation of Anabaenopsis and Cyanospira into separate genera as recently suggested.
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Does the potentially toxic cyanobacterium Microcystis exist in the soda lakes of East Africa
Hydrobiologia, 2011Co-Authors: Kiplagat Kotut, Lothar KrienitzAbstract:Presently, the food chains of the famous saline alkaline flamingo-lakes of East Africa are the focus of intense scientific discussion as the lakes host toxic cyanobacteria, which when consumed by Lesser Flamingos, weaken the birds and therefore make them susceptible to attacks by infective diseases. The distribution, genetic and toxicological aspects of Microcystis in Kenya has been studied extensively. Although there are reports on the occurrence of Microcystis in Kenya’s hypersaline alkaline lakes, they have not been confirmed. Our investigations carried out over a 10-year period in about 50 inland waters showed that Microcystis occurs exclusively in freshwaters, but never in the hypersaline alkaline lakes. Microscopic examinations of the phytoplankton of these lakes revealed the presence of Anabaenopsis abijatae (Nostococales) whose lumpy structure makes it roughly similar to Microcystis when viewed under an inverted microscope. We conclude that the possible occurrence of Microcystis in hypersaline alkaline lakes is doubtful and, as such, confirmatory studies including microphotographic documentation of findings should be carried out.
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Fluctuating algal food populations and the occurrence of lesser flamingos (Phoeniconaias minor) in three Kenyan rift valley lakes.
Journal of Phycology, 2010Co-Authors: Lothar Krienitz, Kiplagat KotutAbstract:The last two decades have witnessed increasing epi- sodes of lesser flamingo die-offs in East Africa. Based on data on phytoplankton composition, biomass, and flamingo population density in three alkaline-saline lakes of Kenya (Bogoria, Nakuru, and Oloidien) in 2001-2010, this study explored the link between sud- den flamingo deaths and fluctuations in algal food quantity and quality. The phytoplankton biomass ran- ged from 13 to 768 mg AE L )1 . Similarly, flamingo numbers varied widely from 500,000 indi- viduals in the study lakes. The dominance of the cya- nobacterium Arthrospira fusiformis (Woron.) Komarek et J. W. G. Lund was interrupted at irregular intervals in each lake and replaced partly by populations of dif- ferent species of the nostocalean Anabaenopsis or by the picoplanktonic chlorophyte Picocystis salinarum Lewin. The populations of Anabaenopsis have the potential of blocking the flamingo food filtration sys- tem with their large and slimy colonies; moreover, they are able to produce cyanotoxins. Estimates of fla- mingo populations suggest that low flamingo num- bers coincided with periods of low algal food quantity and ⁄or poor quality. A food deficit can be theorized to have two effects on the flamingos: (i) it weakens them to the point of being susceptible to attacks of infective diseases, such as the ones caused by Mycobacterium avium and Pseudomonas aeruginosa, and (ii) it predisposes them to poisoning by cyanotox- ins and pollutants, by reducing their capacity to han- dle toxic substances. This study therefore concludes that the challenges facing the flamingos are associ- ated with changes in their environment, which affect food and water supply.
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Changes of phytoplankton communities in Lakes Naivasha and Oloidien, examples of degradation and salinization of lakes in the Kenyan Rift Valley
Hydrobiologia, 2009Co-Authors: Andreas Ballot, Eberto Novelo, Kiplagat Kotut, Lothar KrienitzAbstract:Increasing degradation of the water quality, caused by overuse and salinization, leads to considerable changes of the phytoplankton composition in Kenyan Rift Valley lakes. Exemplarily, the phytoplankton communities and biomasses of deteriorating freshwater Lake Naivasha and salinizing Lake Oloidien were studied between 2001 and 2005, accompanied by physico-chemical measurements (pH, total phosphorus and nitrogen, alkalinity, conductivity). Over the last three decades, the ecology of these two water basins has been subjected to dramatic changes, caused by excessive use of water and catchment area by man. In L. Naivasha a shift in the dominance of coccoid cyanobacteria towards dominance of Chlorophyceae (Botryococcus terribilis) was observed. Lake Oloidien exhibited a shift in the dominance of coccoid Chlorophyceae towards dominance of cyanobacteria (Arthrospira fusiformis, Anabaenopsis elenkinii). Phytoplankton findings and chemical data demonstrate that L. Naivasha has developed towards a eutrophic freshwater lake while L. Oloidien has progressed towards a hypereutrophic alkaline-saline lake.
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Cyanobacteria and cyanobacterial toxins in three alkaline Rift Valley lakes of Kenya - Lakes Bogoria, Nakuru and elmenteita
Journal of Plankton Research, 2004Co-Authors: Andreas Ballot, Geoffrey A Codd, Lothar Krienitz, Kiplagat Kotut, Claudia Wiegand, James S. Metcalf, Stephan PflugmacherAbstract:For decades frequent mass mortalities of Lesser Flamingos (Phoeniconaias minor Geoffroy) have been observed at alkaline-saline Kenyan Rift Valley lakes. To estimate the potential influence of toxic cyanobacteria on these mass deaths, the phytoplankton communities were investigated in Lakes Bogoria, Nakuru and Elmenteita. Cyanobacterial toxins were analyzed both in the phytoplankton from the three lakes and in isolated monocyanobacterial strains of Arthrospira fussiformis, Anabaenopsis abjjatae, Spirulina subsalsa and Phormidium terebriformis. Lake Bogoria was dominated by the cyanobacterium A. fusiformis. In L. Nakuru and L. Elmenteita the phytoplankton mainly consisted of A. fusiformis, A. abjatae and Anabaenopsis arnoldii, and in L. Nakuru an unknown Anabaena sp. was also found. Furthermore, this is the first time A. abijatae and the unknown Anabaena sp. have been found in Kenyan lakes. Phytoplankton wet weight biomass was found to be high, reaching 777 mg L -1 in L. Bogoria, 104 mg L -1 in L. Nakuru and 202 mg L -1 in L. Elmenteita. Using HPLC, the cyanobacterial hepatotoxins microgstin-LR, -RR -γR, -LF and -LA and the neurotoxin anatoxin-a were detected in phytoplankton samples from L. Bogoria and L. Nakuru. Total microcystin concentrations amounted to 155 μg microcystin-LR equivalents g -1 DW in L. Bogoria, and 4593 μg microcystin-LR equivalents g -1 DW in L. Nakuru, with anatoxin-a concentrations at 9 μg g -1 DW in L. Bogoria and 223 μg g -1 DW in L. Nakuru. In L. Elmenteita phytoplankton, no cyanobacterial toxins were found. A. fusiformis was identified as one source of the toxins. The isolated strain of A. fusiformis from L. Bogoria was found to produce both microcystin-YR (15.0 μg g -1 DW) and anatoxin-a (10.4 μg g -1 DW), whilst the A. fusiformis strain from L. Nakuru was found to produce anatoxin-a (0.14 μg g -1 DW). Since A. fusiformis mass developments are characteristic of alkaline-saline lakes, health risks to wildlife, especial the Arthrospira-consuming Lesser Flamingo, may be expected.
Pawan K Dadheech - One of the best experts on this subject based on the ideXlab platform.
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mass developments of the cyanobacteria Anabaenopsis and cyanospira nostocales in the soda lakes of kenya ecological and systematic implications
Hydrobiologia, 2013Co-Authors: Lothar Krienitz, Pawan K Dadheech, Kiplagat KotutAbstract:The food web of the saline–alkaline lakes of East Africa is characterised by a unique interaction between the Lesser Flamingos as consumer birds and the cyanobacterium Arthrospira fusiformis as the primary producer. However, this interaction is disturbed frequently by alterations of the phytoplankton community. During the period 2001–2012, species of the cyanobacteria Anabaenopsis and Cyanospira were observed in four soda lakes of the African Rift Valley and compared to the entire phytoplankton biomass and composition. Their morphology was highly variable. Each species preferred a distinct range of salinity: C. capsulata 30–40 ppt, C. rippkae 25–35 ppt, A. arnoldii and A. abijatae 10–30 ppt, and A. elenkinii 0–15 ppt. Occasional dominance of Anabaenopsis and Cyanospira in the lakes investigated shows that members of these genera are serious competitors of A. fusiformis, the main food for Lesser Flamingos. Furthermore, mass developments of C. capsulata adversely affected food uptake by the flamingos at Lake Bogoria because they formed mucilaginous colonies that clogged the food filter system. From field samples of the three lakes, uncultured Anabaenopsis and Cyanospira spp. clones were obtained and subjected to phylogenetic analyses. The 16S rRNA gene sequencing data put into doubt the differentiation of Anabaenopsis and Cyanospira into separate genera as recently suggested.
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morphological and phylogenetic analysis of Anabaenopsis abijatae and Anabaenopsis elenkinii nostocales cyanobacteria from tropical inland water bodies
Microbial Ecology, 2008Co-Authors: Andreas Ballot, Pawan K Dadheech, Sigrid Haande, Lothar KrienitzAbstract:Anabaenopsis spp. are heterocytous cyanobacteria commonly found in tropical, subtropical, and temperate water bodies. So far, the knowledge about the phylogeny of this genus is poor. Therefore, we have isolated 15 Anabaenopsis spp. strains from Kenyan and Mexican alkaline and saline water bodies and from a Ugandan freshwater body and studied the morphology and phylogeny in a polyphasic approach. Morphologically, the investigated strains could be discriminated in two groups. One group was containing six Anabaenopsis abijatae and A. cf. abijatae strains with up to more than 500 vegetative cells in one filament, mostly single intercalary heterocyte formation, and the ability to branch out. The other group comprised nine strains of Anabaenopsis elenkinii with short filaments with up to 38 vegetative cells, intercalary heterocytes in pairs, and no ability to branch out. The morphological differences were reflected in the two distinct clusters, which were found in the phylogenetic trees of 16S rDNA and PC-IGS. While the high 16S rDNA similarity values >97.5% found between all investigated A. abijatae and A. elenkinii strains support the assignment of these two species to one single genus, the morphological differences and the low similarity values (<87.3) found in PC-IGS sequences between the two clusters indicate two separate genera. A close morphological and phylogenetic relationship was found for A. abijatae and Anabaenopsis (Cyanospira) rippkae.
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Morphological and Phylogenetic Analysis of Anabaenopsis abijatae and Anabaenopsis elenkinii (Nostocales, Cyanobacteria) from Tropical Inland Water Bodies
Microbial Ecology, 2008Co-Authors: Andreas Ballot, Pawan K Dadheech, Sigrid Haande, Lothar KrienitzAbstract:Anabaenopsis spp. are heterocytous cyanobacteria commonly found in tropical, subtropical, and temperate water bodies. So far, the knowledge about the phylogeny of this genus is poor. Therefore, we have isolated 15 Anabaenopsis spp. strains from Kenyan and Mexican alkaline and saline water bodies and from a Ugandan freshwater body and studied the morphology and phylogeny in a polyphasic approach. Morphologically, the investigated strains could be discriminated in two groups. One group was containing six Anabaenopsis abijatae and A. cf. abijatae strains with up to more than 500 vegetative cells in one filament, mostly single intercalary heterocyte formation, and the ability to branch out. The other group comprised nine strains of Anabaenopsis elenkinii with short filaments with up to 38 vegetative cells, intercalary heterocytes in pairs, and no ability to branch out. The morphological differences were reflected in the two distinct clusters, which were found in the phylogenetic trees of 16S rDNA and PC-IGS. While the high 16S rDNA similarity values >97.5% found between all investigated A. abijatae and A. elenkinii strains support the assignment of these two species to one single genus, the morphological differences and the low similarity values (
Chao-chung Kuo - One of the best experts on this subject based on the ideXlab platform.
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Electrophoresis of a soft toroid coaxially along the axis of a cylindrical pore
Chemical Engineering Science, 2009Co-Authors: Jyh-ping Hsu, Chao-chung KuoAbstract:The electrophoresis of a soft toroid, which comprises a rigid core and a porous layer, coaxially along the axis of a cylindrical pore is analyzed under the conditions of low surface potential and weak applied electric field. The geometry considered simulates the electrophoresis of various types of biocolloid such as bacterial DNA, plasmid DNA, and Anabaenopsis, in a confined space. We show that under typical conditions the electrophoretic behavior of a soft toroid can be different from that of a rigid toroid. For instance, the effect that the presence of a boundary can raise the mobility of a rigid toroid may not be present for a soft toroid. Several interesting behaviors are also observed. For example, if the friction coefficient of the membrane layer of a toroid is small, the larger the friction coefficient the greater is the effect electroosmotic flow, and therefore, the larger the mobility, but the reverse trend is observed if the friction coefficient is sufficiently large.
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Electrophoresis of a charge-regulated toroid normal to a large disk.
Electrophoresis, 2008Co-Authors: Jyh-ping Hsu, Chao-chung KuoAbstract:The electrophoresis of a charge-regulated toroid (doughnut-shaped entity) normal to a large disk is investigated under the conditions of low surface potential and weak applied electric field. The system considered is capable of modeling the electrophoretic behavior of various types of biocolloids such as bacterial DNA, plasmid DNA, and Anabaenopsis near a perfectly conducting planar wall. The influences of the size of the toroid, the separation distance between the toroid and the disk, the charged conditions on the surfaces of the toroid and the disk, and the thickness of electric double layer on the electrophoretic mobility of the toroid are discussed. The results of numerical simulation reveal that under typical conditions the electrophoretic behavior of the toroid can be different from that of an integrated entity. For instance, if the surface of the toroid carries both acidic and basic functional groups, its mobility may have a local maximum as the thickness of double layer varies. We show that the electrophoretic behavior of the toroid is different, both qualitatively and quantitatively, from that of the corresponding integrated particle (particle without hole).
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Electrophoresis of a toroid along the axis of a cylindrical pore.
Electrophoresis, 2006Co-Authors: Jyh-ping Hsu, Chao-chung KuoAbstract:The electrophoresis of a toroid (doughnut-shaped entity) along the axis of a long cylindrical pore is analyzed under the conditions of low surface potential and weak applied electric field. The system under consideration is capable of modeling the electrophoretic behavior of various types of biocolloid such as bacterial DNA, plasmid DNA, and Anabaenopsis, in a confined space. The influences of the key parameters of the problem, including the sizes of a toroid, the radius of a pore, and the thickness of the double layer, on the electrophoretic mobility of a toroid are discussed. We show that the electrophoretic behavior of a toroid under typical conditions can be different from that of an integrated entity. For instance, although the presence of the pore wall has the effect of retarding the movement of a particle, it becomes advantageous if a toroid is sufficiently close to the boundary. Several interesting behaviors are also observed, for example, the mobility of a toroid when the boundary effect is significant can be larger than that when it is insignificant.