First records of morphological diversity and ecology of periphytic cyanobacteria from Tukun River, Penang Forest Reserve, Malaysia

Despite the abundance of streams and rivers in Malaysia, the algal communities of these lotic ecosystems have remained largely unstudied. In a one-year floristic survey conducted from December 2014, 24 cyanobacterial morphospecies were identified for the first time from Tukun River, Penang Forest Reserve. Ten morphospecies were identified directly from field specimens while the remaining 14 morphospecies were identified only in cultures derived from the field samples. A total of 17 morphospecies; Leptolyngbya cf. boryana, L. cf. foveolarum, L. valderiana, Chroococcus cf. cohaerens, C. cf. disperses, C. cf. membraninus, C. cf. minutus, C. cf. varius, Gloeocapsopsis cf. crepidinum, Geitlerinema cf. tenuius, Phormidium simplicissimum, Dolichospermum sp., Fischerella sp., Homoeoptyche repens, Nematoplaca inscrustans, Scytonema hofmanii and S. stuposum are new records for Malaysia. Crusts were the most dominant macroscopic forms (seven morphospecies) followed by mats (three morphospecies). Scytonema was the most frequently encountered genus, occurring at 8/9 sampling sites. The presence of heterocytous cyanobacteria (S. stuposum, S. hofmanni) in 8/9 sampling sites is consistent with the low nitrate levels (< 0.74 mg/L) recorded throughout the study stream. Chroococcales were dominant in both upper and middle parts of the stream. The morphospecies present showed distinct distribution patterns despite apparently minimal variations in ecological parameters such as temperature, dissolved oxygen, pH and conductivity between the sampling sites. This study provides important new baseline information in understanding the diversity of periphytic cyanobacteria not only in Penang Island but more widely in Malaysia. This information can make a useful contribution in biomonitoring stream health

First record of the cyanobacterial genus Wilmottia (Coleofasciculaceae, Oscillatoriales) from the South Orkney Islands (Antarctica)

Two cyanobacterial morphotypes isolated from Signy Island, South Orkney Islands, maritime Antarctica were characterised using a polyphasic approach combining morphological, cytological and molecular analyses. These analyses showed that the strains grouped with members of the genus Wilmottia. This genus has three species, W. murrayi, W.stricta, and W. koreana. Both morphotypes analysed in this study were placed within the clade of W. murrayi. This clade showed a well-supported separation from Antarctica and New Zealand strains, as well as the strains from other regions. W. murrayi was first described from Antarctica and is now known from several Antarctic regions. Confirmation of the occurrence of W. murrayi at Signy Island significantly extends its known distribution in Antarctica. In addition, a new combination, W. arthurensis, is suggested for Phormidium arthurensis

Nodosilinea signiensis sp. nov. (Leptolyngbyaceae, Synechococcales), a new terrestrial cyanobacterium isolated from mats collected on Signy Island, South Orkney Islands, Antarctica

Terrestrial cyanobacteria are very diverse and widely distributed in Antarctica, where they can form macroscopically visible biofilms on the surfaces of soils and rocks, and on benthic surfaces in fresh waters. We recently isolated several terrestrial cyanobacteria from soils collected on Signy Island, South Orkney Islands, Antarctica. Among them, we found a novel species of Nodosilinea, named here as Nodosilinea signiensis sp. nov. This new species is morphologically and genetically distinct from other described species. Morphological examination indicated that the new species is differentiated from others in the genus by cell size, cell shape, filament attenuation, sheath morphology and granulation. 16S rDNA phylogenetic analyses clearly confirmed that N. signiensis belongs to the genus Nodosilinea, but that it is genetically distinct from other known species of Nodosilinea. The D1–D1´ helix of the 16S–23S ITS region of the new species was also different from previously described Nodosilinea species. This is the first detailed characterization of a member of the genus Nodosilinea from Antarctica as well as being a newly described species

Phenotypic Diversification Of Terrestrial Cyanobacteria From Selected Habitats On Signy Island, South Orkney Islands, Antarctica

A floristic study was conducted on cyanobacteria from terrestrial habitats in Signy Island (60.7170° S, 45.6000° W), South Orkney Islands during the expedition of British Antarctic Survey (BAS) in austral summer of 2015/2016. Samples were collected following the previous 120 locations that was provided by Broady (1979). Thirty seven out of 120 collection sites established by Broady (1979) were successfully obtained and compared in this study. Changes in the cyanobacteria community at sites previously studied by Broady (1979) will provide excellent baseline information on the status of Antarctic terrestrial cyanobacteria diversity and dispersal. It is crucial to understand how the Antarctic life form is responding to current environmental change and what the continent was like in the past. This study has integrated traditional morphological and modern molecular taxonomic approaches providing new insights into the taxonomy of Antarctic cyanobacteria. Seventeen morphospecies belonging to 14 genera; Chamaesiphon, Cyanosarcina, Desmonostoc, Leptolyngbya, Microcoleus, Nodosilinea, Nostoc, Oscillatoria, Phormidium, Phormidesmis, Pseudanabaena, Synechocystis, Trichocoleus and Wilmottia have been recorded with robust descriptions by using streaking and most probable number techniques. Ten morphospecies recorded were similar to records by Broady (1979). Seven of the morphospecies; Leptolyngbya cf. subcapitata, Nodosilinea signiensis, Oscillatoria cf. subsala, Phormidium uncinatum, Trichocoleus cf. hospitus, Wilmotia murrayi M1 and Wilmottia murrayi M2 are new records for Signy Island

Unveiling The Diversity of Periphytic Cyanobacteria (Cyanophyceae) from Tropical Mangroves in Penang, Malaysia

Cyanobacteria are one of the most important groups of photoautotrophic organisms, contributing to carbon and nitrogen fixation in mangroves worldwide. They also play an important role in soil retention and stabilisation and contribute to high plant productivity through their secretion of plant growth-promoting substances. However, their diversity and distribution in Malaysian mangrove ecosystems have yet to be studied in detail, despite Malaysia hosting a significant element of remaining mangroves globally. In a floristic survey conducted in Penang, peninsular Malaysia, 33 morphospecies of periphytic cyanobacteria were identified and described for the first time from a mangrove ecosystem in Malaysia. Sixteen genera, comprising Aphanocapsa, Chroococcus, Chroococcidiopsis, Cyanobacterium, Desmonostoc, Geitlerinema, Leptolyngbya, Lyngbya, Microcystis, Myxosarcina, Oscillatoria, Phormidium, Pseudanabaena, Spirulina, Trichocoleus and Xenococcus, were obtained from field material growing on diverse natural and artificial substrata. Oscillatoriales was the dominant order with Phormidium the dominant genus at nine of the 15 sampling sites examined. Three of the morphospecies, Aphanocapsa cf. concharum, Xenococcus cf. pallidus and Oscillatoria pseudocurviceps, are rare and poorly known morphospecies worldwide. Chroococcus minutus, Phormidium uncinatum, P. amphigranulata, and some species of Oscillatoriales are considered as pollution indicator species. This study provides important baseline information for further investigation of the cyanobacterial microflora present in other mangrove areas around Malaysia. A complete checklist will enhance understanding of their ecological role and the potential for benefits arising from useful secondary metabolites or threats via toxin production to the ecosystem