Polyphasic Evaluation Of Periphytic Freshwater Cyanobacteria In Tukun River, Penang National Park

Most algae studies in Malaysia have focused on phytoplankton in lakes. Despite the occurrence of numerous streams and rivers in Malaysia, algae community in the lotic ecosystems remained largely unknown. In this study, macroscopic cyanobacteria collected from 9 sites along Tukun River were examined to identify the diversity of the group from December 2014 to November 2015. To the best of our knowledge, this is the pioneer study on periphytic cyanobacteria conducted in the stream of Penang National Park. To date, 24 morphospecies has been identified including 9 family whereby 10 species were encountered from field and the other 14 remaining were identified in cultures. Crust were the most dominant macroscopic forms with 7 morphospecies, followed by mats (3 morphospecies). Scytonema was the most dominant genus occurring at 8 out of 9 sampling sites. Presence of heterocytous cyanobacteria (S. stuposum or S. hofmanni) in 8 out of 9 sampling sites coincide with the low nitrate value (<074mg/L) recorded throughout the study stream. Chroococcales were dominant in both upper and middle stream. Environmental factor were also included in identification of cyanobacterial diversity along the study sites

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

Identification and phenotypic plasticity of Pseudanabaena catenata from the Svalbard archipelago

A filamentous benthic cyanobacteria, strain USMAC16, was isolated from the High Arctic Svalbard archipelago, Norway, and a combination of morphological, ultrastructural and molecular characterisation (16S rRNA gene sequence) used to identify to species level. Cell dimensions, thylakoid arrangement and apical cell shape are consistent with the Pseudanabaena genus description. The molecular characterisation of P. catenata gave 100% similarity with Pseudanabaena catenata SAG 1464-1, originally reported from Germany. Strain USMAC16 was cultured under a range of temperature and photoperiod conditions, in solid and liquid media, and harvested at exponential phase to examine its phenotypic plasticity. Under different culture conditions, we observed considerable variations in cell dimensions. The longest cell (5.91±0.13 μm) was observed at 15°C under 12:12 light:dark, and the widest cell (3.24±0.06 μm) at 4°C under 12:12 light: dark in liquid media. The study provides baseline data documenting the morphological variation of P. catenata in response to changing temperature regimes

Identification and phenotypic plasticity of Pseudanabaena catenata from the Svalbard archipelago

A filamentous benthic cyanobacteria, strain USMAC16, was isolated from the High Arctic Svalbard archipelago, Norway, and a combination of morphological, ultrastructural and molecular characterisation (16S rRNA gene sequence) used to identify to species level. Cell dimensions, thylakoid arrangement and apical cell shape are consistent with the Pseudanabaena genus description. The molecular characterisation of P. catenata gave 100% similarity with Pseudanabaena catenata SAG 1464-1, originally reported from Germany. Strain USMAC16 was cultured under a range of temperature and photoperiod conditions, in solid and liquid media, and harvested at exponential phase to examine its phenotypic plasticity. Under different culture conditions, we observed considerable variations in cell dimensions. The longest cell (5.91±0.13 μm) was observed at 15°C under 12:12 light:dark, and the widest cell (3.24±0.06 μm) at 4°C under 12:12 light: dark in liquid media. The study provides baseline data documenting the morphological variation of P. catenata in response to changing temperature regimes