Chrysosporum ovalisporum is synonymous with the true-branching cyanobacterium Umezakia natans (Nostocales/Aphanizomenonaceae).

True branching is a facultative characteristic only known from two cyanobacteria in the Aphanizomenonaceae, Umezakia natans and Dolichospermum brachiatum. In both cases, its expression has been associated with environmental stress, and its practical use as a diacritical feature has been previously evaluated. In this study, we undertook further evaluation of the phylogeny of Umezakia natans and its relationship to Chrysosporum ovalisporum as a previous study suggested the two were potentially congeneric.

Cryptic diversity within the Scytonema complex: Characterization of the paralytic shellfish toxin producer Heterosyctonema crispum, and the establishment of the family Heteroscytonemataceae (Cyanobacteria/Nostocales).

Strains of the freshwater filamentous, benthic cyanobacterium Scytonema crispum Agardh isolated from six sites in subtropical south-east Queensland were characterised using a combination of phenotypic and genetic traits. Morphologically, the strains were consistent with the description of Scytonemataceae sensu stricto, and the description of Scytonema crispum. However, phylogenetic analysis of the 16S rRNA gene, the 16S-23S rRNA operon, and the nifH gene revealed that these strains and three others from outside Australia formed a monophyletic clade distinct from Scytonema and other species in the Scytonemataceae.

Cyanotoxins: Which detection technique for an optimum risk assessment?

The presence of toxigenic cyanobacteria (blue-green algae) in drinking water reservoirs poses a risk to human and animal health worldwide. Guidelines and health alert levels have been issued in the Australian Drinking Water Guidelines for three major toxins, which are therefore the subject of routine monitoring: microcystin, cylindrospermopsin and saxitoxin. While it is agreed that these toxic compounds should be monitored closely, the routine surveillance of these bioactive chemicals can be done in various ways and deciding which technique to use can therefore be challenging.

Iningainema pulvinus gen nov., sp nov. (Cyanobacteria, Scytonemataceae) a new nodularin producer from Edgbaston Reserve, north-eastern Australia.

A new nodularin producing benthic cyanobacterium Iningainema pulvinus gen nov., sp nov. was isolated from a freshwater ambient spring wetland in tropical, north-eastern Australia and characterised using combined morphological and phylogenetic attributes.

Phylogeny and toxicology of Lyngbya wollei (Cyanobacteria, Oscillatoriales) from north-eastern Australia, with a description of Microseira gen. nov.

Three populations of the freshwater filamentous cyanobacterium Lyngbya wollei (Farlow ex Gomont) Speziale and Dyck have been putatively identified from north-eastern Australia and found to produce the potent cyanotoxin cylindrospermopsin (CYN) and its analog deoxy-cylindrospermopsin (deoxy-CYN). We investigated the phylogeny and toxicology of strains and mats isolated from two of these populations using a combination of molecular and morphological techniques. Morphologically the strains corresponded to the type description, however, the frequency of false-branching was low, and variable over time.

Rapid, multiplex-tandem PCR assay for automated detection and differentiation of toxigenic cyanobacterial blooms.

Cyanobacterial blooms are a major water quality issue and potential public health risk in freshwater, marine and estuarine ecosystems globally, because of their potential to produce cyanotoxins. To date, a significant challenge in the effective management of cyanobacterial has been an inability of classical microscopy-based approaches to consistently and reliably detect and differentiate toxic from non-toxic blooms. The potential of cyanobacteria to produce toxins has been linked to the presence of specific biosynthetic gene clusters.

First report of a toxic Nodularia spumigena (Nostocales/ Cyanobacteria) bloom in sub-tropical Australia. I. Phycological and public health investigations.

Cyanobacterial blooms represent one of the most conspicuous and widespread waterborne microbial hazards to human and ecosystem health. Investigation of a cyanobacterial bloom in a shallow brackish water recreational cable ski lake in south-eastern Queensland, Australia revealed the dominance of the toxigenic species Nodularia spumigena. The bloom spanned three months, during which time cell concentrations exceeded human guideline thresholds for recreational risk, and concentrations of the hepatotoxic cyanotoxin nodularin exceeded 200 µg L(-1).