The heterotrophic eubacterial and archaeal co-inhabitants of the halophilic Dunaliella salina in solar salterns fed by Bay of Bengal along south eastern coast of India.

Halophilic microbes are studied to understand the metabolic pathways adopted by organisms in such extreme environment and for their biotechnological exploitation. In thallosohaline environments worldwide, the autotrophic alga Dunaliella salina Teodoresco is omnipresent, but it is being recently realised that the heterotrophic components vary in different regions. The unexplored eastern coastline of India abutted by Bay of Bengal was investigated for the heterotrophic halophilic microbes in this region. The waters in the salterns - replicas of natural hyper-saline water bodies of that region, were collected at four sites along 650 km of the coastal belt. In cultures set up from these waters, green and pink colonies were observed. The green colonies were found to be those of D. salina while the pink colonies were of heterotrophs. To identify the heterotrophic microbes, light microscopy, 16S rRNA typing and pigment profiling through spectrophotometry and HPLC were done. The cells in pink colonies were rod shaped. 16S rRNA typing of cells in these colonies detected the presence of Halomonas sp. - a eubacterium. The pigment profile of cells in pink cultures matched that of the archaea - Halobacterium; bacterioruberin derivatives were found. Thus, it was concluded that Halomonas and Halobacterium spp. are among the co-inhabitant heterotrophs of D. salina. Cultures of D. salina established from these salterns showed the typical three colours seen in the ponds of different sub-plots of salterns. They were green until 30 days, turning dark orange by 60 days and pink when 90 day old. In the 90 day old cultures, innumerable rod shaped cells were found. These cells were similar to the cells of the waters from the ponds of pink sub-plots of salterns and the pink colonies established from saltern waters in the laboratory. In the old (90 days) laboratory cultures of D. salina, the glycerol and proteins released from degenerating cells and the increase in salt concentration to super saturation levels due to evaporation of water in the medium led to the gregarious appearance of the heterotrophs - the co-inhabitants in natural environment.

In vivo expression of genes in the entomopathogenic fungus Beauveria bassiana during infection of lepidopteran larvae.

The entomopathogenic fungus Beauveria bassiana (Bals.) Vuillemin is commercially available as a bio insecticide. The expression of three genes previously identified to have a role in pathogenicity in in vitro studies was validated in vivo in three lepidopteran insects infected with B. bassiana. Expression of all three genes was observed in all the tested insects starting from 48 or 72h to 10d post infection corroborating their role in pathogenicity. We suggest that it is essential to test the expression of putative pathogenicity genes both in vitro and in vivo to understand their role in different insect species.

Molecular phylogeny of asexual entomopathogenic fungi with special reference to Beauveria bassiana and Nomuraea rileyi.

The phylogenetic lineage, taxonomic affiliation and interrelationships of important asexual entomopathogenic fungal genera were studied using the sequences of partial regions of beta-tubulin and rRNA genes. The species structures of Beauveria bassiana and Nomuraea rileyi were also investigated. A total of 147 fungal entries covering 94 species were analysed. Phylogenetic analysis placed all the asexual entomopathogenic fungal species analysed, in the family Clavicipitaceae of the order Hypocreales of Ascomycota. Deep phylogenetic lineages were observed in B. bassiana iterating the complex nature of this species. Some of the isolates assigned to this species separated out more distinctly than morphologically distinguishable genera. Cryptic speciation was also evident in N. rileyi. It is concluded that the asexual fungi with entomopathogenic habit arose from a single lineage in sexual Clavicipitaceae.

Molecular phylogeny of asexual entomopathogenic fungi with special reference to Beauveria bassiana and Nomuraea rileyi

Basándose en el análisis de las secuencias de regiones parciales de los genes Beta-tubulina y ARN ribosómicosse estudió la filogenia, la taxonomía y las interrelaciones de importantes géneros de hongos entomopatógenosasexuales. Se estudio también la estructura de las especis Beauveria bassiana y Nomuraea rileyi. Seanalizó un total de 174 entradas fúngicas que representaban 94 especies. El análisis filogenético demostróque todas las especies de hongos entomopatogénicos asexuales incluidas en el estudio pertenecían a la familiaClavicipitaceae, del orden Hypocreales de los Ascomycota. Se observaron diferentes linajes dentro deB. bassiana, lo que demostró la complejidad de dicha especie. Algunos de los aislamientos de dicha especiedemostraron estar filogenéticamente más separados que determinados géneros morfológicos. Dentro de laespecie N. rileyi se pudo observar también la presencia de especiación críptica. Se concluye que los hongosasexuales entomopatogénicos han evolucionado de un linaje simple dentro de la familia Clavicipitaceae(AU)

The phylogenetic lineage, taxonomic affiliation and interrelationships of important asexualentomopathogenic fungal genera were studied using the sequences of partial regions of Beta-tubulin andrRNA genes. The species structures of Beauveria bassiana and Nomuraea rileyi were also investigated. Atotal of 147 fungal entries covering 94 species were analysed. Phylogenetic analysis placed all the asexualentomopathogenic fungal species analysed, in the family Clavicipitaceae of the order Hypocreales ofAscomycota. Deep phylogenetic lineages were observed in B. bassiana iterating the complex nature of thisspecies. Some of the isolates assigned to this species separated out more distinctly than morphologicallydistinguishable genera. Cryptic speciation was also evident in N. rileyi. It is concluded that the asexualfungi with entomopathogenic habit arose from a single lineage in sexual Clavicipitaceae(AU)