Lampropedia cohaerens sp. nov., a biofilm-forming bacterium isolated from microbial mats of a hot water spring, and emended description of the genus Lampropedia.

A biofilm-forming, Gram-stain-negative, aerobic, catalase-positive but oxidase-negative strain, designated CT6T, was isolated from the microbial mats (∼45 °C) of a hot water spring, located within the Himalayan ranges at Manikaran, Himachal Pradesh, India. Strain CT6T formed white, smooth colonies with irregular margins. Transmission electron microscopy revealed coccoid, non-flagellated cells with wavy boundaries. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain CT6T belongs to the genus Lampropedia with a sequence similarity value of 95.4 % to the sole member of this genus, Lampropedia hyalina ATCC 11041T. Strain CT6T was found to have phosphatidylethanolamine and phosphatidylglycerol as the major polar lipids. The major cellular fatty acids were C16 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C14 : 0, C19 : 0ω8c cyclo and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The major respiratory quinone was ubiquinone-8. The major polyamines were putrescine, spermidine and the betaproteobacterial-specific 2-hydroxyputrescine. The DNA G+C content was 63.5 mol%. Based on the genotypic, phenotypic, physiological and biochemical data, strain CT6T is considered to represent a novel species of the genus Lampropedia, for which the name Lampropedia cohaerens sp. nov. is proposed ( = DSM 100029T = KCTC 42939T = MCC 2711T).

Real-time image processing using selective erasure in photorefractive two-wave mixing.

We describe a real-time image-processing scheme that uses selective erasure of spatial frequencies at the Fourier transform plane in an arrangement employing photorefractive two-beam coupling. The versatility of the device results from the use of the Fourier transform of the erasure beam, which counterpropagates to the image-bearing beam. The technique can perform spatial-filtering operations such as edge enhancement, bandpass filtering, and pattern recognition by controlling the information available at the erasure-beam Fourier plane. An experimental demonstration has been made on edge enhancement, bandpass filtering, and character recognition.

Formation of a transient corticotype during excystment in Coniculostomum monilata (oxytrichidae, hypotrichida) and its modification by reorganizations.

Protargol impregnation revealed that Coniculostomum monilata, an advanced oxytrichid ciliate with the typical 18 Frontal-Ventral-Transverse (FVT) cirri but with multiple rows of right marginal cirri (RMC) and dorso-marginal cilia (DM), requires at least 3 morphogenetic cycles to acquire the normal vegetative ciliature during excystment. In the first cycle, the FVT cirral pattern is entirely different from that formed during division. The 'first ciliature' comprises 21-32 FVT cirri formed from 5 FVT primordia; these are substituted by 18 FVT cirri developed from 6 FVT primordia in the subsequent reorganization cycle. Furthermore, each successive cycle adds one RMC row and 2 DM rows while previous rows are not resorbed, unlike the FVT cirri and the left marginal cirri. Consequently, multiple RMC and DM rows develop to form a typical vegetative corticotype. Dual information for frontal ciliature appears to be a unique feature of C. monilata as a similar situation has not been observed in the other evolved oxytrichids. Presence of an alternate corticotype information (> 18 FVT cirri) possibly signifies phylogenetic relationship of C. monilata with the lower oxytrichids. Excystment morphogenesis data reaffirms the conclusion from previous investigations that C. monilata has inherited information for only 1 RMC row and 2 DM rows; multiple rows are attained through a characteristic retention of pre-existing/parental rows.

Partial retention of parental ciliature during morphogenesis of the ciliate Coniculostomum monilata (Dragesco & Njiné, 1971) Njiné, 1978 (Oxytrichidae, Hypotrichida).

Morphogenesis of Coniculostomum monilata as revealed by protargol staining shows formation of 18 Frontal-Ventral-Transverse (FVT) cirri from 6 cirral streaks. Only 3 parental FVT cirri participate in the formation of cirral streaks. While only one row of right marginal cirri (RMC) is formed during division, the non-dividing cell possesses 3-5 RMC rows. This corticotype is explained by the fact that during division parental RMC rows are retained and inwardly displaced, the innermost row being resorbed. As the cell elongates, cirri in the retained rows space out; each row is equatorially cleaved during cytokinesis. A similar retention of dorsomarginal rows occurs on the dorsal surface. Based on synapomorphies shared by C. monilata and Stylonychia mytilus, we propose that C. monilata is an evolved oxytrichid. The regular retention of ciliary structures through several generations is, however, a unique character amongst the evolved oxytrichids and may be considered as an autapomorphy to describe C. monilata. Another such feature of C. monilata is the moniliform macronucleus, unique among the advanced oxytrichids. The present study reaffirms the importance of morphogenetic criteria in ciliate systematics. The original description of C. monilata Njiné, 1978 has been rectified with respect to the nomenclature of cirri and phylogenetic status of the species.