G. Seshu Kumar

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Temperature-dependent phosphorylation and dephosphorylation of membrane proteins was studied in vitro in a number of psychrotrophic Antarctic bacteria which grow between 0 and 30 degrees C. One of them, a Pseudomonas syringae isolate, was studied in detail and was found to have three membrane proteins of molecular mass 30, 65 and 85 kDa which were(More)
Eight isolates of bacteria from the soils of maritime Antarctica and Antarctic peninsula have been identified as members of the genus Janthinobacterium. Based on their morphology, physiological characteristics, biochemical characteristics and mole percent G+C content of their DNA six of them have been identified as ‘J. lividum’ and the remaining two as(More)
Phosphorylation of lipopolysaccharide (LPS) from a psychrotrophic bacterium, Pseudomonas syringae, from Antarctica was studied by using sucrose gradient-separated membrane fractions. The bacterium was found to possess an LPS kinase which could phosphorylate more LPS postsynthetically at higher temperatures. The phosphorylation was low at a lower temperature(More)
Thirteen isolates of bacteria from the soils of Schirmacher Oasis, Antarctica have been identified as members of the genus Arthrobacter. All the isolates exhibited a rod-coccus cycle during growth; were gram positive, catalase positive, non-motile and non-fermentative; did not form endospores; and contained MK-8 (H2) as the major menaquinone. The mole %G +(More)
The psychrotrophic, dimorphic yeast Candida humicola, isolated from Antarctic soil, secretes an acidic protease into the medium. The secretion of this protease by C. humicola was found to be dependent on the composition of the medium. In YPD or yeast nitrogen base medium containing either amino acids or ammonium sulfate as the nitrogen source, the activity(More)
Exposure to extremes of temperatures cause stresses which are sometimes lethal to living cells. Microorganisms in nature, however, are extremely diverse and some of them can live happily in the freezing cold of Antarctica. Among the cold adapted psychrotrophs and psychrophiles, the psychrotrophic bacteria are the predominant forms in the continental(More)
The Antarctic psychrotrophic bacterium Pseudomonas syringae was more sensitive to polymyxin B at a lower (4 degrees C) temperature of growth than at a higher (22 degrees C) temperature. The amount of hydroxy fatty acids in the lipopolysaccharides (LPS) also increased at the lower temperature. These changes correlated with the increase in fluidity of the(More)
A DNA-dependent RNA polymerase was purified from the Antarctic psychrotrophic bacterium Pseudomonas syringae. The RNA polymerase showed a typical eubacterial subunit composition with beta, beta', alpha2 and sigma subunits. The subunits cross-reacted with antibodies raised against holoenzyme and the individual subunits of the RNA polymerase of Escherichia(More)
Transcriptional activity was monitored in cells of the Antarctic psychrotrophic bacterium Pseudomonas syringae (Lz4W), which does not grow above 30°C. It was observed that the bacterium was capable of synthesising RNA at a temperature range of 0–37°C, both in vitro and in vivo. The net incorporation of the radioactive precursor, [3H]uridine, into RNA was(More)
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