73 research outputs found
A Characterization of Open Shop Scheduling Problems using the Hall Theorem and Network Flow
Open shop scheduling problems are combinatorial problems where jobs with certain processing requirements on a number of different machines must be arranged in such a way that objectives related to completion time are optimized. Such problems have applications over a wide spectrum including such as communications, routing and manufacturing.
Many open shop problems are NP-hard but there are a number of special cases which possess polynomial solutions in the case of few machines or few jobs or when preemption of jobs is permitted. Many such solutions are based in the theory of matching or Hall\u27s theorem, or more generally network flow. The primary focus of this thesis is to describe a number of polynomial-time solutions which are constructed using these related concepts and methods
<em>Marichromatium indicum</em> sp. nov., a new purple sulfur Gammaproteobacterium from mangroves of Goa, India
A reddish-brown bacterium was isolated from photoheterotrophic enrichments of mangrove soil from the western coast of India, in a medium that contained 10 % (w/v) NaCl. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA100T clusters with species of the genus Marichromatium of the class ‘Gammaproteobacteria’. Cells of strain JA100T are Gram-negative, motile rods with monopolar single flagella; they require NaCl, the optimum concentration being 1–4 %, and tolerate concentrations up to 13 %. The strain has vesicular internal membrane structures, bacteriochlorophyll a and, most probably, carotenoids of the spirilloxanthin series. No growth factors are required. A reduced sulfur source is required for growth, and, during growth on reduced sulfur sources as electron donors, sulfur is intermediately deposited as a single large granule within the cell. Strain JA100T could not grow at the expense of other tricarboxylic acid cycle intermediates, except malate. On the basis of 16S rRNA gene sequence analysis and its morphological and physiological characteristics, strain JA100T is sufficiently different from other Marichromatium species to justify its designation as a novel species, for which the name Marichromatium indicum sp. nov. is proposed. The type strain is JA100T (=DSM 15907T=ATCC BAA-741T=JCM 12653T)
Marichromatium bheemlicum sp. nov., a non-diazotrophic photosynthetic gammaproteobacterium from a marine aquaculture pond
A rod-shaped, phototrophic, purple sulfur bacterium, strain JA124(T), was isolated in pure culture from a marine aquaculture pond, located near Bhimunipatnam, in a medium that contained 3 % NaCl (w/v). Strain JA124(T) is a Gram-negative, motile rod with a single polar flagellum. Strain JA124(T) has a requirement for NaCl, with optimum growth at 1.5-8.5 %, and tolerates up to 11 % NaCl. Intracellular photosynthetic membranes are of the vesicular type. Bacteriochlorophyll a and probably carotenoids of the spirilloxanthin series are present as photosynthetic pigments. Strain JA124(T) was able to utilize sulfide, sulfate, thiosulfate, sulfite, thioglycollate and cysteine as sulfur sources. Strain JA124(T) was able to grow photolithoautotrophically, photolithoheterotrophically and photo-organoheterotrophically. Chemotrophic and fermentative growth could not be demonstrated. Strain JA124(T) lacks diazotrophic growth and acetylene reduction activity. Pyridoxal phosphate is required for growth. During growth on reduced sulfur sources as electron donors, sulfur is deposited intermediately as a number of small granules within the cell. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA124(T) clusters with species of the genus Marichromatium belonging to the class Gammaproteobacteria. The highest sequence similarities of strain JA124(T) were found with the type strains of Marichromatium indicum (98 %), Marichromatium purpuratum (95 %) and Marichromatium gracile (93 %). However, DNA-DNA hybridization with Marichromatium indicum DSM 15907(T) revealed relatedness of only 65 % with strain JA124(T). The DNA base composition of strain JA124(T) was 67 mol% G+C (by HPLC). Based on 16S rRNA gene sequence analysis, morphological and physiological characteristics and DNA-DNA hybridization studies, strain JA124(T) (=ATCC BAA-1316(T)=JCM 13911(T)) is sufficiently different from other Marichromatium species to merit its description as the type strain of a novel species, Marichromatium bheemlicum sp. nov
Rubrivivax benzoatilyticus sp.nov., an aromatic hydrocarbon-degrading purple betaproteobacterium
A brown-coloured bacterium was isolated from photoheterotrophic (benzoate) enrichments of flooded paddy soil from Andhra Pradesh, India. On the basis of 16S rRNA gene sequence analysis, strain JA2(T) was shown to belong to the class Betaproteobacteria, related to Rubrivivax gelatinosus (99 % sequence similarity). Cells of strain JA2(T) are Gram-negative, motile rods with monopolar single flagella. The strain contained bacteriochlorophyll a and most probably the carotenoids spirilloxanthin and sphaeroidene, but did not have internal membrane structures. Intact cells had absorption maxima at 378, 488, 520, 590, 802 and 884 nm. No growth factors were required. Strain JA2(T) grew on benzoate, 2-aminobenzoate (anthranilate), 4-aminobenzoate, 4-hydroxybenzoate, phthalate, phenylalanine, trans-cinnamate, benzamide, salicylate, cyclohexanone, cyclohexanol and cyclohexane-2-carboxylate as carbon sources and/or electron donors. The DNA G+C content was 74.9 mol%. Based on DNA-DNA hybridization studies, 16S rRNA gene sequence analysis and morphological and physiological characteristics, strain JA2(T) is different from representatives of other photosynthetic species of the Betaproteobacteria and was recognised as representing a novel species, for which the name Rubrivivax benzoatilyticus sp. nov. is proposed. The type strain is JA2(T) (=ATCC BAA-35(T)=JCM 13220(T)=MTCC 7087(T))
Rhodovulum marinum sp. nov., a novel phototrophic purple non-sulfur alphaproteobacterium from marine tides of Visakhapatnam, India
A yellowish-brown bacterium was isolated from enrichment cultures inoculated with seawater samples from the eastern coast of India (Visakhapatnam) under photoheterotrophic conditions. Enrichment and isolation in a medium containing 2 % NaCl (w/v) yielded strain JA128T, which has ovoid to rod-shaped cells, also forms chains and is non-motile. Phylogenetic analysis on the basis of 16S rRNA gene sequences showed that strain JA128T clusters with the Alphaproteobacteria and the sequence similarity with its closest relatives, Rhodovulum iodosum and Rhodovulum sulfidophilum, was 95 %. Strain JA128T contained vesicular intracytoplasmic membranes, bacteriochlorophyll a and carotenoids of the spheroidene series. Strain JA128T was mesophilic, slightly acidophilic, slightly halophilic and grew photoheterotrophically with a number of organic compounds as carbon source and electron donor. It was unable to grow photoautotrophically, chemoautotrophically or by fermentative modes. It did not utilize sulfide, thiosulfate or hydrogen as electron donors. Thiamine was required as a growth factor. Based on the 16S rRNA gene sequence analysis, morphological and physiological characteristics, strain JA128T was significantly different from other species of the genus Rhodovulum and was recognized as a novel species for which the name Rhodovulum marinum sp. nov. is proposed. The type strain is JA128T (=ATCC BAA 1215T=CCUG 52183T=JCM 13300T)
<span style="font-size: 21.5pt;mso-bidi-font-size:14.5pt;font-family:"Times New Roman","serif"; color:black">Photobiodegradation of pyridine by <i>Rhodopseudomonas palustris </i>JAI </span>
967-970<span style="font-size:
15.5pt;mso-bidi-font-size:8.5pt;font-family:" times="" new="" roman","serif";="" color:black"="">A purple non-sulfur bacterium isolated from dairy effluent was
identified as Rps. palustris JA1. This organism was able to grow on
pyridine as sole source of carbon in a light dependent anaerobic process with a
doubling time of 30 h. Intermediates of pyridine photobiodegradation were
identified as glycine and malonate, produced in stoichiometric molar ratios
with simultaneous utilization, yielding biomass.<span style="font-size:
18.0pt;mso-bidi-font-size:11.0pt;color:black">
</span
Phytonematode Diversity in Tomato Crops of Chittoor District, Andhra Pradesh, India: A Comprehensive Survey, Distribution, and Community Analysis
The present study was undertaken to analyze the distribution and community analysis of important plant parasitic nematodes associated with the vegetable crop tomato in Chittoor District of Andhra Pradesh. The study revealed that maximum infestation is observed in somala mandal and least in Chowdepalle mandals of Chittoor District of Andhra Pradesh. Plant parasitic nematodes viz., Meloidogyne incognita, Hoplolaimus spp., and Tylenchorynchus spp. etc. was found to be associated with tomato crops. It has been observed that M. incognita population was found to be maximum in tomato crops at Chittoor Districts of Andhra pradesh. The prominence value was found to be maximum for root knot nematode in tomato crops having 8.76/200 cc. The data also revealed that M. incognita absolute frequency in tomato was 100% and absolute density is around 87.60% while the genera Hoplolaimus showed the least occurrence frequency of 40% and absolute density of 1.56%. From these studies it can be interpreted that M. incognita is most predominant nematode and cause damage substantially to tomato crop grown in Chittoor District of Andhra Pradesh
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