Genki I. Matsumoto

Centre for Cellular and Molecular Biology, Bhaganagar, Andhra Pradesh, India

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Publications (44)58.44 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: We studied the geochemical features and compound-specific (CS)-δ13C of hydrocarbons and fatty acids in soil samples from the McMurdo Dry Valleys in the Antarctic to elucidate their source organisms and characteristics of their environments. Total organic carbon contents in soil samples were extremely low reflecting extremely harsh environments for organisms. Normal-alkanes ranging in carbon chain length from n-C14 to n-C38 with the predominance of odd-carbon numbers were found, together with n-alkenes (n-C23:1 to n-C27:1). Normal-alkanoic acids ranging in carbon chain length from n-C10 to n-C30 with the predominance of even-carbon numbers were detected in the samples, along with small amounts of branched (iso and anteiso) and n-alkenoic acids. CS-δ13C values of long-chain n-alkanes (n-C20 to n-C29) ranged from −30.4 to −26.6‰. CS-δ13C values of n-alkanoic acids with short-chain carbon numbers (n-C14 to n-C19) ranging from −27.7 to −21.7‰ were much higher than those of long-chain carbon numbers (n-C20 to n-C30, −32.5 to −25.3‰). The geochemical features and CS-δ13C values of long-chain n-alkanes and n-alkanoic acids revealed that they are originated from lichen and/or vascular plant debris from the pre- and inter-glacial periods in this region, whereas short-chain n-alkanoic acids are come from microalgae and cyanobacterial debris. CS-δ13C values suggest that they are derived from gymnosperms and/or C4 plants in the cold and dry environments of the pre- and inter-glacial periods of the McMurdo Dry Valleys region.
    Polar Science 01/2010;
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    ABSTRACT: We analyzed photosynthetic pigments of algae and phototrophic bacteria in the 81-m sediment core (HDP-04) of Lake Hovsgol, NW Mongolia, to reconstruct the changes in algal assemblage and lake environment for the last 1Ma. In HDP-04, pheophytin a, pyropheophytin a, and steryl esters of pyropheophorbide a (steryl chlorin esters: SCEs-a) were detected as major chlorophyll a derivatives. They indicate that algal productivity fluctuated in response to changes in lacustrine environment, presumably in response to climatic changes. Significant concentrations of intact carotenoids, zexanthin, lutein, and β,β-carotene, as well as cis-isomers of zeaxanthin, diatoxanthin, alloxanthin, and β,β-carotene were found to be preserved in the sediments as old as 1Ma. The relative concentration of these algal carotenoids showed changes in algal assemblage for the last 1Ma. Besides algal pigments, bacteriochlorophylls e and isorenieratene, characterstic to brown-Chlorobium were detected transiently only at the sediment depth of 19–21m, providing evidence for the development of anoxia in photic zone because brown-Chlorobium requires hydrogen sulfide as an electron donor in their photosynthesis. The sediment layers between 21 and 52m where concentrations of algal carotenoids are higher than those of chlorophyll derivatives may correspond to the periods with shallower lake-water level because increased accumulation of algal carotenoids in surface sediments needs short transport pathway in the water column to evade abiotic/biotic oxidation during transportation.
    Quaternary International - QUATERN INT. 01/2009; 205(1):74-83.
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    ABSTRACT: High-time resolution 14C dating of Lake Baikal sediment cores indicates negative and positive anomalies of calculated linear sedimentation rate (LSR; 1.1 and 35.6 cm/ka, respectively) during the period of climate transition from the last glacial to Holocene. The timing of the Lake Baikal apparent LSR anomalies is consistent with that of the changes in the atmospheric radiocarbon concentration (Δ14C) during Younger Dryas rapid cooling event. 14C dating of lipids in the Lake Baikal surface sediments revealed that the sources of sedimentary lipids were different in each basin. In the Northern Basin of Lake Baikal, the 14C age of total lipids from the surface sediment (4.0 14C ka) was found to be older than that of TOC (1.6 14C ka). By contrast, the 14C age of total lipids in the Southern Basin was younger than that of the TOC by ca. 0.7–3.0 ka.In the Lake Hovsgol sediment cores, ages of the main lithologic boundaries during the last glacial–interglacial transition were estimated based on new 14C data sets. TOC concentration in the cores started to rapidly increase at 13.8 ± 0.3 14C ka at the base of the basinwide finely laminated layer deposited during Bølling/Allerød. The base of the layer diatomaceous mud corresponds to the end of Younger Dryas event (10.6 ± 0.1 14C ka).
    Quaternary International 01/2009; 205:12-20. · 1.96 Impact Factor
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    ABSTRACT: Past changes in phytoplankton assemblages in Lake Baikal over the last 4.5 Ma, both in population and composition, are inferred from the downcore profiles of the relatively stable chlorophyll derivatives steryl esters of pyropheophorbides a and b (steryl chlorine esters; SCEs) in the 0–200 m section of the BDP-98 drill core, supplemented by the data on biogenic silica (BSi) and total organic carbon (TOC) contents. SCEs-a and -b dominate among sedimentary chlorophyll derivatives in the BDP-98 sediments except for the upper few meters, indicating their high stability during diagenetic alteration of sediments. The depth (age) profiles of SCEs-a are consistent with BSi and TOC profiles and are interpreted as reflecting primary productivity of the lake in the past. Baikal proxies reveal close correlation with marine oxygen isotope records (MIS stratigraphy). These observations confirm that climate change in the northern hemisphere has been a primary factor controlling the total phytoplankton productivity in Lake Baikal during the last several million years.Among SCEs-a, C30 (dinostanol)-SCE-a, a marker of dinoflagellates was identified by GC–MS analysis. SCE-b, a marker of green algae, was identified by its UV–vis spectrum. The ratio of C30-SCE-a to total SCEs-a (TSCEs-a) was higher during 4.5–4.2 and 1.7–1.3 Ma, suggesting that dinoflagellates proliferated preferentially in those periods. The early Pleistocene maximum of this ratio corresponds to the broad minimum of diatom abundance previously suggested to have recorded a prolonged regional cooling. An abrupt increase in the SCE-b/TSCEs-a ratio was observed at 2.5–2.6 Ma, indicating that green algae containing chlorophyll b have proliferated in Lake Baikal during this period. This interval has also been suggested to contain evidence for a significant regional cooling based on minima of diatom abundance and BSi in sediments. The depth profile of C27Δ5 (cholesterol)-SCE-a relative to TSCEs-a showed a trend similar to that of BSi, suggesting that C27Δ5-SCE-a/TSCEs-a ratio is a potential marker of diatoms in Lake Baikal.Certain mismatches between the Lake Baikal profiles of biological indicators and the marine oxygen isotope records, as well as the slight temporal offsets between different Lake Baikal biological marker signals suggest that the regional component of climatic and/or lacustrine environmental changes also have played a role in determining the composition of the Lake Baikal Plio-Pleistocene phytoplankton assemblage.
    Quaternary International. 01/2009;
  • Genki I. MATSUMOTO, Yuki AKUTSU, Nobuki TAKAMATSU
    Japanese Journal of Limnology (Rikusuigaku Zasshi) 01/2006; 67(1):1-11.
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    ABSTRACT: Twelve strains of psychrophilic bacteria were isolated from cyanobacterial mat samples collected from various water bodies in the McMurdo Dry Valley region of Antarctica. All the isolates were Gram-negative, non-motile, coccoid, psychrophilic, halotolerant bacteria and had C(16 : 1)omega7c, C(17 : 1)omega8c and C(18 : 1)omega9c as the major fatty acids, ubiquinone-8 as the respiratory quinone and DNA G+C content of 41-46 mol%. Based on these characteristics, the isolates were assigned to the genus Psychrobacter. Based on their SDS-PAGE profiles, the 12 isolates could be categorized into three groups. Six isolates of Group I were identified as representing strains of Psychrobacter okhotskensis. However, using detailed phenotypic and chemotaxonomic characteristics and phylogenetic analysis based on their 16S rRNA gene sequences, strain CMS 39(T), the only strain from Group II, and strain CMS 56(T), a representative strain of Group III, were different from each other and from all recognized species of Psychrobacter. Therefore, it is proposed to classify CMS 39(T) (=DSM 15337(T)=MTCC 4208(T)) and CMS 56(T) (=DSM 15339(T)=MTCC 4386(T)) as representing the type strains of novel species of Psychrobacter, for which the names Psychrobacter vallis sp. nov. and Psychrobacter aquaticus sp. nov., respectively, are proposed.
    International journal of systematic and evolutionary microbiology 04/2005; 55(Pt 2):757-62. · 2.11 Impact Factor
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    ABSTRACT: Thirty-one bacteria that belonged to the genus Pseudomonas were isolated from cyanobacterial mat samples that were collected from various water bodies in Antarctica. All 31 isolates were psychrophilic; they could be divided into three groups, based on their protein profiles. Representative strains of each of the three groups, namely CMS 35(T), CMS 38(T) and CMS 64(T), were studied in detail. Based on 16S rRNA gene sequence analysis, it was established that the strains were related closely to the Pseudomonas fluorescens group. Phenotypic and chemotaxonomic characteristics further confirmed their affiliation to this group. The three strains could also be differentiated from each other and the closely related species Pseudomonas orientalis, Pseudomonas brenneri and Pseudomonas migulae, based on phenotypic and chemotaxonomic characteristics and the level of DNA-DNA hybridization. Therefore, it is proposed that strains CMS 35(T) (=MTCC 4992(T)=DSM 15318(T)), CMS 38(T) (=MTCC 4993(T)=DSM 15319(T)) and CMS 64(T) (=MTCC 4994(T)=DSM 15321(T)) should be assigned to novel species of the genus Pseudomonas as Pseudomonas antarctica sp. nov., Pseudomonas meridiana sp. nov. and Pseudomonas proteolytica sp. nov., respectively.
    International journal of systematic and evolutionary microbiology 06/2004; 54(Pt 3):713-9. · 2.11 Impact Factor
  • G S N Reddy, G I Matsumoto, S Shivaji
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    ABSTRACT: Strain CMS 21w(T) was isolated from a cyanobacterial mat sample taken from a pond located in the McMurdo Dry Valleys, Antarctica. Based on its phenotypic, chemotaxonomic and phylogenetic properties, strain CMS 21w(T) was identified as a member of the genus SPOROSARCINA: At the 16S rRNA gene level, CMS 21w(T) exhibited about 93-96 % similarity to all reported species of Sporosarcina and exhibited a maximum similarity of 96 % to both Sporosarcina globispora and Sporosarcina psychrophila. Based on more than 3 % difference at the 16S rRNA gene sequence level and the presence of distinct differences with respect to phenotypic, biochemical and chemotaxonomic features, strain CMS 21w(T) (=MTCC 4670(T)=DSM 15428(T)=CIP 107784(T)) is proposed as the type strain of a novel species of Sporosarcina, Sporosarcina macmurdoensis sp. nov.
    International journal of systematic and evolutionary microbiology 10/2003; 53(Pt 5):1363-7. · 2.11 Impact Factor
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    ABSTRACT: Two unique psychrophilic strains (CMS 76rT and CMS 81yT) were isolated from a cyanobacterial mat sample from a pond in Wright Valley, McMurdo, Antarctica. Both isolates were assigned to the genus Leifsonia, since they were gram-positive, curved rods, non-motile, catalase-positive, contained DL-2,4-diaminobutyric acid, menaquinone MK-11, phosphatidylglycerol and diphosphatidylglycerol, had a high content of anteiso- and iso-branched fatty acids and had a DNA G + C content of 64-66 mol%. In addition, both isolates were related to the five reported species of Leifsonia at a level of about 95-96% 16S rDNA sequence similarity and differed from one another by 2.5%. Strains CMS 76rT and CMS 81yT also differed from one another in many other phenotypic characteristics and exhibited only 30% relatedness at the DNA-DNA level, thus indicating that they represent two different species. Furthermore, these two isolates also showed many distinct differences with respect to the reported species of Leifsonia in terms of their phenotypic characteristics, biochemical properties, chemotaxonomic features, sensitivity to various antibiotics and 16S rDNA similarity, clearly indicating that strains CMS 76rT (= MTCC 4210T = DSM 15304T = CIP 107783T) and CMS 81yT (= MTCC 4657T = DSM 15303T = CIP 107785T) represent the type strains of two novel species of Leifsonia, for which the names Leifsonia rubra sp. nov. and Leifsonia aurea sp. nov. are proposed.
    International journal of systematic and evolutionary microbiology 08/2003; 53(Pt 4):977-84. · 2.11 Impact Factor
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    ABSTRACT: Strain CMS 76orT, an orange-pigmented bacterium, was isolated from a cyanobacterial mat sample from a pond located in McMurdo Dry Valley, Antarctica. On the basis of chemotaxonomic and phylogenetic properties, strain CMS 76orT was identified as a member of the genus Kocuria. It exhibited a 16S rDNA similarity of 99.8% and DNA-DNA similarity of 71% with Kocuria rosea (ATCC 186T). Phenotypic traits confirmed that strain CMS 78orT and K. rosea were well differentiated. Furthermore, strain CMS 76orT could be differentiated from the other reported species of Kocuria, namely Kocuria kristinae (ATCC 27570T), Kocuria varians (ATCC 15306T), Kocuria rhizophila (DSM 11926T) and Kocuria palustris (DSM 11025T), on the basis of a number of phenotypic features. Therefore, it is proposed that strain CMS 76orT (= MTCC 3702T = DSM 14382T) be assigned to a novel species of the genus Kocuria, as Kocuria polaris.
    International journal of systematic and evolutionary microbiology 02/2003; 53(Pt 1):183-7. · 2.11 Impact Factor
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    ABSTRACT: Thirteen orange-pigmented bacteria associated with cyanobacterial mat samples collected from four different lakes in McMurdo, Antarctica, were isolated. Twelve of the isolates, which were coccoid in shape, were very similar and possessed all the characteristics of the genus Planococcus and represented a new species, which was assigned the name Planococcus antarcticus sp. nov. (CMS 26or(T)). Apart from the phenotypic differences, P. antarcticus differed from all reported species of Planococcus by more than 2.5% at the 16S rRNA gene sequence level. In addition, at the DNA-DNA hybridization level, it exhibited very little similarity either with P. mcmeekinii (30%-35%), P. okeanokoites (26%-29%), or CMS 53or(T) (15%-25%), the three species with which it is closely related at the rRNA gene sequence level (2.5%-2.9%). P. antarcticus also showed only 2.5% difference in its 16S rRNA gene sequence compared with the P. alkanoclasticus sequence. But it was distinctly different from P. alkanoclasticus, which exists only as rods, is mesophilic and phosphatase positive, can hydrolyze starch, cannot utilize succinate, glutamate, or glucose, and cannot acidify glucose. Most important, P. antarcticus and P. alkanoclasticus varied distinctly in their fatty acid composition in that C(15:0), C(15:1), C(16:0), iso-C(16:1), and C(17:0) were present only in P. antarcticus but absent in P. alkanoclasticus. CMS 53or(T), the thirteenth isolate, was also identified as a new species of Planococcus and was assigned the name Planococcus psychrophilus sp. nov. This species was distinctly different from all the reported species, including the new species P. antarcticus, with respect to a number of phenotypic characteristics. At the 16S rRNA gene sequence level, it was closely related to P. okeanokoites (98.1%) and P. mcmeekinii (98%), but with respect to the DNA-DNA hybridization, the similarity was only 35%-36%. The type strain of P. antarcticus is CMS 26or(T) (MTCC 3854; DSM 14505), and that of P. psychrophilus is CMS 530r(T) (MTCC 3812; DSM 14507).
    Extremophiles 07/2002; 6(3):253-61. · 2.20 Impact Factor
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    ABSTRACT: Strain CMS 90rT, a red-pigmented bacterium, was isolated from a cyanobacterial mat sample from a pond located in McMurdo, Antarctica. Based on its chemotaxonomic and phylogenetic properties, strain CMS 90r(T) was identified as a member of group I of Arthrobacter. It shared 16S rDNA similarity of 98% with Arthrobacter oxydans ATCC 14358T and Arthrobacter polychromogenes ATCC 15216T, while DNA-DNA similarities determined for these three organisms were less than 70%. It also differed from all 17 reported Arthrobacter species with A3alpha-variant peptidoglycan in that it possessed a unique peptidoglycan (Lys-Gly-Ala3) and contained galactose, glucose, ribose and rhamnose as cell-wall sugars. These data and the presence of diagnostic phenotypic traits support the description of CMS 90r(T) as a novel species of Arthrobacter, for which the name Arthrobacter roseus sp. nov. is proposed. The type strain is strain CMS 90r(T) (= MTCC 3712T = DSM 14508T).
    International journal of systematic and evolutionary microbiology 06/2002; 52(Pt 3):1017-21. · 2.11 Impact Factor
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    G S Reddy, R K Aggarwal, G I Matsumoto, S Shivaji
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    ABSTRACT: CMS 19YT, a psychrophilic bacterium, was isolated from a cyanobacterial mat sample from a pond in Antarctica and was characterized taxonomically. The bacterium was aerobic, gram-positive, non-spore-forming, non-motile, exhibited a rod-coccus growth cycle and produced a yellow pigment that was insoluble in water but soluble in methanol. No growth factors were required and it was able to grow between 5 and 30 degrees C, between pH 6 and pH 9 and tolerated up to 11.5% NaCl. The cell wall peptidoglycan was Lys-Thr-Ala3 (the A3alpha variant) and the major menaquinone was MK-9(H2). The G+C content of the DNA was 64+/-2 mol%. The 16S rDNA analysis indicated that CMS 19YT is closely related to group I Arthrobacter species and showed highest sequence similarity (97.91%) with Arthrobacter agilis. Furthermore, DNA-DNA. hybridization studies also indicated 77% homology between CMS 19YT and A. agilis. It differed from A. agilis, however, in that it was psychrophilic, non-motile, yellow in colour, exhibited a rod-coccus growth cycle, had a higher degree of tolerance to NaCl and was oxidase- and urease-negative and lipase-positive. In addition, it had a distinct fatty acid composition compared to that of A. agilis: the predominant fatty acids were C15:0, anteiso-C15:0, C16:0, iso-C16:0, C17:0, anteiso-C17:0 and C18:0. It is proposed, therefore, that CMS 19YT should be placed in the genus Arthrobacter as a new species, i.e. Arthrobacter flavus sp. nov. The type strain of A. flavus is CMS 19YT (= MTCC 3476T).
    International journal of systematic and evolutionary microbiology 08/2000; 50 Pt 4:1553-61. · 2.11 Impact Factor
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    ABSTRACT: Lithium distributions in lake and pond waters of the McMurdo Dry Valleys of southern Victoria Land, Antarctica were studied to elucidate the origin of dissolved salts and the evolutionary history of the lakes and ponds. The EfLi [(Li/Cl)sample/(Li/Cl)seawater] values of the bottom waters in Lakes Bonney and Fryxell were higher than unity (EfLi=4–7), indicating that the salts originated from sea salts (probably relict seawater) and have been subsequently modified by the contribution of meltwaters containing atmospheric fallout and/or rock and soil weathering products. In contrast, extremely high Li concentrations with high EfLi values in the Don Juan Pond water (EfLi = 180) and the bottom waters of Lake Vanda (EfLi = 40) suggest that the salts originated from deep groundwaters influenced mainly by saline water-rock interactions, as supported by the dissolution experiments of granite in NaCl solution. The low Li concentrations of pond waters with high EfLi values in the Labyrinth indicate that the salts are derived from atmospheric fallout. The decrease of the EfLi values with the increase of Cl concentrations can be explained by the repeated cycles of the migration of Li into the ice phase and subsequent ablation of surface ice, as indicated by seawater freezing experiments.
    Antarctic Science 11/1998; 10(04):439 - 448. · 1.63 Impact Factor
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    Genki I. MATSUMOTO
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    ABSTRACT: The monitoring of climatic changes, water quality, human activity, biomass, biological composition and biological activity in Antarctic lakes and their ecosystems is discussed from a geochemical viewpoint. The changes in lake water levels, ice thickness and the periods of total melting and freezing of lake ice probably reflect climatic changes at the lake sites. Temperature, electric conductivity, pH, dissolved oxygen and redox potential in lake waters could be monitored continuously. Total organic carbon and petroleum-derived hydrocar- bons (such as gasoline, diesel fuels and lubricating oils) could be reflecting human activity in Antarctic lakes near research stations. Chlorophyll-a and/or fatty acid concentrations in lake waters may be useful as markers of biomass. Direct microbial observation by naked eye and/or microscope, culture of orga- nisms, and measurement of biomarkers such as hydrocarbons, fatty acids and sterols are important to monitor biological composition in the lake. Also, 16s rRNA profile may be a useful marker of biological composition. Uptake of 14C labeled compounds and/or DNA synthesis probably reflect biological activity. Normal alkenoic acid/n-alkanoic acid ratios may reflect the degree of degrada- tion of organic matter in the lake. Trandcis-CIA:, alkenoic acid ratios could be used as a starvation or stress lipid index in natural environments.
    01/1994;
  • Genki I. Matsumoto, Kunihiko Watanuki
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    ABSTRACT: Hydrocarbons, n-alkanes, acyclic isoprenoid alkanes, steranes and triterpanes and fatty acids were studied for 6 sediment samples from inland acid hydrothermal environments (Mounts Yakeyama and Tateyama areas and Lake Katanuma) in Japan to clarify their features and to elucidate their source organisms. Normal alkanes carbon chain length ranging from nC13 to nC35 and acyclic isoprenoid alkanes iC16, iC18, pristane, phytane and/or squalane were found, together with steranes and triterpanes. The major hydrocarbons were mainly odd-carbon numbered long-chain , such as nC29 and nC31. Normal alkanoic acids (nC10-nC34) were detected with the predominance of even-carbon numbers maximizing at nC16 and, nC24, nC26 or nC28), along with iso- and anteiso-branched (i, aC12−i, aC17) and n-alkanoic acids nC16:1 (carbon chain length : number of double bonds), nC18:n, nC20:n and nC22:n. These compounds can be attributed to various source organisms bacteria, cyanobacteria, microalgae and vascular plants in and around the hydrothermal environments. Low concentrations of hydrocarbons and fatty acids may reflect the low primary productivity of their harsh environment, but the abundances of n-alkenoic acids reflect that fresh organic matter is continuously supplied by microbial activity and vascular plants. The (22S/22R)-17α,21β(H)-30,31-bishomohopane ratios (0.85–1.5) and (20S/20R)-24-ethyl-5α(H), 17α(H)-cholestane rations (0.25-0.80) revealed that the thermal alteration of biologically synthesized configuration has taken place to a large extent in the hydrothermal environments.
    Organic Geochemistry 01/1990; 15(2):199-208. · 2.52 Impact Factor
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    ABSTRACT: Several strains of bacteria and yeasts were isolated at various depths of a meromictic lake, Lake Vanda, to clarify their physiological properties in rela- tion to their habitats. Gram-negative rods, strains T-1, T-2, T-6, T-14, 3B, and Pseudomonas sp. 3G, were isolated at depths of above 30 m where the temperature is 5-7OC and the chlorinity is low. T-1, T-6, 3B, and 3G grow aerobically below 27OC, optimally about 20° under low salt concentration (
    01/1990;
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    ABSTRACT: Organic geochemical studies of 12 soil samples from Wright and Taylor Valleys of the McMurdo Dry Valleys (Ross Desert) in southern Victoria Land, Antarctica, were carried out. Long-chain n-alkanoic acids (C20−C34), with predominance of even-carbon numbers, were abundant in all the samples. 3-Hydroxy acids (C8-C30) with a predominance of even-carbon numbers were found in the samples, together with 2-, ω- and (ω-1)-hydroxy acids. α,ω-Dicarboxylic acids (C8-C31) were detected having near-unity values of carbon preference indices; mainly the C13 dicarboxylic acid predominated. Visual kerogen revealed that amorphous materials are major components (68–98%) with small amounts of very fine coals (2–32%), but no woody and herbaceous materials. The occurrence of mature isomers of steranes and triterpanes, the paucity of n-alkenoic acids and data from the microscopic study suggest that organic components in the soil samples are derived from erosion of Beacon Supergroup sedimentary rocks and past biological debris containing vascular plan waxes as well as wind-transported cyano-bacterial mats, including cyanobacteria, microalgae, bacteria and fungi, rather than from living organisms.
    Organic Geochemistry. 01/1990;
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    ABSTRACT: A large number of fresh water and saline ponds are located in the Labyrinth (77 33 S, 160 50 E) of the upper Wright Valley in the Dry Valleys region of southern Victoria Land, Antarctica. It is situated near the terminus of the Wright Upper Glacier between 800–1000 m above sea level. From a limnological point of view, the most interesting problems concerning these saline ponds are the origin of their salts and their evolutional history.Chloride ion contents vary remarkably among the ponds ranging from 0.0049 to 52.4 g kg–1. Surprisingly, more than a half of the ponds are saline with the highest chloride ion content being 2.7 times greater than that of seawater. The D and 18O values of the pond waters indicate a snow and/or glacial meltwaters origin, and that the ponds underwent subsequent alteration due to evaporation or freezing. The composition of chemical components reveal no evidence of trapped seawater. Thus the salt concentrations in the Labyrinth pond waters must be explained principally by the accumulation of atmospheric salts and subsequent repeated cycles of evaporation and freezing of the pond waters over considerable time periods.
    Hydrobiologia 02/1989; 172(1):255-264. · 1.99 Impact Factor
  • Genki I. Matsumoto, Kunihiko Watanuki, Tetsuya Torrii
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    ABSTRACT: Vertical distribution of organic constituents, i.e. total organic carbon (TOC), hydrocarbons, fatty acids and hydroxy acids in water and sediment samples from Lake Fryxell (77 35 S, 163 15 E) of southern Victoria Land, Antarctica were studied to elucidate their features in relation to stratification of the lake waters and likely distribution of microorganisms. The TOC content of the surface water (5.0 m; just below the ice cover of 4.50 m thickness) was 1.4 mg l–1. It increased markedly with depth and attained a maximum value of 21.7 mg C l–1 at a depth of 17.5 m, but decreased to the bottom (13.3 mg C l–1). The high TOC content of the anoxic bottom layers (> 15 m) is attributable to the concentration of refractory organic substances over long periods following the degradation of labile organic constituents. Hydrocarbons were not found in the water column, but the major constituent of the bottom sediment was n-C29 : 2 alkene. Total concentrations of fatty acids in the oxic layers ( 10 m) were highest at 10.0 m and much higher than those in the anoxic layers (> 10 m), probably reflecting the phytoplankton population. The content of branched (iso and anteiso) fatty acids and 3-hydroxy acids in the anoxic layers were much greater than those in the oxic layers which would seem to reflect the distribution of bacterial abundance. The differences of organic composition between the water column and sediments imply that sinking dead organisms were quickly degraded in the lake bottom. Also, the composition of microorganisms in the water column must be very different from that in the sediments.
    Hydrobiologia 02/1989; 172(1):291-303. · 1.99 Impact Factor

Publication Stats

540 Citations
58.44 Total Impact Points

Institutions

  • 2000–2005
    • Centre for Cellular and Molecular Biology
      Bhaganagar, Andhra Pradesh, India
  • 1994–2005
    • Otsuma Women's University
      Edo, Tōkyō, Japan
  • 1990
    • Shonan Institute of Technology
      Fujisawa, Kanagawa, Japan
  • 1987–1990
    • The University of Tokyo
      • • College of Art and Science & Graduate School of Arts and Sciences
      • • Department of Chemistry
      Tokyo, Tokyo-to, Japan
  • 1988–1989
    • Chiba Institute of Technology
      Edo, Tōkyō, Japan
  • 1980–1986
    • Tokyo Metropolitan University
      • Department of Chemistry
      Tokyo, Tokyo-to, Japan