摘要:

Chemical differences were noted between two Antarctic cryptoendolithic (hidden within rock) microenvironments colonized by different microbial communities. Microenvironments dominated by cyanobacteria (BPC) had a higher pH (pH 7–8) than those dominated by lichen (LTL) (pH 4.5–5.5). In order to understand the interactions between the microbiota and the inorganic environment, the inorganic environment was characterized. Water‐soluble, carbonate‐bound, metal‐oxide, organically bound, and residual inorganic species were sequentially extracted from rock samples by chemical means. Each fraction was then quantified using inductively coupled plasma atomic emission spectrometry. BPC contained much more water‐soluble and carbonate‐bound Ca and Mg than LTL. Metal‐oxide species of Al, Fe, and Mn were more abundant in LTL than BPC. Metal oxides appeared to be mobilized (in the order Mn > Fe > Al) from the LTL lichen zone but remained immobile in BPC sandstone. The distribution of K and P bound to metal oxide reflected the distribution of iron oxide in LTL, an indication of the importance of iron in controlling the availability of nutrients in this ecosystem. Metal oxides in turn were likely controlled or influenced by organic matter associated with the lichen community. Despite overall depletion of Fe, Al, and K in the lichen zone, SEM X‐ray analysis showed that they were enriched in fungal hyphae. Water‐soluble P was present despite the presence of metal oxides, which sequester phosphate. This has biological relevance since P is an essential nutrient.

ISSN:0149-0451    

DOI:10.1080/01490458909377858

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Bacillus licheniformisproduced a water‐insoluble levan which has potential application as a selective plugging agent in microbial enhanced oil recovery (MEOR). The microorganism grew on sucrose, glucose, and fructose but produced levan only on sucrose. Plugging may thus be selectively controlled in the reservoir by substrate manipulation.B. licheniformisand a crude preparation of its extracellular enzymes were evaluated for their ability to produce levan under reservoir conditions. Oil reservoirs which have a temperature of less than 55°C, a pH between 6 and 9, a pressure less than 500 atm, and a salt concentration of 4% or less are potentially suitable. Examples of such reservoir conditions are found in Lloydminster on the Alberta‐Saskatchewan border, one of the largest Canadian oil reserves.

ISSN:0149-0451    

DOI:10.1080/01490458909377859

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Biogenesis of methane in the heartwood of diseased trees has been shown, but never in timber in service. Studies were undertaken to establish whether methan‐ogens and sulfate‐reducers were present in wooden pit props and drainage water from underground sites in a gold mine. The predominant methanogen in the mine ecosystem was tentatively identified asMethanobacterium bryantii.The sulfate‐reducers comprisedDesulfovibrio desulfuricansandDesulfotomaculum antarcticum.Most probable numbers (MPN) of bacteria indicated that 3.5 × 105methanogenic and 7.9 × 103sulfate‐reducing bacteria were present per milliliter of stagnant drainage water. MPN values per gram of timber were lower for methanogens but comparable for sulfate‐reducers. Laboratory model systems predicted a maximum rate of methan‐ogenesis of 2.3 mL methane/g wood per day; however, rates would never attain this value because of nutrient limitations and environmental restrictions. Analysis of gas samples extracted from sealed areas of the gold mine verified the presence of methane.

ISSN:0149-0451    

DOI:10.1080/01490458909377860

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Two novel strains of rod‐shaped methanogens were isolated from oil‐producing wells of high temperature and moderate salinity in the San Miguelito field. The strains grow at 65°C in media containing 6% NaCl, form large aggregates of cell materials in liquid culture, and produce methane from H2and CO2only. The geochemistry and microbiology of the oil reservoir and surrounding areas support the view that not all methanogens isolated from oil wells are results of colonization during or after human exploration, and that methanogens can exist in situ under thermal, haline conditions.

ISSN:0149-0451    

DOI:10.1080/01490458909377861

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0149-0451    

DOI:10.1080/01490458909377862

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0149-0451    

DOI:10.1080/01490458909377863

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0149-0451    

DOI:10.1080/01490458909377864

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0149-0451    

DOI:10.1080/01490458909377857

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor