scholarly journals THE VASELINE TUBE AND SYRINGE METHOD OF MICRO GAS ANALYSIS OF BACTERIAL CULTURES

1922 ◽  
Vol 35 (5) ◽  
pp. 667-684
Author(s):  
J. Howard Brown

There has been described the use of the vaseline tube and the tuberculin syringe for the study of gas production by bacteria. A comparison is made of some of the results obtained by the use of the method here described, the Smith fermentation tube, and the tube of Eldredge and Rogers. The reports of CO2 production by certain streptococci by Ayers, Rupp, and Mudge and by Bacterium typhosus by Nichols have been confirmed by the author's method. The data presented serve to illustrate the accuracy and technical possibilities of the method. In addition to economy of glassware, medium, and labor, the vaseline tube and syringe method of micro gas analysis possesses the following advantages. (1) Gas produced above either liquid or solid media may be measured and analyzed. (2) The gas produced may be measured in terms of a definite and constant quantity of medium used. (3) The vaseline tube provides a closed system from which gases do not escape into the air. (4) Separate determinations of the CO2 produced in and above fluid media may be made. (5) Determinations may be made from very small samples of material. (6) Numerous gas analyses of the same culture may be made at various times during the growth of the culture without contaminating or destroying it. (7) Gas production may be observed under both anaerobic and controlled aerobic conditions.

2021 ◽  
pp. 48-52
Author(s):  
F.G. Hasanov ◽  
◽  
A.M. Samedov ◽  
S.B. Bairamov ◽  
◽  
...  

Produced water isolated from the oil in oil-gas production is pumped into the injection wells after cleaning from salt deposits and mechanical impurities. In the mixture of high-mineralised produced water, salt deposits making the technological equipment and pipes useless while gathering and transportation, reduce the permeability of injection wells. Carried out experimental researches show that for each ton it is necessary to pump 100 g of KD-7 inhibitor to prevent salt deposition in the mixture of produced water. Technological processes should be performed in a closed system, and the territories contaminated with oil and produced water cleaned and equipped well.


2014 ◽  
Vol 22 (04) ◽  
pp. 1450010 ◽  
Author(s):  
Xu Yang Xiao ◽  
Run Ping Chen

The propagation of elastic longitudinal waves in one-dimensional (1D) phononic crystals (PNCs) consisting of alternating solid and fluid media is comprehensively analyzed in theory. We demonstrate the acoustic band gap (ABG) structure determined by the dispersion relation for longitudinal waves at normal incidence. According to the band structure, we design a sub-PNC by setting a reasonable thickness ratio of fluid and solid media, and then form a phononic heterostructure by merging this PNC and other PNC designed in advance. We have shown that the wide band gap exists in such a phononic heterostructure for elastic longitudinal waves at normal incidence. For oblique incidence, the wide band gap shifts towards high frequency regions, meanwhile a low-frequency band gap is split.


Author(s):  
Gerardo Pamanes-Carrasco ◽  
Manuel Murillo-Ortiz ◽  
Esperanza Herrera-Torres ◽  
Agustin Corral-Luna

The aim of this study was to evaluate the inclusion of water hyacinth (WH) as a possible substitution of alfalfa hay (AH) in diets of beef cattle on in vitro methane production, gas kinetics and chemical composition. AH in the diets was substituted by WH at 0% (T1, as a control), 25% (T2), 50% (T3), 75% (T4) and 100% (T5). Methane, CO2 and gas production parameters were recorded after 24 and 48h of incubation. NDF, condensed tannins and total phenolic compounds increased when AH was substituted. Likewise, the net gas production decreased linearly when AH was substituted. However, gas production rate among treatments were similar. Methane and CO2 production decreased linearly with inclusion of WH. These results indicate that WH arises as a promising alternative for mitigating methane production in ruminants.


2018 ◽  
Author(s):  
Josefine Walz ◽  
Christian Knoblauch ◽  
Ronja Tigges ◽  
Thomas Opel ◽  
Lutz Schirrmeister ◽  
...  

Abstract. Permafrost deposits have been a sink for atmospheric carbon for millennia. Thaw-erosional processes, however, can lead to rapid degradation of ice-rich permafrost and the release of substantial amounts of organic carbon (OC). The amount of the OC stored in these deposits and their potential to be microbially decomposed to the greenhouse gases carbon dioxide (CO2) and methane (CH4) depends on climatic and environmental conditions during deposition and the decomposition history before incorporation into the permafrost. Here, we examine potential greenhouse gas production in degrading ice-rich permafrost deposits from three locations in the northeast Siberian Laptev Sea region. The deposits span a period of about 55 kyr and include deposits from the last glacial and Holocene interglacial periods. Samples from all three locations were aerobically and anaerobically incubated for 134 days at 4 °C. Greenhouse gas production was generally higher in glacial than Holocene deposits. In permafrost deposits from the Holocene and the late glacial transition, only 0.1–4.0 % of the initially available OC could be decomposed to CO2, while 0.2–6.1 % could be decomposed in glacial deposits. Within the glacial deposits from the Kargin interstadial period (Marine Isotope Stage 3), local depositional environments, especially soil moisture, also affected the preservation of OC. Sediments deposited under wet conditions contained more labile OC and thus produced more greenhouse gases than sediments deposited under drier conditions. To assess the long-term production potentials, deposits from two locations were incubated for a total of 785 days. However, more than 50 % of the aerobically produced and more than 80 % of anaerobically produced CO2 after 785 days of incubation were already produced within the first 134 days, highlighting the quantitative importance of the slowly decomposing OC pool in permafrost. CH4 production was generally observed in active layer samples but only sporadically in permafrost samples and was several orders of magnitude smaller than CO2 production.


Author(s):  
Sara Stephanie Valencia Salazar ◽  
Guillermo Jiménez-Ferrer ◽  
Isabel Cristina Molina-Botero ◽  
Juan Carlos Ku-Vera ◽  
Ngonidzashe Chirinda ◽  
...  

Enteric methane (CH4) emitted by ruminant species is known as one of the main greenhouse gases produced by the agricultural sector. The objective of this study was to evaluate the chemical composition, in vitro gas production, dry matter degradation (DMD), digestibility, CO2 production and CH4 mitigation potential of five tropical tree species with novel forage potential including: Spondias mombin, Acacia pennatula, Parmentiera aculeata, Brosimum alicastrum and Bursera simaruba mixed at two levels of inclusion (15 and 30%) with a tropical grass (Pennisetum purpureum). Crude protein content was similar across treatments (135 g kg-1 DM), while P. purpureum was characterized by a high content of acid detergent fiber (335.9 g kg-1 DM) and B. simaruba by a high concentration of condensed tannins (20 g kg-1 DM). Likewise, A. pennatula and P. aculeata were characterized by a high content of cyanogenic glycosides and alkaloids respectively. Treatments SM30-PP70 (30% S. mombin + 70% P. purpureum) and BA30-PP70 (30% B. alicastrum + 70% P. purpureum) resulted in superior digestibility than P. purpureum, while in the AP30-PP70 (30% A. pennatula + 70% P. purpureum) was lower than the control treatment (P≤0.05). At 24 and 48 h, treatments that contained P. aculeata and B. alicastrum produced higher CH4 ml g-1 DOM than P. purpureum (P≤0.05). The inclusion of B. simaruba at 30% reduced CH4 at 25% compared to P. purpureum. Tropical tree species can improve the nutritional quality of ruminant rations and reduce CH4 emissions to consequently contribute to the development of sustainable ruminant production systems that generate diverse ecosystem services.


2018 ◽  
Vol 15 (17) ◽  
pp. 5423-5436 ◽  
Author(s):  
Josefine Walz ◽  
Christian Knoblauch ◽  
Ronja Tigges ◽  
Thomas Opel ◽  
Lutz Schirrmeister ◽  
...  

Abstract. Permafrost deposits have been a sink for atmospheric carbon for millennia. Thaw-erosional processes, however, can lead to rapid degradation of ice-rich permafrost and the release of substantial amounts of organic carbon (OC). The amount of the OC stored in these deposits and their potential to be microbially decomposed to the greenhouse gases carbon dioxide (CO2) and methane (CH4) depends on climatic and environmental conditions during deposition and the decomposition history before incorporation into the permafrost. Here, we examine potential greenhouse gas production as a result of degrading ice-rich permafrost deposits from three locations in the northeastern Siberian Laptev Sea region. The deposits span a period of about 55 kyr from the last glacial period and Holocene interglacial. Samples from all three locations were incubated under aerobic and anaerobic conditions for 134 days at 4 ∘C. Greenhouse gas production was generally higher in deposits from glacial periods, where 0.2 %–6.1 % of the initially available OC was decomposed to CO2. In contrast, only 0.1 %–4.0 % of initial OC was decomposed in permafrost deposits from the Holocene and the late glacial transition. Within the deposits from the Kargin interstadial period (Marine Isotope Stage 3), local depositional environments, especially soil moisture, also affected the preservation of OC. Sediments deposited under wet conditions contained more labile OC and thus produced more greenhouse gases than sediments deposited under drier conditions. To assess the greenhouse gas production potentials over longer periods, deposits from two locations were incubated for a total of 785 days. However, more than 50 % of total CO2 production over 785 days occurred within the first 134 days under aerobic conditions, while 80 % were produced over the same period under anaerobic conditions, which emphasizes the nonlinearity of the OC decomposition processes. Methanogenesis was generally observed in active layer samples but only sporadically in permafrost samples and was several orders of magnitude smaller than CO2 production.


1931 ◽  
Vol 5 (1) ◽  
pp. 111-121 ◽  
Author(s):  
Guilford B. Reed ◽  
Christine E. Rice

Twenty-eight cultures of tubercle bacilli including human, bovine and avian forms from widely differing sources have been compared as to colony structure, habit of growth in fluid media, acid agglutination and virulence for animals.It was found that the recently isolated highly virulent cultures and all the cultures with a long history of high virulence grew on solid media in S colony form; on fluid media, in the case of bovine and human types, as a continuous veil-like pellicle, in the avian types as a diffuse suspension; all were agglutinated only at a high acidity. All the a virulent or low virulent cultures or those with a history of loss of virulence now grow on solid media in R colonies; in fluid media as a heavy pellicle tending to separate into discrete islands; and are agglutinated at a relatively low acidity.


1931 ◽  
Vol 4 (4) ◽  
pp. 389-398 ◽  
Author(s):  
Guilford B. Reed ◽  
Christine E. Rice

Variability studies have been carried out on a considerable series of cultures of tubercle bacilli and related species of acid-fast bacteria. The present paper deals with a rapid-growing strain of the bovine tubercle bacillus. The results are in conformity with claims recently made by Petroff that certain types of tubercle bacilli undergo dissociation.It is shown that this avirulent, rapid-growing strain consists of R types which appear to be stable in acid fluid media and more or less stable on solid media. Rapid transfers through strongly alkaline fluids or growth in large volumes of similar media result in appreciable dissociation into S types. The S types were unstable, particularly in acid fluid media, and readily reverted to the R form.


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