Investigations of nitrogenase activity in rheotrophic peat

1976 ◽  
Vol 22 (10) ◽  
pp. 1561-1566 ◽  
Author(s):  
George John Waughman
Keyword(s):  
Ethylene Production ◽  
Acetylene Reduction ◽  
Nitrogenase Activity ◽  
Anaerobic Bacteria ◽  
Organic Soils ◽  
Nitrogen Fixing ◽  
Anaerobic Conditions ◽  
Time Courses ◽  
Aerobic And Anaerobic ◽  
Stimulation Of

Acetylene reduction by the peat microflora was unaffected by light, but was sensitive to temperature, with an optimum of about 30 °C. The nitrogenase was inactivated by exposure to temperatures above about 35 °C. Activity occurred in completely anaerobic conditions; the rate of ethylene production was of the order of 0.5 nmol C2H4 ml−1h−1. Experiments with time courses indicated that exposure to oxygen caused an initial inhibition of activity followed by a period in which ethylene production was stimulated to rates much higher than in the anaerobic tests; both the inhibition and stimulation appeared to be related to the level of oxygenation. It is suggested that these results could be explained by the existence of nitrogen-fixing associations of aerobic and anaerobic bacteria in the peat. The stimulation of activity caused by exposure to air indicates that care must be taken when interpreting results of the assay obtained from waterlogged organic soils.

Effect of oxygen on batch and continuous cultures of a nitrogen-fixing Arthrobacter sp.

1979 ◽  
Vol 25 (6) ◽  
pp. 746-751 ◽  
Author(s):  
Isabella Cacciari ◽  
Daniela Lippi ◽  
Lucien M. Bordeleau
Keyword(s):  
Respiration Rate ◽  
Acetylene Reduction ◽  
Respiratory Activity ◽  
Nitrogenase Activity ◽  
Nitrogen Fixing ◽  
Anaerobic Conditions ◽  
Continuous Cultures ◽  
Partial Pressures ◽  
Oxygen Tensions ◽  
Effect Of Oxygen

Growth, acetylene reduction, and respiration rate were studied in batch and continuous cultures of Arthrobacter fluorescens at different oxygen partial pressures. The optimum pO2 values for growth and acetylene reduction were 0.05 and 0.025 atm, respectively, but microorganisms can tolerate higher pO2 values. The growth of cultures provided with combined nitrogen was dependent on oxygen availability, and strict anaerobic conditions did not support growth. Acetylene reduction of a population grown in continuous culture and adapted to low pO2 (0.02 atm) was much more sensitive to oxygenation than that of a population adapted to high pO2 (0.4 atm). Their maximum nitrogenase activity, at their optimal pO2 values, were quite different. The respiratory activity of nitrogen-fixing cultures increased with increasing oxygen tensions until a pO2 of 0.2 atm. At higher pO2 values, the respiration rate began to decrease.

Nitrogen fixation (acetylene reduction) by Klebsiella pneumoniae in association with 'Park' Kentucky bluegrass (Poa pratensis L.)

1981 ◽  
Vol 27 (1) ◽  
pp. 52-56 ◽  
Author(s):  
L. V. Wood ◽  
R. V. Klucas ◽  
R. C. Shearman
Keyword(s):  
Nitrogen Fixation ◽  
Klebsiella Pneumoniae ◽  
Ethylene Production ◽  
Acetylene Reduction ◽  
Nitrogenase Activity ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Surface Sterilization ◽  
Reducing Activity ◽  
Acetylene Reducing Activity

Turfs of 'Park' Kentucky bluegrass reestablished in the greenhouse and inoculated with Klebsiella pneumoniae (W6) showed significantly increased nitrogen fixation (acetylene reduction) compared with control turfs. Mean ethylene production rates per pot were 368 nmol h−1 for K. pneumoniae treated turfs, 55 nmol h−1 for heat-killed K. pneumoniae treated turfs, and 44 nmol h−1 for untreated turfs. Calculated lag periods before activity was observed were generally very short (less than 1 h).When 'Park' Kentucky bluegrass was grown from seed on soil-less medium of Turface, a fired aggregate clay, inoculation with K. pneumoniae (W6) resulted in 9 of 11 turfs showing nitrogenase activity (mean ethylene producion rate per pot was 195 nmol h−1). Only 3 of 11 turfs treated with heat-killed K. pneumoniae showed any activity and their mean rate of ethylene production (40 nmol h−1 per pot) was significantly lower than that for turfs treated with K. pneumoniae.Using the 'Park'–Turface soil-less model system it was shown that acetylene reducing activity was (i) root associated, (ii) generally highest at a depth of 1–4 cm below the surface, (iii) enhanced by washing excised roots, and (iv) inhibited by surface sterilization of excised roots. Klebsiella pneumoniae was recovered from Turface and roots showing acetylene reducing activity.

Metabolic requirements for anaerobic active Cl and Na transport in the bullfrog cornea

1979 ◽  
Vol 236 (5) ◽  
pp. C268-C276 ◽  
Author(s):  
P. S. Reinach ◽  
H. F. Schoen ◽  
O. A. Candia
Keyword(s):  
Energy Source ◽  
Amphotericin B ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Anaerobic Glycolysis ◽  
Anaerobic Conditions ◽  
Na Transport ◽  
Sufficient Energy ◽  
Aerobic And Anaerobic ◽  
Stimulation Of

In the bullfrog cornea, the relationships between the rates of aerobic and anaerobic glycolysis and active Cl and Na transport were studied. In NaCl Ringer (glucose-free), the short-circuit current (SCC) declined much more slowly under aerobic than under anaerobic conditions. The aerobic lactate effluxes in glucose-free and glucose-rich NaCl Ringer were 0.08 and 0.23 micromol/h.cm2, respectively. The transition to anoxia caused these values to increase significantly and was accompanied by depletion of endogenous glycogen in glucose-free Ringer. In Na2SO4 Ringer, amphotericin B (10(-5) M) stimulation of the aerobic SCC was not dependent on the presence of glucose but under anoxia, SCC stimulation required glucose. In Na2SO4 (glucose-rich) Ringer, amphotericin B stimulated the aerobic lactate efflux from 0.26 to 0.36 mumol/h.cm2 and anoxia increased it to 0.55 micromol/h.cm2. In NaCl Ringer, the addition of either 0.5 mM adenosine or 1 mM ATP with 26 mM glucose restored the anaerobic-inhibited SCC and lactate efflux of glucose-depleted corneas. The results show that the reactions of glycolysis are a sufficient energy source for supporting active Na and Cl transport.

Degradation of petroleum hydrocarbons by facultative anaerobic bacteria under aerobic and anaerobic conditions

2000 ◽  
Vol 35 (9) ◽  
pp. 889-896 ◽  
Author(s):  
V.G. Grishchenkov ◽  
R.T. Townsend ◽  
T.J. McDonald ◽  
R.L. Autenrieth ◽  
J.S. Bonner ◽  
...  
Keyword(s):  
Petroleum Hydrocarbons ◽  
Anaerobic Bacteria ◽  
Anaerobic Conditions ◽  
Facultative Anaerobic ◽  
Facultative Anaerobic Bacteria ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

The heterocysts of blue-green algae. III. Differentiation and nitrogenase activity

1972 ◽  
Vol 181 (1063) ◽  
pp. 199-209 ◽  
Keyword(s):  
Nitrogenase Activity ◽  
C:N Ratio ◽  
Free Medium ◽  
Anaerobic Conditions ◽  
Blue Green Algae ◽  
Ammonium N ◽  
Storage Granules ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions ◽  
Heterocyst Development

The course of heterocyst development in Anabacna cylindrica was studied in relation to the ability to fix nitrogen. When non-differentiated filaments, grown in the presence of ammonium-N, were transferred into a medium free from combined nitrogen and incubated under photosynthetic conditions, the cellular C:N ratio increased from 4.5:1 to 8:1 before the percentage heterocyst frequency and nitrogenase activity reached a steady value. The initial stages of differentiation were observed 24 h after transfer into nitrogen-free medium, but nitrogenase activity was only detected when the formation of the first heterocysts was completed. The transformation of a vegetative cell into a heterocyst is characterized by the dissolution of storage granules, the deposition of a multilayered envelope, the breakdown of photosynthetic thylakoids and the formation of new membraneous structures. The latter appear to develop by the coalescence of small newly formed vesicles arising in regions of pre-existing thylakoids. The course of heterocyst development was paralleled by that of nitrogenase activity both under aerobic and anaerobic conditions. Anaerobic incubation enhanced heterocyst production as well as nitrogenase activity. The results suggest that nitrogenase synthesis in Anabaena cylindrica is associated with heterocyst formation and that the primary factor which may regulate both processes is the cellular C:N balance of the alga.

scholarly journals Pig and Goat Blood as Substitutes for Sheep Blood in Blood-Supplemented Agar Media

2000 ◽  
Vol 38 (2) ◽  
pp. 591-594 ◽  
Author(s):  
Chandar Anand ◽  
Rhonda Gordon ◽  
Helene Shaw ◽  
Kevin Fonseca ◽  
Merle Olsen
Keyword(s):  
Anaerobic Bacteria ◽  
Blood Agar ◽  
Anaerobic Conditions ◽  
Sheep Blood ◽  
Wide Range ◽  
Horse Blood ◽  
Agar Media ◽  
Higher Temperature ◽  
Camp Test ◽  
Aerobic And Anaerobic

In many developing countries sheep and horse blood, the recommended blood supplements in bacteriological media, are not readily available, whereas pig and goat blood are. Therefore, this study examined the use of pig and goat blood as potential substitutes for sheep blood in blood-supplemented bacteriologic media commonly used in clinical microbiology laboratories. In general, the growth characteristics and colony morphologies of a wide range of aerobic and anaerobic bacteria and Candida albicans were similar on media containing pig, goat, and sheep blood, although differences were found.Enterococcus sp. uniformly produced alpha-hemolysis when incubated in CO2, but in anaerobic conditions the hemolysis varied. In contrast, beta-hemolytic streptococci produced identical hemolytic reactions on all three media. Synergistic hemolysis was not observed on pig blood agar in the CAMP test nor on goat blood agar in the reverse CAMP test. The preparation of chocolate agar (heated) with pig blood required heating to a higher temperature than with sheep or goat blood to yield suitable growth of Haemophilus species. In general, we conclude that pig and goat blood are suitable alternatives to sheep blood for use in bacteriological media in settings where sheep and horse blood are not readily available.

scholarly journals OxyR senses reactive sulfane sulfur and activates genes for its removal in Escherichia coli

2019 ◽  
Author(s):  
Ningke Hou ◽  
Zhenzhen Yan ◽  
Kaili Fan ◽  
Huanjie Li ◽  
Rui Zhao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bioinformatics Analysis ◽  
Anaerobic Bacteria ◽  
Anaerobic Conditions ◽  
Sulfane Sulfur ◽  
New Type ◽  
Cellular Components ◽  
Thioredoxin 2 ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

AbstractReactive sulfane sulfur species such as hydrogen polysulfide and organic persulfide are newly recognized as normal cellular components, involved in signaling and protecting cells from oxidative stress. Their production is extensively studied, but their removal is less characterized. Herein, we showed that reactive sulfane sulfur is toxic at high levels, and it is mainly removed via reduction by thioredoxin and glutaredoxin with the release of H2S in Escherichia coli. OxyR is best known to respond to H2O2, and it also played an important role in responding to reactive sulfane sulfur under both aerobic and anaerobic conditions. It was modified by hydrogen polysulfide to OxyR C199-SSH, which activated the expression of thioredoxin 2 and glutaredoxin 1. This is a new type of OxyR modification. Bioinformatics analysis showed that OxyRs are widely present in bacteria, including strict anaerobic bacteria. Thus, the OxyR sensing of reactive sulfane sulfur may represent a conserved mechanism for bacteria to deal with sulfane sulfur stress.

scholarly journals Anaerobic osteomyelitis

2021 ◽  
Vol 2 (3) ◽  
pp. 494-500
Author(s):  
H. A. Mousa ◽  
S. S. Bakr ◽  
Thamer A. Haman
Keyword(s):  
Prospective Study ◽  
Anaerobic Bacteria ◽  
Bone Infection ◽  
Anaerobic Conditions ◽  
Long Duration ◽  
Pyogenic Osteomyelitis ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions ◽  
Better Than

The prevalence and role of anaerobic bacteria in bone infection were investigated in this prospective study on 134 cases with pyogenic osteomyelitis. Specimens were inoculated immediately in the operating theatre or in the ward and incubated under aerobic and anaerobic conditions without using transport media. Anaerobic organisms were isolated from 39 of the 134 cases [29%] of all types of pyogenic osteomyelitis. The total number of aerobic and anaerobic isolates was 224, of which 50 were anaerobes [22%]. Syringe-aspirated specimens were better than swab specimens for the isolation of anaerobes. Anaerobes were mostly isolated from osteomyelitis cases of long duration

RELEASE OF P IN ORGANIC SOILS UNDER AEROBIC AND ANAEROBIC CONDITIONS

1979 ◽  
Vol 59 (3) ◽  
pp. 337-339 ◽  
Author(s):  
G. J. RACZ
Keyword(s):  
Organic Soil ◽  
Soil Samples ◽  
Organic Soils ◽  
Anaerobic Conditions ◽  
Inorganic P ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

Two organic soil samples were incubated at 10 °C aerobically and anaerobically for varying durations up to 24 mo. After incubation, the inorganic P concentrations were determined by successively extracting the soils with 1 N NH4Cl, 0.5 N neutral NH4, 0.1 N NaOH and 0.5 N H2SO4. All extractable forms of inorganic P increased upon incubation in both samples and for both methods of incubation. Total and all extractable forms of inorganic P for samples incubated anaerobically were usually greater than or about equal to P concentrations in samples incubated aerobically.

Implications of natural ethylene cycling processes for forest soil acetylene reduction assays

1989 ◽  
Vol 35 (7) ◽  
pp. 713-718 ◽  
Author(s):  
O. Q. Hendrickson
Keyword(s):  
Carbon Monoxide ◽  
Forest Soil ◽  
Ethylene Production ◽  
Acetylene Reduction ◽  
Forest Floor ◽  
Nitrogenase Activity ◽  
Mineral Soil ◽  
Ethylene Oxidation ◽  
Acetylene Reduction Activity ◽  
Oxidation Rates

Under aerobic conditions, ethylene production and oxidation occurred simultaneously in organic and mineral horizons of a northern hardwood forest. Ethylene oxidation rates in mineral soil were high (up to 25 nmol∙g−1∙day−1) relative to other forest soils, and exceeded production rates unless moisture contents were raised above saturation. Acetylene inhibits ethylene oxidation while allowing ethylene production to proceed; control samples for acetylene reduction assays should therefore contain acetylene plus a nitrogenase inhibitor such as carbon monoxide if forest soil nitrogenase activity is to be accurately quantified. A level of 7 kPa carbon monoxide gave complete nitrogenase inhibition in active forest floor samples in the presence of acetylene; carbon monoxide was applied 2 h in advance of acetylene to compensate for its lower solubility in water. Use of this methodology revealed a strong inhibitory effect of saturated water contents on forest floor acetylene reduction activity, suggesting that aerobic N2-fixing activity predominated in unamended forest soil samples.Key words: nitrogenase, acetylene reduction, ethylene formation, forest soil.

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