Dinitrogen-fixing bacteria: computer-assisted identification of soil isolates

1980 ◽  
Vol 26 (11) ◽  
pp. 1275-1283 ◽  
Author(s):  
R. J. Rennie
Keyword(s):  
Data Base ◽  
Nitrite Reduction ◽  
Computer Assisted ◽  
Biochemical Tests ◽  
Data Bases ◽  
Accurate Identification ◽  
Agricultural Ecosystems ◽  
Bacillus Spp ◽  
Nitrate And Nitrite ◽  
Reducing Bacteria

Dinitrogen-fixing (acetylene-reducing) bacteria may be readily isolated from soils but extensive biochemical or immunological testing, or both, are required to identify them absolutely. A computer-assisted scheme for identification of nine genera of dinitrogen-fixing bacteria was developed and tested. The computer program is based on interpretation of the 70 biochemical tests of the API 20E and 50E, supplemented with tests for acetylene reduction, nitrate and nitrite reduction, catalase, oxidase, motility, and growth on MacConkey's bile salt medium. Dinitrogen-fixing Enterobacteriaceae (Klebsiella pneumoniae, Enterobacter cloacae, and Erwinia herbicola) were accurately identified using the data base in the API analytical profile index. Nonenteric dinitrogen-fixing bacteria (Azotobacter spp., Azospirillum spp., Derxia sp., Rhodospirillum sp., Clostridium sp., and Bacillus spp.) were subjected to these tests to form a new data base for these bacteria. The API tests agreed with standard biochemical tests commonly used to identify these bacteria, were reproducible with time, and were sufficiently unique to permit accurate identification of each species. The use of the API 20E and 50E tests plus the additional seven tests with these known data bases permitted rapid and precise identification of acetylene-reducing bacteria from various agricultural ecosystems.

scholarly journals Implications of Limited Thermophilicity of Nitrite Reduction for Control of Sulfide Production in Oil Reservoirs

2016 ◽  
Vol 82 (14) ◽  
pp. 4190-4199 ◽  
Author(s):  
Tekle Tafese Fida ◽  
Chuan Chen ◽  
Gloria Okpala ◽  
Gerrit Voordouw
Keyword(s):  
Nitrate Reduction ◽  
Nitrite Reduction ◽  
Oil Fields ◽  
Microbial Consortia ◽  
Subsequent Reduction ◽  
Content Type ◽  
Reduction Activity ◽  
Pure Cultures ◽  
Nitrate And Nitrite ◽  
Reducing Bacteria

ABSTRACTNitrate reduction to nitrite in oil fields appears to be more thermophilic than the subsequent reduction of nitrite. Concentrated microbial consortia from oil fields reduced both nitrate and nitrite at 40 and 45°C but only nitrate at and above 50°C. The abundance of thenirSgene correlated with mesophilic nitrite reduction activity.ThaueraandPseudomonaswere the dominant mesophilic nitrate-reducing bacteria (mNRB), whereasPetrobacterandGeobacilluswere the dominant thermophilic NRB (tNRB) in these consortia. The mNRBThauerasp. strain TK001, isolated in this study, reduced nitrate and nitrite at 40 and 45°C but not at 50°C, whereas the tNRBPetrobactersp. strain TK002 andGeobacillussp. strain TK003 reduced nitrate to nitrite but did not reduce nitrite further from 50 to 70°C. Testing of 12 deposited pure cultures of tNRB with 4 electron donors indicated reduction of nitrate in 40 of 48 and reduction of nitrite in only 9 of 48 incubations. Nitrate is injected into high-temperature oil fields to prevent sulfide formation (souring) by sulfate-reducing bacteria (SRB), which are strongly inhibited by nitrite. Injection of cold seawater to produce oil creates mesothermic zones. Our results suggest that preventing the temperature of these zones from dropping below 50°C will limit the reduction of nitrite, allowing more effective souring control.IMPORTANCENitrite can accumulate at temperatures of 50 to 70°C, because nitrate reduction extends to higher temperatures than the subsequent reduction of nitrite. This is important for understanding the fundamentals of thermophilicity and for the control of souring in oil fields catalyzed by SRB, which are strongly inhibited by nitrite.

Isolation and identification of N2-fixing bacteria associated with sugar cane (Saccharum sp.)

1982 ◽  
Vol 28 (5) ◽  
pp. 462-467 ◽  
Author(s):  
R. J. Rennie ◽  
J. R. de Freitas ◽  
A. P. Ruschel ◽  
P. B. Vose
Keyword(s):  
Sugar Cane ◽  
Carbon Substrate ◽  
Computer Assisted ◽  
Stem Cuttings ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
Whole Plant ◽  
Reducing Activity ◽  
Acetylene Reducing Activity ◽  
Reducing Bacteria

Acetylene-reducing bacteria isolated from the setts (stem cuttings used as seed pieces) and roots of two sugar cane varieties propagated aseptically from stem cuttings were identified using a computer-assisted scheme based on 75 biochemical tests. Because 106 to 108 acetylene-reducing bacteria per gram (fresh weight basis) were found in the roots, while 10 to 100 times fewer were present in the sett, we suggest that the root is the site of bacterial multiplication. Sterilization of the sett surface before planting or root sterilization at harvest reduced or completely removed acetylene-reducing bacteria and associated whole plant acetylene-reducing activity. This indicates that most of the active bacteria were on the sett and root exteriors. Setts did not exhibit acetylene-reducing activity until after emergence of the roots. Since shoot emergence was not necessary for acetylene-reducing activity, the extensive carbohydrate supply of the sett itself must have provided the carbon substrate for bacterial N2 fixation. The acetylene-reducing bacteria isolated were facultative anaerobes of the families Enterobacteriaceae and Bacillaceae. Klebsiella pneumoniae, Enterobacter cloacae, Erwinia herbicola, and Bacillus polymyxa were present inside the sett and the roots but E. herbicola was the dominant bacterium on the root exterior. No Beijerinckia spp. or Azotobacter spp. were found associated with the sett or the roots.

Pl@ntwood: A Computer-Assisted Identification Tool for 110 species of amazon trees based on wood Anatomical Features

IAWA Journal ◽  
2011 ◽  
Vol 32 (2) ◽  
pp. 221-232 ◽  
Author(s):  
Carolina Sarmiento ◽  
Pierre Détienne ◽  
Christine Heinz ◽  
Jean-François Molino ◽  
Pierre Grard ◽  
...  
Keyword(s):  
Tree Species ◽  
Tropical Species ◽  
Computer Assisted ◽  
Accurate Identification ◽  
Anatomical Features ◽  
System A ◽  
Microscopic Features ◽  
On Line ◽  
User Friendly ◽  
Identification Tool

Sustainable management and conservation of tropical trees and forests require accurate identification of tree species. Reliable, user-friendly identification tools based on macroscopic morphological features have already been developed for various tree floras. Wood anatomical features provide also a considerable amount of information that can be used for timber traceability, certification and trade control. Yet, this information is still poorly used, and only a handful of experts are able to use it for plant species identification. Here, we present an interactive, user-friendly tool based on vector graphics, illustrating 99 states of 27 wood characters from 110 Amazonian tree species belonging to 34 families. Pl@ntWood is a graphical identification tool based on the IDAO system, a multimedia approach to plant identification. Wood anatomical characters were selected from the IAWA list of microscopic features for hardwood identification, which will enable us to easily extend this work to a larger number of species. A stand-alone application has been developed and an on-line version will be delivered in the near future. Besides allowing non-specialists to identify plants in a user-friendly interface, this system can be used with different purposes such as teaching, conservation, management, and selftraining in the wood anatomy of tropical species.

The use of thesauri in online retrieval

1984 ◽  
Vol 8 (2) ◽  
pp. 63-66 ◽  
Author(s):  
C.P.R. Dubois
Keyword(s):  
Information Retrieval ◽  
Data Base ◽  
Case Studies ◽  
Controlled Vocabulary ◽  
Free Text ◽  
Data Bases ◽  
Online Data ◽  
Controlled Vocabularies ◽  
Semantic Maps ◽  
Actual Use

The controlled vocabulary versus the free text approach to information retrieval is reviewed from the mid 1960s to the early 1980s. The dominance of the free text approach following the Cranfield tests is increasingly coming into question as a result of tests on existing online data bases and case studies. This is supported by two case studies on the Coffeeline data base. The differences and values of the two approaches are explored considering thesauri as semantic maps. It is suggested that the most appropriate evaluatory technique for indexing languages is to study the actual use made of various techniques in a wide variety of search environments. Such research is becoming more urgent. Economic and other reasons for the scarcity of online thesauri are reviewed and suggestions are made for methods to secure revenue from thesaurus display facilities. Finally, the promising outlook for renewed develop ment of controlled vocabularies with more effective online display techniques is mentioned, although such development must be based on firm research of user behaviour and needs.

Computer-assisted database indexing: the state-of-the-art

1994 ◽  
Vol 19 (1) ◽  
pp. 23-27
Author(s):  
Gail M. Hodge
Keyword(s):  
Data Base ◽  
Production System ◽  
State Of The Art ◽  
The State ◽  
Computer Support ◽  
Computer Assisted ◽  
Computer Assistance ◽  
The Future ◽  
Database Indexing ◽  
Operational Systems

Discusses the state-of-the-art in computer indexing, defines indexing and computer assistance, describes the reasons for renewed interest, identifies the types of computer support in use using selected operational systems, describes the integration of various computer supports in one data base production system, and speculates on the future.

Nitrate and Nitrite Utilization in Sulfate-Reducing Bacteria

Anaerobe ◽  
1997 ◽  
Vol 3 (5) ◽  
pp. 279-290 ◽  
Author(s):  
Isabel Moura ◽  
Sergey Bursakov ◽  
Cristina Costa ◽  
José J.G Moura
Keyword(s):  
Sulfate Reducing Bacteria ◽  
Sulfate Reducing ◽  
Nitrate And Nitrite ◽  
Reducing Bacteria

Effects of pH and alkalinity on sulfur-denitrification in a biological granular filter

1996 ◽  
Vol 34 (1-2) ◽  
pp. 355-362 ◽  
Author(s):  
Hiroaki Furumai ◽  
Hideki Tagui ◽  
Kenji Fujita
Keyword(s):  
Enrichment Culture ◽  
Nitrite Reduction ◽  
The Other ◽  
Nitrite Accumulation ◽  
Ph Dependency ◽  
Effects Of Ph ◽  
Rapid Removal ◽  
Nitrate And Nitrite ◽  
The Relationship ◽  
Biological Filters

Two laboratory-scale biological filters were operated to investigate the effects of alkalinity and pH on removal of nitrate and nitrite in sulfur denitrification filter processes. The concentration of sodium bicarbonate in the feed media was changed from 120 to 240 mg/l during about 3 months in a filter (Run A). The other filter was initially fed with 300 mg/l and then with 240 mg/l (Run B). The performance of the filter was monitored by measuring pH, nitrate, nitrite, sulfate, alkalinity, and thiosulfate. Nitrate concentration in effluent rapidly decreased to lower levels within several days for both filters after inoculation of enrichment culture of sulfur denitrifiers. However there was a large difference in removal of nitrite. When rapid removal of nitrate took place, nitrite accumulation was observed and remained while the bicarbonate concentration was 120 and 150 mg/l. On the other hand the nitrite accumulation disappeared when more bicarbonate (240 and 300 mg/l) was supplied. The experimental results indicated that the nitrite accumulation was closely related to pH condition and alkalinity level in the filter. The stable data of effluent water quality for 5 cases were collected and the relationship discussed between nitrite concentration and pH in effluents. The relationship indicated a strong pH dependency on nitrite accumulation below pH of 7.4. The pH condition around 7 is not so inhibitory to biological activity. Therefore, the pH within the biofilm would be low enough to suppress the nitrite reduction by sulfur denitrifiers, while the pH in effluent was not in the inhibitory range. It was recommended to keep the pH higher than 7.4 to prevent nitrite accumulation in the sulfur denitrification filter.

scholarly journals Application of the Variety-Generator Approach to Searches of Personal Names in Bibliographic Data Bases--Part 2. Optimization of Key-Sets, and Evaluation of Their Retrieval Efficiency

1974 ◽  
Vol 7 (3) ◽  
pp. 201
Author(s):  
Dirk W. Fokker ◽  
Michael F. Lynch
Keyword(s):  
Information Systems ◽  
Data Base ◽  
Variable Length ◽  
Data Bases ◽  
Personal Names ◽  
Fixed Length ◽  
Bibliographic Data ◽  
Retrieval Efficiency ◽  
Types Of Information ◽  
High Degree

<p class="p1">Keys consisting of variable-length chamcter strings from the front and rear of surnames, derived by analysis of author names in a particular data base, am used to provide approximate representations of author names. When combined in appropriate ratios, and used together with keys for each of the first two initials of personal names, they provide a high degree of discrimination in search.</p> <p class="p1">Methods for optimization of key-sets are described, and the performance of key-sets varying in size between <span class="s1">150 </span>and <span class="s1">300 </span>is determined at file sizes of up to <span class="s1">50,000 </span>name entries. The effects of varying the proportions of the queries present in the file are also examined. The results obtained with fixed-length keys are compared with those for variable-length keys, showing the latter to be greatly superior.</p> <p class="p1">Implications of the work for a variety of types of information systems are discussed.</p>

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