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.

Biochemical Methods for Automated Bacterial Identification and Testing Metabolic Activities in Water and Wastewater

1988 ◽  
Vol 20 (11-12) ◽  
pp. 221-227 ◽  
Author(s):  
W. Dott ◽  
P. Kämpfer
Keyword(s):  
Heterotrophic Bacteria ◽  
Carbon Substrate ◽  
Computer Assisted ◽  
Identification System ◽  
Bacterial Identification ◽  
Test Results ◽  
Biochemical Tests ◽  
Conventional Tests ◽  
Water And Wastewater ◽  
Metabolic Activities

The improvements of computer-assisted identification were used to develop a new microplate system for characterization and identification of various gram-negative and gram-positive heterotrophic bacteria from the environment. In standard microtitration plates about 90 biochemical tests, some of them conventional tests, carbon substrate assimilation tests and enzyme tests using chromogenic substrates can be performed. Reading of the test results is done automatically by a photometer coupled to a computer. The applications of this identification system are shown by two waste water samples.

The API 20B microtube system to aid in the identification of N2-fixing Bacillaceae

1987 ◽  
Vol 33 (6) ◽  
pp. 504-509 ◽  
Author(s):  
R. J. Rennie
Keyword(s):  
Heterotrophic Bacteria ◽  
General Procedure ◽  
Bacillus Species ◽  
Computer Assisted ◽  
Growth Media ◽  
Natural Environments ◽  
Bacterial Isolates ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
Carbohydrate Utilization

N2-fixing bacterial isolates from soil have been identified successfully using the API 20E and 50E microtubes in conjunction with a computer-assisted biochemical profile search. The 20E and 50E result in few positive tests with N2-fixing Bacillaceae. Recently, a new battery of 20 microtube tests, the 20B, has been introduced for identifying aerobic, heterotrophic bacteria isolated from natural environments. This system was compared with the 20E and evaluated for N2-fixing bacillus species from soil. It was then used in conjunction with guanine-plus-cytosine analysis to identify the C-11-25 (5DN+) bacillus strain that fixes N2 in association with Canadian wheat cultivars. The API 20E and 20B gave similar results for many biochemical tests, but the 20E resulted in negative tests for carbohydrate utilization by bacillus strains. The use of different growth media or 0.85% NaCl to suspend these bacteria prior to inoculating the cupules did not alter the inability of the 20E in this manner. Carbohydrate utilization in the 20B system agreed well with that in the traditional utilization tests. Hence, I concluded that the API 20E is not suitable to evaluate carbohydrate utilization in N2-fixing Bacillaceae. The spore-forming, acetylene-reducing C-11-25 strain of bacillus was biochemically similar to the ATCC type culture of Bacillus polymyxa (strain 842). Its guanine-plus-cytosine ratio of 48.0 mol% was similar to that of B. polymyxa (43–46 mol%). A general procedure for the isolation and identification of N2-fixing Bacillus from soil is proposed.

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.

The use of antibiotic resistance profiling as a means of tracing sources of fecal contamination in source waters

2010 ◽  
Vol 10 (2) ◽  
pp. 209-215
Author(s):  
M. S. Mthembu ◽  
P. T. Biyela ◽  
T. G. Djarova ◽  
A. K. Basson
Keyword(s):  
Antibiotic Resistance ◽  
Municipal Wastewater ◽  
Fecal Contamination ◽  
Source Tracking ◽  
Human Consumption ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
E Coli ◽  
Intestinal Pathogens ◽  
Source Waters

Fecal contamination of source waters and its associated intestinal pathogens continues to pose risks to public health although the extent and effect of microbial contamination of source waters gets very little attention in designing treatment plants in most developing countries. Coliform counts give an indication of the overall bacterial contamination of water and thus its safety for human consumption. However, their presence fails to provide information about the source of fecal contamination which is vital to managing fecal contamination problems in surface waters. This study explored the use of multiple antibiotic resistance (MAR) indexing as means of differentiating E. coli isolates from different sources. A total of 322 E. coli isolates were obtained from municipal wastewater and from fecal samples from domestic and wild animals. Conventional culture methods and standard chemical and biochemical tests were used for isolation and identification of E. coli. Isolates were assayed against 10 antibiotics using the micro-dilution technique. The results obtained generated antibiotic resistance profiles which were used to statistically group the isolates into different subsets. Correct source classification was obtained for 60% of human-derived and 95% non-human-derived E. coli respectively. These results indicate the validity of the usefulness of MAR indexing as a method of bacterial source tracking.

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.

scholarly journals Observation of Vibrio mediterranei (Pujalte and Garay 1986) / Vibrio shiloi (Kushmaro et al. 2001) bacteria from skin ulcers of the cultured sea cucumber Holothuria poli (Delle Chiaje, 1823)

2021 ◽  
Vol 38 (3) ◽  
pp. 393-397
Author(s):  
Mustafa Tolga Tolon ◽  
Ulviye Karacalar ◽  
Caner Şirin
Keyword(s):  
Sea Cucumber ◽  
Reference Data ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
Skin Ulceration ◽  
Skin Ulcers ◽  
Vibrio Shiloi ◽  
Serious Disease ◽  
Dominant Bacteria ◽  
Major Pathogens

Skin ulcer syndrome is frequently reported as a serious disease affecting the health, growth and mortality of stocks in sea cucumber aquaculture. In this study, bacteria isolated predominantly from skin ulcers of sea cucumber Holothuria poli (Delle Chiaje, 1823), a new candidate for aquaculture in the Mediterranean, were investigated. Morphological and biochemical tests, and molecular analysis methods were used to examine the dominant bacteria in the lesions of H. poli showing skin ulceration, peristome tumour and visceral ejection symptoms in rearing tanks. Present study is the first report for isolation and identification of Vibrio mediterranei (Pujalte and Garay 1986) (called also Vibrio shiloi Kushmaro et al. 2001) as a predominant gram-negative bacterium in the skin ulcers of H. poli. Reference data provided from the present study would lead to understand possible major pathogens causing skin ulceration syndrome and is crucial for the prophylaxis and treatment of such disease in holothuriculture.

scholarly journals Isolation and identification of phosphate solubilizing bacteria and evaluate its effect on of Mung bean (Vigna radita [L.] R.Wilczek) growth

2019 ◽  
Vol 60 (5) ◽  
pp. 985-995
Author(s):  
Yusur Ramzi ◽  
Hutaf A. A. Alsalim
Keyword(s):  
Plant Growth ◽  
Bacillus Cereus ◽  
Mung Bean ◽  
Phosphate Solubilization ◽  
Growth Promotion ◽  
Hydrolytic Enzymes ◽  
Phosphate Solubilizing Bacteria ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
Phosphate Solubilizing

Sixteen soil samples were collected from wheat, barley and yellow corn rhizosphere in Abu-Ghraib, Aqraqof, Latifieh,Tarmiah, Jadriya and  of Agriculture in Baghdad university/ Baghdad city. The results found nine phosphate solubilizing bacteria (PSB) isolates (Y1, Y2, Y3, Y4, Y5, Y6, Y7, Y8, Y9), formed clear zones on National Botanical Research Institute's (NBRIP) agar. The solubility index (SI) of PSB isolates ranged from 2.00 to 3.66. Y4 have the highest SI (3.66) followed by Y3 and Y6 (3.33). Phosphate solubilization abilities varying from (20.10-39.00 μg.ml-1), Y4 was the highest (39.00 μg.ml-1) followed by Y3 (37.00μg.ml-1). The results of hydrolytic enzymes production showed that almost all nine isolates are able to produce protease and pectinase, while Y1 and Y2 showed negative results in cellulase production. Maximum ability for hydrogen cyanide (HCN) and indole acetic acid (IAA) production were showed byY3 and Y4 isolates. The isolate Y4 was found to be the most efficient isolate, so it was selected identified as Bacillus cereus using biochemical tests confirmed by VITEC 2 compact system. The results of High performance liquid chromatography (HPLC) revealed that Bacillus cereus produce oxalic acid (2.996), citric acid (9.117) and malic acid (3.734). Bacillus cereus (Y4) enhanced the growth of mung bean plants. A significant increase in branches number (12.33), plant length (83.0cm), fresh weight (27.25 g) and dry weight (1.427g) were obtained compared with control treatments. The main objective of this study is to isolate PSB and evaluate their roles in plant growth promotion. The results showed the high phosphate solubilization efficiency of PSB isolates and the identified isolates was found to be good enough for plant growth promoting.

scholarly journals Citrobacter braakii Yield False-Positive Identification as Salmonella, a Note of Caution

Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2177
Author(s):  
Joanna Pławińska-Czarnak ◽  
Karolina Wódz ◽  
Magdalena Kizerwetter-Świda ◽  
Tomasz Nowak ◽  
Janusz Bogdan ◽  
...  
Keyword(s):  
False Positive ◽  
Salmonella Enterica ◽  
Meat Products ◽  
Animal Origin ◽  
Biochemical Tests ◽  
Salmonella Spp ◽  
Isolation And Identification ◽  
False Positive Identification ◽  
Food Of Animal Origin ◽  
Meat Samples

Background: Globally, Salmonella enterica is one of the leading causes of foodborne illness in humans. Food of animal origin is obligatorily tested for the presence of this pathogen. Unfortunately, in meat and meat products, this is often hampered by the presence of background microbiota, which may present as false-positive Salmonella. Methods: For the identification of Salmonella spp. from meat samples of beef, pork, and poultry, the authorized detection method is PN-EN ISO 6579-1:2017-04 with the White–Kauffmann–Le Minor scheme, two biochemical tests: API 20E and VITEK II, and a real-time PCR-based technique. Results: Out of 42 presumptive strains of Salmonella, 83.3% Salmonella enterica spp. enterica, 14.3% Citrobacter braakii, and 12.4% Proteus mirabilis were detected from 180 meat samples. Conclusions: Presumptive strains of Salmonella should be identified based on genotypic properties such as DNA-based methods. The aim of this study was the isolation and identification of Salmonella spp. from miscellaneous meat sorts: beef, pork, and poultry.

scholarly journals Isolation, identification and antibiogram profile of Aeromonas hydrophila from broiler chickens in Mymensingh Sadar, Bangladesh

2020 ◽  
Vol 4 (1) ◽  
pp. 22-30
Author(s):  
Basana Sarker ◽  
Mohammad Arif ◽  
Nilofa Eashmen ◽  
Mir Rowshan Akter ◽  
SM Lutful Kabir
Keyword(s):  
Aeromonas Hydrophila ◽  
Broiler Chickens ◽  
Susceptibility Testing ◽  
Specific Detection ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
Alkaline Peptone Water ◽  
Sensitivity Pattern ◽  
Peptone Water

Investigation of Aeromonas hydrophila was conducted to assess the microbial quality of broiler chickens from July to November 2019. A total of 60 samples from 20 broiler chickens were collected from two different locations of Mymensingh Sadar: KR market, Bangladesh Agricultural University (BAU) and Shesh mor bazar (10 birds from each location). Samples included 20 skins, 20 legs and 20 breast samples from 20 broiler chickens. PCR was done for the specific detection of each isolate and finally antimicrobial susceptibility testing was performed to check sensitivity pattern of each isolate. Alkaline peptone water was used for processing and enrichment of the samples followed by inoculation onto Aeromonas selective agar supplemented with ampicillin for the isolation and identification of A. hydrophila. Out of these 60 samples, 27 isolates were confirmed as A. hydrophila through biochemical tests and PCR where 55.56% isolates were recovered from Shesh mor market and other 44.4% isolates from KR market, BAU. Source-wise analysis revealed that maximum isolates of A. hydrophila were recovered from skin (59.26 %) followed by leg (22.22 %) and breast samples (18.52 %). PCR test revealed that all 27 isolates were found carrying lip gene which is specific for A. hydrophila. Isolates of A. hydrophila were found sensitive to ciprofloxacin (92%), gentamycin (66%) and chloramphenicol (50%); intermediate against erythromycin (50%), tetracycline (50%) and imipenem (50%); resistant against co-trimoxazole (84%) and ampicillin (100%). From the present study, it was found that samples were considerably contaminated with Aeromonas hydrophila causing risks for public health. Necessary control actions should be taken in every steps of production, processing and marketing for mitigation of this contamination. Asian Australas. J. Food Saf. Secur. 2020, 4 (1), 22-30

Kinetics of first-cutting regrowth of alfalfa plants and nitrogenase activity in a controlled environment with and without added nitrate

1983 ◽  
Vol 61 (9) ◽  
pp. 2405-2409 ◽  
Author(s):  
F. D. H. Macdowall
Keyword(s):  
Dry Matter ◽  
Rhizobium Meliloti ◽  
Nitrogenase Activity ◽  
Radical Change ◽  
N Nutrition ◽  
Meliloti Strain ◽  
Medicago Sativa L ◽  
Reducing Activity ◽  
Acetylene Reducing Activity ◽  
Kinetics Of

Seedlings of Medicago sativa L. cv. Algonquin were grown in vermiculite and nodulated by Rhizobium meliloti strain 102F70 at two lower levels of N, until flowering when the tops were cut off to leave about 10% shoot stubble. Residual shoot dry matter immediately resumed first-order growth and maintained it throughout regrowth to second flowering. The rate constants of shoot regrowth were 34% lower (at 15 mM NO3−), 25% lower (at 1.5 mM NO3− symbiotically), or 220% higher (at zero NO3− symbiotically) than the values for 1 to 4-week-old seedlings, which indicated a radical change in physiology. Root dry matter resumed exponential growth after a 7-day recession and its recovery and yields were independent of N nutrition. The most pronounced minima occurred in the acetylene-reducing activity of nitrogenase, the kinetics of which paralleled root dry matter except that its redevelopment stopped after two-thirds of the regrowth time. The rate coefficient for the redevelopment of nitrogenase activity equalled that for its development during the seedling stage, which suggested unchanged limitations on that process until its redevelopment stopped.

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