Phenotypic and biochemical characterization of root nodule bacteria naturally associated with woody tree legumes in Saudi Arabia

Thirty root-nodulating bacteria isolates were obtained from the roots of Acacia ampliceps (Maslin), A. ehrenbergiana (Hayne.), A. saligna (Labill.), A. seyal (Del.), A. tortilis (Forssk.), A. tortilis subsp. raddiana (Savi.), Leucaena leucocephala (Lam.) and Vicia faba (L.) trees growing in the Riya...

Full description

Saved in:
Bibliographic Details
Published in:Journal of environmental biology 2015-03, Vol.36 (2), p.363-370
Main Authors: Alshaharani, Thobayet Safar, Shetta, Nader Desouky
Format: Article
Language:English
Subjects:
Acacia
Antibiotics
Bacteria
Bacteria - classification
Bacteria - cytology
Bacteria - metabolism
Bacteriological Techniques
Carbohydrates
Environmental science
Fabaceae - microbiology
Heavy metals
High temperature
Hydrogen-Ion Concentration
Leucaena leucocephala
Nitrates - metabolism
Root Nodules, Plant - microbiology
Saudi Arabia
Sodium chloride
Soil - chemistry
Temperature
Vicia faba
Yeasts
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Thirty root-nodulating bacteria isolates were obtained from the roots of Acacia ampliceps (Maslin), A. ehrenbergiana (Hayne.), A. saligna (Labill.), A. seyal (Del.), A. tortilis (Forssk.), A. tortilis subsp. raddiana (Savi.), Leucaena leucocephala (Lam.) and Vicia faba (L.) trees growing in the Riyadh region. The isolates' phenotypic and biochemical properties were characterized by assessing colony appearance, growth rate, resistance to antibiotics and heavy metals, and tolerance to salinity, elevated temperature and pH. All isolates had same colony morphology and grew on yeast extract mannitol and tryptone yeast agar, but not MGS media. The results also revealed considerable diversity among the isolates, which exhibited different patterns of resistance to abiotic stresses. Most isolates tolerated temperatures up to 37 degrees C and could grow from pH 5.5-8.5 and at a high NaCl concentration (2% w/v). The majority of isolates could utilize a variety of carbohydrates. Most of the isolates displayed resistance to antibiotics in the 75 microg ml(-1) range, with approximately 100 pg ml(-1) the maximum concentration at which growth was observed. All isolates were sensitive to aluminum and resistant to other heavy metals tested, and they were able to reduce nitrate and hydrolyze urea.
ISSN:0254-8704
2394-0379