scholarly journals EPIPHYTIC MICROFLORA OF RICE (ORYZA SATIVA L.) AS A SOURCE OF STRAINS WITH AGRONOMICALLY USEFUL PLANT PROPERTIES

2014 ◽  
Vol 18 ◽  
pp. 100-108
Author(s):  
A. I. Yakubovskay
Keyword(s):  
Oryza Sativa ◽  
Growth And Development ◽  
Oryza Sativa L ◽  
Growth Stimulation ◽  
Positive Influence ◽  
Biochemical Properties ◽  
Rice Roots ◽  
Physiological And Biochemical ◽  
Physiological And Biochemical Properties ◽  
Associative Microorganisms

The paper covers the study of morphological, physiological and biochemical properties of associative microorganisms isolated from rice roots and plants’ response on inoculation. The agronomically useful properties, such as growth stimulation, ability to fix nitrogen and mobilize phosphates were observed. The positive influence of isolated bacteria on growth and development of rice plants was observed.

scholarly journals Active Antibiotics Production by Actinomycetes Indigenous To Saudi Arabia Soils

2021 ◽  
Vol 11 (6) ◽  
pp. 20-29
Author(s):  
Fetoon M ◽  
helaiwi Alk ◽  
Ismet Ara ◽  
Nadine Moubayed
Keyword(s):  
Saudi Arabia ◽  
Biochemical Properties ◽  
Soil Samples ◽  
Fungal Strain ◽  
Pathogenic Microorganisms ◽  
Bacterial Strains ◽  
Desert Soils ◽  
Growth Environment ◽  
Physiological And Biochemical ◽  
Physiological And Biochemical Properties

Streptomyces are the most popular among the Actinomycetes groups and found in soils worldwide. They form an important part of the soil ecology within the Actinomycetales order. Streptomyces are diverse as secondary antibiotic metabolites such as Novobiocin, Amphotericin, Vancomycin, Neomycin, Gentamicin, Chloramphenicol, Tetracycline, Erythromycin and Nystatin. Thus, the current study was aimed to isolate, identify and assess the active antibiotic metabolites produced by different actinomyces sp. found in Saudi Arabian soils. Six samples were collected from desert soils of the Al Thumamah area and analyzed using GS-MS. Scanning Electron Microscopy was used to identify the bacterial strains along with their antibiotic metabolites effectiveness of secondary metabolites (antibiotics) against different Gram-positive (Bacillus subtilis, Staphylococcus aureus), negative pathogens (Pseudomonas aeruginosa, Escherichia coli, Salmonella suis, and Shigella sonnei) as well as the fungal strain Candida albicans was investigated. Thirty active bacterial (F1-30) strains were isolated from the soil samples and the strains F3, F7, F22, F30 have white, gray, pink, yellow and red colours respectively. Only ten strains (F13, F14, F15, F16, FI7, F18, F19, F20, F21, and F22) were found to have antimicrobial activity against at least one pathogen. The optimum growth environment was pH 4-10, temperature (300C), and NaCl (7% w/v) concentration. According to our findings, the extreme desert environment of Al Thumamah from Saudi Arabia is rich in its actinobacterial population with diverse colouring groups and various physiological and biochemical properties. This shows it’s capability of generating secondary metabolite elements that could inhibit pathogenic microorganisms.

scholarly journals Modulation of ascorbate-glutathione cycle by selenate and sulphate treatments in the seedlings of two rice (Oryza sativa L.) cultivars

2020 ◽  
Vol 7 (3) ◽  
Author(s):  
Debarati Das ◽  
Paulin Seal ◽  
Sabarni Biswas ◽  
Asok K Biswas
Keyword(s):  
Oryza Sativa ◽  
Growth And Development ◽  
Elevated Level ◽  
Oryza Sativa L ◽  
Ascorbate Oxidase ◽  
Rice Cultivars ◽  
Rice Seedlings ◽  
Thiol Metabolism ◽  
Regulatory Enzymes ◽  
Glutathione Cycle

The trace element Selenium (Se) has a dual role in the growth and metabolism of plants. Low concentration of selenium (2 ?M selenate) promotes growth and counteracts the detrimental effects of abiotic stress as opposed to higher levels (?10 ?M) where it acts as a pro-oxidant. We focused on both individual and interactive influence of selenate and sulphate on thiol metabolism in seedlings of rice cultivars, satabdi and khitish. Inhibition of ascorbate contents by about 17% on an average, in the test seedlings treated with Se correlated with increased activities of ascorbate peroxidase and ascorbate oxidase in the cultivars. The glutathione levels also increased significantly, on an average by about 102% in roots and 74% in shoots of cv. satabdi compared to a rise, by about 49% in roots and 56% in shoots of cv. khitish. The elevated level of glutathione coincided with the stimulatory influence of Se on its regulatory enzymes. Concomitantly the levels of ?-tocopherol and phytochelatins were also induced in both the test cultivars. Increase in ?-tocopherol activity reached a maximum by about 47% in roots and 80% in shoots of cv. satabdi whereas it increased by about 36% in roots and about 64% in shoots of cv. khitish. Substantive increase in the levels of PC4 followed by PC2 and PC3 was also noted. The effects were found to be less conspicuous in shoots than in roots. Rice seedlings exposed to combined Se and 10mM sulphate treatments showed improved growth and development as a result of better thiol metabolism due to amelioration of the adverse effects caused by selenium alone on all the parameters tested.

scholarly journals Physiology and Nutrition of Treponema primitia, an H2/ CO2-Acetogenic Spirochete from Termite Hindguts

2004 ◽  
Vol 70 (3) ◽  
pp. 1307-1314 ◽  
Author(s):  
Joseph R. Graber ◽  
John A. Breznak
Keyword(s):  
Nadh Oxidase ◽  
Natural Habitat ◽  
Biochemical Properties ◽  
Organic Substrates ◽  
Growth And Survival ◽  
Cell Extracts ◽  
Termite Hindgut ◽  
Physiological And Biochemical ◽  
Physiological And Biochemical Properties

ABSTRACT Treponema primitia strains ZAS-1 and ZAS-2, the first spirochetes to be isolated from termite hindguts (J. R. Leadbetter, T. M. Schmidt, J. R. Graber, and J. A. Breznak, Science 283:686-689, 1999), were examined for nutritional, physiological, and biochemical properties relevant to growth and survival in their natural habitat. In addition to using H2 plus CO2 as substrates, these strains were capable of homoacetogenic growth on mono- and disaccharides and (in the case of ZAS-2) methoxylated benzenoids. Cells were also capable of mixotrophic growth (i.e., simultaneous utilization of H2 and organic substrates). Cell extracts of T. primitia possessed enzyme activities of the Wood/Ljungdahl (acetyl coenzyme A) pathway of acetogenesis, including tetrahydrofolate-dependent enzymes of the methyl group-forming branch. However, a folate compound was required in the medium for growth. ZAS-1 and ZAS-2 growing on H2 plus CO2 displayed H2 thresholds of 650 and 490 ppmv, respectively. Anoxic cultures of ZAS-1 and ZAS-2 maintained growth after the addition of as much as 0.5% (vol/vol) O2 to the headspace atmosphere. Cell extracts exhibited NADH and NADPH peroxidase and NADH oxidase activities but neither catalase nor superoxide dismutase activity. Results indicate that (i) T. primitia is able to exploit a variety of substrates derived from the food of its termite hosts and in so doing contributes to termite nutrition via acetogenesis, (ii) in situ growth of T. primitia is likely dependent on secretion of a folate compound(s) by other members of the gut microbiota, and (iii) cells possess enzymatic adaptations to oxidative stress, which is likely to be encountered in peripheral regions of the termite hindgut.

Sign in / Sign up

Export Citation Format

Share Document