scholarly journals Effect of Some Environmental Factors on the Growth of Azospirillum Species Isolated from Saline Soils of Satkhira District, Bangladesh

1970 ◽  
Vol 23 (2) ◽  
pp. 145-148 ◽  
Author(s):  
M Motiur Rahman ◽  
S Mubassara ◽  
Sirajul Hoque ◽  
Zahed UM Khan
Keyword(s):  
Rhizosphere Soil ◽  
Cynodon Dactylon ◽  
Optimal Growth ◽  
Maximum Growth ◽  
Alkaline Condition ◽  
Saline Soils ◽  
Azospirillum Lipoferum ◽  
Nacl Concentration ◽  
Saline Area ◽  
Soil Rhizosphere

Twelve isolates of Azospirillum, recovered and identified from non-rhizosphere soil, rhizosphere soil of Cynodon dactylon and the roots of the same plant, were collected from five different locations of saline area in the district Satkhira, Bangladesh. The isolates were belonged to Azospirillum lipoferum, A. brasilense, A. halopraeferans and A. amazonense. All isolates, except MR-5, preferred neutral to alkaline condition for their optimal growth. Three isolates (MR-3, MR-4 and MR-8) showed maximum growth at 41°C, while the others grew best at temperature between 35° and 37°C. The optimal NaCl concentration for the growth was found to be 3% for 5 isolates (MR-1, MR-3, MR-4, MR-8 and MR-11) and 5% for the rest 7 isolates (MR-5, MR-6, MR-7, MR-13, MR-14, MR-15 and MR-16). All isolates were true halophilic since they did not show grow in absence of salinity, and all of them were also fungicide (Perfeckthion and Indofil M-45) tolerants to some extent. Keywords: Azospirillum, Growth characteristics, Halophilic, Tolerance to fungicideDOI: http://dx.doi.org/10.3329/bjm.v23i2.881 Bangladesh J Microbiol, Volume 23, Number 2, December 2006, pp 145-148

Mineral nutrition, dinitrogen fixation, and growth of Alnuscrispa and Alnusglutinosa

1985 ◽  
Vol 15 (5) ◽  
pp. 855-861 ◽  
Author(s):  
G. Prégent ◽  
C. Camiré
Keyword(s):  
Mineral Nutrition ◽  
Dry Weight ◽  
Optimal Growth ◽  
Maximum Growth ◽  
Dinitrogen Fixation ◽  
Weight Basis ◽  
Critical Levels ◽  
N Status

Invitro cultures of Alnuscrispa (Ait.) Pursh and Alnusglutinosa (L.) Gaertn. were used to estimate critical foliage levels of selected nutrients for optimal growth and dinitrogen (N2) fixation. For A. crispa to obtain 90% of maximum growth and N2 fixation, foliar levels of 0.12% P, 0.13% Mg, <0.31% K, and <0.04% Ca on a dry weight basis were needed. For A. glutinosa, the critical levels were 0.138% P, 0.10% Mg, 0.29% Ca, and ~0.20% K. From all the deficiencies observed, P had the more pronounced effects on N status of both species.

Divergent response of heavy metal bioavailability in soil rhizosphere to agricultural land use change from paddy field to various drylands

2021 ◽  
Author(s):  
Yujuan Gao ◽  
Jianli Jia ◽  
Beidou Xi ◽  
Dongyu Cui ◽  
Wenbing Tan
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Land Use ◽  
Land Use Change ◽  
Agricultural Land ◽  
Rhizosphere Soil ◽  
Agricultural Land Use ◽  
Metal Bioavailability ◽  
Soil Rhizosphere ◽  
Divergent Response

The heavy metal pollution induced by agricultural land use change has attracted great attention. In this study, the divergent response of bioavailability of heavy metals in rhizosphere soil to different...

scholarly journals OPTIMALISASI PRODUKSI ENZIM KITINASE PADA ISOLAT JAMUR KITINOLITIK DARI SAMPEL TANAH RIZOSFER

2018 ◽  
Vol 3 (01) ◽  
pp. 62-69
Author(s):  
Eka Corneliyawati ◽  
Massora Massora ◽  
Khikmah Khikmah ◽  
As’ad Syamsul Arifin
Keyword(s):  
Biological Control ◽  
Cell Wall ◽  
Rhizosphere Soil ◽  
Plant Root ◽  
Optimal Growth ◽  
Chitinase Activity ◽  
Fungal Species ◽  
Plant Roots ◽  
Chitinase Production

The rhizosphere is the zone of soil surrounding a plant root where plant roots, soil and the soil biota interact with each other. Chitinolytic fungi has been effectively used in biological control agens. The chitinase activity causes lysis of the fungi cell wall pathogen. The aim of the research was to find optimization of activity chitinase enzyme from rhizosphere soil was conducted in vitro. Optimal growth chitinase production for TKR3 fungi isolate were concentration of chitin 0,2% (b/v), pH 5,5, temperature 30ºC, agitation 150 rpm and incubation time at four days. The optimum yield of chitinase production is influenced by fungal species and environmental conditions.

Clostridium tyrobutyricum Strains Show Wide Variation in Growth at Different NaCl, pH, and Temperature Conditions

2012 ◽  
Vol 75 (10) ◽  
pp. 1791-1795 ◽  
Author(s):  
MARJO RUUSUNEN ◽  
ANU SURAKKA ◽  
HANNU KORKEALA ◽  
MIIA LINDSTRÖM
Keyword(s):  
Growth Rates ◽  
Maximum Growth ◽  
Control Measures ◽  
Clostridium Tyrobutyricum ◽  
Food Control ◽  
Acid Fermentation ◽  
Temperature Conditions ◽  
Physiological Diversity ◽  
Nacl Concentration ◽  
Different Strains

Outgrowth from Clostridium tyrobutyricum spores in milk can lead to butyric acid fermentation in cheeses, causing spoilage and economical loss to the dairy industry. The aim of this study was to investigate the growth of 10 C. tyrobutyricum strains at different NaCl, pH, and temperature conditions. Up to 7.5-fold differences among the maximum growth rates of different strains in the presence of 2.0% NaCl were observed. Five of 10 strains were able to grow in the presence of 3.0% NaCl, while a NaCl concentration of 3.5% was completely inhibitory to all strains. Seven of 10 strains were able to grow at pH 5.0, and up to 4- and 12.5-fold differences were observed among the maximum growth rates of different strains at pH 5.5 and 7.5, respectively. The maximum growth temperatures varied from 40.2 to 43.3°C. The temperature of 10°C inhibited the growth of all strains, while 8 of 10 strains grew at 12 and 15°C. Despite showing no growth, all strains were able to survive at 10°C. In conclusion, wide variation was observed among different C. tyrobutyricum strains in their ability to grow at different stressful conditions. Understanding the physiological diversity among the strains is important when designing food control measures and predictive models for the growth of spoilage organisms in cheese.

scholarly journals Digitaria insularis Management and Nematode Dynamics in Off-season Maize

2020 ◽  
Vol 8 (2) ◽  
pp. 729
Author(s):  
Marcos Massuo Kashiwaqui ◽  
Claudia Regina Dias-Arieira ◽  
João Paulo Matias ◽  
André A. Pazinato da Silva ◽  
José Cristimiano dos Santos Neto ◽  
...  
Keyword(s):  
Weed Management ◽  
Management System ◽  
Rhizosphere Soil ◽  
Control Level ◽  
Management Systems ◽  
Acetyl Coa Carboxylase ◽  
Continuous Increase ◽  
Maize Roots ◽  
Excellent Control ◽  
Soil Rhizosphere

Maize stands out as one of the most important crops in succession to soybean in tropic countries. However, the susceptibility of both crops to nematodes, can cause a continuous increase in the nematode population, especially in areas where there is the occurrence of weeds susceptible to the parasites. Thus, the objective was to evaluate the nematodes dynamics in a growing area with off-season maize under chemical weed management. The experiment was installed at Tuneiras do Oeste County, Brazil, designed in randomized blocks, with seven treatments and five replications, constituted by sourgrass (Digitaria insularis) management systems with glyphosate associated to herbicides inhibitors of the enzyme acetyl-CoA carboxylase (ACCase) and auxin-mimetic, and complement with glyphosate + atrazine + tembotrione in post-emergence. The effect of treatments on Pratylenchus spp. population was observed in roots and soil rhizosphere soil of D. insularis and in maize roots. Glyphosate application followed by glyphosate + atrazine was inefficient in controlling sourgrass. Management system with glyphosate + clethodim + 2.4-D followed by glyphosate + atrazine + tembotrione reduced the Pratylenchus spp. population in sourgrass, but any management system repeated this effect in maize. Management systems of D. insularis with associations of glyphosate + clethodim; glyphosate + clethodim + 2.4-D and glyphosate + fenoxaprop-p-ethyl, all followed by glyphosate + atrazine + tembotrione, showed excellent control level of sourgrass without affecting plant height, grain and rank numbers and grain yield. It is concluded that the management system using herbicides association controlled sourgrass and may interferer on Pratylenchus spp. population.

scholarly journals Methanobacterium aggregans sp. nov., a hydrogenotrophic methanogenic archaeon isolated from an anaerobic digester

2015 ◽  
Vol 65 (Pt_6) ◽  
pp. 1975-1980 ◽  
Author(s):  
Tobias Kern ◽  
Mary Linge ◽  
Michael Rother
Keyword(s):  
16S Rrna ◽  
Novel Species ◽  
Sequence Similarity ◽  
Phylogenetic Analyses ◽  
Optimal Growth ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Rrna Gene ◽  
Strictly Anaerobic ◽  
Curved Rods

A novel, strictly anaerobic, hydrogenotrophic methanogen, strain E09F.3T, was isolated from a commercial biogas plant in Germany. Cells of E09F.3T were Gram-stain-negative, non-motile, slightly curved rods, long chains of which formed large aggregates consisting of intertwined bundles of chains. Cells utilized H2+CO2 and, to a lesser extent, formate as substrates for growth and methanogenesis. The optimal growth temperature was around 40 °C; maximum growth rate was obtained at pH around 7.0 with approximately 6.8 mM NaCl. The DNA G+C content of strain E09F.3T was 39.1 mol%. Phylogenetic analyses based on 16S rRNA and mcrA gene sequences placed strain E09F.3T within the genus Methanobacterium. On the basis of 16S rRNA gene sequence similarity, strain E09F.3T was closely related to Methanobacterium congolense CT but morphological, physiological and genomic characteristics indicated that strain E09F.3T represents a novel species. The name Methanobacterium aggregans sp. nov. is proposed for this novel species, with strain E09F.3T ( = DSM 29428T = JCM 30569T) as the type strain.

Enrichment of bacteriorhodopsin with isotopically labeled amino acids by biosynthetic incorporation in Halobacterium halobium

1992 ◽  
Vol 38 (11) ◽  
pp. 1181-1185 ◽  
Author(s):  
S. L. Helgerson ◽  
S. L. Siemsen ◽  
E. A. Dratz
Keyword(s):  
Amino Acids ◽  
Synthetic Medium ◽  
Optimal Growth ◽  
Isotopic Labeling ◽  
Maximum Growth ◽  
Integral Membrane Protein ◽  
Maximum Growth Rate ◽  
Halobacterium Halobium ◽  
Isoleucine Leucine ◽  
Complete Synthetic Medium

The growth of Halobacterium halobium was optimized in a chemically defined synthetic medium. Arginine, isoleucine, leucine, lysine, methionine, tyrosine, and valine were found to be essential for growth. Optimal growth rates and cell yields were obtained when the medium was also supplemented with the nonessential amino acids alanine, asparagine, glutamic acid, glycine, phenylalanine, proline, serine, and threonine. The complete synthetic medium supported the same maximum growth rate, cell yield, and production of the integral membrane protein bacteriorhodopsin as was obtained in a complex peptone-based growth medium. Using this defined synthetic medium, isotopically labeled bacteriorhodopsin was produced with several 13C-enriched amino acids. The yield of 13C-labeled bacteriorhodopsin was greater than 35 milligrams of purified protein per litre of cell culture. Key words: bacteriorhodopsin, biosynthetic isotopic labeling, synthetic culture medium, nuclear magnetic resonance.

scholarly journals Burkholderia humisilvae sp. nov., Burkholderia solisilvae sp. nov. and Burkholderia rhizosphaerae sp. nov., isolated from forest soil and rhizosphere soil

2015 ◽  
Vol 65 (Pt_9) ◽  
pp. 2986-2992 ◽  
Author(s):  
Jae-Chan Lee ◽  
Kyung-Sook Whang
Keyword(s):  
16S Rrna ◽  
Forest Soil ◽  
Type Strain ◽  
Phylogenetic Trees ◽  
Gene Sequence ◽  
Rhizosphere Soil ◽  
Optimal Growth ◽  
Mountain Forest ◽  
Rrna Gene ◽  
Phenotypic Data

Strains Y-12T and Y-47T were isolated from mountain forest soil and strain WR43T was isolated from rhizosphere soil, at Daejeon, Korea. The three strains grew at 10–55 °C (optimal growth at 28–30 °C), at pH 3.0–8.0 (optimal growth at pH 6.0) and in the presence of 0–4.0  % (w/v) NaCl, growing optimally in the absence of added NaCl. On the basis of 16S rRNA gene sequence analysis, the three strains were found to belong to the genus Burkholderia, showing the closest phylogenetic similarity to Burkholderia diazotrophica JPY461T (97.2–97.7  %); the similarity between the three sequences ranged from 98.3 to 98.7  %. Additionally, the three strains formed a distinct group in phylogenetic trees based on the housekeeping genes recA and gyrB. The predominant ubiquinone was Q-8, the major fatty acids were C16 : 0 and C17 : 0 cyclo and the DNA G+C content of the novel isolates was 61.6–64.4 mol%. DNA–DNA relatedness among the three strains and the type strains of the closest species of the genus Burkholderia was less than 50  %. On the basis of 16S rRNA, recA and gyrB gene sequence similarities, chemotaxonomic and phenotypic data, the three strains represent three novel species within the genus Burkholderia, for which the names Burkholderia humisilvae sp. nov. (type strain Y-12T = KACC 17601T = NBRC 109933T = NCAIM B 02543T), Burkholderia solisilvae sp. nov. (type strain Y-47T = KACC 17602T = NBRC 109934T = NCAIM B 02539T) and Burkholderia rhizosphaerae sp. nov. (type strain WR43T = KACC 17603T = NBRC 109935T = NCAIM B 02541T) are proposed.

METABOLIC ACTIVITY AND PHOSPHATE-DISSOLVING CAPABILITY OF BACTERIAL ISOLATES FROM WHEAT ROOTS, RHIZOSPHERE, AND NON-RHIZOSPHERE SOIL

1959 ◽  
Vol 5 (1) ◽  
pp. 79-85 ◽  
Author(s):  
H. Katznelson ◽  
B. Bose
Keyword(s):  
Metabolic Activity ◽  
Rhizosphere Soil ◽  
Root Zone ◽  
Optimal Growth ◽  
Bacterial Isolates ◽  
Wheat Roots ◽  
Soil Extracts ◽  
Large Numbers ◽  
Insoluble Phosphorus ◽  
Phosphate Solubilizing

Bacterial isolates from the roots of wheat (rhizoplane) were more active in oxidizing glucose and alanine than cultures isolated from rhizosphere and non-rhizosphcre soils. In general, metabolic activity was greater with alanine than with glucose. Over one third of the cultures tested were capable of dissolving insoluble phosphorus in the form of CaHPO4 but the roots did not appear to exert a selective effect on these forms. However, the phosphate-solubilizing organisms from the rhizoplane were also the most active in oxidizing glucose and alanine. Those from the rhizosphere soil were intermediate in this respect. By far the majority of these phosphate-dissolving bacteria were in the nutritional group requiring unknown substances in yeast and soil extracts for optimal growth. It was suggested that although these bacteria were not preferentially stimulated in the root zone, their large numbers and their greater metabolic activity may contribute significantly to the phosphate economy of the plant.

Populations of the spinach wilt pathogen, Fusarium oxysporum f. sp. spinaciae, in the root tissues, rhizosphere, and soil in the field

1979 ◽  
Vol 25 (2) ◽  
pp. 227-229 ◽  
Author(s):  
Andres A. Reyes
Keyword(s):  
Fusarium Oxysporum ◽  
Chinese Cabbage ◽  
Rhizosphere Soil ◽  
Infested Field ◽  
Soil Rhizosphere ◽  
Root Tissues

Populations of Fusarium oxysporum f. sp. spinaciae in root tissues and rhizosphere soil of diseased spinach plants were higher than in the root tissues and rhizosphere soil of healthy plants. Populations in soil rhizosphere were higher than in nonrhizosphere soil. The fungus populations were very low in the root tissues of the nonsusceptible strawberry, broccoli, Chinese cabbage, and mustard grown in the infested field. The populations were low at the beginning of the season, increased, and remained high during the summer, then dropped in the fall. The fungus populations ranged from 1600 to 2600 propagules/g in the top 10 cm of soil, declined sharply between 11 and 20 cm, and were nondetectable between 41 and 60 cm.

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