Diversity, adaptation and activity of the bacterial flora in saline environments

Zahran, H. H.

doi:10.1007/s003740050306

Cited by 244 publications

(142 citation statements)

References 135 publications

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“…The positive effects of organic matter on AlP activities exerted indirectly available P. According to Rietz and Haynes (2003), the substantial AlP activities could persist even at high soil salinity and sodicity. Zahran (1997) noted that the production and activity of enzymes from the saline soil bacteria demonstrated salt requirements greater than those of the corresponding enzymes from non-saline bacteria.…”

Section: Resultsmentioning

confidence: 99%

Vertical distribution of phosphorus concentrations, phosphatase activity and further soil chemical properties in salt-affected Mollic Gleysols in Poland

Lemanowicz

Krzyżaniak

2015

Environ Earth Sci

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The paper demonstrates distribution of the content of total and available phosphorus and activity of the alkaline and acid phosphatase against the selected properties of salt-affected Mollic Gleysols. In the adequately prepared soil, the following were determined: pH, total organic carbon, the exchangeable cations (Ca, Mg, Na, K), salinity, the content of phosphorus, the activity of phosphomonoesterases. The distribution of the elements in the soil profiles was described with the value of the Distribution Index. To evaluate the availability of phosphorus, the Index of Mobility was used. The content of phosphorus varies, and it depends on physicochemical soil properties. Both the content of phosphorus available to plants and the activity of phosphatases in the profiles showed a high variation that depends both on the sampling date and on the depth. The lowest content of phosphorus was found in the profiles sampled in spring, during an intensive plant growth, while the greatest content was received in soil profiles sampled in summer. The research showed also a high variation in the time of the activity of phosphatases as well as their changes depending on the soil parameters, which was confirmed by the recorded values of the correlations between the activity of alkaline and acid phosphomonoesterases and the content of carbon, respectively, (r = 0.47, P \ 0.05) and (r = 0.62, P \ 0.05) as well as available phosphorus (r = 0.32, P \ 0.05) and (r = 0.38, P \ 0.05). A many-year seasonal salinity of soil did not decrease the activity of the phosphomonoesterases since it was mostly connected with the natural content of organic carbon.

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Section: Resultsmentioning

confidence: 99%

Vertical distribution of phosphorus concentrations, phosphatase activity and further soil chemical properties in salt-affected Mollic Gleysols in Poland

Lemanowicz

Krzyżaniak

2015

Environ Earth Sci

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“…There are conflicting reports on the effects of salinity on NA. While some studies have found that concentrations of NaCl as low as 75 mM can have a negative impact on NA in symbiotic N fixers (Bolaňos et al, 2006), others have reported no effects from highly saline environments (Zahran, 1997). The extent by which N fixers are constrained by salinity in our system will be explored in future research.…”

Section: Salinity Effectsmentioning

confidence: 92%

Heterotrophic nitrogen fixation in oligotrophic tropical marshes: changes after phosphorus addition

et al. 2009

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In order to determine the impact of nutrient enrichment on phosphorus (P) limited wetlands, we established experimental P additions in marshes throughout northern Belize. P significantly increased macrophyte primary production, which led to the rapid elimination of cyanobacterial mats. The replacement of cyanobacterial mats by macrophytes constrained autotrophic nitrogen (N) fixation, increased the quantity, and changed the quality of organic matter input to the sediments. We predicted that the activity of sediment heterotrophic N fixers will be impacted by these alterations in carbon input. We used the acetylene reduction technique to measure potential (glucose amended) nitrogenase activity (NA) in sediments from controls and treatment plots that have been P enriched for four years and dominated either by Eleocharis cellulosa, or Typha domingensis for two years. NA in P-enriched plots was 2-3 orders of magnitude higher than NA in controls. NA was positively correlated with the soil reactive P, both total organic and microbial carbon, live root biomass, and total phospholipid fatty acids (PLFA) as an indicator of active microbial biomass. It was negatively correlated with the concentration of ammonium-N. Path analysis revealed that the indirect effect of P on NA through the root biomass was more important than the direct effect of P. NA of the upper sediment layer was consistently higher in Eleocharis than in Typha dominated plots, despite the higher litter input by Typha. We feel that the higher levels of lignin and phenolics occurring in Typha litter, relative to Eleocharis, constrained NA in Typha plots.

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“…Nitrogen cycling is mostly controlled by biological activity and at the same time biological processes are affected by climate and physicochemical soil characteristics. In some extreme environments, such as saline soils, the high electrolytic conductivity (EC) inhibits microbial activity and organic matter decomposition and thus affects N cycling (Johnston & Guenzi, 1963;McCormick & Wolf, 1980;Bandyopadhyay & Bandyopadhyay, 1983;Zahran, 1997;Pathak & Rao, 1998). For instance, mineralization of maize and glucose were inhibited in alkaline saline soils with EC > 10 dS m -1 and large amounts of NH 4 + and NO 3 -were immobilized within short periods of time, reducing N availability (Conde et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

“…High concentrations of soluble salts in soil have a negative effect on plant growth in different aspects (Aguirre, 1993;Zahran, 1997). In the first place, high concentrations of specific ions such as Na + are toxic to plants and cause physiologic disorders.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of 14C-labeled glucose and ammonium in saline arable soils

Vuelvas-Solórzano

Hernández-Matehuala

Conde-Barajas

et al. 2009

Rev. Bras. Ciênc. Solo

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SUMMARYOrganic matter dynamics and nutrient availability in saline agricultural soils of the State of Guanajuato might provide information for remediation strategies. 14 C labeled glucose with or without 200 mg kg -1 of NH 4 + -N soil was added to two clayey agricultural soils with different electrolytic conductivity (EC), i.e. 0.94 dS m -1 (low EC; LEC) and 6.72 dS m -1 (high EC; HEC), to investigate the effect of N availability and salt content on organic material decomposition. Inorganic N dynamics and production of CO 2 and 14 CO 2 were monitored. Approximately 60 % of the glucose-14 C added to LEC soil evolved as 14 CO 2 , but only 20 % in HEC soil after the incubation period of 21 days. After one day, < 200 mg 14 C was extractable from LEC soil, but > 500 mg 14 C from HEC soil. No N mineralization occurred in the LEC and HEC soils and glucose addition reduced the concentrations of inorganic N in unamended soil and soil amended with NH 4 + -N. The NO 2 -and NO 3 -concentrations were on average higher in LEC than in HEC soil, with exception of NO 2 -in HEC amended with NH 4 + -N. It was concluded that increases in soil EC reduced mineralization of the easily decomposable C substrate and resulted in Ndepleted soil.Index terms: dynamics of inorganic N, emission of 14 CO 2 and 12 CO 2 , saline soils. Os conhecimentos sobre a dinâmica da matéria orgânica e disponibilidade de nutrientes em solos salinos podem ser úteis para nortear a adoção de estratégias de recuperação e manejo. O objetivo deste trabalho foi avaliar o efeito da condutividade elétrica (EC) e presença de N inorgânico na decomposição da matéria orgânica a dois solos salinos localizados em Guanajuato (México). Nesse sentido, glicose marcada com 14 C com ou sem amônio na dose de 200 mg kg -1 de N foi adicionada em dois tipos de solo com valores de condutividade elétrica de 0,94 dS m -1 (baixo EC; LEC) e 6,72 dS m -1 (alta EC; HEC). Amostras de solos foram incubadas durante 21 dias e, ao longo desse tempo, foram avaliadas as concentrações de N inorgânico e a produção de 12 CO 2 e 14 CO 2 . Após o período de incubação, aproximadamente 60 % da glicose marcada com 14 C adicionado ao solo LEC evoluiu como 14 CO 2 , mas somente 20 % no solo HEC a evolução de 14 CO 2 foi de apenas 20 %. Decorrido um dia de incubação, menos de 200 mg de 14 C foram extraídos do solo LEC, ao passo que no solo HEC foram extraídos mais de 500 mg de 14 C. Não ocorreu mineralização de N nos dois solos e a adição de glicose reduziu as concentrações de N inorgânico no solo controle e no solo que recebeu N-NH 4 + . As concentrações de NO 2 -e NO 3 -foram, em média, maiores no solo LEC do que no solo HEC, com exceção do teor de NO 2 -, que foi maior no HEC tratado com NH 4 + . O aumento da condutividade elétrica promoveu a redução da mineralização de substrato facilmente decomponível e a diminuição do teor de N no solo.Termos de indexação: dinâmica de nitrogênio inorgânico, emissão de 12 CO 2 e 14 CO 2 , solos salinos.

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Diversity, adaptation and activity of the bacterial flora in saline environments

Cited by 244 publications

References 135 publications

Vertical distribution of phosphorus concentrations, phosphatase activity and further soil chemical properties in salt-affected Mollic Gleysols in Poland

Vertical distribution of phosphorus concentrations, phosphatase activity and further soil chemical properties in salt-affected Mollic Gleysols in Poland

Heterotrophic nitrogen fixation in oligotrophic tropical marshes: changes after phosphorus addition

Dynamics of 14C-labeled glucose and ammonium in saline arable soils

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