Phosphatase production and activity in copper (II) accumulating Rhizopus delemar

Tsekova, K.; Galabova, Danka

doi:10.1016/j.enzmictec.2003.06.001

Cited by 28 publications

(21 citation statements)

References 23 publications

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“…However, higher values of Km as 0.95 and 1.3mM were calculated for the acid phosphatases of A. niger (Gargova et al 2006) and Humicola lutea (Micheva-Viteva et al 2000), respectively. Also, Km values of 0.029 and 0.325mM were reported for the intracellular enzymes of A. caespitosus (Guimarães et al 2003) and R. delemar (Tsekova and Galabova 2003), which were low in comparison with the value found in the present work, suggesting that these enzymes had more affinity to the substrate than iAPase. Orthophosphate monoesters was the dominated fraction of organic P compounds found in the soil (Turner et al 2003) and could be used as a source of P for soil organisms after phosphate release by phosphatases enzymes.…”

Section: Effect Of Substrate Concentrationcontrasting

confidence: 51%

Control of Acid Phosphatases Expression from Aspergillus niger by Soil Characteristics

Nahas

2015

Braz. arch. biol. technol.

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Section: Effect Of Substrate Concentrationcontrasting

confidence: 51%

Control of Acid Phosphatases Expression from Aspergillus niger by Soil Characteristics

Nahas

2015

Braz. arch. biol. technol.

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“…Fries et al, (1998) showed the considerable increase in ACP and ALP activities in maize roots were closely correlated with the levels of VAM colonization in roots. Such response has also been observed by Tsckova and Galabova, (2003) in other inoculated plants under heavy metals stress and they suggested the inoculation as a possible process of detoxification and resistance which in divergent with the present results. …”

Section: Phosphatase Activitysupporting

confidence: 80%

Role of Vesicular Arbuscular Mycorrhizal Inoculation of Zea mays on Heavy Metals Tolerance.

2015

Egypt. J. Bot.

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HE STUDY evaluated the physiological responses of maize ……..plant inoculated with vesicular arbuscular mycorrhiza (VAM) isolated from polluted site and growing in heavy metal (Cd or Pb) polluted soil. Chlorophyll, soluble carbohydrate, soluble protein, nutrient elements (P and N) content and phosphatase activity were analyzed. The phosphatase activity in inoculated plants was significantly increased in comparison to the non-inoculated ones. In addition, the contents of N, P, chlorophyll, total soluble carbohydrates and protein were significantly increased in plants inoculated with mycorrhiza grown in heavy metal ( Cd or Pb) contaminated soil in comparing with the non-inoculated ones. Therefore, it can be concluded that the VAM inoculation is capable to alleviate the damage caused by heavy metal (Cd or Pb) on maize plants that maintain the growth and this could be related to nutrient status offered by VAM. Isolation of heavy metal tolerant VAM fungi can be a potential biotechnical tool for inoculation of plant to enhance its heavy metal tolerance.

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“…Similar values were also observed for the Km values for acid phosphatases extracted from fungi (Tsekova & Galabova, 2003) and from vegetables such as S. oligorrhiza (Nakazato et al, 1997), sweet potato tuber and wheat germ . The Km value determined for an acid phosphatase from Selenastrum minutum using phosphoenolpyruvate as substrate (Theodorou et al, 1991) was close to that obtained for P. subcapitata in the present work.…”

Section: Kinetics Studiessupporting

confidence: 65%

“…This element, as well as other metals, can intensify the production of reactive oxygen species (ROS) in soil (Gratão et al, 2005) and in aquatic organisms (Verlecar et al, 2008). ROS toxicity can be avoided by antioxidant enzymes like ascorbate peroxidase, superoxide dismutase and catalase, which are associated to Hg 2+ and Ni 2+ stress in algae (Okamoto et al, 2001;Huang et al, 2006) and in plants (Pompeu et al, 2008), respectively.…”

Section: Introductionmentioning

confidence: 99%

Extraction, partial characterization and susceptibility to Hg2+ of acid phosphatase from the microalgae Pseudokirchneriella subcapitata

Jonsson¹,

Aoyama

2009

Sci. agric. (Piracicaba, Braz.)

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Pseudokirchneriella subcapitata is a unicellular green algae widely distributed in freshwater and soils. Due to its cosmopolitan characteristic, its use is recommended by national and international protocols in ecotoxicity studies. The alteration of phosphatase activities by agriculture pollutants like heavy metals has been extensively used as a biomarker in risk assessment and biomonitoring. In this study, we compared the extraction of acid phosphatase from P. subcapitata by different procedures and we studied the stability, substrates specificity, kinetics and the effect of Hg 2+ in the crude extract. The freezing and thawing technique associated with probe sonication was the most suitable method of extraction. The enzyme was stable when frozen at -20ºC for at least six months, showed an optimum pH of 5 and a Km value of 0.27 mM for p-nitrophenylphosphate (pNPP) as substrate. Some natural organic substrates were cleaved by a similar extent as the synthetic substrate pNPP. RESUMO: Pseudokirchneriella subcapitata é uma alga verde unicelular amplamente distribuída em corpos d´agua e solos. Devido a sua natureza cosmopolita, seu uso é recomendado por protocolos nacionais e internacionais na realização de estudos de ecotoxicidade. A alteração da atividade de fosfatases por agentes poluentes de origem agrícola, como metais pesados, tem sido largamente usada como um biomarcador na avaliação de risco e biomonitoramento. No presente trabalho foi comparada a extração da fosfatase ácida de P. subcapitata por diferentes métodos e estudada a sua estabilidade, especificidade por substratos, cinética e efeito do Hg 2+ no extrato bruto. O congelamento e descongelamento, associado com ultrassom, foi o método que proporcionou maior rendimento de extração. A enzima, praticamente estável por armazenamento a -20ºC, durante aproximadamente seis meses, demonstrou uma atividade ótima em pH 5 e um valor de Km para o p-nitrofenilfostato (pNPP) de 0,27 mM. Alguns substratos naturais foram hidrolisados com uma intensidade semelhante à do substrato sintético pNPP. Diferentemente dos estudos de exposição a curto prazo (24 horas), observou-se inibição da atividade específica nas culturas expostas durante 7 dias, com um valor de CE 50 (concentração de Hg 2+ que promove 50% de decréscimo da atividade específica) equivalente a 12,63 μM Hg 2+ .

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Phosphatase production and activity in copper (II) accumulating Rhizopus delemar

Cited by 28 publications

References 23 publications

Control of Acid Phosphatases Expression from Aspergillus niger by Soil Characteristics

Control of Acid Phosphatases Expression from Aspergillus niger by Soil Characteristics

Role of Vesicular Arbuscular Mycorrhizal Inoculation of Zea mays on Heavy Metals Tolerance.

Extraction, partial characterization and susceptibility to Hg2+ of acid phosphatase from the microalgae Pseudokirchneriella subcapitata

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