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Enjami L Turne - One of the best experts on this subject based on the ideXlab platform.
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variation in ph optima of Hydrolytic Enzyme activities in tropical rain forest soils
Applied and Environmental Microbiology, 2010Co-Authors: Enjami L TurneAbstract:Extracellular Enzymes synthesized by soil microbes play a central role in the biogeochemical cycling of nutrients in the environment. The pH optima of eight Hydrolytic Enzymes involved in the cycles of carbon, nitrogen, phosphorus, and sulfur, were assessed in a series of tropical forest soils of contrasting pH values from the Republic of Panama. Assays were conducted using 4-methylumbelliferone-linked fluorogenic substrates in modified universal buffer. Optimum pH values differed markedly among Enzymes and soils. Enzymes were grouped into three classes based on their pH optima: (i) Enzymes with acidic pH optima that were consistent among soils (cellobiohydrolase, β-xylanase, and arylsulfatase), (ii) Enzymes with acidic pH optima that varied systematically with soil pH, with the most acidic pH optima in the most acidic soils (α-glucosidase, β-glucosidase, and N-acetyl-β-glucosaminidase), and (iii) Enzymes with an optimum pH in either the acid range or the alkaline range depending on soil pH (phosphomonoesterase and phosphodiesterase). The optimum pH values of phosphomonoesterase were consistent among soils, being 4 to 5 for acid phosphomonoesterase and 10 to 11 for alkaline phosphomonoesterase. In contrast, the optimum pH for phosphodiesterase activity varied systematically with soil pH, with the most acidic pH optima (3.0) in the most acidic soils and the most alkaline pH optima (pH 10) in near-neutral soils. Arylsulfatase activity had a very acidic optimum pH in all soils (pH ≤3.0) irrespective of soil pH. The differences in pH optima may be linked to the origins of the Enzymes and/or the degree of stabilization on solid surfaces. The results have important implications for the interpretation of Hydrolytic Enzyme assays using fluorogenic substrates.
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stability of Hydrolytic Enzyme activity and microbial phosphorus during storage of tropical rain forest soils
Soil Biology & Biochemistry, 2010Co-Authors: Enjami L Turne, Tania RomeroAbstract:Abstract Storage can markedly influence microbial and biochemical properties in soils, yet recommendations for sample storage are based on studies of temperate soils that regularly experience extended cold periods. We assessed the influence of storage conditions on microbial phosphorus and the activity of four Hydrolytic Enzymes (phosphomonoesterase, phosphodiesterase, β-glucosidase, and N-acetyl-β- d -glucosaminidase) in three lowland tropical forest soils from the Republic of Panama that experience a constant warm temperature. The soils spanned a strong rainfall gradient and contained contrasting physical and chemical properties (pH 3.6–5.9; total carbon 26–50 g C kg−1; clay 33–62%; total phosphorus 0.30–0.60 g P kg−1). Storage treatments were: (i) room temperature (22 °C in the dark), (ii) refrigerated (4 °C in the dark), (iii) air-dried (10 d, 22 °C), and (iv) frozen (−35 °C). There were significant changes in Enzyme activities and microbial phosphorus during refrigerated and room temperature storage, although changes were relatively small during the first two weeks. An initial marked decline in Enzyme activities for one soil analyzed within 2 h of sampling was attributed to a flush of activity caused by sampling and soil preparation (sieving, etc.). For longer-term storage (>2 weeks), ambient laboratory temperature appeared preferable to freezing and cold storage, because one month of storage caused a marked decline in Enzyme activities and microbial phosphorus in one soil. Freezing preserved the activities of some Enzymes in some soils at rates comparable to cold or room temperature storage, but caused a marked decline in microbial phosphorus in two soils. Air-drying caused a marked decline in microbial phosphorus and the activity of all Enzymes. We therefore conclude that Enzyme assays and microbial phosphorus should be determined in tropical forest soils after no more than two weeks storage in the dark at ambient laboratory temperature.
Tania Romero - One of the best experts on this subject based on the ideXlab platform.
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stability of Hydrolytic Enzyme activity and microbial phosphorus during storage of tropical rain forest soils
Soil Biology & Biochemistry, 2010Co-Authors: Enjami L Turne, Tania RomeroAbstract:Abstract Storage can markedly influence microbial and biochemical properties in soils, yet recommendations for sample storage are based on studies of temperate soils that regularly experience extended cold periods. We assessed the influence of storage conditions on microbial phosphorus and the activity of four Hydrolytic Enzymes (phosphomonoesterase, phosphodiesterase, β-glucosidase, and N-acetyl-β- d -glucosaminidase) in three lowland tropical forest soils from the Republic of Panama that experience a constant warm temperature. The soils spanned a strong rainfall gradient and contained contrasting physical and chemical properties (pH 3.6–5.9; total carbon 26–50 g C kg−1; clay 33–62%; total phosphorus 0.30–0.60 g P kg−1). Storage treatments were: (i) room temperature (22 °C in the dark), (ii) refrigerated (4 °C in the dark), (iii) air-dried (10 d, 22 °C), and (iv) frozen (−35 °C). There were significant changes in Enzyme activities and microbial phosphorus during refrigerated and room temperature storage, although changes were relatively small during the first two weeks. An initial marked decline in Enzyme activities for one soil analyzed within 2 h of sampling was attributed to a flush of activity caused by sampling and soil preparation (sieving, etc.). For longer-term storage (>2 weeks), ambient laboratory temperature appeared preferable to freezing and cold storage, because one month of storage caused a marked decline in Enzyme activities and microbial phosphorus in one soil. Freezing preserved the activities of some Enzymes in some soils at rates comparable to cold or room temperature storage, but caused a marked decline in microbial phosphorus in two soils. Air-drying caused a marked decline in microbial phosphorus and the activity of all Enzymes. We therefore conclude that Enzyme assays and microbial phosphorus should be determined in tropical forest soils after no more than two weeks storage in the dark at ambient laboratory temperature.
Hasa A Altalhi - One of the best experts on this subject based on the ideXlab platform.
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saccharification and Hydrolytic Enzyme production of alkali pre treated wheat bran by trichoderma virens under solid state fermentation
BMC Biotechnology, 2015Co-Authors: Reda M Elshishtawy, Saleh A Mohamed, Abdullah M Asiri, A M Gomaa, Ibrahim H Ibrahim, Hasa A AltalhiAbstract:Background In continuation of our previously interest in the saccharification of agriculture wastes by Bacillus megatherium in solid state fermentation (SSF), we wish to report an investigation and comparative evaluation among Trichoderma sp. for the saccharification of four alkali-pretreated agricultural residues and production of Hydrolytic Enzymes, carboxymethyl cellulase (CMCase), filter paperase (FPase), pectinase (PGase) and xylanase (Xylase) in SSF. The optimization of the physiological conditions of production of Hydrolytic Enzymes and saccharification content from Trichoderma virens using alkali-pretreated wheat bran was the last goal.
Antonio Carlos Augusto Da Costa - One of the best experts on this subject based on the ideXlab platform.
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Hydrolytic Enzyme production in solid state fermentation by aspergillus niger 3t5b8
Process Biochemistry, 2000Co-Authors: Sonia Couri, Selma Da Costa Terzi, Gustavo Adolfo Saavedra Pinto, Suely Pereira Freitas, Antonio Carlos Augusto Da CostaAbstract:Abstract A mixture containing polygalacturonase, cellulase, xylanase and protease Enzymes was produced using Aspergillus niger 3T5B8 on different agroindustrial residues by solid-state fermentation and tested for vegetable oil extraction. The enzymic activities were evaluated using second-order empirical models from experimental data as a function of fermentation time and cellobiose concentration in the fermentation medium. The use of wheat bran as substrate without cellobiose addition and 42 h of fermentation were the most favourable conditions for producing the mixture of Hydrolytic Enzymes (polygalacturonase 30.75 U/ml, xylanase 30.62 U/ml, protease 5.27 U/ml). Another favourable condition was obtained when mango peel was used as substrate in the presence of 0.2% cellobiose and 24 h of fermentation (FPCAse 3.5 U/ml, xylanase 20.33 U/ml). Enzymic formulations with suitable polygalacturonase and FPCAse activities were favourable to extract oil from the pulp of tropical fruits and oleaginous seeds.
Reda M Elshishtawy - One of the best experts on this subject based on the ideXlab platform.
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saccharification and Hydrolytic Enzyme production of alkali pre treated wheat bran by trichoderma virens under solid state fermentation
BMC Biotechnology, 2015Co-Authors: Reda M Elshishtawy, Saleh A Mohamed, Abdullah M Asiri, A M Gomaa, Ibrahim H Ibrahim, Hasa A AltalhiAbstract:Background In continuation of our previously interest in the saccharification of agriculture wastes by Bacillus megatherium in solid state fermentation (SSF), we wish to report an investigation and comparative evaluation among Trichoderma sp. for the saccharification of four alkali-pretreated agricultural residues and production of Hydrolytic Enzymes, carboxymethyl cellulase (CMCase), filter paperase (FPase), pectinase (PGase) and xylanase (Xylase) in SSF. The optimization of the physiological conditions of production of Hydrolytic Enzymes and saccharification content from Trichoderma virens using alkali-pretreated wheat bran was the last goal.
