scholarly journals Effect of cultivation conditions on ligninolytic enzyme production by Ganoderma carnosum

2009 ◽  
pp. 289-295 ◽  
Author(s):  
Jasmina Simonic ◽  
Jelena Vukojevic ◽  
Mirjana Stajic ◽  
Jasmina Glamoclija
Keyword(s):  
Carbon Source ◽  
Wheat Straw ◽  
Raw Materials ◽  
Nitrogen Concentration ◽  
Synthetic Medium ◽  
Carbon Sources ◽  
Maximum Level ◽  
Total Protein Content ◽  
Phenol Red ◽  
Plant Raw Materials

Ganoderma carnosum has been found in Europe only, at coniferous trees and it is difficult to distinguish it morphologically from G. lucidum. Since G. carnosum has not been studied biochemically yet, the aim of this study was to analyse its ability to produce Mn-dependent peroxidase (MnP), versatile peroxidase (VP) and laccase (Lac) under conditions of solid-state fermentation of selected plant raw materials as carbon sources, in the presence of different nitrogen concentrations in the medium. Wheat straw, corn stem, oak and grapevine sawdust were the analysed plant raw materials. Nitrogen source in synthetic medium was NH4NO3 and its concentrations were: 10mM N and 20 mM N. Enzyme activity was determined spectrophotometrically, using ABTS and phenol red, as the substrates for Lac and Mn-oxidizing peroxidases, respectively. Maximum level of MnP activity (56.82 U/l) was obtained in the medium with wheat straw and nitrogen concentration of 10 mM. Best carbon source for VP production was grapevine sawdust at nitrogen concentration of 10 mM (80.80 U/l). The obtained Lac activity was very low in the medium with wheat straw (1.80 U/l), while it was not detected in the presence of other three analyzed plant raw materials. Maximum of total protein content (0.06 mgml-1) was noted in the medium where oak sawdust was carbon source and nitrogen concentration was 20 mM.

scholarly journals Trametes suaveolens as ligninolytic enzyme producer

2013 ◽  
pp. 437-444 ◽  
Author(s):  
Aleksandar Knezevic ◽  
Ivan Milovanovic ◽  
Mirjana Stajic ◽  
Jelena Vukojevic
Keyword(s):  
Enzyme Activity ◽  
Solid State ◽  
Wheat Straw ◽  
Solid State Fermentation ◽  
Nitrogen Concentration ◽  
Pollution Prevention ◽  
Ligninolytic Enzyme ◽  
Species Selection ◽  
Submerged Cultivation ◽  
Phenol Red

Species of the genus Trametes represent one of the most efficient lignin-degraders which can be attributed to a well developed ligninolytic enzyme system. Current trends are screening of ability of new species to produce these enzymes, as well as the optimization of conditions for their overproduction. Therefore, the aim of the study was to evaluate the potential of T. suaveolens to synthesize laccase and Mn-oxidizing peroxidases during fermentation of the selected plant raw materials. Level of enzyme activities was measured on 7, 10 and 14th day of submersion, as well as the solid-state fermentation of wheat straw and oak sawdust in the presence of NH4NO3 in previously determined optimal nitrogen concentration of 25 mM. The enzyme activity was determined spectrophotometrically using ABTS and phenol red as the substrates. The highest level of laccase activity (1087.1 U/L) was noted after 7 days of wheat straw solid-state fermentation, while during the submerged cultivation the production of the enzyme was not noted. Submerged cultivation in oak sawdust-enriched medium was the optimal for activity of Mn-dependent peroxidase (1767.7 U/L on day 14) and Mn-independent peroxidase (1113.7 U/L on day 7). Introduction of T. suaveolens to produce ligninolytic enzyme represented the base for further study, as well as the determination of relation between enzyme activity and rate of lignin degradation. It could lead to greater possibility of fungal species selection with high delignification capacity, which could take participation in sustainable production of food, feed, fibres, and energy, environmentally friendly pollution prevention, and bioremediation.

Enhanced Heterotrophic Denitrification for the Treatment of Nitrate Contaminated Groundwater by Wheat Straw

2013 ◽  
Vol 316-317 ◽  
pp. 625-628
Author(s):  
Jian Mei Zhang ◽  
Chuan Ping Feng ◽  
Si Qi Hong ◽  
Hui Ling Hao
Keyword(s):  
Carbon Source ◽  
Wheat Straw ◽  
Carbon Sources ◽  
Complete Removal ◽  
Contaminated Groundwater ◽  
Column Experiments ◽  
Inlet Concentration ◽  
Reducing Conditions ◽  
Organic Carbon Sources ◽  
Heterotrophic Denitrification

The method of the heterotrophic denitrification remediation of nitrate-polluted groundwater involves the study of organic carbon sources as electron donor. The aim of the present study was to evaluate wheat straw for its ability to enhance denitrification in column experiments. The inlet concentration was 50.0 mgNO3--N/L and the column operated at the flow rate of 2.0 ml/min. The result showed that in the presence of wheat straw, highly reducing conditions were generated and complete removal of nitrate (>95%) was achieved, with less accumulation of nitrite. Consequently, wheat straw is an attractive carbon source for groundwater denitrification.

Groundwater denitrification with alternative carbon sources

1998 ◽  
Vol 38 (6) ◽  
pp. 237-243 ◽  
Author(s):  
A. Mohseni-Bandpi ◽  
D. J. Elliott
Keyword(s):  
Acetic Acid ◽  
Carbon Source ◽  
Nitrate Nitrogen ◽  
Nitrogen Concentration ◽  
Nitrate Removal ◽  
Carbon Sources ◽  
Pilot Scale ◽  
Rotating Biological Contactor ◽  
Nitrogen Ratio ◽  
Biological Nitrate Removal

A pilot scale rotating biological contactor (RBC) was used to investigate the removal of nitrate-nitrogen from groundwater using three different carbon sources, i.e., methanol, ethanol and acetic acid. Optimum carbon sources to influent nitrate-nitrogen ratio were established by varying the influent concentration of carbon sources. The optimum ratio of methanol, ethanol and acetic acid to nitrate-nitrogen ratios were found to be 2.9, 2.35 and 4.3 respectively. The nitrate-nitrogen removal efficiency averaged 93, 91 and 98 for methanol, ethanol and acetic acid respectively at a loading rate of 76 mg/m2.h. The results of this study show that the acetic acid is the most efficient carbon source for removal of nitrate-nitrogen. Effluent nitrite-nitrogen concentration was minimum for acetic acid as compared with ethanol and methanol. The effluent contained minimum suspended solids and turbidity for methanol as a carbon source. The results of this study indicate that biological nitrate removal using a RBC is a reliable and stable system under all the three carbon sources. The denitrified water in all cases requires some post treatment to oxidise the residual carbon source and remove biomass before distribution.

Comparative Analysis of Nitrate Removal in Sub-Surface Flow Constructed Wetlands by Different External Carbon Sources

2014 ◽  
Vol 1073-1076 ◽  
pp. 779-783
Author(s):  
Patience Awhavbera ◽  
Lian Fang Zhao
Keyword(s):  
Carbon Source ◽  
Wheat Straw ◽  
Constructed Wetlands ◽  
Nitrate Removal ◽  
Waste Product ◽  
Carbon Sources ◽  
Surface Flow ◽  
Synthetic Wastewater ◽  
External Carbon Source ◽  
N Removal

External carbon sources provide additional nutrients that improve the efficiency of nitrate removal in constructed wetlands. Typha angustifolia L. were planted in four vertical subsurface-flow constructed wetlands. Different external carbon sources were fed into the columns, to investigate and compare their treatment of nitrate in synthetic wastewater, with initial influent C/N ratio of 1:1. Wetland A (WA) with 50g wheat straw as external carbon source, wetland B (WB) with 50g woodchips, wetland C (WC) with additional 10mg/L glucose and wetland D (WD) without external carbon source to serve as the control, were used in the lab-scale experimental study. WA, WB, WC and WD within a period of 24 days, cumulatively removed 109.38mg/L, 93.75mg/L, 85.14mg/L, and 64.01mg/L nitrate, respectively, from the influent. The nitrate-nitrogen (NO3–N) removal efficiency as aided by the external carbon sources was in the order: wheat straw > woodchips > glucose > control. Wheat straw treated 93% NO3–N, woodchips 78%, glucose 72% and the control 53%. The results indicate that WA, WB and WC outperformed the control system, due to the additional carbon sources. In general, the wheat straw had a better performance than wood chips and glucose. Thus, wheat straw as low cost biological waste product is recommended for the treatment of nitrate in wetlands.

scholarly journals Ligninolytic enzyme production by Lenzites betulinus on selected plant raw materials

2011 ◽  
pp. 333-338
Author(s):  
Aleksandar Knezevic ◽  
Ivan Milovanovic ◽  
Mirjana Stajic ◽  
Jelena Vukojevic
Keyword(s):  
Solid State ◽  
Wheat Straw ◽  
Solid State Fermentation ◽  
Peroxidase Activity ◽  
Submerged Fermentation ◽  
Laccase Activity ◽  
Raw Materials ◽  
Carbon Sources ◽  
Ligninolytic Enzyme ◽  
Plant Residues

To get a better insight into the ligninolytic system of Lenzites betulinus, the effect of wheat straw and oak sawdust, as carbon sources, on production of Mn-oxidizing peroxidases and laccase, under solid-state and submerged fermentation, was studied. Obtained results revealed considerable differences related to the both factors affecting enzyme activities. Wheat straw was more favorable carbon source for Mn-oxidizing peroxidases and oak sawdust for laccase activity. Solid-state fermentation of wheat straw was optimal for Mn-dependent peroxidase activity (72.1 Ul-1). In contrary to this, submerged fermentation of the same residue gave the highest level of versatile peroxidase activity (25.4 Ul-1). The peak of laccase activity was noted during solid-state fermentation of oak sawdust (32.3 Ul-1), while this enzyme was not detected under submerged fermentation of any plant residues.

scholarly journals Influence of the cultivation conditions on ligninolytic enzyme production in Pleurotus pulmonarius

2007 ◽  
pp. 303-312
Author(s):  
Mirjana Stajic ◽  
Jelena Vukojevic ◽  
Sonja Duletic-Lausevic
Keyword(s):  
Carbon Source ◽  
Enzyme Production ◽  
Laccase Activity ◽  
Nitrogen Concentration ◽  
Ligninolytic Enzyme ◽  
Phenol Red ◽  
Cultivation Conditions ◽  
Pleurotus Pulmonarius ◽  
State Culture ◽  
Solid State Culture

The highest level of laccase activity (391 Ul-1), as well as significant Mn-oxidizing peroxidases production, were found in solid-state culture with grapevine sawdust as the carbon source. After purification of extracellular crude enzyme mixture of Pleurotus pulmonarius, grown in the medium with the best carbon source (grapevine sawdust), three peaks of laccase activity were noted. The results obtained by purification also showed that the levels of phenol red oxidation, in absence of external Mn2+, were higher than phenol red oxidation levels in presence of external Mn2+. The highest laccase activity was in the medium with grapevine sawdust, as carbon source, and NH4Cl at a nitrogen concentration of 30 mM (441 Ul-1). The best nitrogen source for Mn-oxidizing peroxidase production was NH4NO3 at nitrogen concentration of 30 mM. The highest laccase activity was found in the presence of 5 mM Cu2+, and 5 mM Mn2+, respectively. The absence of Cu2+ and Mn2+, as well as their presence at the concentration of 1 mM, led to the peaks of Mn-oxidizing peroxidases activities. Zn2+ and Fe2+ caused a decrease, and Se, in all investigated forms, an increase of laccase and peroxidases activities.

Behavior of solid carbon sources for biological denitrification in groundwater remediation

2012 ◽  
Vol 65 (9) ◽  
pp. 1696-1704 ◽  
Author(s):  
Jianmei Zhang ◽  
Chuanping Feng ◽  
Siqi Hong ◽  
Huiling Hao ◽  
Yingnan Yang
Keyword(s):  
Carbon Source ◽  
Wheat Straw ◽  
Groundwater Remediation ◽  
Nitrate Removal ◽  
Carbon Sources ◽  
Batch Experiments ◽  
Denitrification Activity ◽  
Leaching Experiments ◽  
Potential Carbon ◽  
Stimulation Of

The present study was conducted to compare the behavior of wheat straw, sawdust and biodegradable plastic (BP) as potential carbon sources for denitrification in groundwater remediation. The results showed that a greater amount of nitrogen compounds were released from wheat straw and sawdust than from BP in leaching experiments. In batch experiments, BP showed higher nitrate removal efficiency and longer service life than wheat straw and sawdust, which illustrated that BP is the most appropriate carbon source for stimulation of denitrification activity. In column experiments, BP was able to support complete denitrification at influent nitrate concentrations of 50, 60, 70, 80, and 90 mg NO3−-N/L, showing corresponding denitrification rates of 0.12, 0.14, 0.17, 0.19, and 0.22 mg NO3−-N.L−1.d−1.g−1, respectively. These findings indicate that BP is applicable for use as a carbon source for nitrate-polluted groundwater remediation.

scholarly journals Glycerol as a carbon source for xantan production by Xanthomonas campestris isolates

2015 ◽  
pp. 197-206
Author(s):  
Bojana Bajic ◽  
Zorana Roncevic ◽  
Sinisa Dodic ◽  
Jovana Grahovac ◽  
Jelena Dodic
Keyword(s):  
Carbon Source ◽  
Xanthomonas Campestris ◽  
Raw Materials ◽  
Carbon Sources ◽  
Production Costs ◽  
Submerged Cultivation ◽  
Media Composition ◽  
Experimental Conditions ◽  
Cheap Alternative ◽  
Different Strains

The success of xanthan biosynthesis depends on several factors, most importantly the genetic potential of the production microorganism and cultivation media composition. Cultivation media composition affects the yield and quality of the desired product as well as production costs. This is why many studies focus on finding cheap alternative raw materials, especially carbon sources, to replace commercially used glucose and sucrose. In addition to the Xanthomonas campestris ATCC 13951 which is the primary industrial production microorganism, other Xanthomonas strains can produce xanthan as well. Under the same conditions, different strains produce different amounts of the biopolymer of varying quality. The aim of this paper is to compare producibility of phytopathogenic X. campestris strains, isolated from the environment with the reference X. campestris ATCC 13951 strain and to estimate the possibility of xanthan production using alternative glycerol-based media than the synthetic glucose-based media. Submerged cultivation on the medium based on glucose or glycerol (2.0 %w/v) was performed using the reference strain and eight isolated X. campestris strains. In order to assess the success of biosynthesis, xanthan yield and rheological properties were determined. Strains isolated from the environment produced yields between 2.98 g/L and 12.17 g/L on the glucose-based medium and 1.68 g/L and 6.31 g/L on the glycerol-based medium. Additionally, X. campestris ATCC 13951 provided the highest yield when using glucose (13.24 g/L), as well as glycerol-based medium (7.44 g/L). The obtained results indicate that in the applied experimental conditions and using all tested strains, glycerol is viable as a carbon source for the production of xanthan.

scholarly journals OBTAINING PULP FROM WHEAT STRAW IN A TWO-STAGE SYSTEM “ACETIC ACID – HYDROGEN PEROXIDE – WATER – ETHANOL”

2020 ◽  
pp. 210-221
Author(s):  
Irina Trembus ◽  
◽  
Nina Semenenko ◽  
Keyword(s):  
Hydrogen Peroxide ◽  
Acetic Acid ◽  
Wheat Straw ◽  
Ethyl Alcohol ◽  
Raw Materials ◽  
Cellulose Content ◽  
Technological Parameters ◽  
Plant Raw Materials ◽  
Second Stage ◽  
Vegetable Raw Materials

Urgency of the research. Involvement of secondary raw materials in the form of agricultural waste and development of new ecologically safe ways of delignification of vegetable raw materials to solve problems of environmental pollution.Target setting. Available methods of delignification of vegetable raw materials using oxidant - hydrogen peroxide allow to obtain a fibrous semi-finished product with a high yield, but with strength values of 15-30% lower compared to fibrous semi-finished products obtained bycooking solutions at pH > 7. Therefore, it is necessary to improve existing methods. hydrogen peroxide in acetic acid.Actual scientific researches and issues analysis. The latest available domestic and foreign publications on oxidative-organosolvent methods of delignification of plant raw materials using peroxyacids and alcohols were considered in detail.Uninvestigated parts of general matters defining. Research of technology of oxidative-organosolvent delignification of vegetable raw materials with useof alcohol as a part of a cooking solution and definition of optimum values of technological parameters (temperature and duration) of process of reception of straw fibrous semi-finished products.The research objective. Investigation of technological parameters of straw cellulose production in the system acetic acid-hydrogen peroxide-water-ethyl alcohol in order to increase the physical and mechanical parameters and the yield of the target product.The statement of basic materials.A two-stage method for producing straw pulp from wheat straw at the first stage has been investigated. Delignification was carried out in the “acetic acid-hydrogen peroxide-water” environment at a hydrogen peroxide consumption of 50% of the mass of absolutely dry raw material (a.d.r.m.) and at the second stage of cooking, 40 volume% of ethyl alcohol was added to the cooking solution to replace the same amount of spent cooking solution after the first stage. The content of the main components in the original plant raw materials isdetermined. The influence of delignifica-tion conditions, namely temperature and duration of cooking on the yield of fibrous semi-finished product, the content of re-sidual lignin, cellulose content and strength indicators was studied. It is shown that the temperature increase at the first stage of the process from 50 ºС to 70 ºС, at the second stage from 80 to 100 ºС and the duration of processing of vegetable raw materials from 60 to 120 min. and from 60 to 180 minutes, according to the stages of the delignification process, leads to a decrease in yield by 7.9-18.9%, the residual lignin content by 4.27-9.11%, while the cellulose content in the fibrous semi-finished product increases by 10.1-15.8%. It is investigated that the indicators of mechanical strength of the obtained fibrous semi - finished products increase with increasing temperature and duration of processing of raw materials. Regression equa-tions for each stage of cooking are calculated, which adequately describe the experimentaldata and can be used as a mathe-matical model of the process of delignification of wheat straw with hydrogen peroxide in acetic acid. The method of multicrite-ria optimization of delignification conditions determines the optimal values of technological parameters of the wheat straw cooking process. The lignin-carbohydrate diagram of delignification of vegetable raw materials is offered. The number in which various methods of delignification of wheat straw are located on efficiency is defined.Conclusions. The technology of obtaining straw fibrous semi-finished products in the system "acetic acid-hydrogen per-oxide-water-ethanol" has been developed. Regression equations are calculated that adequately describe the experimental data and can be usedas a mathematical model of the investigated method of obtaining straw fibrous semi-finished product. The optimal technological parameters are established, which ensure the production of the final product with high quality indicators. The lignin-carbohydrate diagram of delignification of wheat straw stalks by different cooking methods is given.

REGULATION OF PROTEINASE FORMATION IN A SPECIES OF MICROCOCCUS

1966 ◽  
Vol 12 (6) ◽  
pp. 1175-1185 ◽  
Author(s):  
I. J. McDonald ◽  
Alice K. Chambers
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Carbon Source ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Synthetic Medium ◽  
Carbon Sources ◽  
Extracellular Proteinase ◽  
Proteinase Production

Micrococcus sp. ATCC No. 407 (M. freudenreichii) produced relatively large amounts of extracellular proteinase in synthetic medium containing methionine, thiamine, biotin, NH4Cl, NaHCO3, NaCl, MgSO4, and FeSO4, with aspartic acid, asparagine, glutamic acid, or glutamine as the carbon source. The organism produced relatively small amounts of proteinase with succinate, malate, fumarate, maltose, maltotriose, or maltotetraose as the carbon source. In synthetic medium containing maltose, any one of several amino acids stimulated growth and proteinase production. The results indicated that the organism is a partial constitutive strain with respect to proteinase production and suggested that proteinase formation is controlled by a form of end-product induction. In the presence of inducer, carbon sources such as succinate or maltose caused suppression of proteinase formation, suggesting control by metabolic repression as well. Because extracellular proteinase formation is induced by amino acids and suppressed by carbon sources such as succinate or maltose, and because the organism can utilize amino acids as carbon sources for growth, it. is suggested that the function of extracellular proteinase in this organism is to ensure a supply of carbon for growth rather than a supply of amino acids for protein synthesis.

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