Endoglucanase activity of cellulolytic bacteria from lake sediments and its application in hydrophyte degradation

2020 ◽  
Author(s):  
Hongpei Zhang ◽  
Qianzheng Li ◽  
Yuqing Zhao ◽  
Mingzhen Zhang ◽  
Dong Xu ◽  
...  
Keyword(s):  
Degradation Rate ◽  
Hydrilla Verticillata ◽  
Aquatic Organisms ◽  
Plant Residue ◽  
Plant Residues ◽  
Cellulose Content ◽  
Cellulolytic Bacteria ◽  
Bacterial Strains ◽  
Submerged Plants ◽  
Endoglucanase Activity

Abstract Hydrophytes are plants that grow in or on water. Their overgrowth adversely affects the ecosystem because of crowding out other aquatic organisms and polluting the environment with plant residue. In principle, cellulolytic bacteria can be used to degrade hydrophyte biomass. We here isolated and characterized four cellulolytic bacterial strains from Lake Donghu sediments (Wuhan, China) that are rich in organic matter and plant residues. The isolates (WDHS-01 to 04) represent Bacillus, Micromonospora, and Streptomyces genera. The bacteria exhibited pronounced endoglucanase activities (from 0.022 to 0.064 U mL–1). They did not extensively degrade the emerged plant Canna indica L. However, in an Hydrilla verticillata (submerged plant) degradation medium, strain WDHS-02 exhibited a high degradation rate (54.91%), endoglucanase activity of 0.35 U mL–1 and the conversion rate of cellulose to reducing sugars of 7.15%. Correlation analysis revealed that bacterial endoglucanase activity was significantly correlated with the degradation rate, and acid detergent lignin, ash and cellulose content of the residual H. verticillata powder. In conclusion, the identified bacteria efficiently decomposed submerged plants without the need for acid–base pretreatment. They expand the set of known cellulolytic bacteria and can be used for natural degradation of submerged plants.

scholarly journals Endoglucanase Activity of Novel Aspergillus sydowii Isolate WIU-01 and Application for Hydrophyte Degradation

2021 ◽  
Keyword(s):  
Degradation Rate ◽  
Hydrilla Verticillata ◽  
Sample Pretreatment ◽  
Neutral Detergent Fiber ◽  
Cellulose Content ◽  
Aspergillus Sydowii ◽  
Eutrophic Lakes ◽  
Endoglucanase Activity ◽  
Cellulolytic Microorganisms ◽  
Isolation And Characterization

<p>Many eutrophic lakes contain rapidly growing hydrophytes. Overgrown biomass is usually me-chanically harvested and thrown away, leading to resource waste and secondary environmental pollution. Microbial degradation is an economically and environmentally friendly approach for managing hydrophytic waste, fuelling the search for efficient biomass degraders. Here, we present isolation and characterization of Aspergillus sydowii WIU-01, a novel cellulolytic fungus. Strain WIU-01 was isolated from air. The degradation rate (29.75 vs. 21.95%) and endoglucanase activi-ty (0.31 vs. 0.16 U mL–1) of the fungus were higher in Canna indica (emergent plant) medium than in Hydrilla verticillata (submerged plant) medium, accordingly. Further, fungal endoglucanase ac-tivity was significantly positively correlated with the degradation rate, neutral detergent fiber con-tent, and acid detergent fiber content of hydrophyte powder. Fungal biomass was significantly negatively correlated with reducing sugar and cellulose content of hydrophyte medium, but was significantly positively correlated with hemicellulose, acid detergent lignin, and ash content of the medium. Collectively, these observations indicate that A. sydowii decomposes emergent and sub-merged plant mass without acid–base sample pretreatment, albeit its endoglucanase activity is rela-tively low. This highlights the role of cellulolytic microorganisms in the natural environment and the notion that the environment can be a source of cellulolytic microorganisms for potential envi-ronmentally friendly applications.</p>

scholarly journals Use of Cellulolytic Marine Bacteria for Enzymatic Pretreatment in Microalgal Biogas Production

2014 ◽  
Vol 80 (14) ◽  
pp. 4199-4206 ◽  
Author(s):  
Camilo Muñoz ◽  
Catalina Hidalgo ◽  
Manuel Zapata ◽  
David Jeison ◽  
Carlos Riquelme ◽  
...  
Keyword(s):  
Biogas Production ◽  
Botryococcus Braunii ◽  
Aeromonas Salmonicida ◽  
Cellulolytic Bacteria ◽  
Bacterial Strains ◽  
Endoglucanase Activity ◽  
Nannochloropsis Gaditana ◽  
Enzymatic Pretreatment ◽  
Whole Cell ◽  
Content Type

ABSTRACTIn this study, we designed and evaluated a microalgal pretreatment method using cellulolytic bacteria that naturally degrades microalgae in their native habitat. Bacterial strains were isolated from each of two mollusk species in a medium containing 1% carboxymethyl cellulose agar. We selected nine bacterial strains that had endoglucanase activity: five strains fromMytilus chilensis, a Chilean mussel, and four strains fromMesodesma donacium, a clam found in the Southern Pacific. These strains were identified phylogenetically as belonging to the generaAeromonas,Pseudomonas,Chryseobacterium, andRaoultella. The cellulase-producing capacities of these strains were characterized, and the degradation of cell walls inBotryococcus brauniiandNannochloropsis gaditanawas tested with “whole-cell” cellulolytic experiments.Aeromonas bivalviumMA2,Raoultella ornithinolyticaMA5, andAeromonas salmonicidaMC25 degradedB. braunii, andR. ornithinolyticaMC3 and MA5 degradedN. gaditana. In addition,N. gaditanawas pretreated withR. ornithinolyticastrains MC3 and MA5 and was then subjected to an anaerobic digestion process, which increased the yield of methane by 140.32% and 158.68%, respectively, over that from nonpretreated microalgae. Therefore, a “whole-cell” cellulolytic pretreatment can increase the performance and efficiency of biogas production.

scholarly journals Fate of carbon and nitrogen from plant residue decomposition in a calcareous soil

2011 ◽  
Vol 52 (No. 3) ◽  
pp. 137-140 ◽  
Author(s):  
F. Nourbakhsh
Keyword(s):  
Biochemical Properties ◽  
Plant Residue ◽  
Plant Residues ◽  
Order Kinetic ◽  
Nitrogen Transformations ◽  
Plant Materials ◽  
Carbon And Nitrogen ◽  
Residue Decomposition ◽  
N Concentration ◽  
Order Kinetic Model

Carbon and nitrogen transformations in soil are microbially mediated processes that are functionally related. The fate of C and N was monitored in a clay-textured soil (Typic Haplocambid) which was either unamended (control) or amended with various plant materials at the rate of 10 g residue C/kg soil. To evaluate C mineralization, soils were incubated for 46 days under aerobic conditions. Nitrogen mineralization/immobilization was evaluated at the end of eight-week incubation experiment. All CO<sub>2</sub> evolution data conformed well to a first-order kinetic model, C<sub>m&nbsp;</sub>= C<sub>0</sub> (1 &ndash; e<sup>&ndash;Kt</sup>). The product of K and C<sub>0 </sub>(KC<sub>0</sub>) was significantly correlated with some chemical and biochemical properties of the plant residues, including N concentration (r = 0.83, P &lt; 0.001), C:N (r = &ndash;0.64, P &lt; 0.05) and lignin:N (r = &ndash;0.81, P &lt; 0.001). Among the plant residue composition characteristics, N concentration (r = 0.96, P &lt; 0.001), C:N (r = &ndash;0.69, P &lt; 0.01) and lignin:N (r = &ndash;0.68, P &lt; 0.01) were significantly correlated with the net rates of N mineralization/immobilization (N<sub>m/i</sub>).

scholarly journals Changes in Denitrifier Abundance, Denitrification Gene mRNA Levels, Nitrous Oxide Emissions, and Denitrification in Anoxic Soil Microcosms Amended with Glucose and Plant Residues

2010 ◽  
Vol 76 (7) ◽  
pp. 2155-2164 ◽  
Author(s):  
Sherri L. Henderson ◽  
Catherine E. Dandie ◽  
Cheryl L. Patten ◽  
Bernie J. Zebarth ◽  
David L. Burton ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Organic Carbon ◽  
Plant Residue ◽  
Plant Residues ◽  
Barley Plant ◽  
Mrna Levels ◽  
Soil Microcosms ◽  
Denitrification Gene ◽  
Gene Mrna ◽  
Amended Soil

ABSTRACT In agricultural cropping systems, crop residues are sources of organic carbon (C), an important factor influencing denitrification. The effects of red clover, soybean, and barley plant residues and of glucose on denitrifier abundance, denitrification gene mRNA levels, nitrous oxide (N2O) emissions, and denitrification rates were quantified in anoxic soil microcosms for 72 h. nosZ gene abundances and mRNA levels significantly increased in response to all organic carbon treatments over time. In contrast, the abundance and mRNA levels of Pseudomonas mandelii and closely related species (nirS P) increased only in glucose-amended soil: the nirS P guild abundance increased 5-fold over the 72-h incubation period (P < 0.001), while the mRNA level significantly increased more than 15-fold at 12 h (P < 0.001) and then subsequently decreased. The nosZ gene abundance was greater in plant residue-amended soil than in glucose-amended soil. Although plant residue carbon-to-nitrogen (C:N) ratios varied from 15:1 to 30:1, nosZ gene and mRNA levels were not significantly different among plant residue treatments, with an average of 3.5 � 107 gene copies and 6.9 � 107 transcripts g−1 dry soil. Cumulative N2O emissions and denitrification rates increased over 72 h in both glucose- and plant-tissue-C-treated soil. The nirS P and nosZ communities responded differently to glucose and plant residue amendments. However, the targeted denitrifier communities responded similarly to the different plant residues under the conditions tested despite changes in the quality of organic C and different C:N ratios.

Tracing the nitrogen, sulfur, and carbon released from plant residues in a soil/plant system

Soil Research ◽  
2000 ◽  
Vol 38 (3) ◽  
pp. 699 ◽  
Author(s):  
Yothin Konboon ◽  
Graeme Blair ◽  
Rod Lefroy ◽  
Anthony Whitbread
Keyword(s):  
Triticum Aestivum ◽  
Nutrient Cycling ◽  
Wheat Straw ◽  
Medicago Truncatula ◽  
Plant Residue ◽  
Plant Residues ◽  
Plant Nutrient ◽  
N Loss ◽  
Leaching Losses ◽  
Nutrient Demand

Matching plant residue mineralisation rate to plant nutrient demand is one way of increasing the efficiency of nutrient cycling. A glasshouse experiment was conducted in a Soloth soil with a C4d13 C signature using drained pots to examine the effect on the yield of Japanese millet (Echinochloa frumentocea) and the fate of 15 N, 35 S, and C (using d 13 C shift) from the C 3 plants Flemingia macrophylla, Medicago truncatula hay, and wheat (Triticum aestivum) straw applied at 3 t/ha in the presence of N and NPKS fertiliser. The yield of Japanese millet at 91 days was highest where medic hay had been added (13.7 g/pot) and lowest where wheat straw was used (11.5 g/pot). Recovery of 35 S by the millet was highest in the wheat straw and medic hay treatments (mean 11.5%), whilst recovery of 15 N was highest from medic hay (15.8%). Leaching losses of 35 S were highest in the Flemingia and medic treatments (mean 8.1%), and 15 N loss in leachate was highest in the medic hay treatment (6.6%). A maximum of 1.5% of the C added in residues was recovered in the leachate of the medic hay treatment.

scholarly journals Defense Mechanisms of Two Pioneer Submerged Plants during Their Optimal Performance Period in the Bioaccumulation of Lead: A Comparative Study

2018 ◽  
Vol 15 (12) ◽  
pp. 2844 ◽  
Author(s):  
Dian Li ◽  
Linglei Zhang ◽  
Min Chen ◽  
Xiaojia He ◽  
Jia Li ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Protein Content ◽  
Defense Mechanisms ◽  
Hydrilla Verticillata ◽  
Optimal Performance ◽  
Ceratophyllum Demersum ◽  
Contaminated Water ◽  
Submerged Plants ◽  
Significant Difference ◽  
Mda Content

Ceratophyllum demersum L. and Hydrilla verticillata (L.f.) Royle, two pioneer, submerged plants, effectively remove heavy metals from contaminated water. The present work evaluates the bioaccumulation and defense mechanisms of these plants in the accumulation of lead from contaminated water during their optimal performance period. C. demersum and H. verticillata were investigated after 14 days of exposure to various lead concentrations (5–80 μM). The lead accumulation in both C. demersum and H. verticillata increased with an increasing lead concentration, reaching maximum values of 2462.7 and 1792 mg kg−1 dw, respectively, at 80 μM. The biomass and protein content decreased significantly in C. demersum when exposed to lead. The biomass of H. verticillata exposed to lead had no significant difference from that of the controls, and the protein content increased for the 5–10 μM exposure groups. The malondialdehyde (MDA) content and superoxide dismutase (SOD), peroxidase (POD), and polyphenol oxidase (PPO) activities were much higher in C. demersum, suggesting considerable damage from lipid peroxidation and sensitivity to lead stress. Enzyme inhibition and inactivation were also observed in C. demersum at high lead concentrations (40–80 μM). The excellent growth status, low damage from lipid peroxidation, and high activity of catalase (CAT) and phenylalanine ammonia-lyase (PAL) observed in H. verticillata illustrate its better tolerance under the same lead stress.

scholarly journals Simulating soil organic C dynamics in managed grasslands under humid temperate climatic conditions

2020 ◽  
Author(s):  
Asma Jebari ◽  
Jorge Álvaro-Fuentes ◽  
Guillermo Pardo ◽  
María Almagro ◽  
Agustin del Prado
Keyword(s):  
Field Experiments ◽  
Model Performance ◽  
Climatic Conditions ◽  
Plant Residue ◽  
Plant Residues ◽  
Organic C ◽  
Natural Grasslands ◽  
Rothc Model ◽  
Below Ground ◽  
Intensively Managed

Abstract. Temperate grasslands are of paramount importance in terms of soil organic carbon (SOC) dynamics. Globally, research on SOC dynamics has largely focused on forests, croplands and natural grasslands, while intensively managed grasslands has received much less attention. In this regard, we aimed to improve the prediction of SOC dynamics in managed grasslands under humid temperate regions. In order to do so, we modified and recalibrated the SOC model RothC, originally developed to model the turnover of SOC in arable topsoils, which requires limited amount of readily available input data. The modifications proposed for the RothC are: (1) water content up to saturation conditions in the soil water function of RothC to fit the humid temperate climatic conditions, (2) entry pools that account for particularity of exogenous organic matter (EOM) applied (e.g., ruminant excreta), (3) annual variation in the carbon inputs derived from plant residues considering both above- and below-ground plant residue and rhizodeposits components as well as their quality, and (4) the livestock treading effect (i.e., poaching damage) as a common problem in humid areas with higher annual precipitation. In the paper, we describe the basis of these modifications, carry out a simple sensitivity analysis and validate predictions against data from existing field experiments from four sites in Europe. Model performance showed that modified RothC reasonably captures well the different modifications. However, the model seems to be more sensitive to soil moisture and plant residues modifications than to the other modifications. The applied changes in RothC model could be appropriate to simulate both farm and regional SOC dynamics from managed grassland-based systems under humid temperate conditions.

scholarly journals Biodegradation of two organic UV-Filters by single bacteria strains

2021 ◽  
Author(s):  
Florentina Laura Chiriac ◽  
Catalina Stoica ◽  
Iuiana Paun ◽  
Florinela Pirvu ◽  
Toma Galaon ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Emerging Contaminants ◽  
Degradation Products ◽  
Aquatic Organisms ◽  
Uv Filters ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Biodegradation Process ◽  
Salmonella Thyphimurium ◽  
Organic Uv Filters

Abstract Organic UV-filters, including 4-hydroxybenzophenone (4-HBP) and 2,4-dihydroxybenzophenone (BP-1), are persistent emerging contaminants whose presence in the environment poses a threat to aquatic organisms due to their endocrine disruptor’s properties. For this reason, finding suitable technological processes for their safety and efficient removal from the environment represent a priority for the scientific community. To the author’s knowledge, until now, there are no studies reporting the biodegradation of 4-HBP and BP-1 by a single bacteria strain. In this paper, there were tested the 4-HBP and BP-1 biodegradation potential of two Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and two Gram-negative (Salmonella typhimurium and Serratia rubidae). The 4-HPB biodegradation process was observed only in the presence of Gram-negative bacterial strains. Thus, the biodegradation rates of 4-HBP reached up to 12.7% after 24h of incubation in presence of Salmonella thyphimurium and up to 24.0% after 24h of incubation with Serratia rubidae. Staphylococcus aureus was able to biodegrade 26.7% of BP-1, while Salmonella thiphymurium was able to biodegrade 14.7% of BP-1 after 24h of incubation. Their biodegradation products generated during the 4-HBP biodegradation process by Serratia rubidae were analyzed through LC-MS/MS analysis. The (bio)degradation products were benzophenone and a multi-hydroxylated derivative of 4-HBP and the degradation pathways were proposed. The data obtained in this study gave important information regarding the 4-HBP and BP-1 potential biodegradation by single bacterial strains.

scholarly journals Ability of the soil cellulolytic bacteria to colonize endophytic niche of barley grains

2020 ◽  
Author(s):  
O.V. Sviridova ◽  
◽  
N.I. Vorobyov ◽  
Ya.V. Pukhalsky ◽  
O.N. Kurchak ◽  
...  
Keyword(s):  
Micrococcus Luteus ◽  
Growing Season ◽  
Barley Straw ◽  
Mineral Fertilizers ◽  
Plant Residues ◽  
Cellulolytic Bacteria ◽  
Biological Product ◽  
Presowing Treatment ◽  
Pure Cultures ◽  
Barley Grains

To identify microorganisms that can penetrate into the endophytic niche of the grain of barley plants, many years of vegetative experiments were conducted on sod-podzolic soil without the use of mineral fertilizers. In the non-growing season, a biological product, consisting of cellulolytic association of bacteria with genotypic passport, decomposed barley straw. Presowing treatment of seeds was not carried out, therefore, during the growing season; local microorganisms decomposing plant residues could be present in the barley rhizosphere. After six years of rotation of barley plants, the microbiological composition of its seed niche was studied. As a result, it was found that in the seeds of barley bacteria are present in an amount of 240 ± 20 CFU/g of grain. Isolated pure cultures of microorganisms were identified as Cellulomonas gelida, Micrococcus luteus and Bacillus licheniformis by the sequence of ITS fragments of 16S rRNA. These types of bacteria were also present in the used biological product. Based on the research conducted, it can be assumed, that permanent cultivation of barley plants and sowing of seeds of the previous year can contribute to the formation of effective microbial and plant biosystems that are resistant to environmental stress.

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