scholarly journals Organic Matter And Anaerobic Cellulolytic Activity In Sediments of Ashtamudi Estuary, Kerala, India

2021 ◽  
Author(s):  
Dennison Bindhulekha Arya ◽  
Salom Gnana Thanga Vincent ◽  
J.K Reshma ◽  
Junaid Hassan Salahudeen
Keyword(s):  
Organic Matter ◽  
Enzyme Activity ◽  
Industrial Applications ◽  
Estuarine Sediments ◽  
Crystalline Cellulose ◽  
Cellulolytic Activity ◽  
Labile Organic Matter ◽  
Sediment Samples ◽  
Cellulase Enzyme ◽  
Thermophilic Conditions

Abstract Estuarine sediments are best suited for bioprospecting cellulose degrading microorganisms because of continuous input of cellulosic carbon from rivers and terrestrial runoff, and such sediments act as a substrate for decomposition by microbes. Sediment samples were collected from thirteen stations of Ashtamudi estuary, a tropical Ramsar site during April 2016 and January 2017 and analysed for environmental variables such as temperature, pH, electrical conductivity, oxidation- reduction potential, sulphate, total organic carbon (Corg), carbohydrate, protein, lipid and labile organic matter. Microcosm experiments were conducted in the sediment samples to compare native and substrate-induced cellulase enzyme activities in mesophilic and thermophilic conditions added with crystalline cellulose and cellobiose as substrates. Abundance of cellulolytic anaerobes in the roll tubes was higher with cellobiose than crystalline cellulose. Substrate induced enzyme activity was more than native enzyme activity [0.0012±0.0001- 0.004±0.002 (April 2016) and 0.004±0.001- 0.161±0.002 mg glucose h-1 (January 2017)] in the sediment samples and cellulolytic activity was more pronounced in thermophilic conditions during April 2016. Redundancy analysis indicated that salinity was the highest determining factor for explaining variations among bacterial abundance and activity during April 2016 and sediment lipid content during January 2017. The study reveals that estuarine sediments can act as a potential source of thermophilic cellulase enzyme producing bacteria, which needs to be further explored owing to their vast industrial applications.

scholarly journals Using Cellulolytic Nitrogen Fixing Bacterium, Azomonas agilis for Effective Degradation of Agricultural Residues

2018 ◽  
Vol 12 (1) ◽  
pp. 154-162 ◽  
Author(s):  
Zaw K. Latt ◽  
San S. Yu ◽  
Ei P. Kyaw ◽  
Tin M. Lynn ◽  
May T. Nwe ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Screening Method ◽  
Carbon Sources ◽  
Cellulase Activity ◽  
Agricultural Residues ◽  
Cellulolytic Activity ◽  
Nitrogen Fixing ◽  
Cellulase Enzyme ◽  
Ammonium Accumulation ◽  
Test Kit

Introduction:Azomonas agilis, a nitrogen-fixing bacterium, was isolated from rhizospheric soil in central Myanmar.Methods & Materials:The nitrogen-fixing activity of this bacterium was detected by plate screening method using glucose nitrogen free mineral medium and ammonium test-kit Cellulolytic activity was screened by plat assay and detected by Dinitrosalicyclic acid method (DNS).Results & Discussion:The isolatedA. agilisgrew in media containing 3-12% of NaCl, although the growth became poor when NaCl concentrations increased. Among various carbon sources, sucrose was the best source for ammonium accumulation of this bacterium, whereas arabinose was not the suitable carbon source. Although the nitrogen-fixing activity ofA. agiliswas highest after one week incubation, cellulase enzyme production was highest after 2-3 days of incubation. It was observed that cellulase enzyme activity ofA. agilisfor cellulose and sodium carboxymethyl cellulose (CMC) was almost the same. Three agricultural wastes were used to detect the cellulase enzyme activity ofA. agilis, cellulase activity was better on filter paper as a substrate when compared to rice-straw and sawdust.Conclusion:So, the isolatedA. agilishas high potential as an effective bacterial strain to use in sustainable agriculture and degradation of some agricultural residues.

Particle Size Effects on Concentration of Metals in Lake Erie Bottom Sediments

1984 ◽  
Vol 19 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Alena Mudroch
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Clay Minerals ◽  
Surface Sediment ◽  
Size Effects ◽  
Lake Erie ◽  
Size Fraction ◽  
Mineralogical Composition ◽  
Major Elements ◽  
Sediment Samples

Abstract Surface sediment samples obtained at the offshore and nearshore area of Lake Erie were separated into eight different size fractions ranging from <2 µm to 250 µm. The concentration of major elements (Si, Al, Ca, Mg, K, Na, Fe, Mn and P), metals (Zn, Cu, Cr, Ni, V, Co and Pb) and organic matter was determined together with the mineralogical composition and morphology of the particles in each size fraction. The distribution of the metals in the offshore sediment was bimodal with the majority of the metals divided between the 63 to 250 um size fraction which also contained the highest concentration of organic matter (about 20%) and the <4 µm fraction containing up to 60% of clay minerals. However, the metals in the nearshore sediment were associated mainly with the clay minerals.

scholarly journals Benthic fluxes of dissolved organic nitrogen in the lower St. Lawrence estuary and implications for selective organic matter degradation

2013 ◽  
Vol 10 (11) ◽  
pp. 7609-7622 ◽  
Author(s):  
M. Alkhatib ◽  
P. A. del Giorgio ◽  
Y. Gelinas ◽  
M. F. Lehmann
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Bottom Water ◽  
Estuarine Sediments ◽  
Internal Source ◽  
Lawrence Estuary ◽  
Element Partitioning ◽  
Sediment Porewaters ◽  
St Lawrence Estuary

Abstract. The distribution of dissolved organic nitrogen (DON) and carbon (DOC) in sediment porewaters was determined at nine locations along the St. Lawrence estuary and in the gulf of St. Lawrence. In a previous manuscript (Alkhatib et al., 2012a), we have shown that this study area is characterized by gradients in the sedimentary particulate organic matter (POM) reactivity, bottom water oxygen concentrations, and benthic respiration rates. Based on the porewater profiles, we estimated the benthic diffusive fluxes of DON and DOC in the same area. Our results show that DON fluxed out of the sediments at significant rates (110 to 430 μmol m−2 d−1). DON fluxes were positively correlated with sedimentary POM reactivity and varied inversely with sediment oxygen exposure time (OET), suggesting direct links between POM quality, aerobic remineralization and the release of DON to the water column. DON fluxes were on the order of 30 to 64% of the total benthic inorganic fixed N loss due to denitrification, and often exceeded the diffusive nitrate fluxes into the sediments. Hence they represented a large fraction of the total benthic N exchange, a result that is particularly important in light of the fact that DON fluxes are usually not accounted for in estuarine and coastal zone nutrient budgets. In contrast to DON, DOC fluxes out of the sediments did not show any significant spatial variation along the Laurentian Channel (LC) between the estuary and the gulf (2100 ± 100 μmol m−2 d−1). The molar C / N ratio of dissolved organic matter (DOM) in porewater and the overlying bottom water varied significantly along the transect, with lowest C / N in the lower estuary (5–6) and highest C / N (> 10) in the gulf. Large differences between the C / N ratios of porewater DOM and POM are mainly attributed to a combination of selective POM hydrolysis and elemental fractionation during subsequent DOM mineralization, but selective adsorption of DOM to mineral phases could not be excluded as a potential C / N fractionating process. The extent of this C- versus N- element partitioning seems to be linked to POM reactivity and redox conditions in the sediment porewaters. Our results thus highlight the variable effects selective organic matter (OM) preservation can have on bulk sedimentary C / N ratios, decoupling the primary source C / N signatures from those in sedimentary paleoenvironmental archives. Our study further underscores that the role of estuarine sediments as efficient sinks of bioavailable nitrogen is strongly influenced by the release of DON during early diagenetic reactions, and that DON fluxes from continental margin sediments represent an important internal source of N to the ocean.

scholarly journals Two β-glucuronosyltransferases involved in the biosynthesis of type II arabinogalactans function in mucilage polysaccharide matrix organization in Arabidopsis thaliana

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Oyeyemi O. Ajayi ◽  
Michael A. Held ◽  
Allan M. Showalter
Keyword(s):  
Arabidopsis Thaliana ◽  
Seed Size ◽  
Seed Coat ◽  
Glucuronic Acid ◽  
Industrial Applications ◽  
Crystalline Cellulose ◽  
Sugar Residue ◽  
Composition Analysis ◽  
Cellulose Content ◽  
Type Ii

Abstract Background Arabinogalactan-proteins (AGPs) are heavily glycosylated with type II arabinogalactan (AG) polysaccharides attached to hydroxyproline residues in their protein backbone. Type II AGs are necessary for plant growth and critically important for the establishment of normal cellular functions. Despite the importance of type II AGs in plant development, our understanding of the underlying role of these glycans/sugar residues in mucilage formation and seed coat epidermal cell development is poorly understood and far from complete. One such sugar residue is the glucuronic acid residues of AGPs that are transferred onto AGP glycans by the action of β-glucuronosyltransferase genes/enzymes. Results Here, we have characterized two β-glucuronosyltransferase genes, GLCAT14A and GLCAT14C, that are involved in the transfer of β-glucuronic acid (GlcA) to type II AGs. Using a reverse genetics approach, we observed that glcat14a-1 mutants displayed subtle alterations in mucilage pectin homogalacturonan (HG) compared to wild type (WT), while glcat14a-1glcat14c-1 mutants displayed much more severe mucilage phenotypes, including loss of adherent mucilage and significant alterations in cellulose ray formation and seed coat morphology. Monosaccharide composition analysis showed significant alterations in the sugar amounts of glcat14a-1glcat14c-1 mutants relative to WT in the adherent and non-adherent seed mucilage. Also, a reduction in total mucilage content was observed in glcat14a-1glcat14c-1 mutants relative to WT. In addition, glcat14a-1glcat14c-1 mutants showed defects in pectin formation, calcium content and the degree of pectin methyl-esterification (DM) as well as reductions in crystalline cellulose content and seed size. Conclusions These results raise important questions regarding cell wall polymer interactions and organization during mucilage formation. We propose that the enzymatic activities of GLCAT14A and GLCAT14C play partially redundant roles and are required for the organization of the mucilage matrix and seed size in Arabidopsis thaliana. This work brings us a step closer towards identifying potential gene targets for engineering plant cell walls for industrial applications.

scholarly journals Lipid biomarkers in Holocene and glacial sediments from ancient Lake Ohrid (Macedonia, Albania)

2010 ◽  
Vol 7 (11) ◽  
pp. 3473-3489 ◽  
Author(s):  
J. Holtvoeth ◽  
H. Vogel ◽  
B. Wagner ◽  
G. A. Wolff
Keyword(s):  
Organic Matter ◽  
Lipid Biomarkers ◽  
Lake Ohrid ◽  
Labile Organic Matter ◽  
Glacial Sediments ◽  
Plant Matter ◽  
Lipid Biomarker ◽  
First Results ◽  
Near Shore

Abstract. Organic matter preserved in Lake Ohrid sediments originates from aquatic and terrestrial sources. Its variable composition reflects climate-controlled changes in the lake basin's hydrology and related organic matter export, i.e. changes in primary productivity, terrestrial plant matter input and soil erosion. Here, we present first results from lipid biomarker investigations of Lake Ohrid sediments from two near-shore settings: site Lz1120 near the southern shore, with low-lying lands nearby and probably influenced by river discharge, and site Co1202 which is close to the steep eastern slopes. Variable proportions of terrestrial n-alkanoic acids and n-alkanols as well as compositional changes of ω-hydroxy acids document differences in soil organic matter supply between the sites and during different climate stages (glacial, Holocene, 8.2 ka cooling event). Changes in the vegetation cover are suggested by changes in the dominant chain length of terrestrial n-alkanols. Effective microbial degradation of labile organic matter and in situ contribution of organic matter derived from the microbes themselves are both evident in the sediments. We found evidence for anoxic conditions within the photic zone by detecting epicholestanol and tetrahymanol from sulphur-oxidising phototrophic bacteria and bacterivorous ciliates and for the influence of a settled human community from the occurrence of coprostanol, a biomarker for human and animal faeces (pigs, sheep, goats), in an early Holocene sample. This study illustrates the potential of lipid biomarkers for future environmental reconstructions using one of Europe's oldest continental climate archives, Lake Ohrid.

scholarly journals Spatiotemporal variability of sedimentary organic matter supply and recycling processes in coral reefs of Tayrona National Natural Park, Colombian Caribbean

2014 ◽  
Vol 11 (11) ◽  
pp. 2977-2990 ◽  
Author(s):  
E. Bayraktarov ◽  
C. Wild
Keyword(s):  
Organic Matter ◽  
Coral Reef ◽  
Coastal Upwelling ◽  
Sediment Traps ◽  
Sedimentary Organic Matter ◽  
Spatiotemporal Variability ◽  
Water Current ◽  
Labile Organic Matter ◽  
Natural Park ◽  
River Mouths

Abstract. Sediments are fundamental for the function of oligotrophic coral reef ecosystems because they are major places for organic matter recycling. The Tayrona National Natural Park (TNNP, Colombian Caribbean) is located between the population center Santa Marta (>455 000 inhabitants) in the southwest and several river mouths in the east. Here, coral reef sediments experience pronounced changes in environmental conditions due to seasonal coastal upwelling, but knowledge of relevant spatiotemporal effects on organic matter supply to the sediments and recycling processes is not available. Therefore, sediment traps were deployed monthly over 14 months complemented by assessment of sedimentary properties (e.g., porosity, grain size, content of particulate organic matter and pigments) and sedimentary O2 demand (SOD) at water-current-exposed and sheltered sites along distance gradients (12–20 km) to Santa Marta and the eastern river mouths (17–27 km). Findings revealed that seasonal upwelling delivered strong (75–79% of annual supply) pulses of labile organic matter mainly composed of fresh phytoplankton detritus (C : N ratio 6–8) to the seafloor. Sedimentary chlorophyll a contents and SOD increased significantly with decreasing distance to the eastern rivers, but only during upwelling. This suggests sedimentary organic matter supply controlled by nutrient-enriched upwelling waters and riverine runoff rather than by the countercurrent-located city of Santa Marta. Organic matter pulses led to significantly higher SOD (more than 30%) at the water-current-sheltered sites as compared to the exposed sites, ensuing a rapid recycling of the supplied labile organic matter in the permeable silicate reef sands.

scholarly journals Produksi Enzim Selulase olehAspergillus niger pada Ampas Sagu

2015 ◽  
Vol 16 (1) ◽  
pp. 1 ◽  
Author(s):  
Nora Idiawati ◽  
Elliska Murni Harfinda ◽  
Lucy Arianie
Keyword(s):  
Enzyme Activity ◽  
Aspergillus Niger ◽  
Moisture Content ◽  
Cellulase Enzymes ◽  
Fermentation Time ◽  
Cellulase Enzyme ◽  
Sago Waste ◽  
Solid Fermentation

Production of cellulase by Aspergillus niger was carried out by growing the cultureson sago waste. Sago waste containscellulose that has not been used optimally. Cellulose is a polysaccharide consisting of glucose monomers linked by β-1,4-glycosides bonds. Glycoside bonds in cellulose can be enzymatically hydrolyzed into glucose with cellulase enzymes. Solid fermentation used to produce cellulase on sago waste as substrate was influenced by pH (3 to 6), moisture content(40% to 85%), and fermentation time (4 to 10 days). Products of the cellulase enzyme activity was measured by phenolsulfuricacid method. The results showed that the highest cellulase enzyme activity was 0.172 U/mL obtained at 85%moisture content, pH 5, and 8 days of fermentation time.

scholarly journals Physio-chemical properties and dynamic of the surface sediment in riparian mangroves along the Tien river, Tien Giang province

2019 ◽  
Vol 2 (5) ◽  
pp. 50-58
Author(s):  
Hung Duc Nguyen ◽  
Ngot Van Pham ◽  
Duy Van Nguyen
Keyword(s):  
Electrical Conductivity ◽  
Organic Matter ◽  
Surface Sediment ◽  
Chemical Properties ◽  
Total Sulfur ◽  
Mean Sea Level ◽  
Factors Affecting ◽  
Sediment Samples ◽  
Mesohaline Zone ◽  
Saturated Extract

This study was conducted to investigate the physio-chemical properties and vertical dynamic of the surface sediment (0–5 cm) in riparian mangroves along the Tien river, Tien Giang province. The distribution of riparian mangroves located from the polyhaline zone (transect S1 and S2) to the mesohaline zone (transect S3 and S4) and the oligohaline zone (transect S5). Three plots (10x10 m) per transect were set based on the elevation of the mangrove floor (cm + mean sea level) and dominant plants. A total of 28 sediment samples were collected in December 2016 and April 2017. Seasonal variation of pH, redox potential (Eh), electrical conductivity of saturated extract (ECse), bulk density, sediment organic matter (SOM) and total sulfur (TS) were measured in accordance with the standard protocols. Seasonal trends of vertical erosion and accumulation were tested by the tracer stick method. The ECse values and TS concentrations were higher in the dry season and in transects closed to the estuary (S1, S2 and S3) but these trends weren’t found for pH, Eh, and SOM. In most of the riparian mangroves along the Tiền river, low elevation (0–50 cm) was one of important factors affecting the Eh and ECse. In the rainy season, major changes in vertical erosion and acumulation have occurred in the transects near the mouth of the river.

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