scholarly journals Exogenous Production of Cold-Active Cellulase From Psychrophilic Actinobacteria With Increased Cellulose Hydrolysis Efficiency

2021 ◽  
Author(s):  
Sivasankar Palaniappan ◽  
Poongodi Subramaniam ◽  
Sivakumar Kannan ◽  
Wahidah H Al-Qahtani ◽  
Arokiyaraj Selvaraj ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Specific Activity ◽  
Terrestrial Ecosystems ◽  
Cellulose Hydrolysis ◽  
Industrial Applications ◽  
Polar Front ◽  
Biologically Active ◽  
Cellulolytic Activity ◽  
Cold Active ◽  
Cold Tolerant

Abstract Actinobacteria form the largest phylum consisting of diverse, ecologically unique and biologically active members. The actinobacteria are omnipresent and occur in various habitats such as cold environment, aquatic, desert and terrestrial ecosystems. Though the studies are available on actinobacteria at various habitats very few reports are available on cold tolerant/loving actinobacteria in the Southern Ocean part of the Antarctic Ocean. In this context, the present work was designed to isolate and characterize the actinobacteria in the Polar Front region of the Southern Ocean waters and species of Nocardiopsis and Streptomyces were identified. Among those, the psychrophilic actinobacterium, Nocardiopsis dassonvillei PSY13 was found to have good cellulolytic activity and it was further studied for the production and characterization of cold-active cellulase enzyme. The latter was found to have a specific activity of 6.36 U/mg and a molar mass of 48 kDa with a 22.9-fold purification and 5% recovery at an optimum pH of 7.5 and a temperature of 10 ºC. Given the importance of psychrophilic actinobacteria N. dassonvillei PSY13 can be further exploited for its benefits, meaning that the Southern Ocean harbours biotechnologically important microorganisms that can be further explored for versatile biotechnological and industrial applications.

scholarly journals Evaluation of Cellulolytic Endo-1,4-β-D-Glucanase Activity in the Digestive Fluid of Adult Phytophagous Beetle Hoplasoma unicolor

2021 ◽  
Vol 32 (3) ◽  
pp. 53-68
Author(s):  
Mohammad Mosleh Uddin ◽  
Suzana Afrin Lima ◽  
Tanim Jabid Hossain ◽  
Newton Kar ◽  
Yeasmin Zahan ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Specific Activity ◽  
Agar Plate ◽  
Industrial Applications ◽  
Cellulolytic Activity ◽  
Glucanase Activity ◽  
Endoglucanase Activity ◽  
Sds Page ◽  
Ph Range ◽  
Digestive Fluid

Insects of the taxonomic order Coleoptera are recognised for considerable cellulolytic activity in their digestive fluid. The cellulolytic activity of the gut fluid in Hoplasoma unicolor, a member of Coleoptera, however, remains unexplored. In this study, we, for the first time, report the qualitative and quantitative analysis of cellulolytic activity in the digestive fluid of this insect. The cellulolytic endo-1,4-β-D-glucanase activity was confirmed in the supernatant of the insect’s digestive fluid by agar plate assay using carboxymethyl cellulose as the substrate. To determine the optimum pH, enzyme activity was further assessed in an acidic pH range of 5 to 6, and the highest activity was observed at pH 5.3. For quantitative analysis, endoglucanase activity was measured using 3,5-dinitrosalicylic acid method which revealed that the specific activity of the gut sample was 0.69 (±0.01) units per mg of protein. For further characterisation of the cellulases in the sample, SDS-PAGE and zymogram analysis were carried out. Two active cellulolytic bands were detected on the zymogram suggesting the presence of two distinct endoglucanases which completely disappeared upon heating the sample at 55°C. Our study, therefore, highlights prospect of the gut fluid of H. unicolor as an important source of cellulase enzymes that merits further investigations into their extensive characterisation for potential industrial applications.

scholarly journals Isolation and characterization of a new cold-active protease from psychrotrophic bacteria of Western Himalayan glacial soil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saleem Farooq ◽  
Ruqeya Nazir ◽  
Shabir Ahmad Ganai ◽  
Bashir Ahmad Ganai
Keyword(s):  
Specific Activity ◽  
Temperature Range ◽  
Psychrotrophic Bacteria ◽  
Isolation And Characterization ◽  
Cold Active ◽  
Active Protease ◽  
Quantitative Screening ◽  
First Time ◽  
Low K

AbstractAs an approach to the exploration of cold-active enzymes, in this study, we isolated a cold-active protease produced by psychrotrophic bacteria from glacial soils of Thajwas Glacier, Himalayas. The isolated strain BO1, identified as Bacillus pumilus, grew well within a temperature range of 4–30 °C. After its qualitative and quantitative screening, the cold-active protease (Apr-BO1) was purified. The Apr-BO1 had a molecular mass of 38 kDa and showed maximum (37.02 U/mg) specific activity at 20 °C, with casein as substrate. It was stable and active between the temperature range of 5–35 °C and pH 6.0–12.0, with an optimum temperature of 20 °C at pH 9.0. The Apr-BO1 had low Km value of 1.0 mg/ml and Vmax 10.0 µmol/ml/min. Moreover, it displayed better tolerance to organic solvents, surfactants, metal ions and reducing agents than most alkaline proteases. The results exhibited that it effectively removed the stains even in a cold wash and could be considered a decent detergent additive. Furthermore, through protein modelling, the structure of this protease was generated from template, subtilisin E of Bacillus subtilis (PDB ID: 3WHI), and different methods checked its quality. For the first time, this study reported the protein sequence for psychrotrophic Apr-BO1 and brought forth its novelty among other cold-active proteases.

scholarly journals Expression of novel acidic lipase from Micrococcus luteus in Pichia pastoris and its application in transesterification

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Selfela Restu Adina ◽  
Antonius Suwanto ◽  
Anja Meryandini ◽  
Esti Puspitasari
Keyword(s):  
Fatty Acid ◽  
Pichia Pastoris ◽  
Specific Activity ◽  
Signal Sequence ◽  
Micrococcus Luteus ◽  
Acid Methyl Ester ◽  
Industrial Applications ◽  
Expression Level ◽  
Lipase Gene ◽  
Acidic Lipase

Abstract Background Lipases are promising biocatalysts for industrial applications and attract attention to be explored. A novel acidic lipase has been isolated from the lipolytic bacteria Micrococcus luteus EMP48-D (LipEMP48-D) screened from tempeh. The lipase gene had previously been overexpressed in Escherichia coli BL21, but the expression level obtained was relatively low. Here, to improve the expression level, the lipase gene was cloned to Pichia pastoris. We eliminated the native signal sequence of M. luteus and replaced it with α-mating factor (α-MF) signal sequence. We also optimized and synthesized the lipase gene based on codon preference in P. pastoris. Results LipEMP48-D lipase was expressed as an extracellular protein. Codon optimization has been conducted for 20 codons, with the codon adaption index reaching 0.995. The highest extracellular lipase activity obtained reached 145.4 ± 4.8 U/mg under AOX1 promoter in P. pastoris KM71 strain, which was 9.7-fold higher than the previous activity in E. coli. LipEMP48-D showed the highest specific activity at pH 5.0 and stable within the pH range 3.0–5.0 at 40 °C. LipEMP48-D also has the capability of hydrolyzing various long-chain triglycerides, particularly olive oil (100%) followed by sunflower oil (88.5%). LipEMP48-D exhibited high tolerance for various polar organic solvents with low log P, such as isopropanol (115.7%) and butanol (114.6%). The metal ions (Na+, K+, Ca2+, Mg2+, Mn+) decreased enzyme activity up to 43.1%, while Fe2+ increased relative activity of enzymes up to 200%. The conversion of free fatty acid (FFA) into fatty acid methyl ester (FAME) was low around 2.95%. Conclusions This study was the first to report overexpression of Micrococcus lipase in yeast. The extracellular expression of this acidic lipase could be potential for biocatalyst in industrial fields, especially organic synthesis, food industry, and production of biodiesel.

P. vortex-mediated strategies for polysaccharides decomposition

TECHNOLOGY ◽  
2015 ◽  
Vol 03 (02n03) ◽  
pp. 80-83
Author(s):  
Mark Polikovsky ◽  
Eshel Ben-Jacob ◽  
Alin Finkelshtein
Keyword(s):  
Degradation Products ◽  
Cellulose Degradation ◽  
Cellulose Hydrolysis ◽  
Industrial Applications ◽  
Biofuel Production ◽  
E Coli ◽  
Novel Approach ◽  
Textile Manufacture ◽  
Hydrolysis Of Cellulose ◽  
The Relationship

Cellulose hydrolysis has many industrial applications such as biofuel production, food, paper and textile manufacture. Here, we present a novel approach to cellulose hydrolysis using a consortium of motile bacteria, Paenibacillus vortex, that can swarm on solid medium carrying a non-motile recombinant E. coli cargo strain expressing the β-glucosidase and cellulase genes that facilitate the hydrolysis of cellulose. These two species cooperate; the relationship is mutually beneficial: the E. coli is dispersed over long distances, while the P. vortex bacteria gain from the supply of cellulose degradation products. This enables the use of such consortia in this area of biotechnology.

scholarly journals Unveiling the Si cycle using isotopes in an iron-fertilized zone of the Southern Ocean: from mixed-layer supply to export

2016 ◽  
Vol 13 (21) ◽  
pp. 6049-6066 ◽  
Author(s):  
Ivia Closset ◽  
Damien Cardinal ◽  
Mathieu Rembauville ◽  
François Thil ◽  
Stéphane Blain
Keyword(s):  
Southern Ocean ◽  
Isotopic Composition ◽  
Mass Balance ◽  
Silicic Acid ◽  
Surface Waters ◽  
Polar Front ◽  
Biogeochemical Cycle ◽  
Reference Station ◽  
Kerguelen Plateau ◽  
Fractionation Factor

Abstract. A massive diatom bloom forms annually in the surface waters of the naturally iron-fertilized Kerguelen Plateau (Southern Ocean). In this study, silicon isotopic signatures (δ30Si) of silicic acid (DSi) and suspended biogenic silica (BSi) were investigated through the whole water column with unprecedented spatial resolution, during the KEOPS-2 experiment (spring 2011). We used δ30Si measurements to track the sources of silicon that fuelled the bloom, and investigated the seasonal evolution of the Si biogeochemical cycle in the iron-fertilized area. We compared the results from stations with various degrees of iron enrichment and bloom conditions to an HNLC reference station. Dissolved and particulate δ30Si signatures were highly variable in the upper 500 m, reflecting the effect of intense silicon utilization in spring, while they were quite homogeneous in deeper waters. The Si isotopic and mass balance identified a unique Winter Water (WW) Si source for the iron-fertilized area that originated from southeast of the Kerguelen Plateau and spread northward. When the WW reached a retroflection of the Polar Front (PF), the δ30Si composition of the silicic acid pool became progressively heavier. This would result from sequential diapycnal and isopycnal mixings between the initial WW and ML water masses, highlighting the strong circulation of surface waters that defined this zone. When comparing the results from the two KEOPS expeditions, the relationship between DSi depletion, BSi production, and their isotopic composition appears decoupled in the iron-fertilized area. This seasonal decoupling could help to explain the low apparent fractionation factor observed in the ML at the end of summer. Taking into account these considerations, we refined the seasonal net BSi production in the ML of the iron-fertilized area to 3.0 ± 0.3 mol Si m−2 yr−1, which was exclusively sustained by surface water phytoplankton populations. These insights confirm that the isotopic composition of dissolved and particulate silicon is a promising tool to improve our understanding of the Si biogeochemical cycle since the isotopic and mass balance allows resolution of processes in the Si cycle (i.e. uptake, dissolution, mixing).

The distribution and abundance of viruses in the Southern Ocean during spring

2000 ◽  
Vol 12 (4) ◽  
pp. 414-417 ◽  
Author(s):  
Harvey Marchant ◽  
Andrew Davidson ◽  
Simon Wright ◽  
John Glazebrook
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Surface Waters ◽  
Significant Relationship ◽  
Polar Front ◽  
Open Ocean ◽  
Bacterial Concentration ◽  
Viral Abundance ◽  
Chroococcoid Cyanobacteria ◽  
Bacterial Concentrations

The concentrations of viruses, bacteria, chroococcoid cyanobacteria and chlorophyll a were determined in surface waters of the Southern Ocean during spring. Viral concentrations declined southward from around 4 × 106 ml−1 near Tasmania to a minimum of around 1 × 106 ml−1 at the Polar Front. South of the Front, virus concentrations increased again, reaching around 4 × 106 ml−1 in the sea-ice zone south of 60°S. Bacterial concentration decreased southwards across the Southern Ocean from around 6.5 × 105 ml−1 near Tasmania to < 1.0 × 105 ml−1 in the sea-ice zone. Cyanobacteria accounted for < 8% of the prokaryotes. There was no significant relationship between viral abundance and eithercyanobacterial or chl a concentration. Viral and bacterial concentrations were not significantly correlated north (P {0.10 < r < 0.20}) or south (P {0.20 < r < 0.5}) of the Polar Front. The virus to bacteria ratio (VBR) was between 3 and 15 in the open ocean but varied between 15 and 40 in the sea-ice region. These virus concentrations and VBRs indicate that viruses are no less important in Southern Ocean ecosystems than elsewhere in the world's oceans.

scholarly journals Purification, characterization and application of novel alkaline protease from new Bacillus cereus UV-15 mutant

2017 ◽  
Vol 7 (4) ◽  
pp. 1 ◽  
Author(s):  
Sreedevi Basavaraju ◽  
Chandrasekhar Kathera ◽  
Pramoda Kumari Jasti
Keyword(s):  
Bacillus Cereus ◽  
Ammonium Sulphate ◽  
Alkaline Protease ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Industrial Applications ◽  
Tween 20 ◽  
Original Activity ◽  
Protease Enzyme

The alkaline protease produced by Bacillus cereus UV-15 mutant was purified by precipitation with ammonium sulphate and gel filtration through sephadex G-100. The enzyme has shown to have a molecular weight of 29kDa by SDS polyacrylamide gel electrophoresis. The extracted protease enzyme was purified by 16.64 fold through ammonium sulphate precipitation and chromatography separation in Sephadex G-100. The purified protease had a specific activity of 2915 (U/mg). The zymogram also revealed a clear hydrolytic zone due to proteolytic activity, which coincided with the band obtained with SDS–PAGE. The enzyme was remained active and stable at pH 8-11, with an optimum at pH 10.0. The protease was stable in the temperature ranging from 40°C to 60°C, but gradually decreased at temperature 70°C. The optimum temperature for protease activity was determined at 60°C. The enzyme showed stability towards non-ionic and anionic surfactants, and oxidizing agents. At 1% concentration of Tween-20 and Tween-80, the enzyme retained 78% and 94% relative activity respectively. Alkaline protease retained 95% activity toward 0.5% concentration of the anionic detergent SDS. The enzyme showed compatibility at 50°C with commercial detergents such as Ariel, Surf excel, Rin, wheel, Tide and Nirma. In the presence of Ariel and Rin the enzyme retained about 72 and 75% of the original activity respectively. The supplementation of the enzyme in detergents could improve the cleansing performance towards the blood stains and suggested to be used as a detergent additive. The enzyme also removed goat hide hairs completely after 15 hr of incubation. These characteristics may make the enzyme suitable for several industrial applications, especially in leather industries.

scholarly journals Carbonate saturation state of surface waters in the Ross Sea and Southern Ocean: controls and implications for the onset of aragonite undersaturation

2015 ◽  
Vol 12 (11) ◽  
pp. 8429-8465 ◽  
Author(s):  
H. B. DeJong ◽  
R. B. Dunbar ◽  
D. A. Mucciarone ◽  
D. A. Koweek
Keyword(s):  
Southern Ocean ◽  
Surface Waters ◽  
Ross Sea ◽  
Polar Front ◽  
Early Spring ◽  
Total Alkalinity ◽  
Saturation State ◽  
System Data ◽  
Algal Photosynthesis ◽  
Carbon System

Abstract. Predicting when surface waters of the Ross Sea and Southern Ocean will become undersaturated with respect to biogenic carbonate minerals is challenging in part due to the lack of baseline high resolution carbon system data. Here we present ~ 1700 surface total alkalinity measurements from the Ross Sea and along a transect between the Ross Sea and southern Chile from the austral autumn (February–March 2013). We calculate the saturation state of aragonite (ΩAr) and calcite (ΩCa) using measured total alkalinity and pCO2. In the Ross Sea and south of the Polar Front, variability in carbonate saturation state (Ω) is mainly driven by algal photosynthesis. Freshwater dilution and calcification have minimal influence on Ω variability. We estimate an early spring surface water ΩAr value of ~ 1.2 for the Ross Sea using a total alkalinity–salinity relationship and historical pCO2 measurements. Our results suggest that the Ross Sea is not likely to become undersaturated with respect to aragonite until the year 2070.

scholarly journals Watermasses as a unifying framework for understanding the Southern Ocean carbon cycle

2010 ◽  
Vol 7 (3) ◽  
pp. 3393-3451 ◽  
Author(s):  
D. Iudicone ◽  
I. Stendardo ◽  
O. Aumont ◽  
K. B. Rodgers ◽  
G. Madec ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Large Scale ◽  
Thermohaline Circulation ◽  
Model Simulation ◽  
Polar Front ◽  
Global Ocean ◽  
Inversion Method ◽  
Co2 Fluxes ◽  
Meridional Transport ◽  
Regional Patterns

Abstract. A watermass-based framework is presented for a quantitative understanding of the processes controlling the cycling of carbon in the Southern Ocean. The approach is developed using a model simulation of the global carbon transports within the ocean and with the atmosphere. It is shown how the watermass framework sheds light on the interplay between biology, air-sea gas exchange, and internal ocean transport including diapycnal processes, and the way in which this interplay controls the large-scale ocean-atmosphere carbon exchange. The simulated pre-industrial regional patterns of DIC distribution and the global distribution of the pre-industrial air-sea CO2 fluxes compare well with other model results and with results from an ocean inversion method. The main differences are found in the Southern Ocean where the model presents a stronger CO2 outgassing south of the polar front, a result of the upwelling of DIC-rich deep waters into the surface layer. North of the subantarctic front the typical temperature-driven solubility effect produces a net ingassing of CO2. The biological controls on surface CO2 fluxes through primary production is generally smaller than the temperature effect on solubility. Novel to this study is also a Lagrangian trajectory analysis of the meridional transport of DIC. The analysis allows to evaluate the contribution of separate branches of the global thermohaline circulation (identified by watermasses) to the vertical distribution of DIC throughout the Southern Ocean and towards the global ocean. The most important new result is that the overturning associated with Subantarctic Mode Waters sustains a northward net transport of DIC (15.7×107 mol/s across 30° S). This new finding, which has also relevant implications on the prediction of anthropogenic carbon redistribution, results from the specific mechanism of SAMW formation and its source waters whose consequences on tracer transports are analyzed for the first time in this study.

scholarly journals Introducing a Thermo-Alkali-Stable, Metallic Ion-Tolerant Laccase Purified From White Rot Fungus Trametes hirsuta

2021 ◽  
Vol 12 ◽  
Author(s):  
Jing Si ◽  
Hongfei Ma ◽  
Yongjia Cao ◽  
Baokai Cui ◽  
Yucheng Dai
Keyword(s):  
Specific Activity ◽  
Endocrine Disrupting Chemicals ◽  
Environmental Pollutants ◽  
Fold Increase ◽  
Industrial Applications ◽  
White Rot ◽  
White Rot Fungus ◽  
Metallic Ions ◽  
Trametes Hirsuta ◽  
Ph Range

This study introduces a valuable laccase, designated ThLacc-S, purified from white rot fungus Trametes hirsuta. ThLacc-S is a monomeric protein in nature with a molecular weight of 57.0 kDa and can efficiently metabolize endocrine disrupting chemicals. The enzyme was successfully purified to homogeneity via three consecutive steps consisting of salt precipitation and column chromatography, resulting in a 20.76-fold increase in purity and 46.79% yield, with specific activity of 22.111 U/mg protein. ThLacc-S was deciphered as a novel member of the laccase family and is a rare metalloenzyme that contains cysteine, serine, histidine, and tyrosine residues in its catalytic site, and follows Michaelis-Menten kinetic behavior with a Km and a kcat/Km of 87.466 μM and 1.479 s–1μM–1, respectively. ThLacc-S exerted excellent thermo-alkali stability, since it was markedly active after a 2-h incubation at temperatures ranging from 20 to 70°C and retained more than 50% of its activity after incubation for 72 h in a broad pH range of 5.0–10.0. Enzymatic activities of ThLacc-S were enhanced and preserved when exposed to metallic ions, surfactants, and organic solvents, rendering this novel enzyme of interest as a green catalyst for versatile biotechnological and industrial applications that require these singularities of laccases, particularly biodegradation and bioremediation of environmental pollutants.

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