Optimization of Colloidal Chitin and Inoculum Concentration in Chitinase Production by Streptomyces sp. PB2 Using Response Surface Methodology

Chitinase is an enzyme capable of catalyzing the hydrolysis of chitin. Bacteria is one of the sources for chitinase and the modification process of production are continously developed. Streptomyces sp. is one of Actinomycetes group that shows high activity in hydrolyzing chitin. This study aimed to find the optimal conditions of Streptomyces sp. PB2 for producing chitinase at various colloidal chitin (0.5%, 1%, 1.5%) and inoculum (0.5%, 1%, 1.5%) concentration in the chitin broth medium using Respons Surface Methodology (RSM). The examined parameters included Total Plate Count (CFU/ml) and chitinase activity (U/ml). Chitinase activity was statistically analyzed by MiniTab 17 to obtain a mathematical model, then were validated. The mathematical model of chitinase activity was Y = -0.000075 + 0.00056 K + 0.00067 I, with the optimum colloidal chitin concentration (K) of 1.5% and inoculum concentration (I) of 1.5%. The highest chitinase activity of 0.0019 U/ml in day-2 fermentation. The validation test showed that the mathematical model had a low accuracy with the SSE value of 0.5306. This study shows that colloidal chitin and inoculum concentration are important factors to be optimized. However, further model is needed to be developed for a better estimation of process.

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The chitinolytic activity of the Curtobacterium sp. isolated from field-grown soybean and analysis of its genome sequence

PLoS ONE ◽

10.1371/journal.pone.0259465 ◽

2021 ◽

Vol 16 (11) ◽

pp. e0259465

Author(s):

Ivica Dimkić ◽

Vibha Bhardwaj ◽

Valeria Carpentieri-Pipolo ◽

Nemanja Kuzmanović ◽

Giuliano Degrassi

Keyword(s):

Specific Activity ◽

Gene Clusters ◽

Defense Responses ◽

Chitinase Activity ◽

Glycosyl Hydrolases ◽

Phylogenetic Cluster ◽

Genome Visualization ◽

Chitinase Production ◽

Or Gene ◽

Hydrolysis Of

Curtobacterium sp. GD1 was isolated from leaves of conventionally grown soybean in Brazil. It was noteworthy that among all bacteria previously isolated from the same origin, only Curtobacterium sp. GD1 showed a strong chitinase activity. The enzyme was secreted and its production was induced by the presence of colloidal chitin in the medium. The chitinase was partially purified and characterized: molecular weight was approximately 37 kDa and specific activity 90.8 U/mg. Furthermore, Curtobacterium sp. GD1 genome was sequenced and analyzed. Our isolate formed a phylogenetic cluster with four other Curtobacterium spp. strains, with ANIb/ANIm ≥ 98%, representing a new, still non described Curtobacterium species. The circular genome visualization and comparison of genome sequences of strains forming new cluster indicated that most regions within their genomes were highly conserved. The gene associated with chitinase production was identified and the distribution pattern of glycosyl hydrolases genes was assessed. Also, genes associated with catabolism of structural carbohydrates such as oligosaccharides, mixed polysaccharides, plant and animal polysaccharides, as well as genes or gene clusters associated with resistance to antibiotics, toxic compounds and auxin biosynthesis subsystem products were identified. The abundance of putative glycosyl hydrolases in the genome of Curtobacterium sp. GD1 suggests that it has the tools for the hydrolysis of different polysaccharides. Therefore, Curtobacterium sp. GD1 isolated from soybean might be a bioremediator, biocontrol agent, an elicitor of the plant defense responses or simply degrader.

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A Novel GH Family 20 β-N-acetylhexosaminidase With Both Chitosanase and Chitinase Activity From Aspergillus oryzae

Frontiers in Molecular Biosciences ◽

10.3389/fmolb.2021.684086 ◽

2021 ◽

Vol 8 ◽

Author(s):

Tianle Qu ◽

Chunyue Zhang ◽

Zhen Qin ◽

Liqiang Fan ◽

Lihua Jiang ◽

...

Keyword(s):

Pichia Pastoris ◽

Kinetic Parameters ◽

Aspergillus Oryzae ◽

Biological Activities ◽

Maximal Activity ◽

Chitinase Activity ◽

Ph Stability ◽

Colloidal Chitin ◽

Chitin And Chitosan ◽

Hydrolysis Of

Aminooligosaccharides possess various biological activities and can exploit wide applications in food, pharmaceutical and cosmetic industries. Commercial aminooligosaccharides are often prepared by the hydrolysis of chitin and chitosan. In this study, a novel GH family 20 β-N-acetylhexosaminidases gene named AoNagase was cloned from Aspergillus oryzae and expressed in Pichia pastoris. The purified AoNagase had maximal activity at pH 5.5 and 65°C. It exhibited good pH stability in the range of pH 6.0–7.5 and at temperatures below 50°C. AoNagase was capable of hydrolyzing not only colloidal chitosan (508.26 U/mg) but also chitin (29.78 U/mg). The kinetic parameters (Km and Vmax) of AoNagase were 1.51 mM, 1106.02 U/mg for chitosan and 0.41 mM, 40.31 U/mg for colloidal chitin. To our knowledge, AoNagase is the first GH family 20 β-N-acetylhexosaminidase capable of hydrolyzing both chitosan and chitin. AoNagase is an endo-type β-N-acetylhexosaminidases and can potentially be used for the manufacturing of aminooligosaccharides.

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DETERMINATION OF PERFORMANCE INDICATORS OF THE TRUCK KrAZ-6510TE

Avtoshliakhovyk Ukrayiny ◽

10.33868/0365-8392-2020-1-261-19-26 ◽

2020 ◽

pp. 19-26

Author(s):

Olexandr Pavlenko ◽

Serhii Dun ◽

Maksym Skliar

Keyword(s):

Mathematical Model ◽

Surface Friction ◽

Building Structures ◽

Maximum Torque ◽

Military Equipment ◽

Military Vehicles ◽

Force Magnitude ◽

Vehicle Mobility ◽

The Mathematical Model

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.

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EXPERIMENTAL STUDIES OF CAR PROPERTIES ON A PHYSICAL MODEL

Avtoshliakhovyk Ukrayiny ◽

10.33868/0365-8392-2019-4-260-10-16 ◽

2019 ◽

pp. 10-16

Author(s):

Oleksii Timkov ◽

Dmytro Yashchenko ◽

Volodymyr Bosenko

Keyword(s):

Mathematical Model ◽

Remote Control ◽

Physical Model ◽

Model Experiment ◽

Experimental Studies ◽

Electrical Energy ◽

Short Term ◽

Motor Current ◽

Memory Card ◽

The Mathematical Model

The article deals with the development of a physical model of a car equipped with measuring, recording and remote control equipment for experimental study of car properties. A detailed description of the design of the physical model and of the electronic modules used is given, links to application libraries and the code of the first part of the program for remote control of the model are given. Atmega microcontroller on the Arduino Uno platform was used to manage the model and register the parameters. When moving the car on the memory card saved such parameters as speed, voltage on the motor, current on the motor, the angle of the steered wheel, acceleration along three coordinate axes are recorded. Use of more powerful microcontrollers will allow to expand the list of the registered parameters of movement of the car. It is possible to measure the forces acting on the elements of the car and other parameters. In the future, it is planned to develop a mathematical model of motion of the car and check its adequacy in conducting experimental studies on maneuverability on the physical model. In addition, it is possible to conduct studies of stability and consumption of electrical energy. The physical model allows to quickly change geometric dimensions and mass parameters. In the study of highway trains, this approach will allow to investigate the various layout schemes of highway trains in the short term. It is possible to make two-axle road trains and saddle towed trains, three-way hitched trains of different layout. The results obtained will allow us to improve not only the mathematical model, but also the experimental physical model, and move on to further study the properties of hybrid road trains with an active trailer link. This approach allows to reduce material and time costs when researching the properties of cars and road trains. Keywords: car, physical model, experiment, road trains, sensor, remote control, maneuverability, stability.

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RESEARCH OF INDICATORS OF A VEHICLE WITH A DIESEL WORKING ON DIESEL AND DIESEL GAS CYCLES USING THE MATHEMATICAL MODEL

Avtoshliakhovyk Ukrayiny ◽

10.33868/0365-8392-2020-1-261-14-19 ◽

2020 ◽

pp. 14-19

Author(s):

Serhii Kovbasenko ◽

Andriy Holyk ◽

Serhii Hutarevych

Keyword(s):

Mathematical Model ◽

Diesel Engine ◽

Environmental Performance ◽

Energy Performance ◽

Dual Fuel ◽

Fuel System ◽

Compressed Natural Gas ◽

Diesel Vehicles ◽

Diesel Cycle ◽

The Mathematical Model

The features of an advanced mathematical model of motion of a truck with a diesel engine operating on the diesel and diesel gas cycles are presented in the article. As a result of calculations using the mathematical model, a decrease in total mass emissions as a result of carbon monoxide emissions is observed due to a decrease in emissions of nitrogen oxides and emissions of soot in the diesel gas cycle compared to the diesel cycle. The mathematical model of a motion of a truck on a city driving cycle according to GOST 20306-90 allows to study the fuel-economic, environmental and energy indicators of a diesel and diesel gas vehicle. The results of the calculations on the mathematical model will make it possible to conclude on the feasibility of converting diesel vehicles to using compressed natural gas. Object of the study – the fuel-economic, environmental and energy performance diesel engine that runs on dual fuel system using CNG. Purpose of the study – study of changes in fuel, economic, environmental and energy performance of vehicles with diesel engines operating on diesel and diesel gas cycles, according to urban driving cycle modes. Method of the study – calculations on a mathematical model and comparison of results with road tests. Bench and road tests, results of calculations on the mathematical model of motion of a truck with diesel, working on diesel and diesel gas cycles, show the improvement of environmental performance of diesel vehicles during the converting to compressed natural gas in operation. Improvement of environmental performance is obtained mainly through the reduction of soot emissions and nitrogen oxides emissions from diesel gas cycle operations compared to diesel cycle operations. The results of the article can be used to further develop dual fuel system using CNG. Keywords: diesel engine, diesel gas engine, CNG

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Glycemia monitoring

Nonlinear Analysis Modelling and Control ◽

10.15388/na.1998.2.0.15282 ◽

1998 ◽

Vol 2 ◽

pp. 23-30

Author(s):

Igor Basov ◽

Donatas Švitra

Keyword(s):

Diabetes Mellitus ◽

Mathematical Model ◽

Numerical Methods ◽

Differential Equations ◽

Blood Sugar ◽

Self Regulation ◽

Physiological System ◽

Non Linear ◽

The Mathematical Model

Here a system of two non-linear difference-differential equations, which is mathematical model of self-regulation of the sugar level in blood, is investigated. The analysis carried out by qualitative and numerical methods allows us to conclude that the mathematical model explains the functioning of the physiological system "insulin-blood sugar" in both normal and pathological cases, i.e. diabetes mellitus and hyperinsulinism.

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Mathematical Models of Papermaking

Nonlinear Analysis Modelling and Control ◽

10.15388/na.2001.6.1.15221 ◽

2001 ◽

Vol 6 (1) ◽

pp. 9-19 ◽

Cited By ~ 1

Author(s):

A. Buikis ◽

J. Cepitis ◽

H. Kalis ◽

A. Reinfelds ◽

A. Ancitis ◽

...

Keyword(s):

Mathematical Model ◽

Initial Value Problems ◽

Moisture Transfer ◽

Bound Water ◽

Drying Process ◽

Initial Value ◽

First Order ◽

Heat And Moisture ◽

The Mathematical Model ◽

The Web

The mathematical model of wood drying based on detailed transport phenomena considering both heat and moisture transfer have been offered in article. The adjustment of this model to the drying process of papermaking is carried out for the range of moisture content corresponding to the period of drying in which vapour movement and bound water diffusion in the web are possible. By averaging as the desired models are obtained sequence of the initial value problems for systems of two nonlinear first order ordinary differential equations.

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The mathematical modelling of corrosion in hot dip galvanized steel reinforced concrete

International Review of Applied Sciences and Engineering ◽

10.1556/irase.2.2011.1.1 ◽

2011 ◽

Vol 2 (1) ◽

pp. 1-12

Author(s):

A. Hegyi ◽

H. Vermeşan ◽

V. Rus

Keyword(s):

Mathematical Model ◽

Reinforced Concrete ◽

Numerical Model ◽

Equation System ◽

Galvanized Steel ◽

Steel Reinforced Concrete ◽

Numeric Model ◽

Physical And Mathematical Models ◽

Physical Phenomena ◽

The Mathematical Model

Abstract In this paper we wish to present the numerical model elaborated in order to simulate some physical phenomena that influence the general deterioration of steel, whether hot dip galvanized or not, in reinforced concrete. We describe the physical and mathematical models, establishing the corresponding equation system, the initial and boundary conditions. We have also presented the numeric model associated to the mathematical model and the numeric methods of discretization and solution of the differential equations system that describes the mathematical model.

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