scholarly journals Characteristics and Activity Anti Qourum Sensing Bacillus spp. Isolated from Penaeus vannamei Shrimp Ponds

2021 ◽  
Vol 29 (1) ◽  
pp. 97-106
Author(s):  
Iman Rusmana ◽  
Yuni Puji Hastuti ◽  
Rizal Khoirun Alfisah ◽  
Alina Akhdiya
Keyword(s):  
Quorum Sensing ◽  
Pigment Formation ◽  
Shrimp Ponds ◽  
Genes Encoding ◽  
Bacillus Spp ◽  
Violacein Production ◽  
Index Value ◽  
Acute Hepatopancreatic Necrosis Disease ◽  
Selection Of

Certain strains of V. parahaemolyticus carry a gene that encodes a toxin that causes Acute hepatopancreatic necrosis disease (AHPND) in P. vannamei. AHPND attacks shrimp post larvae within 20-30 days after stocking causing up to 100% mortality. The expression of these virulent genes is controlled by the quorum sensing system. This system is inhibited by an anti-quorum sensing (AQS) mechanism. Several Bacillus strains have AQS mechanism by producing AHL-Lactonase enzyme. Therefore, this study aimed to obtain Bacillus spp. having AQS activity for controlling AHPND. The study was conducted from isolation and selection of Bacillus isolates, as well as determination of AQS activity. From 22 samples consisting of shrimp intestines, water and pond sediment samples, a total of 151 isolates of Bacillus spp. were isolated. The screening test for AQS activity obtained 11 isolates that showed AQS activity on Cromobacterium violaceum. Determination of violacein pigment in liquid cultures of C. violaceum showed the index value of the pigment formation was between 0.025-0.166 and 0.026-0.567 at 24-hour and between 48-hour incubations, respectively. The quantitative analysis of violacein production showed that there were six isolates of Bacillus could inhibit the pigment production more than 75%. The isolates were identified as Bacillus cereus (four isolates), Bacillus thuringiensis (one isolate), and Bacillus velezensis (one isolate), respectively. The molecular analysis had confirmed that the isolates have aiiA genes encoding AHL-lactonase enzyme. These Bacillus isolates have potential application for controlling AHNPD disease.

scholarly journals Selection of Bacillus spp. isolates having enzyme producing ability and antagonistic to Vibrio parahaemolyticus causing the early mortality syndrome (EMS) on shrimp

2018 ◽  
Vol 1 (6) ◽  
pp. 23-31
Author(s):  
Dung Thi Thanh Do ◽  
Binh Thanh Le ◽  
Duong Thi Dang Hoang ◽  
Quang Dinh Vo ◽  
Trang Thi Phuong Phan
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Extracellular Enzymes ◽  
Early Mortality ◽  
Testing Methods ◽  
Shrimp Ponds ◽  
Early Mortality Syndrome ◽  
Rdna Sequencing ◽  
Potential Applications ◽  
Bacillus Spp ◽  
Selection Of

The aim of this study is to select some Bacillus isolates which are capable of yielding several beneficial enzymes and antagonism to Vibrio parahaemolyticus causing the EMS shrimp disease. In this study, we isolated and screened total of 54 Bacillus isolates from 30 mud, water and shrimp samples at shrimp ponds in Soc Trang province. Among these, 19 isolates were resistant against Vibrio parahaemolyticus strains causing the EMS shrimp disease via two testing methods. Three of them including NA2B13, NA10B2, NA8B1 isolates showed strongresistance and strong one to three kinds of extracellular enzymes to produce. Result of 16S rDNA sequencing and MALDI -TOF showed that NA2B13 and NA8B1 were Bacillus subtilis and NA10B2 was B. amyloliquefaciens. These two species were regarded safe and having potential applications in the production of biological products to prevent EMS shrimp disease.

scholarly journals Analysis of Ratios of Propulsion Energy Demand for Transport by Bulk Carriers

2019 ◽  
Vol 26 (3) ◽  
pp. 173-180
Author(s):  
Stanisław Polanowski
Keyword(s):  
Energy Demand ◽  
Load Capacity ◽  
Travel Speed ◽  
Statistical Dependence ◽  
Generalized Polynomials ◽  
Bulk Carriers ◽  
Index Value ◽  
The Relationship ◽  
Selection Of

Abstract The article presents the results of calculations and analysis of the eM ratio of the propulsion energy consumption per the nautical mile and the eMt ratio of the propulsion energy demand for the transport of 1-ton cargo per the nautical mile for bulk carriers. The relationship between eM and eMt indicators with the EIV (Estimated Index Value) ratio is shown. The output data for the determination of eM and eMt indicators was taken from the quoted MAN publication, reading (reproducing) the values of power, velocity v and DWT tonnage from the charts included in this publication. Calculations and analyses were made for velocity v between 11-15 knots and for DWT from 5-400 kt (kilo tonnes). The graphs of eM and eMt ratios in the function of speed v and load capacity DWT are presented. Using the stepwise method of least squares, models of statistical dependence of indicators on velocity v and load capacity of bulk carriers were developed. They were based on generalized polynomials with integer exponents. Derivatives deM / dv and deMt / dv and derivatives deM / dDWT and deMt / dDWT were determined. The main observations resulting from the conducted analyses are observed with the increase of DWT (within the range of 80-100 kt) a significant decrease in the value of the eM index. For DWT values> 100 kt, the decrease in eMt is slow − eMt asymptotically tends to a constant value. The results of the analyses carried out can be used at the stage of designing the transport capacity (tonnage) and nominal speed of the ship as well as selection of ship tonnage and travel speed in a given transport situation.

DETERMINING THE DESALINATION UNIT COMPOSITION FOR COSTAL AREAS AND SMALL ISLANDS USE ANALYTIC HIERARCHY PROCESS

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Imam Setiadi ◽  
Dinda Rita K. Hartaja
Keyword(s):  
Analytic Hierarchy Process ◽  
Energy Demand ◽  
Pairwise Comparison ◽  
Small Islands ◽  
Ahp Method ◽  
Analytic Hierarchy ◽  
Comparison Research ◽  
Hierarchy Process ◽  
Selection Of

Selection of the appropriate composition desalination units can be done with a variety of method approaches, one of the method is the Analytic Hierarchy Process. In determining the desalination unit with AHP method to consider is setting a goal, an alternative criteria and pairwise comparison. Research for the determination of the exact composition of the desalination unit in order to achieve sustainable drinking water suppy in coastal areas and small islands has been conducted. The results of the study are as follows, the energy demand of 50.83%, operator costs of 26.64%, maintenance costs of 14.13% and chemical requirement 8.4%. For an alternative composition desalination unit of RO 10 m3 / day is the best alternative composition with value of 59.61%, the composition of the next alternative is RO 20 m3/ day of 30.40% and the last alternative of the desalination unit composition is RO 120 m3/ day of 09.99%.Key words : Desalination, Mukti Stage Flash Composition, AHP

Optimization of the selection of analysis methods for the determination of naturally occurring radionuclides

Kerntechnik ◽  
2008 ◽  
Vol 73 (3) ◽  
pp. 118-121
Author(s):  
T. Heinrich ◽  
L. Funke ◽  
M. Köhler ◽  
U.-K. Schkade ◽  
F. Ullrich ◽  
...  
Keyword(s):  
Naturally Occurring ◽  
Analysis Methods ◽  
Naturally Occurring Radionuclides ◽  
Selection Of

Determination of the minimum number of technological bases of a part

2020 ◽  
pp. 73-75
Author(s):  
B.M. Bazrov ◽  
T.M. Gaynutdinov
Keyword(s):  
Cost Price ◽  
Labor Input ◽  
Part Surface ◽  
Technological Base ◽  
Size Accuracy ◽  
Minimum Number ◽  
The Cost ◽  
Input Cost ◽  
Selection Of

The selection of technological bases is considered before the choice of the type of billet and the development of the route of the technological process. A technique is proposed for selecting the minimum number of sets of technological bases according to the criterion of equality in the cost price of manufacturing the part according to the principle of unity and combination of bases at this stage. Keywords: part, surface, coordinating size, accuracy, design and technological base, labor input, cost price. [email protected]

Is Hydraulics Over-Used or Under-Used in Storm Drainage?

1994 ◽  
Vol 29 (1-2) ◽  
pp. 53-61
Author(s):  
Ben Chie Yen
Keyword(s):  
Unsteady Flow ◽  
Computational Time ◽  
Time Step ◽  
Flow Routing ◽  
Kinematic Wave Equation ◽  
Storm Drainage ◽  
Saint Venant Equations ◽  
Unsteady Flow Routing ◽  
Selection Of

Urban drainage models utilize hydraulics of different levels. Developing or selecting a model appropriate to a particular project is not an easy task. Not knowing the hydraulic principles and numerical techniques used in an existing model, users often misuse and abuse the model. Hydraulically, the use of the Saint-Venant equations is not always necessary. In many cases the kinematic wave equation is inadequate because of the backwater effect, whereas in designing sewers, often Manning's formula is adequate. The flow travel time provides a guide in selecting the computational time step At, which in turn, together with flow unsteadiness, helps in the selection of steady or unsteady flow routing. Often the noninertia model is the appropriate model for unsteady flow routing, whereas delivery curves are very useful for stepwise steady nonuniform flow routing and for determination of channel capacity.

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