scholarly journals Isolation of A Molybdenum-reducing Bacillus sp. strain Zeid 15 and Modeling of its Growth on Amides

2021 ◽  
Vol 5 (2) ◽  
pp. 19-27
Author(s):  
I.M. Abu Zeid ◽  
M.F. Rahman ◽  
Mohd Yunus Shukor
Keyword(s):  
Heavy Metals ◽  
Specific Growth ◽  
Growth Parameters ◽  
Gompertz Model ◽  
Electron Donors ◽  
Bacillus Sp ◽  
Aquatic Life ◽  
Molybdenum Blue ◽  
Specific Growth Rates ◽  
Modified Gompertz Model

More and more people are looking at bioremediation as a cheaper option to physhiochemical techniques for cleaning up pollution from farming, mines, and other chemical industries. Toxic effects of molybdenum on spermatogenesis harm not only humans but also livestock and aquatic life. As a result, efforts are being made to remove it from the ecosystem. A microorganism that can convert soluble molybdenum into colloidal molybdenum blue has been discovered. Phosphate concentrations were optimum between 2.5 and 5, molybdate concentrations between 15 and 20, pH between 6, and temperature between 25 and 34 degrees Celsius for the bacteria to thrive. Absorption spectrum of Mo-blue shows a peak at 865 nm and a shoulder at 700 nm, which indicates that it is in fact reduced phosphomolybdate. Copper, mercury, silver, copper, and chromium are all hazardous heavy metals that hinder the synthesis of Mo-blue. Bacillus sp. strain Zeid 15 is the most likely candidate for the bacterium's identity. As part of our screening, we look for the bacterium's capacity to employ different nitriles and amides as potential electron donors for molybdenum reduction or as substrates for growth. A microplate format was used for the screening. The bacterium was able to use the amides acrylamide and propionamide as sources of electron donor for reduction. Mo-blue production was best supported by acrylamide between 750 and 1250 mg/L, and propionamide between 750 and 1000 mg/L. In addition, these amides including acetamide could support the growth of the bacterium. The modified Gompertz model was utilized to model the growth of this bacterium on amides. The model’s growth parameters obtained were lag periods of 1.372, 1.562 and 1.639 d and maximum specific growth rates of 1.38, 0.95 and 0.734 d-1, for acrylamide, acetamide and propionamide, respectively. The capacity of this bacterium to decontaminate simultaneously amides and molybdenum is a novel characteristic that will be very beneficial in bioremediation.

scholarly journals Isolation and Characterization of a PEG-degrading and Mo-reducing Escherichia coli strain Amr-13 in soils from Egypt

2021 ◽  
Vol 9 (2) ◽  
pp. 23-29
Author(s):  
Nubli Shuhaimi ◽  
M. Abd AbdEl-Mongy ◽  
N.A. Shamaan ◽  
Chaing Hin Lee ◽  
M.A. Syed ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Parameters ◽  
Sodium Molybdate ◽  
Gompertz Model ◽  
Coli Strain ◽  
Molybdenum Blue ◽  
Isolation And Characterization ◽  
Specific Growth Rates ◽  
Peg 600

Molybdenum is a pollutant that shows toxicity to spermatogenesis while polyethylene glycols (PEG) are used predominantly in detergents. The pollution of molybdenum and PEGs are reported worldwide. We have isolated ten molybdenum-reducing bacterial isolates from soil that can reduce molybdenum (sodium molybdate) into the colloidal molybdenum blue (Mo-blue). The screening of these isolates for PEG-degrading ability showed that one isolate was capable to utilize PEG 200, 300 and 600 for optimal conditions were pHs between 5.5 and 8.0, temperatures between 30 and 37 oC, phosphate at 5 mM, molybdate between 10 and 30 mM, and glucose as the electron donor. Biochemical analysis of the bacterium identifies it as Escherichia coli strain Amr-13. Growth was best supported by all PEGs at concentrations of between 600 and 1,000 mg/L. A complete degradation for PEG 200 and PEG 300 at 1,000 mg/L was observed on day four and five, respectively, while nearly 90% of PEG 600 was degraded on day six. The growth of this bacterium on these PEGs was modelled using the modified Gompertz model, and produced growth parameters values, which were maximum specific growth rates of 1.51, 1.45 and 1.18 d-1 and lag periods of 0.53, 0.87 and 1.02 day for PEG 200, PEG 300 and PEG 600, respectively. PEG 200 was the most preferred substrate for this bacterium, while PEG 600 was the least preferred.

One-Step Analysis for Listeria monocytogenes Growth in Ready-to-Eat Braised Beef at Dynamic and Static Conditions

2019 ◽  
Vol 82 (11) ◽  
pp. 1820-1827 ◽  
Author(s):  
YANGTAI LIU ◽  
XIANG WANG ◽  
BAOLIN LIU ◽  
QINGLI DONG
Keyword(s):  
Listeria Monocytogenes ◽  
Specific Growth ◽  
Growth Parameters ◽  
Dynamic Condition ◽  
Physiological State ◽  
External Validation ◽  
One Step ◽  
Lag Period ◽  
Specific Growth Rates ◽  
Static Conditions

ABSTRACT This study aimed to estimate the growth parameters of Listeria monocytogenes growth in ready-to-eat (RTE) braised beef by one-step dynamic and static kinetic analysis. The Baranyi model and cardinal parameters model were integrated into a dynamic and static model to estimate the kinetic parameters under one dynamic condition (−20 to 40.0°C) and eight static conditions (4, 8, 15, 20, 30, 35, 37, and 40°C). Based on the dynamic and static methods, the respective dynamic and static results for estimated growth boundaries of L. monocytogenes in RTE braised beef were from −2.5 and −2.7°C to 40.5 and 40.7°C with optimal specific growth rates of 1.078 and 0.913 per h at temperatures of 35.7 and 35.0°C. Temperature effects on the specific growth rate and lag period were developed and used to simulate the change of the physiological state of inocula during the bacterial growth. Subsequently, three additional dynamic temperature profiles were implemented for external validation. The root mean square error of the model developed by dynamic regression (0.19 log CFU/g) is slightly better than that of the model developed by static regression (0.23 log CFU/g). Comparing the validation results, one-step dynamic analysis might be a preferable method for prediction, especially when the growth approaches the stationary phase. Generally, both one-step dynamic and static analyses could be used to accurately predict L. monocytogenes growth in RTE braised beef under fluctuating temperatures.

Comparison on the growth heterogeneity of Vibrio parahaemolyticus coupled with strain sources and genotypes analyses in different oligotrophic conditions

2021 ◽  
Author(s):  
Jun Shi ◽  
Wei Zhao ◽  
Jing Xie ◽  
Yongheng Zhu ◽  
Yingjie Pan ◽  
...  
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Specific Growth ◽  
Growth Curves ◽  
Gompertz Model ◽  
Growth Variability ◽  
Aquatic Products ◽  
Theoretical Support ◽  
Food Borne ◽  
Modified Gompertz Model

Vibrio parahaemolyticus is an important food-borne pathogen in aquatic products, which can survive long-term in an oligotrophic environment and maintain pathogenicity. In this study, the growth curves of 38 strains of V.parahaemolyticus (pathogenic and environmental strains) under different oligotrophic conditions (tryptone soy broth (TSB), TSB diluted 2, 4, and 6 times medium) were simulated and their growth heterogeneity was compared. The growth kinetic parameters (maximum specific growth rate ( µ max ) and lag time (LT)) were calculated by the modified Gompertz model. The results showed that oligotrophic conditions affected the growth variability of strains, and the coefficient of variation (CV) of all strains reached the maximum in the 4-fold dilution of TSB. Under different oligotrophic conditions, the LT of the pathogenic strains was shorter than that of the environmental strains, while the µ max of the environmental strains was greater. This indicated that pathogenic strains were more adaptable to the nutrient-deficient environment. The analysis of different genotypes revealed that the strains with genotype tlh + /tdh + /trh − showed a greater growth variability in oligotrophic environments. These results provided theoretical support for the accuracy of the risk assessment of aquatic products.

scholarly journals Bioremoval of toxic Molybdenum using dialysis tubing

2016 ◽  
Vol 18 (1) ◽  
pp. 6
Author(s):  
Mohd Shukri Shukor ◽  
Mohd Yunus Shukor
Keyword(s):  
Chemical Engineering ◽  
Gompertz Model ◽  
Maximal Rate ◽  
Dialysis Tubing ◽  
Engineering Research ◽  
Molybdenum Blue ◽  
Rate Of Increase ◽  
Enzymatic Reduction ◽  
Haldane Model ◽  
Modified Gompertz Model

<p>The toxicity of molybdenum to ruminants and its general toxicity to spermatogenesis in animals are increasingly being reported. Its contamination of aquatic bodies has been reported, and this necessitates its removal. In this work, we utilize the dialysis tubing method coupled with the molybdenum-reducing activity of <em>S. marcescens </em>strain Dr.Y6 to remove molybdenum from solution. The enzymatic reduction of molybdenum into the colloidal molybdenum blue traps the reduced product in the dialysis tubing. The initial rate of increase of Mo-blue product was determined using the modified Gompertz model while the resultant inhibition kinetics profile was carried out using the Haldane model. The calculated maximal rate of Mo-blue production was 153 µmole (Mo-blue.hr)<sup>-1</sup> and the concentration of molybdate resulting in the half-maximal rate of reduction (<em>K</em><em>s</em>), and the inhibition constant (<em>K</em><em>i</em>) were 0.22 and 506 mM, respectively. The results indicate that the system using dialysis tubing coupled with the Mo-reducing bacterium is a good candidate for a method for molybdenum bioremoval from solution.</p><p>Chemical Engineering Research Bulletin 18(2015) 6-11</p>

Lactobacillus reuteri β-galactosidase activity and low milk acidification ability

2005 ◽  
Vol 51 (3) ◽  
pp. 261-267 ◽  
Author(s):  
Madeleine Hidalgo-Morales ◽  
Victor Robles-Olvera ◽  
Hugo S García
Keyword(s):  
Lactobacillus Reuteri ◽  
Specific Growth ◽  
Cell Concentration ◽  
Growth Parameters ◽  
Skim Milk ◽  
Nitrogen Sources ◽  
Broth Culture ◽  
Galactosidase Activity ◽  
Carbon And Nitrogen ◽  
Specific Growth Rates

β-galactosidase activity was studied as a possible cause of the low milk acidification ability observed in Lactobacillus reuteri NRRL 14171. Enzymatic activity was determined in MRS broth supplemented with either glucose or lactose and milk at the middle and final stage of the exponential phase, as well as at the stationary phase. Results were compared with β-galactosidase activity in Lactobacillus casei NRRL-B1922, a strain that shows the milk acidification ability. The effects of the types of carbon and nitrogen sources were established by comparison of growth parameters (higher maximum cell concentration and specific growth rate) in broth culture and skim milk supplemented with 2% glucose or 1% casein peptone. In milk, L. reuteri showed higher β-galactosidase activity in all growth phases compared with L. casei. Greater cell concentration maxima, specific growth rates, and acidification abilities were observed in L. reuteri when it was cultured in milk supplemented with 1% casein peptone compared with non-supplemented milk cultures. Results suggest that the poor milk acidification ability observed in L. reuteri may be more related to a weak proteolytic system than to deficient β-galactosidase activity.Key words: Lactobacillus reuteri, growth parameters, β-galactosidase, acidification.

Oscillating conditions for influencing the composition of mixed biological cultures

1998 ◽  
Vol 37 (4-5) ◽  
pp. 259-262 ◽  
Author(s):  
Bjarne R. Horntvedt ◽  
Morten Rambekk ◽  
Rune Bakke
Keyword(s):  
Growth Rate ◽  
Specific Growth ◽  
Heterotrophic Bacteria ◽  
Bacterial Species ◽  
Rate Reduction ◽  
Similar Strategy ◽  
Sinusoidal Oscillations ◽  
Specific Growth Rates ◽  
Rate Limiting ◽  
Concentration Levels

This paper presents a strategy in which mixed biological cultures are exposed to oscillating concentration levels, to improve the potential for coexistence of desired bacterial species. A mechanistic mathematical model is constructed to investigate and illustrate this strategy. This paper is focused on competition between nitrifying, denitrifying and aerobic heterotrophic bacteria in a CSTR with sludge recycle. For nitrifying and aerobic heterotrophic cultures, the effect of sinusoidal oscillations in DO levels with an amplitude of 1.0 mg/l is a 16% specific growth rate reduction compared to that at a constant DO level. The denitrifiers growth rate is increased by an average of 59%, compared to the constant DO level situation. A similar strategy has been tested in a pilot plant. It is concluded that the influence on specific growth rates is a function of the amplitude of the oscillations. The effects are greatest when concentrations fluctuate around the half saturation concentration of the rate limiting component(s).

scholarly journals Batch Anaerobic Co-Digestion and Biochemical Methane Potential Analysis of Goat Manure and Food Waste

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1952
Author(s):  
Ayobami Orangun ◽  
Harjinder Kaur ◽  
Raghava R. Kommalapati
Keyword(s):  
Food Waste ◽  
Gompertz Model ◽  
Water Displacement ◽  
Biochemical Methane Potential ◽  
Greenhouse Gasses ◽  
Nonlinear Regression Models ◽  
The Us ◽  
Methane Potential ◽  
Goat Manure ◽  
Modified Gompertz Model

The improper management of goat manure from concentrated goat feeding operations and food waste leads to the emission of greenhouse gasses and water pollution in the US. The wastes were collected from the International Goat Research Center and a dining facility at Prairie View A&M University. The biochemical methane potential of these two substrates in mono and co-digestion at varied proportions was determined in triplicates and processes were evaluated using two nonlinear regression models. The experiments were conducted at 36 ± 1 °C with an inoculum to substrate ratio of 2.0. The biomethane was measured by water displacement method (pH 10:30), absorbing carbon dioxide. The cumulative yields in goat manure and food waste mono-digestions were 169.7 and 206.0 mL/gVS, respectively. Among co-digestion, 60% goat manure achieved the highest biomethane yields of 380.5 mL/gVS. The biodegradabilities of 33.5 and 65.7% were observed in goat manure and food waste mono-digestions, while 97.4% were observed in the co-digestion having 60% goat manure. The modified Gompertz model is an excellent fit in simulating the anaerobic digestion of food waste and goat manure substrates. These findings provide useful insights into the co-digestion of these substrates.

scholarly journals Optimizing anaerobic co-digestion of goat manure and cotton gin trash using biochemical methane potential (BMP) test and mathematical modeling

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Harjinder Kaur ◽  
Raghava R. Kommalapati
Keyword(s):  
Liquid Fraction ◽  
Gompertz Model ◽  
Biochemical Methane Potential ◽  
Methane Potential ◽  
Mathematical Equations ◽  
Goat Manure ◽  
Bmp Test ◽  
Batch Bioreactors ◽  
Modified Gompertz Model ◽  
Cotton Gin

AbstractAnaerobic co-digestion is widely adopted to enhance process efficacy by balancing the C/N ratio of the feedstock while converting organic wastes to biomethane. Goat manure (GM) and cotton gin trash (CGT) were anaerobically co-digested in triplicate batch bioreactors. The process was optimized and evaluated utilizing mathematical equations. The liquid fraction of the digestate was analyzed for nitrate and phosphate. The co-digestions with 10 and 20% CGT having the C/N ratios of 17.7 and 19.8 yielded the highest and statistically similar 261.4 ± 4.8 and 262.6 ± 4.2 mL/gvs biomethane, respectively. The biodegradability (BD) of GM and CGT was 94.5 ± 2.7 and 37.6 ± 0.8%, respectively. The BD decreased proportionally with an increase in CGT percentage. The co-digestion having 10% CGT yielded 80–90% of biomethane in 26–39 d. The modified Gompertz model-predicted and experimental biomethane values were similar. The highest synergistic effect index of 15.6 ± 4.7% was observed in GM/CGT; 30:70 co-digestion. The concentration of nitrate and phosphate was lower in the liquid fraction of digestate than the feedstocks, indicating that these nutrients stay in the solid fraction. The results provide important insights in agro-waste management, further studies determining the effects of effluent application on plants need to be conducted.

scholarly journals Effect of Co-Inoculation of Bacillus sp. Strain with Bacterial Endophytes on Plant Growth and Colonization in Tomato Plant (Solanum lycopersicum)

2021 ◽  
Vol 12 (2) ◽  
pp. 480-490
Author(s):  
Ahsanul Salehin ◽  
Ramesh Raj Puri ◽  
Md Hafizur Rahman Hafiz ◽  
Kazuhito Itoh
Keyword(s):  
Plant Growth ◽  
Solanum Lycopersicum ◽  
Plant Growth Promotion ◽  
Tomato Plant ◽  
Growth Promotion ◽  
Growth Parameters ◽  
The Other ◽  
Time Interval ◽  
Bacillus Sp ◽  
F 33

Colonization of a biofertilizer Bacillus sp. OYK strain, which was isolated from a soil, was compared with three rhizospheric and endophytic Bacillus sp. strains to evaluate the colonization potential of the Bacillus sp. strains with a different origin. Surface-sterilized seeds of tomato (Solanum lycopersicum L. cv. Chika) were sown in the sterilized vermiculite, and four Bacillus sp. strains were each inoculated onto the seed zone. After cultivation in a phytotron, plant growth parameters and populations of the inoculants in the root, shoot, and rhizosphere were determined. In addition, effects of co-inoculation and time interval inoculation of Bacillus sp. F-33 with the other endophytes were examined. All Bacillus sp. strains promoted plant growth except for Bacillus sp. RF-37, and populations of the rhizospheric and endophytic Bacillus sp. strains were 1.4–2.8 orders higher in the tomato plant than that of Bacillus sp. OYK. The plant growth promotion by Bacillus sp. F-33 was reduced by co-inoculation with the other endophytic strains: Klebsiella sp. Sal 1, Enterobacter sp. Sal 3, and Herbaspirillum sp. Sal 6., though the population of Bacillus sp. F-33 maintained or slightly decreased. When Klebsiella sp. Sal 1 was inoculated after Bacillus sp. F-33, the plant growth-promoting effects by Bacillus sp. F-33 were reduced without a reduction of its population, while when Bacillus sp. F-33 was inoculated after Klebsiella sp. Sal 1, the effects were increased in spite of the reduction of its population. Klebsiella sp. Sal 1 colonized dominantly under both conditions. The higher population of rhizospheric and endophytic Bacillus sp. in the plant suggests the importance of the origin of the strains for their colonization. The plant growth promotion and colonization potentials were independently affected by the co-existing microorganisms.

Effects of turbidity on prey consumption and growth in brook trout and implications for bioenergetics modeling

2001 ◽  
Vol 58 (2) ◽  
pp. 386-393 ◽  
Author(s):  
John A Sweka ◽  
Kyle J Hartman
Keyword(s):  
Growth Rates ◽  
Brook Trout ◽  
Specific Growth ◽  
Abiotic Factors ◽  
Foraging Strategies ◽  
Turbid Water ◽  
Daily Consumption ◽  
Consumption Rates ◽  
The Difference ◽  
Specific Growth Rates

Brook trout (Salvelinus fontinalis) were held in an artificial stream to observe the influence of turbidity on mean daily consumption and specific growth rates. Treatment turbidity levels ranged from clear (<3.0 nephelometric turbidity units (NTU)) to very turbid water (> 40 NTU). Observed mean daily specific consumption rates were standardized to the mean weight of all brook trout tested. Turbidity had no significant effect on mean daily consumption, but specific growth rates decreased significantly as turbidity increased. Brook trout in turbid water became more active and switched foraging strategies from drift feeding to active searching. This switch was energetically costly and resulted in lower specific growth rates in turbid water as compared with clear water. Bioenergetics simulations were run to compare observed growth with that predicted by the model. Observed growth values fell below those predicted by the model and the difference increased as turbidity increased. Abiotic factors, such as turbidity, which bring about changes in the activity rates of fish, can have implications for the accuracy of predicted growth by bioenergetics models.

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