Explanation on the industrial production of penicillin covering the history, fermentors, specific conditions required for penicillin production, how to increase yield amongst others.
Folding depends upon sequence of Amino Acids not the Composition. Folding starts with the secondary structure and ends at quaternary structure.
Denaturation occur at secondary, tertiary & quaternary level but not at primary level.
Explanation on the industrial production of penicillin covering the history, fermentors, specific conditions required for penicillin production, how to increase yield amongst others.
Folding depends upon sequence of Amino Acids not the Composition. Folding starts with the secondary structure and ends at quaternary structure.
Denaturation occur at secondary, tertiary & quaternary level but not at primary level.
MICROBIAL STRESS RESPONSE REGULATORY ENZYME AND THEIR PHARMACEUTICAL APPLICATIONEDITOR IJCRCPS
Ability of adaptation according to variable environmental conditions is essential for bacterial surveillance; those don’t have ability to
face the challenge is eliminated. To counter the damaging effect of reactive oxygen species, cells have evolved anti-oxidant
defense systems, whose expression is usually induced by reactive oxygen species and/or oxidants. Bacteria survive in several
kind of environmental stress condition due to alteration in cell membrane and genetic material by fatal enzyme. Other inducers of
the general stress response might also cause transient genetic instability and so promote bacterial adaptation to stressful
environments. Regulatory mechanisms which help bacteria to maintain their balanced and rather constant cellular composition
mostly occur at the genetic level. Many studies clarified the efficacy of stress enzyme as a therapy in the treatment of many
diseases, in addition to their inclusion in cosmetic products to reduce free radical damage to skin.
Keywords: Bacterial response, Environmental stress and regulatory enzyme.
Introduction :
Antibiotics are antimicrobial agents produced naturally by other microbes (usually fungi or bacteria)
The first antibiotic was discovered in 1896 by Ernest Duchesne and in 1928 "rediscovered" by Alexander Fleming from the filamentous fungus Penicilium notatum.
The antibiotic substance, named penicillin, was not purified until the 1940s (by Florey and Chain), just in time to be used at the end of the second world war.
Penicillin was the first important commercial product produced by an aerobic, submerged fermentation
the ionophores are the a part of membrane transport system. these slides include general concept of ionophores. useful for the paramedical, medical students.
Methods to detect potability of water samplevimala rodhe
Water is precious and it is the base for living, Several disease causing pathogens are transmitted through water. There are various methods to detect the presence of pathogens in drinking water samples.Some of the methods to detect microbiological quality of water are discussed.
This presentation explains the concept of the use of Single Cell protein as an alternative food source. It lists the source, production, advantages and disadvantages of the SCP.
Here is brief ppt on industrial production of amino acids - glutamine, lysine, tryptophan.
Please share your feedback and queries. Constructive criticism is appreciated.
Thank you
Analyzing Fusion Genes Using Next-Generation SequencingQIAGEN
Fusion genes are hybrid genes formed by the fusion of two separate genes. Translocation, interstitial deletion and chromosomal inversions are some of the genetic events that can lead to the formation of fusion genes. The occurrence of fusion genes and its implications in cancer have already been known, but the emergence of NGS technology – especially RNA sequencing – offers the potential to detect novel gene fusions. You can learn more about fusion genes and applying NGS to detect them at our upcoming webinar, presented by Raed Samara, Ph.D., QIAGEN’s Global Product Manager for NGS technologies.
In this webinar, Dr. Raed Samara will cover:
1. Fusion genes: what they are and a historical perspective
2. Fusion gene detection: the current status
3. RNA sequencing vs. digital RNA sequencing
4. How to detect and accurately quantify novel fusion genes in your sample
MICROBIAL STRESS RESPONSE REGULATORY ENZYME AND THEIR PHARMACEUTICAL APPLICATIONEDITOR IJCRCPS
Ability of adaptation according to variable environmental conditions is essential for bacterial surveillance; those don’t have ability to
face the challenge is eliminated. To counter the damaging effect of reactive oxygen species, cells have evolved anti-oxidant
defense systems, whose expression is usually induced by reactive oxygen species and/or oxidants. Bacteria survive in several
kind of environmental stress condition due to alteration in cell membrane and genetic material by fatal enzyme. Other inducers of
the general stress response might also cause transient genetic instability and so promote bacterial adaptation to stressful
environments. Regulatory mechanisms which help bacteria to maintain their balanced and rather constant cellular composition
mostly occur at the genetic level. Many studies clarified the efficacy of stress enzyme as a therapy in the treatment of many
diseases, in addition to their inclusion in cosmetic products to reduce free radical damage to skin.
Keywords: Bacterial response, Environmental stress and regulatory enzyme.
Introduction :
Antibiotics are antimicrobial agents produced naturally by other microbes (usually fungi or bacteria)
The first antibiotic was discovered in 1896 by Ernest Duchesne and in 1928 "rediscovered" by Alexander Fleming from the filamentous fungus Penicilium notatum.
The antibiotic substance, named penicillin, was not purified until the 1940s (by Florey and Chain), just in time to be used at the end of the second world war.
Penicillin was the first important commercial product produced by an aerobic, submerged fermentation
the ionophores are the a part of membrane transport system. these slides include general concept of ionophores. useful for the paramedical, medical students.
Methods to detect potability of water samplevimala rodhe
Water is precious and it is the base for living, Several disease causing pathogens are transmitted through water. There are various methods to detect the presence of pathogens in drinking water samples.Some of the methods to detect microbiological quality of water are discussed.
This presentation explains the concept of the use of Single Cell protein as an alternative food source. It lists the source, production, advantages and disadvantages of the SCP.
Here is brief ppt on industrial production of amino acids - glutamine, lysine, tryptophan.
Please share your feedback and queries. Constructive criticism is appreciated.
Thank you
Analyzing Fusion Genes Using Next-Generation SequencingQIAGEN
Fusion genes are hybrid genes formed by the fusion of two separate genes. Translocation, interstitial deletion and chromosomal inversions are some of the genetic events that can lead to the formation of fusion genes. The occurrence of fusion genes and its implications in cancer have already been known, but the emergence of NGS technology – especially RNA sequencing – offers the potential to detect novel gene fusions. You can learn more about fusion genes and applying NGS to detect them at our upcoming webinar, presented by Raed Samara, Ph.D., QIAGEN’s Global Product Manager for NGS technologies.
In this webinar, Dr. Raed Samara will cover:
1. Fusion genes: what they are and a historical perspective
2. Fusion gene detection: the current status
3. RNA sequencing vs. digital RNA sequencing
4. How to detect and accurately quantify novel fusion genes in your sample
The availability of affordable, high quality, custom gene synthesis has greatly expanded what is possible for labs in numerous research areas. IDT offers a variety of gene synthesis solutions, including our revolutionary double-stranded gBlocks Gene Fragments. In this presentation, Dr Adam Clore discusses the many applications of gBlocks Gene Fragments, such as controls for qPCR and next generation sequencing, and donor templates for homology directed repair in CRISPR experiments. Learn more at www.idtdna.com/gblocks
this presentation discuses:
Mechanism of microbial death;
The concepts of D,Z and F values and their relationship;
How D-value, Z-value and F-value be determined;
The difference between clock time and thermal death time/F value;
How minimum Fo value and lethal rate can be determined.
Sterilization: F0 - what it means - how to calculate it - how to use itFedegari Group
F0: A technical note
- What it means
- How to calculate it
- How to use it for adjustment, control and
validation of moist-heat sterilization processes
ER Publication,
IJETR, IJMCTR,
Journals,
International Journals,
High Impact Journals,
Monthly Journal,
Good quality Journals,
Research,
Research Papers,
Research Article,
Free Journals, Open access Journals,
erpublication.org,
Engineering Journal,
Science Journals,
Fermentation technology, Bioprocess Principles, History of Industrial Biotechnology, Bioreactor Principles, Bioreactor Design, Parameters to be monitored in Bioreactor, Fermentation Technology, Agitation and Mixing, Baffles
"Impact of front-end architecture on development cost", Viktor TurskyiFwdays
I have heard many times that architecture is not important for the front-end. Also, many times I have seen how developers implement features on the front-end just following the standard rules for a framework and think that this is enough to successfully launch the project, and then the project fails. How to prevent this and what approach to choose? I have launched dozens of complex projects and during the talk we will analyze which approaches have worked for me and which have not.
Let's dive deeper into the world of ODC! Ricardo Alves (OutSystems) will join us to tell all about the new Data Fabric. After that, Sezen de Bruijn (OutSystems) will get into the details on how to best design a sturdy architecture within ODC.
JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
To view the webinar recording, go to:
https://www.rttsweb.com/jmeter-integration-webinar
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
UiPath Test Automation using UiPath Test Suite series, part 3DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 3. In this session, we will cover desktop automation along with UI automation.
Topics covered:
UI automation Introduction,
UI automation Sample
Desktop automation flow
Pradeep Chinnala, Senior Consultant Automation Developer @WonderBotz and UiPath MVP
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Search and Society: Reimagining Information Access for Radical FuturesBhaskar Mitra
The field of Information retrieval (IR) is currently undergoing a transformative shift, at least partly due to the emerging applications of generative AI to information access. In this talk, we will deliberate on the sociotechnical implications of generative AI for information access. We will argue that there is both a critical necessity and an exciting opportunity for the IR community to re-center our research agendas on societal needs while dismantling the artificial separation between the work on fairness, accountability, transparency, and ethics in IR and the rest of IR research. Instead of adopting a reactionary strategy of trying to mitigate potential social harms from emerging technologies, the community should aim to proactively set the research agenda for the kinds of systems we should build inspired by diverse explicitly stated sociotechnical imaginaries. The sociotechnical imaginaries that underpin the design and development of information access technologies needs to be explicitly articulated, and we need to develop theories of change in context of these diverse perspectives. Our guiding future imaginaries must be informed by other academic fields, such as democratic theory and critical theory, and should be co-developed with social science scholars, legal scholars, civil rights and social justice activists, and artists, among others.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...
Media Sterilisation
1. If the fermentation is contaminated
1. The medium would have to support the growth of
both producer and contaminant organism resulting
in loss of productivity.
2. In case of continuous cultivation the contaminant
may outgrow the producer organism.
3. In case of biomass as product, the contaminant will
result in total loss of product.
4. The contaminant may produce compounds, which
make downstream processing difficult.
5. The contaminant may degrade the product; this is
common in antibiotics fermentation eg. β
Lactamase producing organism degrade β-Lactum
antibiotics.
6. Contaminant with phage could result in the lysis of
culture.
2. For avoiding contamination
1. Use pure inoculum to start the
fermentation
2. Sterilizing the medium to be employed
3. Sterilizing the fermenter
4. Sterilizing all materials to be added
during fermentation
5. Maintaining the aseptic condition
during fermentation
3. Some fermentations are described as protected i.e
the medium may not be utilised by the other
organisms or the extreme pH are used for
cultivation etc.,
Brewing of Beer falls into this category i.e Hop
resins used as the supplement in the medium
inhibit growth of most of the organism.
In such case of fermentations the medium can be
boiled ,the reactors can be cleaned with
disinfectants before fermentation not
necessarily sterilized.
But most of the fermentation are not protected
5. Many cellular materials absorb ultraviolet light, leading
to DNA damage and consequently to cell death.
Wavelengths around 265 nm have the highest bacterial
efficiency.
However they have very little ability to penetrate. Use
is limited to clean chambers, operation theatre etc.,
X-rays are lethal and have penetration ability. However
due to expensive and safety concerns it is not used
RadiationRadiation
6. Chemical agents are frequently used for disinfection.
Major antimicrobial chemical agents are :
phenol and compounds (phenol, cresol, orthophenylphenol)
alcohol (ethyl,methyl)
halogens (iodine, hypochlorites, chloramines)
detergents,acids, alkali,
gaseous chemosterlizers (ethylene oxide, formaldehyde)
Chemical SterilizationChemical Sterilization
7. Destruction of microorganisms by steam is
represented by first order reaction
-dN/dt = kN ------------[1]
Where N no of viable organisms present
t sterlization treatment time
k rate constant or Sp. Death rate
It is important to note that we are considering the
number of organisms and not the concentration –
the minimum number of organism required to
contaminate the batch is one regardless of the
volume
8. Rearranging the eqn [1]
-dN/N = kdt
Upon Integration
ln (Nt/No) = - kt-------[2]
Nt/No = e-kt
------------[3]
Nt = No of organisms present after sterlization
No = No of organisms present before sterlization
9. o
t
N
N
Time Time
o
t
N
N
ln
Nt/No = e-kt
An infinite time is required to achieve sterile
condition i.e Nt=0
After certain period there will be less than
one viable cell present i.e Nt<1
ln (Nt/No) = - kt
10. Nt<1 is the probability of an organism
surviving the treatment
i.e Nt=0.1 is the probability that one organism
surviving ten treatments.
In other words one in ten batches may get
contaminated due to improper sterlization.
The value of k dependant on temperature,
species and its physiological form.
But your sterlization media contains mixture
of microorganism.
13. As in any first order, The reaction rate
increases with increase in temperature i.e k
increases with increase in temperature.
This relation ship is given by Arrhenius eqn
E activation energy
R gas constant
T absolute temperature
A Arrhenius constant
RTE
Aek /−
= [4]
14. Taking logarithm of eqn 4
[5]
Plot of ln k Vs 1/T will give a straight line
1/T
Ln k
Intercept = ln A
Slope = -E/R
15. RTE
to etANN −
⋅⋅=ln
to NNln=∇
RTE
etA −
⋅⋅=∇
Combining eqn 2 and 4
[5]
Del factor is the sterilization criterion
( )ARTEt ∇+= lnln
16. Thus it is evident from the eqn that the
temperature and time are inversely proportional
and same degree of sterilization can be achieved
by varying time and temperature.
Also we have seen that the sterlization criterion
depend mainly on heat resistant organism.
Bacillus stereothermophilus is the known most
heat resistant organism
Assume all the contaminants are B.st and
calculate the temperature and time.
E=67.7 kcal/mole
A=1 X 1036.2
1/sec
Industrially accepted level of contamination is
0.001. i.e 1 in 1000 batches can get
contaminated.
17. Another common factor used in food industry is
decimal reduction time D. It is the time required
to reduce the cell population by 10 fold.
D=2.303/k
Decimal reduction timeDecimal reduction time
19. Step 1
Plot ln No/Nt Vs Time for each temperature and find out
the slope. Slope will give k value.
Step 2
Plot ln k Vs 1/T from the above values. Slope will give
E/R values and Intercept will give you the A value
Step 3
From the above graph calculate the k value for 100 o
C
Step 4
From the k value calculate time required to kill 99%
spores
ktNN to =ln
23. E/R = 26869 o
K
R = 8.3144 J/K/gmol
E = 26869 X 8.3144 = 2.24 X 105
J/gmol=224 KJ/gmol
A =4.7 X 1030
min-1
kd= 4.7 X 1030
e-26869/T
T=100 +273 =373 o
K
kd=0.244 min-1
Ln(100/1)=0.244 t
t=18.9 min
ktNN to =ln
24. Batch sterilization
Sterilization of the medium in a fermenter can
be carried out in batch mode by direct steam
sparging, by electrical heaters or by
circulating constant pressure condensing
steam through heating coil or jacket.
Cooling the medium is carried out by
sparging the steam through the cooling coil or
jacket.
27. Heating CurveHeating Curve RTE
etA −
⋅⋅=∇
1
11
RTE
etA −
⋅⋅=∇
2
22
RTE
etA −
⋅⋅=∇
3
33
RTE
etA −
⋅⋅=∇
TimeTime
TemperatureTemperature
t1 t2 t3
T3
T2
T1
•••+∇+∇+∇=∇ 321heating
28. The initial number of contaminants is 1014
and the decimal reduction value at 121o
C is
1.5 min. Calculate the time required to
bring down the contaminants to industrially
acceptable limits.
ProblemProblem
29. D is the time required to reduce the
contaminants by 10 fold.
Del value is 1017
Time required = 17 X D = 17 X 1.5
Time required = 25.5 min
30. The initial concentration of
contaminants is 106
per ml and the
fermenter volume is 10000 litres. The
del factor contribution from heating is
9.8 and that of cooling is 10.1. Calculate
the holdup time assuming all the
contaminants are B.st having kd value at
121o
C of 2.54 min-1
ProblemProblem
32. An autoclave is used for sterilizing 10 litre complex
medium containing 105
spores/ml. Due to the problem
in autoclave the temperature reached only 110o
C. If
same holdup time of 20 min is maintained what is the
probability of contamination. Compare that with of
regular autoclaving at 121o
C.
ProblemProblem
E=2.83 X 105
J/gmol
A=1036.2
sec-1
R = 8.3144 J/K/gmol
38. Batch sterlization is carriedout in 1 litre fermenter to
prevent contamination. The initial no of spores in
the medium is 1010
spores/litre.
a) Calculate the holding time required to achieve
standard contamination levels neglecting heating
and cooling periods.
b) What is the probability of contamination if a 100
litre fermenter is heated for the same time.
c) Redo the calculation for part (a) assuming constant
temperature steam heating and constant
temperature cooling. Heat exchange coils are used.
For steam heating α and β are 0.05 sec-1
and -0.25
and that of cooling 0.065 sec-1
and 0.20. The heating
and cooling periods are 3 min and 10 min
respectively.
d) Redo the calculation for part (a) using the
temperature profile
41. A steam sterilizer is used to sterilize
liquid medium for fermentation. The
initial concentration of contaminants is
108
per litre. How long 1 m3
medium be
treated if the temperature is 80o
C,
121o
C, 140o
C
Assume all the contaminants are B.st.
E=283 KJ/gmol
A=1036.2
sec-1
R = 8.3144 J/K/gmol
ProblemProblem
42. RTE
etA −
⋅⋅=∇
E=2.83 X 105
J/gmol
A=1036.2
sec-1
R = 8.3144 J/K/gmol
No=1011
Nt=0.001
Ln(No/Nt)=34.54
-E/R=-3.4X104 o
K
T -E/RT exp(-E/RT) A*exp(-E/RT)
time
(min)
353 -9.64E+01 1.33047E-42 2.10866E-06 272991.8
394 -8.64E+01 3.03152E-38 0.048046344 11.98106
413 -8.24E+01 1.61319E-36 2.556734665 0.225149
43. It is evident from theIt is evident from the
problem that a regime ofproblem that a regime of
time and temperature maytime and temperature may
now be determined tonow be determined to
achieve the desiredachieve the desired
sterilization.sterilization.
However the fermentationHowever the fermentation
media is not an inertmedia is not an inert
mixture.mixture.
Due to sterilizationDue to sterilization
deleterious reactions maydeleterious reactions may
occur resulting in loss ofoccur resulting in loss of
nutrient qualitynutrient quality
Duration of sterilizationProductyield
44. Loss of nutrient quality is due to two reasons
i) Interactions between nutrient components of the
medium
Maillard type browning reaction – reactions of the
carbonyl group usually from reducing sugar with the
amino group of aminoacids, proteins.
Effect of sterilization time on availability of glucose
in CSL medium was investigated
Time Glucose remaining
60 min 35%
40 min 46%
30 min 64%
Problems of this type are normally resolved by
sterilizing sugar separately and adding to the medium
45. II. Degradation of heat labile components
Certain vitamins, amino acids and proteins may be
degraded during sterilization regime
In certain cases such as animal cell culture media
filtration is used
In other cases judicious choice of sterilization regime is
selected.
Nutrient destruction follows first order reaction
Activation energy for nutrient destruction
– 10 to 30 kcal/mole
Activation energy for B.st – 67.7 kcal/mole
kt
o
t e
x
x −
=
46. Lnk
1/T
Spores destruction
Nutrient destruction
From the graph it isFrom the graph it is
evident that sterilizingevident that sterilizing
the medium at higherthe medium at higher
temperature for lessertemperature for lesser
time will result in sporestime will result in spores
destruction with lesserdestruction with lesser
loss in nutrient quality.loss in nutrient quality.
Heating the huge reactorsHeating the huge reactors
for higher temperaturefor higher temperature
and cooling down in shortand cooling down in short
duration is impossibleduration is impossible
Alternately continuousAlternately continuous
sterilizer can be usedsterilizer can be used
47. Advantages of continuousAdvantages of continuous
sterilizationsterilization
Superior maintenance ofSuperior maintenance of
medium qualitymedium quality
Ease of scale upEase of scale up
Easier automatic controlEasier automatic control
Reduction in fermenterReduction in fermenter
corrosioncorrosion
Advantages of BatchAdvantages of Batch
sterilizationsterilization
Lower capitalLower capital
equipment costequipment cost
Lower risk ofLower risk of
contaminationcontamination
Easier to use withEasier to use with
media containing solidmedia containing solid
suspended matter.suspended matter.
48.
49.
50. Performance ofPerformance of
continuous sterilizercontinuous sterilizer
depends on the nature ofdepends on the nature of
fluid flow in the systemfluid flow in the system
Plug flow is an ideal flowPlug flow is an ideal flow
where no mixing orwhere no mixing or
change in velocity occurchange in velocity occur
Deviation from plug flowDeviation from plug flow
is characterized by axialis characterized by axial
dispersion the degree todispersion the degree to
which mixing occurswhich mixing occurs
along the length of thealong the length of the
pipe.pipe.
Axial dispersion is theAxial dispersion is the
critical factor in designcritical factor in design
of continuous sterilizer.of continuous sterilizer.
51.
52. Axial dispersion and flow through the pipe isAxial dispersion and flow through the pipe is
characterized by dimensionless variable PECLETcharacterized by dimensionless variable PECLET
NumberNumber
u – linear velocityu – linear velocity
L- Length of the pipeL- Length of the pipe
DDzz- axial dispersion- axial dispersion
For perfect plug flow axial dispersion is zero and NFor perfect plug flow axial dispersion is zero and NPePe isis
infiniteinfinite
NNPePe between 3 – 600 is typical.between 3 – 600 is typical.
Once the NOnce the NPePe is known the extent of cell destruction andis known the extent of cell destruction and
another dimension less variable Damkohler number cananother dimension less variable Damkohler number can
be calculatedbe calculated
kkdd- specific death rate- specific death rate
zD
uL
Pe =
u
Lk
Da d
=
53.
54.
55. Soln to Problem 1
N1= 1.44 X 1016
N2/N1=6.9X 10 -17
u= 254.6m/h
Re=7.07X103
58. Damkholer number for Pe 368 and N2/N1 6.9 X 10 -17
is
42 (From graph)
k=445.6 1/h
T=-(E/R)/ln(k/A)
T=398.4 K
59.
60. For perfect plug flow Dz is zero.
Hence Pe number is infinity.
Dilution rate = Feed rate/reactor volume
For first part calculate Nt/No.
From the graph for this Nt/No value and Pe infinity
calculate the Da Number.
Calculate Kd with the given value of Arrhenius
constant, activation energy and temperature 130o
C
Calculate velocity u from the feed rate and diameter
of the steriliser.
Length of the sterliser holding section can be
calculated from the above.
61.
62. Second part:
Calculate NRe.
From the graph calculate Dz/uD
Calculate Dz
Calculate Pe number using the length
calculated in the first part.
Now using the Pe number and Nt/No value
calculate Da number.
From this calculate length.
63.
64.
65. For third part
Using the length of perfect plug flow calculate
Da number.
For this Da number and Peclet number
calculated in the second part, Calculate Nt/No
value from the graph.
From this calculate No and find the
contamination rate . i.e 1 organism in how
many days.
66.
67. A continuous steirliser with a steam injector and a flash cooler will beA continuous steirliser with a steam injector and a flash cooler will be
employed to sterlize medium continuously with the flow rate of 2 memployed to sterlize medium continuously with the flow rate of 2 m33
/h. The/h. The
time for heating and cooling is negligible with this type of steriliser. Thetime for heating and cooling is negligible with this type of steriliser. The
typical bacterial count of the medium is about 5 X 10typical bacterial count of the medium is about 5 X 101212
mm-3-3
, which needs to be, which needs to be
reduced to such an extent that only one organism can survive during tworeduced to such an extent that only one organism can survive during two
months of operation. The heat reesistant bacterial spores in the mediummonths of operation. The heat reesistant bacterial spores in the medium
can be characterized by A of 5.7 X 10can be characterized by A of 5.7 X 103939
1/h and E of 2.834X101/h and E of 2.834X1055
KJ/Kmol. TheKJ/Kmol. The
steriliser will be constructed with the pipe with an inner diameter of 0.102m.steriliser will be constructed with the pipe with an inner diameter of 0.102m.
Steam is available at a temperature of 125Steam is available at a temperature of 125oo
C. The physical properties of theC. The physical properties of the
medium aremedium are ρρ=1000kg/m=1000kg/m33
andand μμ=4 Kg/m/h R=8.3144 J/K/g mol=4 Kg/m/h R=8.3144 J/K/g mol
What length should the pipe be in the sterliser if you assume ideal plugWhat length should the pipe be in the sterliser if you assume ideal plug
flowflow
What length should the pipe be in the sterliser if the effect of axialWhat length should the pipe be in the sterliser if the effect of axial
dispersion is considered.dispersion is considered.
68. The following equations can be used for the
design:
Dz/uD=2 X 107
(NRe) -1.951
for NRe < 10000
Dz/uD=1.6317(NRe) –0.1505
for NRe > 10000
ln(Nt/No)= -Da + (Da2
/Pe)
Solution to ax2
+bx+c=0 is
a
acbb
x
2
42
−±−
=
69. C.s.area 0.008174571 sq.m
Vol. flow rate 2 cu.m/h
Velocity 244.6611443 m/h
Dia 0.102 m
density 1000 Kg/cu.m
Viscosity 4 Kg/m/h
Reynolds no 6238.85918
Dz/UD 0.788460214
Dz 19.67636897 sq.m/h
70. Nt 1
No 1.44E+16
Nt/No 6.94444E-17
ln(Nt/No) -37.2060046
A 5E+39 1/h
E 283400 J/gmol
R 8.3144 J/K/gmol
T 398 K
K 320.0387736 1/h
71. Peclet infinity
Da=KL/U 37.2
L=DaU/K 28.43841221 m
Peclet=UL/Dz 353.6106933
a 1
b -353.61
c 13156.41529
Da 42.25540789
L=DaU/K 32.3031373 m
72. Filter sterilizationFilter sterilization
Suspended solids may be separated from aSuspended solids may be separated from a
fluid during sterilization by the followingfluid during sterilization by the following
mechanismsmechanisms
1.1. Inertial ImpactionInertial Impaction
2.2. DiffusionDiffusion
3.3. Electrostatic attractionElectrostatic attraction
4.4. InterceptionInterception
73. Inertial ImpactionInertial Impaction
The fluid will tend to move through the leastThe fluid will tend to move through the least
resistance path during filtration.resistance path during filtration.
Suspended particles in the fluid stream haveSuspended particles in the fluid stream have
momentum.momentum.
Due to this they tend to move straight andDue to this they tend to move straight and
therefore impact on the filtration fibres wheretherefore impact on the filtration fibres where
they may be retained.they may be retained.
This mechanism is more prominent in filtration ofThis mechanism is more prominent in filtration of
gases than liquids.gases than liquids.
74. DiffusionDiffusion
Extremely small particles suspended in the fluidExtremely small particles suspended in the fluid
are subjected to Brownian movement which isare subjected to Brownian movement which is
random movement due to collision of particles.random movement due to collision of particles.
Thus due to this the fluid particles deviate fromThus due to this the fluid particles deviate from
the path of movement and impact on the filterthe path of movement and impact on the filter
fibres.fibres.
Diffusion is more significant in the filtration ofDiffusion is more significant in the filtration of
gases than liquids.gases than liquids.
75. Electrostatic attractionElectrostatic attraction
Charged particles are attracted byCharged particles are attracted by
opposite charges on the surface of theopposite charges on the surface of the
filtration mediumfiltration medium
76. InterceptionInterception
The fibres comprising filter are interwoven to definite openingThe fibres comprising filter are interwoven to definite opening
of different sizes eg: 0.22 µm etc.,of different sizes eg: 0.22 µm etc.,
Particles which are larger than these pore sizes are removed byParticles which are larger than these pore sizes are removed by
direct interception.direct interception.
Also significant number of smaller size particles are alsoAlso significant number of smaller size particles are also
retained due to:retained due to:
More than one particle arriving at a time to the pore.More than one particle arriving at a time to the pore.
An irregularly shaped particle may bridge the pore.An irregularly shaped particle may bridge the pore.
Interception is the equally important mechanism in both liquidsInterception is the equally important mechanism in both liquids
and gases.and gases.
77. Filters are classified into two typesFilters are classified into two types
Depth filter Or Non fixed pore filterDepth filter Or Non fixed pore filter
In depth filter the pore sizes are larger than theIn depth filter the pore sizes are larger than the
particle to be removedparticle to be removed
In these filters particles are removed more byIn these filters particles are removed more by
impaction, diffusion and electrostatic attractionimpaction, diffusion and electrostatic attraction
rather than interceptionrather than interception
Absolute filter Or Fixed pore filterAbsolute filter Or Fixed pore filter
In this the pore sizes are smaller than the particle toIn this the pore sizes are smaller than the particle to
be removed.be removed.
Particles are removed by interception.Particles are removed by interception.
78. In depth filters the removal of microorganism is aIn depth filters the removal of microorganism is a
probability and it cannot be absolute.probability and it cannot be absolute.
Thus always there is probability that microorganismThus always there is probability that microorganism
can pass through the filter immaterial of the depth ofcan pass through the filter immaterial of the depth of
the filter.the filter.
Fibres are just tightly packed and not fixed in the filter.Fibres are just tightly packed and not fixed in the filter.
Hence due to larger pressure movement of materialHence due to larger pressure movement of material
and creation of larger channels is possible.and creation of larger channels is possible.
Also increased pressure may sometime remove theAlso increased pressure may sometime remove the
previously trapped particles.previously trapped particles.
79. Filter sterilization of mediumFilter sterilization of medium
During Animal cell culture media filtration followingDuring Animal cell culture media filtration following
precautions have to be taken.precautions have to be taken.
Filtered medium should be free of fungal,Filtered medium should be free of fungal,
bacterial and mycoplasma contamination.bacterial and mycoplasma contamination.
Minimal adsorption of the proteins from theMinimal adsorption of the proteins from the
medium during filtrationmedium during filtration
Medium should be free of viruses andMedium should be free of viruses and
endotoxins.endotoxins.
80. Absolute filters are used.Absolute filters are used.
Pressure drop in these filters are high hence thePressure drop in these filters are high hence the
pleated structure membranes are used.pleated structure membranes are used.
Pore sizes of these membranes are well controlledPore sizes of these membranes are well controlled
during manufacture.during manufacture.
To extend the life of the filter prefilters of bigger poreTo extend the life of the filter prefilters of bigger pore
sizes are used.sizes are used.
Generally polypropylene or nylon membranes are usedGenerally polypropylene or nylon membranes are used
Filter should be steam sterilizable in between batches.Filter should be steam sterilizable in between batches.
81. Filter sterilization of airFilter sterilization of air
For aerobic fermentations air needs to be supplied continuously.For aerobic fermentations air needs to be supplied continuously.
Typical aeration rates are 0.5 to 2 vvm.Typical aeration rates are 0.5 to 2 vvm.
This requires continuous and large amount of air free of microbialThis requires continuous and large amount of air free of microbial
contaminants.contaminants.
Sterilization of air by means of heat is economically not viable.Sterilization of air by means of heat is economically not viable.
Most effective technique is filtration by fibrous or membrane filtersMost effective technique is filtration by fibrous or membrane filters
The cotton plug used as closure for flasks during cultivation is good exampleThe cotton plug used as closure for flasks during cultivation is good example
of fibrous filter.of fibrous filter.
Simple air filter can be made by packing cotton in the tube.Simple air filter can be made by packing cotton in the tube.
However the pressure drop is huge and wet cotton may become source forHowever the pressure drop is huge and wet cotton may become source for
contamination.contamination.
Therefore glass wool is favourable filtration medium.Therefore glass wool is favourable filtration medium.
In the case of absolute filters the filter should be hydrophobic (PTFEIn the case of absolute filters the filter should be hydrophobic (PTFE
membranes).membranes).
83. Theory of Depth filters
To reduce the population entering into the filter and exiting out,
Expression given as,
dN/dx = - KN
Where, N is the concentration of particles in the air at a depth x in the
filter
& K is a constant,
On integrating above expression, we get:
N/No = e-kt
Where,
No is the no. of particles entering the filter
N is the no. of particles leaving the filter
Efficiency of filter is given by E = (No – N) / No
But, (No – N) / No = 1 – (N/No)
Thus, (No – N) / No = 1 – e-kt
84. The log penetration relationship has been used by
Humphery and Garden (1955) in the filter design, by
using the concept X90 the depth of filter required to
remove 90% of the total no. of particles entering the
filter,
Thus If, No were 10 and x were X90, then N would be 1,
ln (1/10) = - K X90
2.303 log10 (1/10) = - K X90
2.303 (-1) = - K X90
X90 = 2.303 / K