The document discusses the history and types of dyes, their toxicity, and the importance of bioremediation in wastewater treatment. It highlights the transition from natural to synthetic dyes, the environmental impacts of dye effluents, and various biological techniques for reducing dye toxicity. The role of bioprocessing and specific microorganisms in purifying by-products in biotechnological applications is also emphasized.

2. QUESTION NO.1
IS DYE END PRODUCTS ARE ECO-FRIENDLY AFTER THE PROCESS OF
BIOPREMEDIATION ?
Dye
 It isa substance usedto colourthe clothes,paperorothermaterials.
 The colouring isnot readily alteredbywashing,heat, lightorotherfactorsto whichthe material
islikelytobe exposed.
 Dyesdistinguished frompigments(whichare finelypoweredsolidsdispersedinaliquid,suchas
paintor ink,or blendedwithothermaterials).
 Most dyesare organic compounds (because theyhave carbon),Onthe otherhand,pigmentsmay
be inorganiccompounds (withoutcarbon) ororganic compounds.
History of dyes
Natural dyes
 Until the 1850s,all dyes were get from natural sources, most commonly from vegetable
such as plant ,tree etc.
 Evidence show that dyeing methods are more than 4,000 years old.
 Two natural dyes, AlizarinandIndigo have majorimportance.
 Alizarinis a reddye extractedfromthe roots of the madderplant,Rubia tinctorium.
 The oldest known dye is the blue dye indigo, get from
the leaves of the dyerswoad herb, Isatis tinctoria in
Europe and in Asia from the indigo plant, Indigofera
tinctoria.
 Natural yellowdyesconsistof louting,fromthe leavesof
weld, Reseda luteola,andquercetin,fromthe barkof the
NorthAmericanoaktree, Quercustinctoria.
 The carotenoids are group of compund present in all
green plants, produce yellow to red shades.
 Lycopene compound from which all carotenoids are
originate produces the red colour of tomatoes.
 Crocetin is an ancient dye which was obtained from
the stigmas of Crocus sativus; this dye is undoubtedly
derived from lycopene in the plant.
 Logwood is the only natural dye used now a days.
 Heartwood extracts from the logwood tree which yield
hematoxylin, that oxidizes to hematein during isolation.it is used mostly to dye silk and
leather.

3. Decline of natural dyes
 Several factors contributed to the commercial decline of natural dyes.
 In 1850 the Industrial Revolution in Europe led to increased demand for readily
available, inexpensive, and easily applied dyes and revealed the important economic
limitations of natural dyes.
Synthetic dyes
 In 1856,the first successful synthetic dye, mauve, was discovered by British chemist
William H. Perkin.
 It quickly used in commercial level.
 The establishment of mauve trigger lowers the dominance of natural dyes in world
markets.
 By 1850 coal tar was an industrial inconvence because only a fraction was utilized as
wood.
 Recognition of the tetravalency of carbon and the nature of the benzene ring were key
factors required to reduce the molecular structures of the well-known natural dyes (e.g.,
indigo and alizarin) and the new synthetics (e.g., mauve, magenta and the azo dyes).
Many types of dyes:
Acid dye:
 Acid dyes are water-soluble anionic dyes, containing one or more sulfonic acid
substituents or other acidic groups.
 An example of the class is Acid Yellow 36.
 Acid dyes applied to fibers such as silk, wool, nylon and modified acrylic fibers using
neutral to acid dye baths.
Basic or Cationic Dye:
 This group was the first of the synthetic dyes that derived from coal-tar derivatives.
 Now a days it is used in discharge printing, and for preparing leather, paper, wood, and
straw.
 More recently they are used in some readymade fibers, especially the acrylics.
Basic dyes were originally used to color wool, silk, linen, hemp, etc., without the use of a
mordant, or using agent.
 Basic Brown 1 is an example of a Basic dye.
Azoic Dye:

4.  Azo Dyes contain at least one azo group (-N=N-) attached to one or two aromatic
rings.
 These dyes are used mostly for bright red shades in dying and printing.
 The production of bluish red azoic dye is an example.
Nitro Dye:
 Nitro dyes are polynitro derivatives of phenols containing at least one nitro group ortho
or para to the hydroxyl group.
 It is used to dye wool.
 It Consist of two or more aromatic rings (benzene, naphthalene).
 Example of nitro dyes are Martins yellow, Palatine orange and nitroso green
Disperse Dye:
 Disperse Dye were developed for dyeing secondary cellulose acetate fibers.
 Disperse yellow 3, Disperse Red 4, and Disperse Blue 27 are good examples of
disperse dyes.
Vat Dye:
 The term vat comes from the old indigo method dyeing in a vat: indigo had to be
reduced to light form.
 They are used on cotton, linen, rayon, wool, silk, and sometimes nylon.
 Vat dyes are also used in the continuous piece of dyeing process sometimes called the
pigment application process.
 The dyeings produced in this way have high wash and light fastness.
 An example of a vat dye is Vat Blue 4 (Indanthrene).
Reactive Dye:
 These dyes react with the cellulosic fiber to form a covalent bond. This produces dyed fiber
with extremely high wash fastness properties.
 The chemical reaction of the colour is fast and is very prolonged.
 Cotton, wool or silk can be dyed with this type of dye.
 Example: This type is the Reactive Blue 5 dye.
Solvent Dye:
 These coloursare appliedby mixinginthe target,whichis alipidornon-polarsolvent.
 Each dye is namedaccording to the pattern: – solvent+base colour+ number.
 Theyare usedforcoloringsynthetics, plastics,gasoline,oilsandwaxes.
 Example of solventdye are Solvent Red 24.
Sulfur Dye:
 The sulphur dyesprovide verydeepshades,whichhave excellentresistancetowashingbut very
low resistance tosunlight.T
 heywill dye cotton,linen,andrayon
 Theyare lowcost andhave good fastnesstolight,washingsandacids.

5. Some dye application:
Name of Dyes Application
Acid dye Man made fiber (Nylon),
Natural fiber (Silk, Wool)
Direct Dye Man made fiber (Viscose),
Natural fiber (Cotton)
Vat dye Man made fiber (Viscose),
Natural fiber (Cotton, Silk, Wool)
Disperse dye Nylon, Polyester, Acrylic, Tri-
acetate, Di-acetate
Basic dye Jute, Acrylic
Reactive dye Cotton, Wool, Silk, Viscose, Nylon
Sulfur dye Cotton, Viscose
Mordant dye Cotton, Wool, Silk
Pigment Cotton, Man made fiber
Mineral Cotton, Wool, Silk
Azoic dye Cotton, Viscose
Aniline Black Cotton
Rapid and Rapidson
dye
Cotton
Onium dye Cotton, Jute
The toxicity of dye(s) through their end products
 Dye toxicity has been explained in many researches.
 The acute toxicity of dyes is generally less.
 Only a few dyes and pigments are considered to be carcinogenic by U.S. regulatory
agencies.
 Azo dyes are rarely directly mutagenic or carcinogenic except for some azo dyes with
free amino groups.
 After cleavage of azo bonds from other group, toxic amines are released to water.
 These intermediate products cause severe detrimental effects on human beings and
aquatic life.
 For human being, these intermediates damage the vital organs such as the brain, liver,
kidneys, central nervous system, and reproductive system.
 They can also stop photosynthetic activity by reducing light penetration.
 In this way, the hazardous effects of dyes are shown from their discharge point to
receive water. That’s the reason it is urged for researchers to find out the way for removal
of such toxic components in industrialized countries in the world.
 Wastewater treatment is a difficult task by conventional methods such as physical,
chemical, and biological due to its complex molecular structure of dyes. Some new
technologies are being investigated by which decoloration of the problem could be
solved.

6. Pollution from the dye-containing effluents
 The colored effluent brings a negative beauty and taste effect on the wastewater.
 The absorption and reflection of sunlight by the colored effluents affect the water
transparency and gas solubility.
 The heavy-metal ions from textile dyes effluents have also been reported at high
concentrations in both algae and higher plants in water bodies.
 Some of the dyes and their biodegraded products are also toxic, carcinogenic, and
mutagenic.
 As the treatment process for such toxic pollutants in proper manner is an expensive,
they are eventually discarded into the environment that is about 40% of the total
industrial wastewater.
 Researches are done to promotes the eco-friendly technologies that will reduce the
consumption of freshwater and lower output of wastewater.
Biological techniques to reduce the toxicity of Dyes
 Coagulation techniques generate large amounts of sludge that requires safe disposal.
Adsorption of membrane filtration techniques lead to secondary waste streams that need
further treatment.
 There are many reports on the use of physicochemical methods for color removal from
dye-containing effluents apart from that present scenario biological treatment methods
are most suitable and widely used due to their cost effectiveness, ability to produce less
sludge, and eco-friendly nature.
 Bioremediation is normally carried out by the use of microorganisms to remove the
pollution from the environment, which is a key research area in the environmental
engineering.
 In such approaches, microorganisms adapt themselves to the toxic wastes and develop
into new resistant strains naturally, which then transform various toxic chemicals into
less harmful forms. The mechanism behind the biodegradation of compounds in the
microbial system is based on the action of the biotransformation enzymes.
 An herb Blumea malcommi was found to degrade textile dyes.
Microbial treatment
 Microorganisms are already present in the wastewater treatment feed on the complex
substances in the wastewater, converting them into simpler substances.The biological
treatment is nowadays common and extensive technique employed in dye wastewater
treatment.
 There are many reports where a large number of species have been used for the removal
and complete mineralization of different sorts of dyes.
 The main advantage of this process is inexpensive, low running costs, and nontoxic end
products.

7.  These process may be aerobic (in the presence of oxygen), anaerobic (without oxygen),
or combined aerobic–anaerobic. Bacteria and fungi are normally used in aerobic
treatment for their ability to treat dye wastewaters.
Aerobic treatment
 In aerobic treatment, enzymes secreted by bacteria present in the wastewater for the
simplification of organic compounds. For more than two decades,t
 Reseaches onthe work to identify and isolate aerobic bacteria capable of degrading
various dyes has been going on since more than two decades.
 A number of triphenylmethane dyes, such as magenta, crystal violet, pararosaniline,
brilliant green, malachite green, and ethyl violet, have been found to be decolorized by
the Kurthia sp.
 Microorganisms including Rhyzopus oryzae, Cyathus bulleri, Coriolus versicolour,
Funalia trogii, Laetiporous sulphureus, Streptomyces sp., Trametes versicolour, and so
on have also been tested for the decolorization and biodegrading of dyes.
 It is reported that different operating parameters such as initial amount of pollutants,
initial pH, and temperature of the effluent affect the process. Several strategies may be
used after fungal treatment.
 It noticed that the treatability of the effluent by other microorganisms can be improved
for satisfactory removal of dyes.
 It is clear that these techniques are suitable for some dyes; however, most of the dyes are
resistance to biological breakdown or are nontransformable under aerobic conditions.
Anaerobic treatment
 The anaerobic treatment is quiet favorable for the degradation of a wide range of
synthetic dyes.
 It has been reported that under anaerobic conditions, some dyes have been degraded or
mineralized.
 Another study proved that the application of anaerobic granular sludge for the total
decolorization of 20 azo dyes. An anaerobic pre-treatment step could be a cheap
alternative compared with aerobic systems as expensive aeration is absent and problems
with bulking sludge are avoided.
 It is reported that anaerobic treatment of effluent for dye removal can be efficiently
carried out; however, heavy metals can be retained through sulfate reduction. In addition,
due to foaming problems, associat for surfactants and high effluent temperatures along
with high pH is the main limitation for degradation of dyes.
 It is also mentioned that BOD removal can be insufficient; dyes and other refractory
organics are not mineralized; nutrients (N and P) are not removed; and sulfates give rise
to sulfides.

8. Combined aerobic–anaerobic treatment
 For the better removal of dyestuff from the wastewater of textile effluent, the
combination of aerobic and anaerobic treatments may give promising results.
 It is advantageous because the complete mineralization is achieved due to the combined
action of different organisms. It has been reported that the reduction of the azo bond can
be achieved under the reducing conditions in anaerobic bioreactors. In consequence,
colorless aromatic amines may be formed, which are mineralized under aerobic
conditions. As a result, the combined anaerobic–aerobic azo dye treatment system is an
attractive approach for the researchers.
 An anaerobic decolorization followed by aerobic post-treatment is generally
recommended for treating dye wastewaters.
 Mostly the operating conditions such as initial assembely of dyes, initial pH of solution,
and temperature of the effluent play an important role for decolorization of dyes.In
addition, this technique is cost competitive and suitable for various dyes.
 The main limitation of the biological treatment is low biodegradability, less flexibility in
design and operation, larger land area requirement, and longer times required for
decolorization processes. Therefore, it is an desire for scientist for removal of dyes from
effluent on a continuous basis in liquid-state fermentations.
 Bioremediation of Dyes in Textile Effluents by Aspergillus oryzae is very effective for
the degradation.
 Bioremediation of Textile Azo Dyes are done efficiently by Trichophyton rubrum
QUESTION NO.2
What is the link of bioremediation for purification of by-product in
bioprocessing
Bioprocessing
 Bioprocessingisexplained asanyprocessthat usescomplete livingcellsortheircomponents
(e.g.,bacteria,enzymes,chloroplasts) to getdesiredproducts.
 Bioprocessingisalso importantto several emergingindustriesandtechnologies,includingthe
productionof renewablebiofuelssuchasethanol andbiodiesel,therapeuticstemcells,gene
therapyvectors,andnewvaccines.
 The Food andDrug Administrationimposes strictregulationsonbioprocessinginthe biotech
industry;thisenvironmenthasanenormousimpactonplantoperationsandproduct
manufacture.
 A varietyof methodsfor recovery,separation,andpurificationinbiotechnologyhave been
reportedinrecent years.

9. Recent applications of Vitreoscilla hemoglobin technology in
Bioproduct Synthesis,Bioremediation and Bioprocessing
 The firstuse in 1990 to increase productionof α-amylase inE.coli, engineeringof heterologous
hoststo expressthe hemoglobinfromthe bacterium Vitreoscilla (VHb) hasbecome popular
strategyto enhance productionof avarietyof bioproducts,stimulate bioremediation,and
increase growthandsurvival of engineeredorganisms.
 The hosts are varietyof bacteria,yeast,fungi,higherplants,andevenanimals.The beneficial
effectsof VHbexpressionare presumablythe resultof one or more of itsactivities.The available
evidence showsthatthe oxygenbindinganddeliverytothe respiratorychainandoxygenases,
protectionagainstreactive oxygenspecies,andcontrol of gene expression.
 In the past 4 to 5 years,the use of this“VHb technology”has continuedinavarietyof
biotechnological applicationsinawide range of organisms.These include improvementof
productionof an everwiderarrayof bioproducts,new applicationsinbioremediation,apossible
role inenhancingaerobicwaste watertreatment,andthe potentialtoenhance growthand
survival of bothplantsandanimalsof economicimportance.
Aspergillus awamori´s Lipase Production are used in partial purification
and application in oil effluent treatment
 Marine fungus separate from seawater and identified as Aspergillus awamori was
observed to produce an extracellular lipase which could minimize 92% fat and oil content
in the effluent laden with oil.
 In this study, medium for lipase production under submerged fermentation was
optimized statistically employing response surface method toward maximal enzyme
production.
 The time course experiment under optimized condition, after statistical modeling,
indicated that enzyme production commenced after 36 hours of incubation and reached a
maximum after 96 hours, whereas maximal specific activity of enzyme was recorded at
108 hours.
 After optimization an overall 4.6-fold increase in lipase production was achieved. Partial
purification by (NH4)2SO4 precipitation and ion exchange chromatography resulted in
33.7% final yield. The lipase was noted to have a molecular mass of 90 kDa and optimal
activity at pH 7 and 40 °C. Results indicated the scope for potential application of this
marine fungal lipase in bioremediation
Free and Immobilised Polyphenoloxidases uses in Bioremediation and
Bioprocessing of Food Industry pollutants
 Enzymes are specific biological catalysts able to react under sepcific conditions of
temperature and pH and their use in food industry for bioremediation is well known.
 Researchin recent years has been intense, much of it obtain by the great number of
different usable enzymes.

10.  Employment of enzymes in many bioremediation processes is made in order to protect
the environment from damage caused by industrial polluting effluents.
 The food industry is one of the most prominent sectors among the manufacturing
industries as far as production values are concerned; because food industry processes
involve large amounts of water and contribute to pollution loads discharged into water
resources.
 In particular,the presence of phenols in agroindustrial effluents has attracted interest for
laccases and tyrosinases use in wastewater treatment and bioremediation.
 The presence of phenolic compounds in drinking and irrigation water or in cultivated
land represents a significant health and/or environmental hazard that’s why the
development of methods for their removal and transformation have received increased
attention in recent years.
 The main purpose of this paper was to present the most recent results dealing with the
fundamental and applied aspects of free and immobilised polyphenoloxidases for food
industry wastewater processing.
REFERENCES
 https://www.britannica.com/technology/dye/Synthetic-dyes
 https://www.ncbi.nlm.nih.gov/books/NBK385442/
 https://textilelearner.blogspot.com/2015/01/different-types-of-dyes-with-chemical.html
 https://www.worldofchemicals.com/407/chemistry-articles/colors-family-inks-dyes-and-
pigments.html
 https://www.intechopen.com/books/eco-friendly-textile-dyeing-and-finishing/textile-dyes-
dyeing-process-and-environmental-impact
 https://www.intechopen.com/books/textile-wastewater-treatment/bioremediation-and-
detoxification-technology-for-treatment-of-dye-s-from-textile-effluent
 https://www.sciencedirect.com/science/article/pii/S2452072119300413
 https://www.sciencedirect.com/science/article/pii/S2405844019357287
 https://reader.elsevier.com/reader/sd/pii/S2452072119300413?token=CF9BEF0DC79BF22C9AE
724489E7983678E6E3395C45DC52AEB51911CDBC8CA6AA96DDF35788E33E085CCE84A0C01FD
3F
 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6945995/
 https://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000300039
 https://www.researchgate.net/publication/23456818_Bioremediation_of_Dyes_in_Textile_Efflu
ents_by_Aspergillus_oryzae
 https://www.pharma-iq.com/glossary/bioprocessing
 https://link.springer.com/article/10.1007/s002530100701
 https://link.springer.com/chapter/10.1007/978-3-642-74227-9_19
 https://onlinelibrary.wiley.com/doi/pdf/10.1002/ceat.200800068
 https://link.springer.com/article/10.1007/s00253-014-6350-y
 https://www.sciencedirect.com/science/article/abs/pii/S187167841100094X

11.  https://www.medigraphic.com/cgi-
bin/new/resumenI.cgi?IDREVISTA=281&IDARTICULO=36404&IDPUBLICACION=3874
 https://journals.sagepub.com/doi/abs/10.1177/1082013204049388