Waste utilization (Edited By Ayan Santra)

1. waste utilization

2. • Whole Liquid Whey
• The untreated whole liquid whey is used as an animal feed,
particularly for pigs, although transport of liquid whey over any
distance is both diffi cult and uneconomical
• it is incorporated into the cattle and sheep feed rations up to 25-30%
of dry matter as liquid whey

3. • Concentrated Whole Whey
• These are comcentrated whole whey in order to reduce the costs of
transport and storage as well to improve the quality of the product
• Whey is concentrated either by evaporation or by reverse osmosis

4. whole whey powder
• Firstly, dry matter in whey is brought down to 50% by evaporation
and then followed by spray drying
• The main industries using whey powder are infant food
manufacturers, bakers, confectioners and meat processing plants
• Whey powder is extremely used in hog rations and also in milk
replacers for unweaned calves. This outlet is very important in Europe
and especially in France.

5. whey protein concentrate
• These products derived from cheese whey processing have a protein content
of 30-60%
• Whey proteins represent about 20% of the milk proteins. The most abundant
of these are β-lactoglobulin (50%), α-lactoalbumin (12%), immunoglobulins
(10%), serum albumin (5%) and protease peptones (0.23%)
• The most commonly used methods now-a-days are ultrafi ltration and diafi
ltration, because of their advantages of cost reduction, high process speed,
the absence of denaturation or protein structure modifi cation; and the fact
that the protein concentrate is free of salts, thereby making it suitable for all
kinds of human foods, even diabetic or baby foods

6. • Demineralized Whey
• Demineralization helps to reduce the mineral content of the whey,
which is too high for some food applications. It can be achieved by
ion-exchange, electrodialysis or a combination of electrodialysis
followed by an ion-exchange ‘fi nisher’, prior to spray drying

7. whey permeate
• Whey permeate is a by-product of ultrafi ltration of whey which is
rich in lactose content. It poses serious disposal problems
• The ultrafi ltration of whey is carried out using ultramembranes
• . Whey permeate produced after ultrafi ltration is an economical
source for refi ned lactose production, as an animal feed supplement
or as a substrate for various fermentation processes.
• calcium can be removed by heat treatment resulting in the
production of better quality crystalline lactose from whey permeate.
In pharmaceutical industry, lactose is used as a carrier for the
preparation of tablets and pills.

8. ethanol production
• Alcoholic fermentation is an interesting alternative for the bioethanol
remediation of the polluting cheese whey and whey permeate.
• Although the yeasts that assimilate lactose aerobically are
widespread, while those that ferment lactose are rather rare
• the microorganisms producing ethanol from whey are Torula cremoris
, Kluyveromyces marxianus

9. organic acids
• L. helveticus is the generally preferred organism, as
• it produces almost twice the amount of lactic acid as compared to
other common LAB (S. thermophilus and L. delbrueckii ssp. bulgaris)
• . It is homolactic fermentative and produces a racemic mixture (DL) as
compared to D-lactic acid produced by L. delbrieckii
• Lactic acid from cheese whey or whey permeate without nutrients
supplementation is of limited application to industrial scale because
of low productivity
• Nutrient supplementation is a key factor limiting the process effi
ciency

10. scp production
• yeast species namely Kluyveromyces lactis, K. fragilis and Torulopsis
• can use cheese-whey permeate
• Whole cheese whey is not used for this purpose, because these
microorganisms can not metabolize its proteins.
• Moreover, proteins promote yeast fl occulation, which inhibits the
fermentation.
• Depending upon the whey used, sometimes it may be necessary to
add nitrogen and phosphorous
• The yield in dried yeast is 50% of the weight of the lactose used.

11. 6. BIOGAS PRODUCTION
• Anaerobic digestion of cheese whey for methane production is
generally carried out under mesophillic conditions (35-37 °C) by
methanobacteria
• The main products formed from the proteins anaerobic
• biodegradation by proteases are polypeptides, amino acids and
ammonia.
• some proteins such as casein (main milk protein 80%) are quite
resistant to degradation by microorganisms
• can cause the partial inhibition in the methanogenesis phase

12. hydrogen production
• The use of carbohydrate rich wastewaters, like cheese whey,cheese whey powder
solution and cheese whey permeate powder is an economically viable substrate for
fermentative hydrogen production
• These processes have a theoretical yield of 8 mol of hydrogen per mol of lactose.
The hydrogen produced is a mixture containing both CH4 and CO2
• Various microorganisms including obligatory anaerobes like Clostridia butyricum, C.
• pasteurianum and facultative anaerobic species such as Enterobacter sp., Citrobacter sp.
and Escherichia coli are used in anaerobic fermentation of cheese whey to produce
hydrogen.

13. . DIRECT PRODUCTION OF ELECTRICITY THROUGH
MICROBIAL FUEL CELLS
• MFCs consist of two compartments: one anaerobic and another aerobic,
containing an anode and a cathode, respectively.
• In the anaerobic compartment, the microorganisms oxidize the organic matter
with the formation of carbon dioxide, protons and electrons
• Protons migrate to the cathode chamber (aerobic compartment) permeating
through the proton exchange membrane (thereafter protons combine with
oxygen), while the electrons are transferred to the cathode through an
external circuit, with oxygen reduction to water.
• This electron fl ow produces an electrical current that can be measured
• Enterobacter cloacae mico used

14. references
• www.google.com