Ch4 IndAppEnz

8/9/2019 Ch4 IndAppEnz

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Industrial Applications

of Enzymes

Carbohydrates

Essential components of all livingorganisms and most abundant.

Chemical & Energy Balance in theBiosphere

Photosynthesis: Conversion ofatmospheric CO2 into carbohydrate

Respiration: Carbohydrates areingested by higher animals to yieldenergy and CO2 is released

nCO nH O nO CH O)2 2 2 2 n+ ⇔ + (



Monosaccharides

(CH2O)n

Derivatives of

Polyhydroxy (-OH) aldehyde (-CHO) – Aldose

polyhydroxy (-OH) ketone (=CO)

– Ketose

n = 3 ~ 8 triose

tetrose

pentose

hexos

heptose



Asymmetric carbon (AC):

Carbon with 4 different substituents

Number of stereo isomer = 2AC

Aldohexos has 4 AC.

It has 16 possible isometric forms. 8 L form: OH on the left side of

the highest AC

8 D form: OH on the right side



Glucose

Glucopyranose



Haworth Projection

α-D-glucopyranose



Fructose

CH OH2

C=O

HOCH

HCOH

CH OH2

b

b

-D-fructose

( -D-fructofuranose)

HCOH

D-fructose

OHOH C2

CH OH2

OH

H



Disaccharides

OCH OH2

OHOH C2

CH OH2

OH

O

Sucrose

OCH OH2

OCH OH2

OH

O

Lactose ( form)b

OCH OH2

OCH OH2

OH

O

Cellobiose ( form)b

OCH OH2

OCH OH2

OHO

Maltose ( form)a



Amylose

Amylopectin

Cellulose



Starch Hydrolysis Corn (or Glucose) Syrup

Ethanol Fermentation

High Fructose Corn Syrup – 42% fructose (Similar sweetness as

sugar)

Fructose

– 2.3 times sweeter than glucose

– 1.4 times sweeter than sugar

UsageSoft drinks, Canned fruits, Juice, Icecream, etc

Source:

Corn

– Low costs

– Useful by-products: oil, gluten, cornmeal, dry starch, fiber, etc.



Corn Refining Process

α− amylase

StarchSlurry

Liquefactiontank

80 - 150 °CpH 6 - 73 hrs.

Saccharifi-cation tank

55 - 60 °CpH 4 - 4.5

40 to 80 hrs.

Flash Cooler

Filtration

Carbon Refining

Ion Exchanger

Evaporator

Isomerizationwith Immobilized

Glucose Isomerase

60 - 65 °CpH 7 - 8.530 mins. Filtration

Carbon Refining

Ion Exchanger

Evaporator

Cooler

HFCS42% Fructose

Glucose Syrup

Fungal Glucoamylase

15% D.E.

95%D.E.



Cellulose Hydrolysis

Cellulose:

Most abundant in nature Typical Dry Wood

Cellulose 41%

Hemicellulose 26%

– Lower MW than cellulose – Contains pentoses

Lignin 28%

– Cementing stiffening polymer

– Polymers of phenolic compoundsOther 5%



Structure of Cellulose Fibers

Cellulose Moleculres

Elementaryfibrils

Microfibrils

Cell wall

componentof wood

Elementaryfibril

Polyoses

Lignin



Economic Bottlenects to

Biomass Utilization

Availability in large quantity

High costs of pretreatment

Total biomass utilization

Low solid reaction High cost of separation

Economic Bottlenects forEnzyme Hydrolysis

Slow reaction rate

High costs of enzymes High costs of pretreatment



Attrition Bioreactor (ABR)



0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

0 1 2 3 4 5 6

T i m e ( h o u r s )

R e d u c i n g

S u g a r ( m g / g D M )

A B R w i t h 0 . 4 7 6 c m S .S . b a l l s

S T R w i t h 1 w k b a l l m i l l i n g

S T R

Hydrolysis of Newsprint in ABR



0

0 .2

0 .4

0 .6

0 .8

1

1 .2

0 4 8 12 1 6 2 0Tim e (hours)

R e l a t i v e E n z y m e A c t i v i t y

Se a led Reactor

O p e n R e a c to r

Enzyme Stability in ABR

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Ch4 IndAppEnz