Presentation based on various industrial techniques to produce commercial lactic acid chemically or biologically by fermentation.

1. COMMERCIAL PRODUCTION
OF LACTIC ACID
DEPARTMENT OF MICROBIOLOGY
(2016-2017)
DR. SHAKUNTALA MISRA NATIONAL
REHABILITATION UNIVERSITY
SUBMITTED TO:
Dr. D.C. SHARMA
H.O.D OF MICROBIOLOGY
SUBMITTED BY:-
SUDHIR KUMAR
M.Sc. 2nd Sem
(Microbiology)

2. LACTIC ACID: INTRODUCTION
1) IUPAC NAME: 2- HYDROXY PROPANOIC ACID.
2) CHEMICAL FORMULA: C3H6O3 or CH3CHOHCOOH.
3) MOLAR MASS: 90.08 g·mol−1
4) MELTING POINT: L: 53 °C
D: 53 °C
D/L: 16.8 °C
5) BOILING POINT: 122 °C.
6) DENSITY: 1.206 g/ml at 25 °C

3. STRUCTURE OF D(-) AND L(+)
LACTIC ACID
Lactic acid is chiral, consist of 2 optical isomers.
When both added in equal quantity to form a
mixture is known as DL-lactic acid,

4. Production of lactic acid

5. SYNTHESIS OF LACTIC ACID
CHEMICAL SYNTHESIS:
:- used to produce racemic
mixture (DL -lactic acid).
:- LACTONITRILE is hydrolysed
by conc. Sulphuric acid to get
lactic acid and ammonium salt.
MICROBIAL SYNTHESIS:
:- used to produce pure L(+)
and D(-)
lactic acid.
:- mainly CARBOHYDRATE
is a substrate for LAB’S
(LACTIC ACID BACTERIA )
& Rhizopus oryzae.

6. TYPES OF BACTERIAL
FERMENTATION
HOMOFERMENTATIVE
BACTERIA
HETEROFERMENTATIVE
BACTERIA
:-Lactobacillus,
Lactococcus,
Enterococcus,Streptococ
cus &Pediococcus speci
es.
:- Undergoes Glycolysis.
:- 2 NADH undergoes
oxidation to form NAD+
to produce lactic acid
from 2 moles of Pyruvic
acid.
:-include Leuconostoc,
Oenococcus, Weissella,
and certain lactobacilli.
:- undergoes
Phosphoketolase
pathway(HMP).
:-catabolise glucose into
ethanol, carbon di-oxide as
well as Lactic acid and
acetic acid.
ONLY HOMOFERMENTATIVE BACTERIA’S ARE AVAILABLE FOR LACTIC
ACID PRODUCTION.

7. LACTIC ACID PRODUCTION BY MICROBIAL
FERMENTATION
:- Inoculam should be 5-10% of the liquid volume of the
Fermentor.
:- Temprature: 35 °C (95 °F) to 46° C (115 °F).
:- pH: 5-6.5 (maintained by adding base like ammonium
hydroxide).
:- BATCH FERMENTATION is preferred.
:-BATCH & FED-BATCH FERMENTATION- High
concentration of lactic acid is achieved.
:-CONTINOUES FERMENTATION- High productivity of
Lactic acid is achieved.
:- Airlift Bioreactor is preferred for Rhizopus oryzae.
(filamentous fungi).

8. MICROBIAL CULTURE:
1) Rhizopus oryzae: convert starch directly into amylolytic enzyme
activity.
2) Lactobacillus delbrueckii: convert hexoses into lactic acid in
fermentor at pH= 5.0 to 6.5 and temprature 46° C (115 °F) to 60 °
C (140 °F).
3) Lactobacillus bulgaricus: convert hexoses into lactic acid in
fermentor at pH= 6.0 to 7.0 and temprature 43° C.
4) Mixed culture of Lactobacillus brevis & Lactobacillus pentosus
were used by GARDE to produce lactic acid on large scale
production
5) YUN produced lactic acid from Enterococcus faecalis RKY1 from
single and mixed sugar.
Note: Rhizopus species can form L(+) lactic acid but yield is
very low and the mycelia of the fungi increases the viscosity

9. DIFFERENT SUBSTRATES:
MEDIA COMPOSITION:-
CARBON SOURCE:
1) Carbohydrates derived from beet-sugar, whey, cane
molasses, barley and malt.
2) Biomass of Lignocellulose: renewable carbon source. It is
a low cost and extensively available.
For ex:- sugarcane waste, banana waste, pomegranate waste,
apple waste, peanut husk, banana stalk, wheat straw.
LIGNOCELLULOSE=CELLULOSE+HEMICELLULOSE
HEMICELLLULOSE= HEXOSE +PENTOSE.

10. MEDIA OPTIMIZATION:
Productivity is affected by temprature, fermentation time and level of
substrate.
Highest yield obtained after 7 days fermentation by 18% substrate level
is 7.76g/100ml i.e. 77.6g/l.
Maximum recovery 78.30% w.r.t initial whole sugar
concentration(9.91g/100ml)
Rhizopus oryzae NRRL 395 is immobilised in polyurethane foam by
using response surface methodology.
Max. production of lactic acid is obtained 93.2g/L by using glucose
concentration 150g/L at pH=6.39 and rate of agitation 147 rpm.
Production of lactic acid by immobilised whole cells are 55% higher than
suspension culture.
Calcium aliginate (jelly type compound) is utilized to immobilize
Lactobacillus delbrueckii by using pineapple waste.

11. Two low cost Nitrogen source CSL(corn steep liquor) and YA(yeast
autolysate).
Produce D(-) Lactic acid with Lactobacillus LMI8 sp.
Maximum production of D(-) lactic acid calculated was 41.42g/L which
corresponds to 5g/L of YA and 15g/L of CSL.
Production of lactic acid by immobilised cells of Lactococcus lactis IO-1

12. Product recovery
1) ION EXCHANGE CHROMATOGRAPHY.
2) NEW MEMBRANE INTEGRATED
TECHNOLOGY(NANOFILTERATION)
3)Strong acid Cation Exchange Resin (Sulfonic acid on Polyesterene).
4)Foam separation technique.

14. References
http://refhub.elsevier.com/S1687-8507(14)00031-4/sref1
http://dx.doi.org/10.1016/j.jrras.2014.02.003
http://refhub.elsevier.com/S1687-8507(14)00031-4/sref4
http://refhub.elsevier.com/S1687-8507(14)00031-4/sref5
http://refhub.elsevier.com/S1687-8507(14)00031-4/sref9
http://refhub.elsevier.com/S1687-8507(14)00031-4/sref10
http://refhub.elsevier.com/S1687-8507(14)00031-4/sref15
http://refhub.elsevier.com/S1687-8507(14)00031-4/sref21
http://refhub.elsevier.com/S1687-8507(14)00031-4/sref24
Journal of Radiation Research and Applied Sciences 7 (2014) 222e229
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