# US 12,110,530 B2 · Process for second generation lactic acid production

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- Number: US 12,110,530 B2
- Document ID: US12110530B2
- Status: Granted
- Kind: B2
- Application number: 17/691,912
- Filed: 2022-03-10
- Published: 2022-09-15
- Granted: 2024-10-08
- Earliest claimed: 2021-03-10
- Assignees: Indian Oil Corporation Limited; Department of Biotechnology
- Applicants: Indian Oil Corporation Limited; Department Of Biotechnology
- Inventors: Periyasamy Sivagurunathan; Alok Satlewal; Tirath Raj; Ravindra Kumar; Ravi Prakash Gupta; Suresh Kumar Puri; Sankara Sri Venkata Ramakumar
- Web page: https://patentgrep.com/patent/US12110530B2

## CPC

- C12P 7/56: Lactic acid
- C12P 7/10: substrate containing cellulosic material
- C12P 19/14: produced by the action of a carbohydrase {(EC 3.2.x)}, e.g. by alpha-amylase {, e.g. by cellulase, hemicellulase}
- C12P 2201/00: Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis
- C12P 2203/00: Fermentation products obtained from optionally pretreated or hydrolyzed cellulosic or lignocellulosic material as the carbon source
- C12R 2001/225: Lactobacillus
- C12P: FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE {(brewing of beer C12C; producing vinegar C12J; producing specific peptides or proteins C07K; producing enzymes C12N9/00; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; measuring or testing processes involving enzymes or microorganisms C12Q; measuring or testing processes involving nucleic acid amplification reactions C12Q1/6844; fermentation processes to form a food composition, A21 or A23; compounds in general, see the relevant compound class, e.g. C01, C07)}
- C12R: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES C12C - C12Q, RELATING TO MICROORGANISMS

## Abstract

The present invention provides an improved process for high titer lactic acid production using simultaneous saccharification and co-fermentation process using acid treated lignocellulosic biomass. The process comprises of pretreating lignocellulosic biomass comprising C5 and C6 sugars with dilute acid and superheated steam at a temperature ranging from 150-210° C.; neutralizing the pretreated lignocellulosic biomass of step (i) with NaOH pellets; and adding cellulase enzyme in the range of 1.5 to 10 FPU/g, bacteria, nutrients and buffering agent to the neutralized slurry obtained in step (ii) for hydrolysis and co-fermentation of C5 and C6 sugars at a temperature ranging from 40-45° C. for a period of 120-144 hours to obtain lactic acid. The process of the present invention requires simple nutrients and results in high titer lactic acid production within shortest duration of time.

## Claims

### Claim 1

A process for production of a lactic acid from a lignocellulosic biomass, the process consisting of:
i. pretreating the lignocellulosic biomass with a dilute acid and a superheated steam at a temperature in a range of 150-210° C., wherein the lignocellulosic biomass consists of C5 and C6 sugars C to obtain a pretreated lignocellulosic biomass;
ii. neutralizing the pretreated lignocellulosic biomass of step (i) with NaOH pellets to obtain a neutralized biomass slurry; and
iii. adding a cellulase enzyme in a range of 1.5 to 5 filter-paper units/gram, a Lactobacillus bacteria, nutrients, and a buffering agent to the neutralized biomass slurry obtained in step (ii) for hydrolysing and co-fermenting the C5 and the C6 sugars at a temperature in a range of 40-45° C. for a period of 120-144 hours to obtain the lactic acid,
wherein the Lactobacillus bacteria is selected from the group consisting of Lactobacillus lactis 2369 (NCIM) and Lactobacillus delbrueckii 2365 (NCIM),
wherein the lignocellulosic biomass is selected from the group consisting of rice straw, wheat straw, sugarcane bagasse, cotton stalk, barley stalk, bamboo, and agriculture residues, wherein the agricultural residues comprise cellulose, hemicellulose, or both, and wherein hydrolysing and co-fermenting are carried out in a single unit system.

### Claim 2 (depends on 1)

The process as claimed in claim 1, wherein the pretreatment of neutralized biomass slurry further comprises adjusting pH of the neutralized biomass slurry to 5.0-5.5 with a pH adjuster.

### Claim 3 (depends on 2)

The process as claimed in claim 2, wherein the pH adjuster is selected from the group consisting of an aqueous ammonium hydroxide, NaOH, KOH and CaCO3.

### Claim 4 (depends on 1)

The process as claimed in claim 1, wherein the nutrients is selected from the group consisting of yeast extract and diammonium hydrogen phosphate (NH4)2HPO4.

### Claim 5 (depends on 1)

The process as claimed in claim 1, wherein the buffering agent is calcium carbonate (CaCO3).

### Claim 6 (depends on 1)

The process as claimed in claim 1, wherein the pre-treated neutralized biomass slurry is subjected to fermentation without detoxification.

### Claim 7 (depends on 1)

The process as claimed in claim 1, wherein the C5 sugar is xylose and the C6 sugar is glucose.

### Claim 8 (depends on 1)

The process as claimed in claim 1, wherein the process yields ˜90 g/L lactic acid within 120 hours of fermentation.

### Claim 9 (depends on 1)

The process as claimed in claim 1, wherein the fermentation reaction is a batch process.

### Claim 10 (depends on 1)

The process as claimed in claim 1, wherein producing lactic acid comprises producing lactic acid by simultaneous saccharification and co-fermentation of the lignocellulosic biomass.