Objective

To reduce contamination levels and lactic acid in fermenters through the application of Bactoferm®.

Plant Profile

  • Industry: Distillery
  • Location: Uttar Pradesh, North India
  • Process Area: Fermentation
  • Application Area: Fermentation Process Optimization

Process Challenges

The fermentation process was experiencing elevated lactic acid levels and bacterial contamination, which affected overall process stability and residual control. The objective of the trial was to evaluate the effectiveness of Bactoferm® in reducing contamination and improving fermentation performance.

Plant Profile

  • Plant capacity: 85 KLPD ethanol
  • Location: Uttar Pradesh, North India
  • Fermentation mode: Fed-batch
  • Fermentation system: 2 pre-fermenters and 8 fermenters
  • Fermenter working volumes: 200–400 m³ and 750 m³
  • Pre-fermenter working volume: 40–80 m³

Catalyst Solution - Bactoferm®

  • Bactoferm® was applied during the fermentation process to evaluate its impact on lactic acid reduction, bacterial growth, and residual control under plant operating conditions.

Trial Observations

Following the application of Bactoferm®, the trial demonstrated noticeable improvements in process performance:
  • Lactic acid reduced from an average of 12,225 ppm to 7,960 ppm.
  • The process operated smoothly with improved residual control.
  • Residual Sugar (RS%) remained within an average range of 0.15% to 0.18%.
  • Residual Starch (RSt%) remained within an average range of  0.45% to 0.48%.
  • Bacterial growth observed on the cell slide was reduced compared to the control fermenters.

Lactic Acid Profiles during observation period

Fermenter no. Control (ppm) Trial (ppm)
4 12,275 8,250
1 11,950 7,750
3 11,350 7,900
4 12,850 8,400
1 12,700 7,500
Average 12,225 7,960

Performance Highlights

Fermenter no. Control Trial
Average Lactic Acid 12,225 ppm 7,960 ppm

The trial demonstrated a substantial reduction in lactic acid levels across all evaluated fermenters, along with improved bacterial control and smoother process operation.

Recommendations

  • Complete CIP of the entire process, including the liquefaction section.
  • Use Bactoferm® continuously to reduce lactic acid to standard limits.
  • Thorough cleaning of PHE in the liquefaction section, fermentation section, and PF using caustic.

Key Outcomes

  • Lactic acid reduced by 4,265 ppm on average.
  • Improved control over bacterial contamination compared to control fermenters.
  • Overall process stability improved following the Bactoferm® application.

Conclusion

The Bactoferm® trial demonstrated effective reduction of lactic acid levels from an average of 12,225 ppm to 7,960 ppm, along with reduced bacterial growth and improved residual control. Continuous use of the product on a regular basis can further reduce the lactic acid levels to much lower levels. The fermentation process operated smoothly during the trial, indicating improved process stability under the evaluated operating conditions.