P.S.R. Babu

Bio: P.S.R. Babu is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Fermentation & Penicillin amidase. The author has an hindex of 1, co-authored 1 publications receiving 6 citations.

Broth recycle in a yeast fermentation.

Abstract: Fermentation is a water-intensive process requiring treatment of large amounts of effluent broth. It is desirable to increase the ratio of product produced to the volume of effluent by minimizing the discharge of effluent from the fermentation process. A study of recycling spent fermentation process. A study of recycling spent fermentation broth for the subsequent fermentation was carried out with Apiotrichum curvatum an oleaginous yeast, as the working culture. Spent broth from a defined medium was recycled t replace as much as 75% of the water and salts for subsequent batches and this was repeated for seven sequential batches without affecting cell mass and lipid production. A 64% vlume reduction of wastewater was achieved in this manner. However, when using whey permeate as the medium, lipid production dropped after three consecutive recycle operations at 50% recycle, and after two consecutive recycle operations at 75% and 100% recycle. Accumulation of ions in the broth appeared to be responsible for the inhibition. An ion exchange step was able to eliminate the ion buildup and restore fermentation performance. © 1994 John Wiley & Sons, Inc.

Water reuse in the L‐lysine fermentation process

Abstract: L-Lysine is produced commercially by fermentation. As is typical for fermentation processes, a large amount of liquid waste is generated. To minimize the waste, which is mostly the broth effluent from the cation exchange column used for l-lysine recovery, the authors investigated a strategy of recycling a large fraction of this broth effluent to the subsequent fermentation. This was done on a lab-scale process with Corynebacterium glutamicum ATCC 21253 as the l-lysine-producing organisms. Broth effluent from a fermentation in a defined medium was able to replace 75% of the water for the subsequent batch; this recycle ratio was maintained for 3 sequential batches without affecting cell mass and l-lysine production. Broth effluent was recycled at 50% recycle ratio in a fermentation in a complex medium containing beet molasses. The first recycle batch had an 8% lower final l-lysine level, but 8% higher maximum cell mass. In addition to reducing the volume of liquid waste, this recycle strategy has the additional advantage of utilizing the ammonium desorbed from the ion-exchange column as a nitrogen source in the recycle fermentation. The major problem of recycling the effluent from the complex medium was in the cation-exchange operation, where column capacity was 17% lowermore » for the recycle batch. The loss of column capacity probably results from the buildup of cations competing with l-lysine for binding.« less

Repeated batch fermentation with water recycling and cell separation for microbial lipid production

Abstract: Large waste water disposal was the major problem in microbial lipid fermentation because of low yield of lipid. In this study, the repeated batch fermentation was investigated for reducing waste water generated in the lipid fermentation of an oleaginous yeast Trichosporon cutaneum CX1 strain. The waste fermentation broth was recycled in the next batch operation after the cells were separated using two different methods, centrifugation and flocculation. Two different sugar substrates, glucose and inulin, were applied to the proposed operation. The result showed that at least 70% of the waste water was reduced, while lipid production maintained satisfactory in the initial four cycles. Furthermore, it is suggested that T. cutaneum CX1 cells might produce certain naturally occurring inulin hydrolyzing enzyme(s) for obtaining fructose and glucose from inulin directly. Our method provided a practical option for reducing the waste water generated from microbial lipid fermentation.

Broth Recycling in Liquid Cultivation of Nostoc Flagelliforme Cells

Abstract: Broth recycling is a favorable way to make the most of nutrients in culture medium and to minimize the discharge of waste water from the fermentation process. In this study, the recycling of the effluent broth after the collection of Nostoc flagelliforme cells and polysaccharides was examined in consecutive batch fermentations with and without new nutrient elements supplemented. Nostoc flagelliforme cells grew well in consecutive batch fermentations with broth recycling for three cycles and there are no significant differences in cell growth rate and polysaccharide’s accumulation when nutrient elements equivalent to 50% of the BG-11 culture medium were supplemented into the recycling broth after each cycle of cultivation. However, the cell growth rate and the polysaccharide’s accumulation decreased distinctly and chlorisis of cells took place in the 3rd run of the consecutive batch fermentations without new nutrient elements supplemented. On the latter occasion, the content of inorganic nutrients in fermentation broth after three cycles of fermentation decreased to a considerable low extent, thus the influence of discharging fermentation broth on environment can be minimized. As a conclusion, the broth recycling is a promising method for improving the utilization efficiency of culture medium and lowering the waste water discharge.

Integrated Rotating Fibrous Bed Bioreactor-Ultrafiltration Process for Xanthan Gum Production from Whey Lactose

Abstract: .............................................................................................................................. ii Dedication .......................................................................................................................... iv Acknowledgments............................................................................................................... v Vita ..................................................................................................................................... vi Fields of Study ................................................................................................................... vi Table of