Author
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: Cellulase & Penicillin. The author has an hindex of 1, co-authored 2 publications receiving 8 citations.
Papers
More filters
TL;DR: For improved biosynthesis of penicillin amidase by E. coli, NCIM 2400, the participation of different carboxylic acids and polyols has been studied in association with the effect of phenylacetic acid in a modified defined medium.
Abstract: For improved biosynthesis of penicillin amidase by E coli, NCIM 2400, the participation of different carboxylic acids and polyols has been studied in association with the effect of phenylacetic acid A modified defined medium has been devised for this purpose
8 citations
TL;DR: The level of α-mannanase in mixed fungal culture of Trichoderma reesei, D1-6, and Aspergillus wentii, Pt 2804, affects the extracellular activities of cellulase.
Abstract: The level of α-mannanase in mixed fungal culture of Trichoderma reesei, D1-6, and Aspergillus wentii, Pt 2804, affects the extracellular activities of cellulase. The endoglucanase component of the cellulase system is a glycoprotein having mannose and other sugars and sugaramines in its glycan moiety. Its activity is inhibited by α-mannanase. The inactivation of endoglucanase by α-mannanase can be prevented by galactose.
Cited by
More filters
TL;DR: The whole cell immobilization technique has been optimized for different process parameters and the granular catalyst has good mechanical strength, low protein leachability, and high retention of penicillin amidase activity.
24 citations
TL;DR: The secretion of the biologically active enzyme into the medium indicated that the postranslational processing of the PAC molecule, including the excision of a 54 amino acid spacer peptide between the α and β subunit, is not carried out in the periplasmic space, but occurs at the cytoplasmic membrane or autocatalytically.
Abstract: L-form strains of Proteus mirabilis and Escherichia coli lacking the cell wall represent an alternative prokaryotic cell system for the production of recombinant proteins (KLESSEN et al. 1988, LAPLACE et al. 1988a, 1989b). We could demonstrate that they are also able to synthesize the enzyme penicillin G acylase (PAC)1). PAC was processed and secreted into the medium by recombinant L-form strains. The synthesis of PAC was growth-associated and stably regulated. Expression, secretion, and processing were not temperature-dependent and occurred at 26 degrees C, 32 degrees C and even 37 degrees C. The expression vector pHC1 carried the pac gene under the control of the lac UV promotor and a kanamycin resistance gene. It could be maintained in L-form cells, showing low structural as well as segregational instability. The secretion of the biologically active enzyme into the medium indicated that the postranslational processing of the PAC molecule, including the excision of a 54 amino acid spacer peptide between the alpha and beta subunit, is not carried out in the periplasmic space, but occurs at the cytoplasmic membrane or autocatalytically.
19 citations
01 Jan 2008
TL;DR: In this paper, the authors define peptides as heteropolymers composed by amino acid residues linked by peptidic bonds between the carboxyl group of one amino acid residue and the α-amino group of the next one.
Abstract: Peptides are heteropolymers composed by amino acid residues linked by peptidic bonds between the carboxyl group of one amino acid residue and the α-amino group of the next one. The definition is rather vague in terms of chain length, peptides ranging from two residues to a few dozens residues. Its upper limit of molecular mass has been set rather arbitrarily in 6,000 Da. The size of the molecule determines the technology most suitable for its production. Recombinant DNA technology is particularly suitable for the synthesis of large peptides and proteins, as illustrated by the case of insulin and other hormones (Walsh 2005). Chemical synthesis is a viable technology for the production of small and medium size peptides ranging from about 5 to 80 residues (Kimmerlin and Seebach 2005). Enzymatic synthesis is more restricted and has been hardly applied for the synthesis of peptides exceeding 10 residues. Its potential relies on the synthesis of very small peptides and, in fact, most of the cases reported correspond to dipeptides and tripeptides (Kumar and Bhalla 2005). In this sense, the technologies for peptide production are not competitive with each other in most of the cases. © Springer Science+Business Media B.V. 2008.
11 citations
TL;DR: In this investigation cell-free culture filtrate was used instead of process water and an extracellular protein factor was found to influence the synthesis of penicillin amidase.
6 citations
TL;DR: Experimental findings show that the periplasmic penicillin amidase does not show any variation by the chloroform treatment, and this analysis was also extended to the E. coli cells grown at various concentrations of phenylacetic acid plus glucose and lactic acid.
Abstract: Penicillin amidase is a periplasmic enzyme in Escherichia coli. Conventionally, the periplasmic enzymes are released into the medium by osmotic shock which is tedious involving a number of centrifugation steps. The present communication deals with a simple technique for the release of penicillin amidase by chloroform shock. Experimental findings show that the periplasmic penicillin amidase does not show any variation by the chloroform treatment. This analysis was also extended to the E. coli cells grown at various concentrations of phenylacetic acid, optimal concentration of phenylacetic acid plus glucose and lactic acid.
4 citations