Hydrolysis of protein and model dipeptide substrated by attached and nonattached marine Pseudomonas sp. strain NCIMB 2021
- Univ. of Maryland System, Baltimore (USA)
Rates of substrate hydrolysis by nonattached bacteria and by bacteria attached to particles derived from marine diatom frustules were estimated by using two substrates, a dipeptide analog and a protein. Adsorption of the two substrates onto the particles was also evaluated. Methyl-coumarinyl-amide-leucine (MCA-leucine) was used to estimate hydrolysis of dipeptides by measuring an increase in fluorescence as MCA-leucine was hydrolyzed to leucine and the fluorochrome methylcoumarin. To examine hydrolysis of a larger molecule, was prepared a radiolabeled protein by {sup 14}C-methylation of bovine serum albumin. The rate of protein hydrolysis in samples of particle-attached or nonattached bacteria was estimated by precipitating all nonhydrolyzed protein with cold trichloroacetic acid and then determining the trichloroacetic acid-soluble radiolabeled material, which represented methyl-{sup 14}C-peptides and -amino acids. About 25% of the MCA-leucine adsorbed to the particles. MCA-leucine was hydrolyzed faster by nonattached than attached bacteria, which was probably related to its tendency to remain dissolved in the liquid phase. In contrast, almost 100% of the labeled protein adsorbed to the particles. Accordingly, protein was much less available to nonattached bacteria but was rapidly hydrolyzed by attached bacteria.
- OSTI ID:
- 5347007
- Journal Information:
- Applied and Environmental Microbiology; (United States), Vol. 57:8; ISSN 0099-2240
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
PEPTIDES
HYDROLYSIS
PROTEINS
PSEUDOMONAS
METABOLISM
ADSORPTION
CARBON 14 COMPOUNDS
LEUCINE
SEAS
SUBSTRATES
TRACER TECHNIQUES
AMINO ACIDS
BACTERIA
CARBON COMPOUNDS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
DECOMPOSITION
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LYSIS
MICROORGANISMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
SOLVOLYSIS
SORPTION
SURFACE WATERS
090900* - Biomass Fuels- Processing- (1990-)
550501 - Metabolism- Tracer Techniques