- Email: [email protected]
New Zealand — ‘Brown pack’ spoilage in gas-impermeable plastic casings
:::::::::::::::::::.~::::::::::::~~~~:~:.:.:.:.:,:,:,:,:,~,:,:.:.~.:.: .:.:. :, ~~~~~~ :::. ...
Biosensors & Bioelectronics Vol. 12 No. I (1997)
:::::::::::I::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::~
changes afterintravenous glucose
(l-2 min lag) or insulin (3-7 min lag) and (iii) achieving a correlation between tissue and blood glucose values under dynamic conditions (? = 0.98, y = 0.99x + 0.23). Reassessment of the electrode response in vitro, following a 4 h monitoring period, provided a sensor response within 3% of the original electrode sensitivity, indicating little or no surface fouling and avoiding the requirement for repeated in vivo calibrations at least over the initial implantation period. Contact: University of Manchester, Medicine-Clinical Biochemistry, Hope Hospital, Eccles Old Road, Sarford M6 8HD, UK. of ultravioletGermany - Development polymerizable enzyme pastes In ANALYST (12 l/6 (877-88 1) 1996) I. Rohm,
M. Gemich, W. Collier & U. Bilitewski of GBF-Gesellschaft report on ‘Development of ultraviolet-polymerizable pastes: enzyme Bioprocess applications of screen-printed L-lactate sensors’. The development of an amperometric L-lactate-specific enzyme electrode fabricated entirely using screen-printing technology is described. The sensor is based on immobilization of lactate oxidase from Pediococcus sp. by printing and subsequent UV irradiation within a polymer&able paste containing different supplements. The sensor optimization is described with respect to the most important features, such as composition and viscosity of the paste, stability, optimum pH and analytical range. The sensor was applied in a flow-through chamber within a flow injection (FI) system based on dialysis to off-line and on-line bioprocess monitoring of Geotrichum candidum cultivations in complex media. The sensor exhibited good operational stability; 4200 single injections (60 measurements per hour) led to a decrease of only 8.7%,thestandarddeviationbeing< l%(n=60). Using an FI system with direct sample injection (3 x 10m51 sample injection volume), the detection limit was 2 x lo-* mol 1-l and the linear range extended up to 1 x lo” mol 1-l. The linear range of
...
Vlll
the dialysis-based FI system extended from 5 5 x 10w4to 5 x 1O-*mol 1-l. The correlation between results obtained by analysis of diluted off-line bioprocess samples with the amperometric device and with a homogeneous photometric assay using lactate dehydrogenase was r = 0.985. By on-line injection analysis of undiluted complex fermentation broth over a period of 12 h prior to the inoculation, no significant loss of sensor response was observed, which demonstrates the good operational stability of the system even with complex real samples. Additional investigations indicated the necessity for pH conformity of the sample and standard solutions. Contact: Department of Enzymolog, GBF-Gesellschaft,Biotechnologische Forschung D-381 24 mbH, Mascheroder Weg 1, Braunschweig, Germany. UK - Optical study of biomolecular interactions In Q. REV. BIOPI-IYS. (29/l (91-117) 1996) P.B. Garland. of The Institute of Cancer Research reports on ‘Optical evanescent wave methods for the study of biomolecular interactions’. No abstract given Contact: Chester Beatty Laboratories, The Institute of Cancer Research, Fulham Rd., London SW3 4IB, UK. New Zealand gas-impermeable
- ‘Blown pack’ spoilage plastic casings
in
In INT. J. FOOD MICROBIOL. (29/2-3 (335-352) 1996) D.M. Broda, K.M. DeLacy, R.G. Bell, T.J. Braggins & R.L. Cook of the Meat Industry Research Inst. NZ Inc., report on ‘Psychrotrophic Clostridium spp. associated with ‘blown pack’ spoilage of chilled vacuum-packed red meats and dog rolls in gas-impermeable plastic casings’. ‘Blown pack’ spoilage of vacuum-packed chilled beef, lamb and venison, a cooked meat product, and chilled dog rolls packed in an plastic was oxygen-impermeable casing, characterised by sensory, chemical and microbiological analysis. Investigation of the probable causative agents led to the isolation of
Biosensors & Bioelectronics Vol. 12 No. 1 (1997)
eight strains of psychrotrophic clostridia. Three strains have been provisionally identified as C. d@cile, C. beijerinckii and C. lituseburense; the other five remain unidentified. In inoculation studies only one isolate produced significant amount of gas on meat, causing pack ‘blowing’. It is, therefore, possible that ‘blown pack’ spoilage involves a synergism with one or more other organisms. Contact: Microbiology and Food Safety Section, Meat Industry Research Inst. NZ Inc., PO Box 617, Hamilton, New Zealand. Italy -Flow-through
tyrosinase enzyme reactor
In ANAL. CHIM. ACTA (326/l-3 (149-154) 1996) G.E. De Benedetto, F. Palmisano & P.G. Zambonin of Universita degli Studi di Bari report on ‘Flow-through tyrosinase enzyme reactor based on reticulated vitreous carbon functional&d by an electrochemically synthesized film’. The authors decribe the use of electrochemically synthesized polymers to modify the surface of reticulated vitreous carbon (RVC) electrodes, introducing functional groups useful for a covalent linking of enzymes. Tyrosinase was immobilized by glutaraldehyde crosslinking over a poly(tyramine) modified RVC. The usefulness of such an approach is demonstrated by the fabrication of a RVC flow-through tyrosinase reactor. Dipartimento di Contact: Chimica, Universita degli Studi di Bari, Via Orabona 4, I70126 Bari, Italy. Denmark - Biosensor measurement of binding of insulin-like growth factors
In J. BIOL. CHEM. (271/24 (13948-13952) 1996) A. Heding, R. Gill, Y. Oawa, P. De Meyts & R.M. Shymko of the Hagedom Research Institute report on ‘Biosensor measurement of the binding of insulin-like growth factors I and II and their analogues to the insulin-like growth factor-binding protein-3’. Most insulin-like growth factor (IGF) molecules in the circulation are found in a
150~kDa complex containing IGF-binding protein-3 (IGFBP3) and an acid-labile subunit, which does not itself bind IGF. Affinities (K(d) values) between 0.03 and 0.5 nM have been reported for IGF-I/IGFBP-3 binding, but no kinetic data are available. In this study the high affinity binding of unlabeled IGFs and IGF analogues to recombinant unglycosylated IGFBP3 were measured using a BIAcore(TM) instrument (Pharmacia Biosensor AB). IGF-I binding showed fast association and slow non-first-order dissociation kinetics, and an equilibrium K(d) of 0.23 nM. IGF-II had similar kinetics with slightly higher affinity. Analogues with mutations in the first 3 amino acids of the B-region (des(1-3) IGF-I and long IGF-I) showed 25 and 50 times lower affmity than IGF-I. Replacement of residues 28-37 by Gly-GlyGly-Gly or deletion of residues 29-41 in the C-region had little effect on the kinetic parameters, contrasting with the markedly impaired binding of these analogues to the IGF-I receptor. Swapping of the disulfide bridges in IGF-I and the C-region mutants decreased the affinity dramatically for IGFBP3, primarily by decreasing the association rate. Insulin had approximately 1000 times lower affinity than IGF-I. Contact: Hagedom Research Institute, Niels Steensens Vej 6, DK-2820 Gentofte, Denmark. Japan - Interaction between the amino-terminal SH3 domain of CRK and its natural target proteins
In J. BIOL. CHEM. (271/24 (14468-14472) 1996) M. Matsuda, Gta, R. Tanimura, H. Nakamura, K. Matuoka, T. Takenawa, K. Nagashima & T. Kurata of the Dept. of Pathology, report on ‘Interaction between the amino-temtinal SH3 domain of CRK and its natural target proteins’. CRK is a human homolog of chicken v-Crk, which is an adaptor protein. The !%I2 domain of CRK binds to several tyrosine-phosphorylated proteins, including the epidemtal growth factor receptor, p 130(Cas), She, and paxillin. The SH3
ix
Biosensors & Bioelectronics Vol. 12 No. I (1997)
:::::::::::I::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::~
changes afterintravenous glucose
(l-2 min lag) or insulin (3-7 min lag) and (iii) achieving a correlation between tissue and blood glucose values under dynamic conditions (? = 0.98, y = 0.99x + 0.23). Reassessment of the electrode response in vitro, following a 4 h monitoring period, provided a sensor response within 3% of the original electrode sensitivity, indicating little or no surface fouling and avoiding the requirement for repeated in vivo calibrations at least over the initial implantation period. Contact: University of Manchester, Medicine-Clinical Biochemistry, Hope Hospital, Eccles Old Road, Sarford M6 8HD, UK. of ultravioletGermany - Development polymerizable enzyme pastes In ANALYST (12 l/6 (877-88 1) 1996) I. Rohm,
M. Gemich, W. Collier & U. Bilitewski of GBF-Gesellschaft report on ‘Development of ultraviolet-polymerizable pastes: enzyme Bioprocess applications of screen-printed L-lactate sensors’. The development of an amperometric L-lactate-specific enzyme electrode fabricated entirely using screen-printing technology is described. The sensor is based on immobilization of lactate oxidase from Pediococcus sp. by printing and subsequent UV irradiation within a polymer&able paste containing different supplements. The sensor optimization is described with respect to the most important features, such as composition and viscosity of the paste, stability, optimum pH and analytical range. The sensor was applied in a flow-through chamber within a flow injection (FI) system based on dialysis to off-line and on-line bioprocess monitoring of Geotrichum candidum cultivations in complex media. The sensor exhibited good operational stability; 4200 single injections (60 measurements per hour) led to a decrease of only 8.7%,thestandarddeviationbeing< l%(n=60). Using an FI system with direct sample injection (3 x 10m51 sample injection volume), the detection limit was 2 x lo-* mol 1-l and the linear range extended up to 1 x lo” mol 1-l. The linear range of
...
Vlll
the dialysis-based FI system extended from 5 5 x 10w4to 5 x 1O-*mol 1-l. The correlation between results obtained by analysis of diluted off-line bioprocess samples with the amperometric device and with a homogeneous photometric assay using lactate dehydrogenase was r = 0.985. By on-line injection analysis of undiluted complex fermentation broth over a period of 12 h prior to the inoculation, no significant loss of sensor response was observed, which demonstrates the good operational stability of the system even with complex real samples. Additional investigations indicated the necessity for pH conformity of the sample and standard solutions. Contact: Department of Enzymolog, GBF-Gesellschaft,Biotechnologische Forschung D-381 24 mbH, Mascheroder Weg 1, Braunschweig, Germany. UK - Optical study of biomolecular interactions In Q. REV. BIOPI-IYS. (29/l (91-117) 1996) P.B. Garland. of The Institute of Cancer Research reports on ‘Optical evanescent wave methods for the study of biomolecular interactions’. No abstract given Contact: Chester Beatty Laboratories, The Institute of Cancer Research, Fulham Rd., London SW3 4IB, UK. New Zealand gas-impermeable
- ‘Blown pack’ spoilage plastic casings
in
In INT. J. FOOD MICROBIOL. (29/2-3 (335-352) 1996) D.M. Broda, K.M. DeLacy, R.G. Bell, T.J. Braggins & R.L. Cook of the Meat Industry Research Inst. NZ Inc., report on ‘Psychrotrophic Clostridium spp. associated with ‘blown pack’ spoilage of chilled vacuum-packed red meats and dog rolls in gas-impermeable plastic casings’. ‘Blown pack’ spoilage of vacuum-packed chilled beef, lamb and venison, a cooked meat product, and chilled dog rolls packed in an plastic was oxygen-impermeable casing, characterised by sensory, chemical and microbiological analysis. Investigation of the probable causative agents led to the isolation of
Biosensors & Bioelectronics Vol. 12 No. 1 (1997)
eight strains of psychrotrophic clostridia. Three strains have been provisionally identified as C. d@cile, C. beijerinckii and C. lituseburense; the other five remain unidentified. In inoculation studies only one isolate produced significant amount of gas on meat, causing pack ‘blowing’. It is, therefore, possible that ‘blown pack’ spoilage involves a synergism with one or more other organisms. Contact: Microbiology and Food Safety Section, Meat Industry Research Inst. NZ Inc., PO Box 617, Hamilton, New Zealand. Italy -Flow-through
tyrosinase enzyme reactor
In ANAL. CHIM. ACTA (326/l-3 (149-154) 1996) G.E. De Benedetto, F. Palmisano & P.G. Zambonin of Universita degli Studi di Bari report on ‘Flow-through tyrosinase enzyme reactor based on reticulated vitreous carbon functional&d by an electrochemically synthesized film’. The authors decribe the use of electrochemically synthesized polymers to modify the surface of reticulated vitreous carbon (RVC) electrodes, introducing functional groups useful for a covalent linking of enzymes. Tyrosinase was immobilized by glutaraldehyde crosslinking over a poly(tyramine) modified RVC. The usefulness of such an approach is demonstrated by the fabrication of a RVC flow-through tyrosinase reactor. Dipartimento di Contact: Chimica, Universita degli Studi di Bari, Via Orabona 4, I70126 Bari, Italy. Denmark - Biosensor measurement of binding of insulin-like growth factors
In J. BIOL. CHEM. (271/24 (13948-13952) 1996) A. Heding, R. Gill, Y. Oawa, P. De Meyts & R.M. Shymko of the Hagedom Research Institute report on ‘Biosensor measurement of the binding of insulin-like growth factors I and II and their analogues to the insulin-like growth factor-binding protein-3’. Most insulin-like growth factor (IGF) molecules in the circulation are found in a
150~kDa complex containing IGF-binding protein-3 (IGFBP3) and an acid-labile subunit, which does not itself bind IGF. Affinities (K(d) values) between 0.03 and 0.5 nM have been reported for IGF-I/IGFBP-3 binding, but no kinetic data are available. In this study the high affinity binding of unlabeled IGFs and IGF analogues to recombinant unglycosylated IGFBP3 were measured using a BIAcore(TM) instrument (Pharmacia Biosensor AB). IGF-I binding showed fast association and slow non-first-order dissociation kinetics, and an equilibrium K(d) of 0.23 nM. IGF-II had similar kinetics with slightly higher affinity. Analogues with mutations in the first 3 amino acids of the B-region (des(1-3) IGF-I and long IGF-I) showed 25 and 50 times lower affmity than IGF-I. Replacement of residues 28-37 by Gly-GlyGly-Gly or deletion of residues 29-41 in the C-region had little effect on the kinetic parameters, contrasting with the markedly impaired binding of these analogues to the IGF-I receptor. Swapping of the disulfide bridges in IGF-I and the C-region mutants decreased the affinity dramatically for IGFBP3, primarily by decreasing the association rate. Insulin had approximately 1000 times lower affinity than IGF-I. Contact: Hagedom Research Institute, Niels Steensens Vej 6, DK-2820 Gentofte, Denmark. Japan - Interaction between the amino-terminal SH3 domain of CRK and its natural target proteins
In J. BIOL. CHEM. (271/24 (14468-14472) 1996) M. Matsuda, Gta, R. Tanimura, H. Nakamura, K. Matuoka, T. Takenawa, K. Nagashima & T. Kurata of the Dept. of Pathology, report on ‘Interaction between the amino-temtinal SH3 domain of CRK and its natural target proteins’. CRK is a human homolog of chicken v-Crk, which is an adaptor protein. The !%I2 domain of CRK binds to several tyrosine-phosphorylated proteins, including the epidemtal growth factor receptor, p 130(Cas), She, and paxillin. The SH3
ix