An unsupervised "aerobics" physical training programme in middle-aged factory workers: feasibility, validation and response

This paper describes a controlled study of the effects of an unsupervised walking-programme in 108 volunteers from among 580 middle-aged employees in a Nottingham light industrial company. Objective measurements of physical condition and of customary activity were made on four occasions at 12-week intervals. The subjects were randomly allocated to three groups and encouraged to follow a walking-programme in the first, second or third periods of the study: no activity was prescribed in the other periods. Compliance with the programme was estimated from log-cards and from a week's pedometer record. Although there were no significant differences between the changes seen in subjects following the walking-programme and those in control subjects, there were significant small improvements in physical condition and modest increases in customary activity in a) those subjects actually completing the programme, and b) the subjects measured before and after their programme, pooled without regard to the period of measurement. At least some of the increased activity is maintained for 12 weeks after the programme. The marginal changes suggest that the intensity of the training-programme as experienced by the subjects was close to the threshold for maintenance of physical condition in this age-group of workers.     

Biocatalytic potential of laccase-like multicopper oxidases from Aspergillus niger

Background

The integration of biotechnology into chemical manufacturing has been recognized as a key technology to build a sustainable society. However, the practical applications of biocatalytic chemical conversions are often restricted due to their complexities involving the unpredictability of product yield and the troublesome controls in fermentation processes. One of the possible strategies to overcome these limitations is to eliminate the use of living microorganisms and to use only enzymes involved in the metabolic pathway. Use of recombinant mesophiles producing thermophilic enzymes at high temperature results in denaturation of indigenous proteins and elimination of undesired side reactions; consequently, highly selective and stable biocatalytic modules can be readily prepared. By rationally combining those modules together, artificial synthetic pathways specialized for chemical manufacturing could be designed and constructed.

Results

A chimeric Embden-Meyerhof (EM) pathway with balanced consumption and regeneration of ATP and ADP was constructed by using nine recombinant E. coli strains overproducing either one of the seven glycolytic enzymes of Thermus thermophilus, the cofactor-independent phosphoglycerate mutase of Pyrococcus horikoshii, or the non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase of Thermococcus kodakarensis. By coupling this pathway with the Thermus malate/lactate dehydrogenase, a stoichiometric amount of lactate was produced from glucose with an overall ATP turnover number of 31.

Conclusions

In this study, a novel and simple technology for flexible design of a bespoke metabolic pathway was developed. The concept has been testified via a non-ATP-forming chimeric EM pathway. We designated this technology as “synthetic metabolic engineering”. Our technology is, in principle, applicable to all thermophilic enzymes as long as they can be functionally expressed in the host, and thus would be potentially applicable to the biocatalytic manufacture of any chemicals or materials on demand.