Carnitine is an essential cofactor in the transport of long-chain fatty acids into the mitochondrial matrix and plays an important role in energy production via b b-oxidation. Vitamin C (VC) has long been considered a requirement for the activities of two enzymes in the carnitine biosynthetic pathway, i.e., 6-N-trimethyllysine dioxygenase and g g-butyrobetaine dioxygenase. Our present study using senescence marker protein-30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice, which cannot synthesize VC in vivo, led to the conclusion that this notion is not true. After weaning at 40 d of age, SMP30/GNL KO mice were fed a diet lacking VC and carnitine, then given water containing 1.5 g/l VC (VC(؉) mice) or no VC (VC(؊) mice) for 75 d. Subsequently, total VC and carnitine levels were measured in the cerebrum, cerebellum, liver, kidney, soleus muscle, extensor digitorum longus muscle, heart, plasma and serum. The total VC levels in all tissues and plasma from VC(؊) SMP30/GNL KO mice were negligible, i.e., Ͻ2% of the levels in SMP30/GNL KO VC(؉) mice; however, the total carnitine levels of both groups were similar in all tissues and serum. In addition, carnitine was produced by incubated liver homogenates from the VC-depleted SMP30/GNL KO mice irrespective of the presence or absence of 1 mM VC. Collectively, these results indicate that VC is not essential for carnitine biosynthesis in vivo.

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Linecin A is produced by Brevibacterium linens ATCC9175 and kills some strains of B. linens. Maximumextracellular linecin A activity was 8 units/ml at 48 hr of cultivation, but intracellular linecin A activity rapidly increased after 18 hr of cultivation, reaching 160 units/ml at 36 hr. To release intracellular linecin A from cells, mitomycin C was added to a culture of B. linens ATCC9175 at a final concentration of 0.3 j*g/ml. The extracellular linecin A activity increased to nearly 15-fold that of normal cultivation.The extracellular linecin A was purified to a homogeneous state on polyacrylamide gel electrophoresis by DEAE-cellulofine, Sephacryl S-500, and Sephacryl S-300 column chromatography. Linecin Aconsisted of mostly protein and the molecular weight was estimated to be about 95,000 by gel filtration. Linecin A was a thermolabile protein as the activity was completely lost by incubating at 45°C for 60min.There are numerous reports on the characterization of bacteriocins, especially colicins.1 ""5) However, little is known concerning bacteriocins from amino acid-or nucleic acid-producing bacteria and related species.6'7) Wereported earlier on bacteriocin activities in Brevibacterium linens (linecin A) and 4 related species.6) In general, bacteriocins are produced spontaneously in cultures of bacteriocinogenic strains, but some of them can also be induced by treating cells with ultraviolet light or mitomycin C. Linecin A has a narrow antibacterial spectrum and its activity in culture broth (extracellular activity) is very low, while its activity in the cells (intracellular activity) rapidly increases after 18 hr of cultivation.This paper describes the production, purification, and characterization of linecin A from Brevibacterium linens ATCC9175. Materials and MethodsBacterial strains. Brevibacterium linens ATCC9 1 75 was 161 used as the producer strain oflinecin A and B. linens ATCC 8377 as the indicator strain. Other strains were listed in Media and culture conditions. Bouillon medium6) was used for the maintenance of strains and the assay of bacteriocin. Microorganisms were aerobically incubated at 30°C for the desired times.

The occurrence of lysogeny and bacteriocinogeny was systematically investigated in 106 strains of Clostridium species (non-pathogenic and mostly acetone-butanol-or isopropanol butanol-producing) by cross-testing all the strains against each other. Consequently, it was found that 4 strains were lysogenic and other 18 strains bacteriocinogenic, and that all the strains were sensitive to one or more of bacteriocins and 15 strains of them were sensitive to the phages as well as bacteriocins. The four temperate phages isolated were indistinguishable from each other in their host ranges, serological properties and other characteristics tested, and named as KT. Grouping of the bacteriocins on the basis of their activity spectra and their specificity against bacteriocin-resistant mutants showed that 18 bacteriocins fell into 5 groups. The bacteriocins were named as clostocin, and groups of clostocin were designated as A, B, C, D and E, respectively. There was cross-resistance between KT-phage and clostocin A, suggesting a common receptor. There were no correlations between the KT-phage or clostocins and the HMphages of Cl. saccharoperbutylacetonicum.