ALBERT

Notes: Streptococcus lactis INIA 12, a selected nonbitter strain, reached its maximum counts and its highest lactic acid production in a culture medium containing 125 g/L skim milk powder, fortified with 5 g/L yeast extract and digested with 10 ppm papain for 20 min at 65°C. Lactose added to the medium did not enhance growth rate or biomass production. A growth temperature of 32°C and the maintenance of pH at 6.80, with 10N NaOH as the neutralizer, were the optimum fermentation parameters in batch cultures. In ten 40-L fermentations carried out at 32°C and pH 6.80, with a 5% inoculum, a 0.2 kg/cm2 nitrogen head space pressure and a stirring rate of 80 rpm, maximum counts of S. lactis (1010 CFU/mL) were reached after incubation for 6 hr at 32°C and pH 6.80.

Notes: Plant cells have two cytoplasmic pathways of glycolysis and gluconeogenesis for the reversible interconversion of fructose 6-phosphate (F-6-P) and fructose 1,6-bisphosphate (F-1,6-P2). One pathway is described as a maintenance pathway that is catalyzed by a nucleotide triphosphate-dependent phosphofructokinase (EC 2.7.1.11; ATP-PFK) glycolytically and a F-1,6 bisphosphatase (EC 3.1.3.11) gluconeogenically. These are non-equilibrium reactions that are energy consuming. The second pathway, described as an adaptive pathway, is catalyzed by a readily reversible pyrophosphate-dependent phosphofructokinase (EC 2.7.1.90; PP-PFK) in an equilibrium reaction that conserves energy through the utilization and the synthesis of pyrophosphate. A constitutive regulator cycle is also present for the synthesis and hydrolysis of fructose 2,6-bisphosphate (F-2,6-P2) via a 2-kinase and a 2-phosphatase, respectively. The pathway catalyzed by the ATP-PFK and F-1,6-bisphosphatase, the maintenance pathway, is fairly constant in maximum activity in various plant tissues and shows less regulation by F-2,6-P2. Plants use F-2,6-P2 initially to regulate the adaptive pathway at the reversible PPi-PFK step. The adaptive pathway, catalyzed by PPi-PFK, varies in maximum activity with a variety of phenomena such as plant development or changing biological and physical environments. Plants can change F-2,6-P2 levels rapidly, in less than 1 min when subjected to rapid environmental change, or change levels slowly over periods of hours and days as tissues develop. Both types of change enable plants to cope with the environmental and developmental changes that occur during their lifetimes. The two pathways of sugar metabolism can be efficiently linked by the cycling of uridylates and pyrophosphate required for sucrose breakdown via a proposed sucrose synthase pathway. The breakdown of sucrose via the sucrose synthase pathway requires half the net energy of breakdown via the invertase pathway. Pyrophosphate occurs in plant tissues as a substrate pool for biosynthetic reactions such as the PPi-PFK or uridine diphosphate glucose pyrophosphorylase (EC 2.7.7.9; UDPG pyrophosphorylase) that function in the breakdown of imported sucrose. Also, pyrophosphate links the two glycolytic/gluco-neogenic pathways; and in a reciprocal manner pyrophosphate is produced as an energy source during gluconeogenic carbon flow from F-1,6-P2 toward sucrose synthesis.

Notes: A selected group of 195 oils from the Spanish “Toxic Oil” Syndrome (TOS) epidemic including 29 high-probability “case” and 64 “control” oils were examined to investigate the relationship between oil composition and the risk of TOS. As indicated by fatty acid and sterol patterns, the presence of rapeseed oil was significantly more prevalent in the case than in the control oils, but fatty acid anilides were the most useful markers of case-related samples. Anilides were detected in 62% of case oils and at lower concentrations in 23% of the control samples. The ratios of individual anilides were quite constant in these oils and most consistent with their formation in the original (undiluted) rapeseed oil.