Efficient conversion of hemicellulose sugars from spent sulfite liquor into optically pure L-lactic acid by Enterococcus mundtii

Spent sulfite liquor (SSL), a waste stream from wood pulp production, has great potential as carbon source for future industrial fermentations. In the present study, SSL was separated into a hemicellulose derived sugar syrup (HDSS) and a lignosulfonic fraction by simulated moving bed chromatography. The recovery of SSL sugars in the HDSS was 89% and the fermentation inhibitors furfural, 5-hydroxymethylfurfural and acetic acid were removed by 98.7%, 60.5% and 75.5%, respectively. The obtained sugars have been converted to L-lactic acid, a building block for bioplastics, by fermentation with the lactic acid bacterium Enterococcus mundtii DSM4838. Batch fermentations on HDSS produced up to 56.3 g/L L-lactic acid. Simultaneous conversion of pentose and hexose sugars during fed-batch fermentation of wildtype E. mundtii led to 87.9 g/L optically pure (>99%) L-lactic acid, with maximum productivities of 3.25 g/L.h and yields approaching 1.00 g/g during feeding phase from HDSS as carbon source.

Naltrexone effects on diazepam intoxication and pharmacokinetics in humans

The opiate antagonist naltrexone (NTX) blocks relapse drinking in alcoholics and modifies some of the subjective effects of alcohol intoxication. Benzodiazepines have demonstrated cross-dependence and cross-tolerance to alcohol. Furthermore, benzodiazepine intoxication has effects on mood and psychomotor performance that are similar to alcohol intoxication. The effects of NTX on diazepam intoxication were investigated in non-drug abusing individuals. Eighteen men and eight women were randomly assigned to receive either 50 mg NTX or placebo PO, on two different occasions in a within-subjects, crossover, double-blind protocol. Diazepam was taken by mouth, 90 min after NTX. At -90, 45, 75, 135, 210 min, subjects were tested with repeated assessments of several mood and sensation scales and a computer-generated psychomotor test battery (CTB). Blood samples were also obtained and analyzed for serum diazepam levels. Diazepam induced several sensations and mood effects similar to those induced by alcohol. Negative mood states such as sedation, fatigue, and anxiety were higher for NTX than for placebo. Positive mood states such as friendliness, vigor, liking the effects of diazepam, and feeling high from diazepam were all lower for NTX than for placebo. There were no group differences on the CTB performance. NTX delayed the time to reach peak diazepam levels, so that peak levels occurred at 75 min for placebo compared to 135 min for NTX. A sub-analysis was conducted with 14 subjects who were FHP for alcoholism, but no differences were found on these outcome measures.

Naltrexone increases the latency to drink alcohol in social drinkers

We investigated the effects of naltrexone (NTX) on alcohol drinking, urge to drink alcohol, and alcohol-induced sensations and mood states in social drinkers consuming alcohol ad libitum in a cocktail bar. Sixteen college-age men and women participated in a double-blind, placebo-controlled, within-subjects, cross-over study. Subjects were tested during each of three drug conditions: NTX, 50 mg/ day, po; inactive placebo; and no drug. Each treatment condition lasted 8 to 11 days. Small groups of subjects consumed alcohol ad libitum during three 2-hr evening drinking sessions, separated by approximately-2 weeks. NTX treatment significantly increased the latency (time in seconds) to first sip the first (p < 0.05) and second alcoholic beverages consumed (p < 0.01). Moreover, the mean blood alcohol concentration at the end of the session was significantly lower when subjects were treated with NTX (p < 0.05). No differences were found on self-report urge to drink alcohol. Subjects reported more fatigue and tension on the Profile of Mood States (p < 0.05), before drinking, and increases in nausea on the Alcohol Sensation Scale (p < 0.05) when treated with NTX. The increase in the latency to sip the first and second alcoholic beverages may reflect the capacity of NTX to block urge for alcohol elicited from external cues (before consuming alcohol), as well as urge for alcohol after priming from ingested alcohol. Thus, the effectiveness of NTX for reducing drinking behaviors of alcoholics may be partially caused by anticraving properties of NTX.