O-2 uptake during solid-state fermentation in a rotating drum bioreactor

The maximum O-2 uptake by Rhizopus oligosporus grown in a 200 litre rotating drum bioreactor at 0.5 rpm ranged from 6.7 to 7.6 mmol per min per kg initial dry substrate (IDS), for runs done with 4 baffles each 17 cm wide, and 12 baffles each 5 cm wide. Without baffles, the maximum O-2 uptake rate at 5 rpm was 6.9 mmol/(min.kg IDS), compared to 5.1 mmol/(min.kg IDS) obtained at 0.5 rpm. Therefore O-2 supply is adequate in rotating drum bioreactors as long as slumping flow regimes of the substrate bed are avoided.

Selection of a strain of Aspergillus for the production of citric acid from pineapple waste in solid-state fermentation

Aspergillus foetidus ACR I 3996 (=FRR 3558) and three strains of Aspergillus niger ACM 4992 (=ATCC 9142), ACM 4993 (=ATCC 10577), ACM 4994 (=ATCC 12846) were compared for the production of citric acid from pineapple peel in solid-state fermentation. A. niger ACM 4992 produced the highest amount of citric acid, with a yield of 19.4 g of citric acid per 100 g of dry fermented pineapple waste under optimum conditions, representing a yield of 0.74 g citric acid/g sugar consumed. Optimal conditions were 65% (w/w) initial moisture content, 3% (v/w) methanol, 30 degrees C, an unadjusted initial pH of 3.4, a particle size of 2 mm and 5 ppm Fe2+. Citric acid production was best in flasks, with lower yields being obtained in tray and rotating drum bioreactors.

Increased expression of mitochondrial genes in human alcoholic brain revealed by differential display

Polymerase chain reaction (PCR)-based differential display was used to screen for alterations in gene expression in the mesolimbic system of the human alcoholic brain. Total RNA was extracted from the nucleus accumbens of five alcoholic and five control brains. A selected subpopulation of mRNA was reverse-transcribed to cDNA and amplified by PCR. A differentially expressed cDNA fragment was recovered, cloned, and sequenced. Full sequence analysis of this 467 bp fragment revealed 98.2% homology with the human mitochondrial 12S rRNA gene. Dot-blot analysis showed increased expression of this gem in nucleus accumbens and hippocampus, but not in the superior frontal cortex, primary motor cortex, caudate, and pallidus/putamen In a total of eight human alcoholic brains, compared with seven control brains. A similar increased expression was observed by dot-blot analysis, using RNA from the cerebral cortex of rats chronically treated with alcohol vapor. Hybridization of a 16S rRNA oligonucleotide probe indicated that the expression of both rRNAs genes was significantly increased in nucleus accumbens. These results indicate that chronic alcohol consumption induces alteration in expression of mitochondrial genes in selected brain regions. The altered gene expression may reflect mitochondrial dysfunction In the alcohol-affected brain.

Approach to designing rotating drum bioreactors for solid-state fermentation on the basis of dimensionless design factors

The development of large-scale solid-stale fermentation (SSF) processes is hampered by the lack of simple tools for the design of SSF bioreactors. The use of semifundamental mathematical models to design and operate SSF bioreactors can be complex. In this work, dimensionless design factors are used to predict the effects of scale and of operational variables on the performance of rotating drum bioreactors. The dimensionless design factor (DDF) is a ratio of the rate of heat generation to the rate of heat removal at the time of peak heat production. It can be used to predict maximum temperatures reached within the substrate bed for given operational variables. Alternatively, given the maximum temperature that can be tolerated during the fermentation, it can be used to explore the combinations of operating variables that prevent that temperature from being exceeded. Comparison of the predictions of the DDF approach with literature data for operation of rotating drums suggests that the DDF is a useful tool. The DDF approach was used to explore the consequences of three scale-up strategies on the required air flow rates and maximum temperatures achieved in the substrate bed as the bioreactor size was increased on the basis of geometric similarity. The first of these strategies was to maintain the superficial flow rate of the process air through the drum constant. The second was to maintain the ratio of volumes of air per volume of bioreactor constant. The third strategy was to adjust the air flow rate with increase in scale in such a manner as to maintain constant the maximum temperature attained in the substrate bed during the fermentation. (C) 2000 John Wiley & Sons, Inc.

Pectinase production by solid fermentation from Aspergillus niger by a new prescription experiment

The Ordos Plateau in China is covered with up to 300,000 ha of peashrub (Caragana) which is the dominant natural vegetation and ideal for fodder production. To exploit peashrub fodder, it is crucially important to optimize the culture conditions, especially culture substrate to produce pectinase complex. In this study, a new prescription process was developed. The process, based on a uniform experimental design, first optimizes the solid substrate and second, after incubation, applies two different temperature treatments (30 degrees C for the first 30 h and 23 degrees C for the second 42 h) in the fermentation process. A multivariate regression analysis is applied to a number of independent variables (water, wheat bran, rice dextrose, ammonium sulfate, and Tween 80) to develop a predictive model of pectinase activity. A second-degree polynomial model is developed which accounts for an excellent proportion of the explained variation (R-2 = 97.7%). Using unconstrained mathematical programming, an optimized substrate prescription for pectinase production is subsequently developed. The mathematical analysis revealed that the optimal formula for pectinase production from Aspergillus niger by solid fermentation under the conditions of natural aeration, natural substrate pH (about 6.5), and environmental humidity of 60% is rice dextrose 8%, wheat bran 24%, ammonium sulfate ((NH4)(2)SO4) 6%, and water 61%. Tween 80 was found to have a negative effect on the production of pectinase in solid substrate. With this substrate prescription, pectinase produced by solid fermentation of A. niger reached 36.3IU/(gDM). Goats fed on the pectinase complex obtain an incremental increase of 0.47 kg day(-1) during the initial 25 days of feeding, which is a very promising new feeding prospect for the local peashrub. It is concluded that the new formula may be very useful for the sustainable development of and and semiarid pastures such as those of the Ordos Plateau. (c) 2005 Elsevier Inc. All rights reserved.

Molecular cloning and characterization of hNP22: a gene up-regulated in human alcoholic brain

An improved differential display technique was used to search for changes in gene expression in the superior frontal cortex of alcoholics, A cDNA fragment was retrieved and cloned. Further sequence of the cDNA was determined from 5' RACE and screening of a human brain cDNA library. The gene was named hNP22 (human neuronal protein 22). The deduced protein sequence of hNP22 has an estimated molecular mass of 22.4 kDa with a putative calcium-binding site, and phosphorylation sites for casein kinase II and protein kinase C. The deduced amino acid sequence of hNP22 shares homology (from 67% to 42%) with four other proteins, SM22 alpha, calponin, myophilin and mp20. Sequence homology suggests a potential interaction of hNP22 with cytoskeletal elements. hNP22 mRNA was expressed in various brain regions but in alcoholics, greater mRNA expression occurred in the superior frontal cortex, but not in the primary motor cortex or cerebellum. The results suggest that hNP22 may have a role in alcohol-related adaptations and may mediate regulatory signal transduction pathways in neurones.

Recent advances in the pathology of alcoholic myopathy

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chairs were Victor R. Preedy and Junko Adachi. The presentations were (1) Alcoholic myopathy: Past, present and future, by Timothy J. Peters and Victor R. Preedy; (2) Protein adducts in the type I and II fiber-predominant muscles of the ethanol-fed rat, by Simon Worrall, Seppo Parkkila, and Onni Niemela; (3) Hydroperoxides and changes in alcoholic myopathy, by Junko Adachi, Migiwa Asamo, and Yasuhino Ueno; and (4) A close association between testicular atrophy, muscle atrophy, and the increase in protein catabolism after chronic ethanol administration, by Kunihiko Takeda, Masayoshi Yamauchi, Kazuhiko Sakamoto, Masaru Takagi, Hisato Nakajima, and Gotaro Toda.

Effect of supplementation with a by-product of molasses fermentation or a non-protein nitrogen/mineral mix on feed intake and microbial protein supply in sheep consuming chopped oat (Avena sativa) hay

Crossbred ewes, weighing 30-40 kg, were assigned to three groups of six animals. One group of sheep was fed chopped oat hay (control), the second group was fed the control diet plus 30 g per head per day spray dried residue from the fermentation of molasses and the third group was fed the control diet plus 30 g per head per day of a non-protein nitrogen/mineral mix. Voluntary feed intake, digestibility of DM, OM and nitrogen, nitrogen balance and microbial nitrogen flow to the intestines were significantly increased by supplementation but efficiency of microbial protein production was not affected. (C) 2001 Elsevier Science BN. All rights reserved,

Alcoholic liver disease: A clinical series in an Australian private practice

Background and Aim: The published literature on alcoholic liver disease (ALD) in Australia lacks a large clinical series out of private practice as distinct from hospital-based hepatology referral units. This series describes the presentation and clinical features of ALD in a consecutive series out of metropolitan private practice in Australia. Methods: A retrospective descriptive study by case-note review found 297 cases of ALD at a Brisbane practice over 20 years. The main outcome measures were: clinical features and stage at presentation, reasons for referral, and the predictive value of aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio. Results: Most patients (57.9%) had no symptoms of liver disease and 29 patients (9.8%) had neither symptoms nor signs. Cirrhosis was found in 41% of patients and hepatitis-fibrosis was found in 26% of patients. The male to female (M: F) ratio was 4.7:1. The AST/ALT ratio was not reliably predictive of ALD stage. The average reported daily alcohol intake was 131 g. Females drank less on average and presented a more vigorous clinical picture. Conclusions: This series presents the spectrum of ALD in a metropolitan Australian private practice. Many patients are asymptomatic on presentation. All heavy drinkers should be targeted for early investigation without waiting for volunteered symptoms or abnormal physical signs. The male to female ratio in ALD is higher than hitherto reported. The AST/ALT ratio is not generally applicable in the staging of ALD. The differences from hospital series data suggest the demography and epidemiology of ALD in Australia are incomplete, and further study is warranted. (C) 2001 Blackwell Science Asia Pty Ltd.

Free radicals in alcoholic myopathy: Indices of damage and preventive studies

Chronic alcoholic myopathy affects up to two-thirds of all alcohol misusers and is characterized by selective atrophy of Type If (glycolytic, fast-twitch, anaerobic) fibers. In contrast, the Type I fibers (oxidative, slow-twitch, aerobic) are relatively protected. Alcohol increases the concentration of cholesterol hydroperoxides and malondialdehyde-protein adducts, though protein-carbonyl concentration levels do not appear to be overtly increased and may actually decrease in some studies. In alcoholics, plasma concentrations of a-tocopherol may be reduced in myopathic patients. However, a-tocopherol supplementation has failed to prevent either the loss of skeletal muscle protein or the reductions in protein synthesis in alcohol-dosed animals. The evidence for increased oxidative stress in alcohol-exposed skeletal muscle is thus inconsistent. Further work into the role of ROS in alcoholic myopathy is clearly warranted. (C) 2002 Elsevier Science Inc.

Increased TUNEL positive cells in human alcoholic brains

Alcohol-sensitive neuronal cell loss, which has been reported in the superior frontal cortex and hippocampus, may underlie the pathogenesis of subsequent cognitive deficits. In the present study, we have used the TUNEL labeling to detect the DNA damage in human alcoholic brains. Seven out of eleven alcoholics exhibited TUNEL-positive cells in both superior frontal cortex and hippocampus, which were co-localized with GFAP immunoreactivity. In contrast, almost no positive cells were detected in the non-alcoholic controls. None of the TUNEL-positive cells showed any typical morphological features of apoptosis or necrosis. TUNEL-positive cells observed in the present study may indicate DNA damage induced by ethanol-related overproduction of reactive oxygen species. (C) 2003 Elsevier Ireland Ltd. All rights reserved.