PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “MOLASSES”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources
PubMed1979

[On the contamination of the citric acid fermentation. II. Sodium 5-nitrofurylacrylate as an antiseptic against representatives of the Enterobacteriaceae (author's transl)].

In context with the first communication which deals with the characterization of the so-called brown contamination called forth by Enterobacteriaceae in the citric acid fermentation of molasses, the present paper describes the screening of antiseptic substances able to suppress the contamination mentioned without damaging the normal growth of the producing mould Aspergillus niger and its ability of producing citric acid. Among the substances tested the sodium salt of 5-nitrofurylacrylic acid (5-NFA) excelled partly because of its antiseptic effect in relatively small concentrations and partly because the mould tolerates appreciable amounts of this antiseptic. Therefore there may be applied, in the presence of a heavy contamination, relatively high concentrations of the antiseptic without fear of damaging the producing mould. Usually a dose of 10 to 15 mg 5-NFA in 11 of medium was sufficient to suppress the brown contamination.

Acrylates↗
PubMed1980

[Studies of the nitrogen and carbon content of culture media and of mushrooms, as well as the free amino acid composition of myecelia and fruiting bodies of Lentinus edodes].

The level contents of nitrogen and carbon in the analysed nature substances may be considered the reason for the good growth of Lentinus edodes on this culture medium (sugar-beet molasses and sawdust). The separate parts of fruit-bodies are showing differences in contents of nitrogen, carbon and free amino-acids; the gills have the highest, the stalk the lowest concentration, that of the hats is taking a middle position. Young and old mycelia as well as the separate parts of fruit bodies are different out of total concentration also in composition of free amino acids. This may be a direction to development and transformations during the change from the vegetative to the reproductive phase.

Agaricales↗
PubMed1993

[Microbial silage production from eviscerated fish].

Microbial fish silage was produced from a mixture of several fish species that belong to the shrimp by-catch. They were mixed with molasses, fruits (pineapple and papaya), sorbate and a starter of Lactobacillus plantarum ATCC8014. Process was evaluated by pH, acidity, consistency, exudate liquid, non-protein nitrogen, total volatile bases, microbial and toxicological tests. Results indicated that acid production and pH reduction occurs during the first two days of processing, later these values were maintained stable during 64 storage days. Total volatile bases increased during storage period. Consistency, non-protein nitrogen and exudate liquid showed that hydrolysis and liquefaction occurs during the first 8 days of processing. Raw material showed high counts of aerobic mesophilic and psicrotrophic organisms, in addition to Pseudomonas, coliform and S. aureus. However silage showed only a few aerobic mesophilic organisms due to low pH values and development of lactic acid bacteria. Silage dehydration reduces possibilities of microbial growth, and only spores of Bacillus were observed. Low levels of lead, mercury and chrome were detected in the dry silage. Proximal analysis values did not change during process and storage period.

Aerobiosis↗
PubMed1998

Agar immobilized yeast cells in tubular reactor for ethanol production.

Saccharomyces cerevisiae cells were immobilized in agar gel and used in a tubular reactor for conversion of cane molasses to ethanol at 30 degrees C, pH 4.5. Reactor was used in a continuous operation to test the operational stability and ethanol productivity. After 100 days of continuous fermentation at a dilution rate of 0.67 hr-1, some deactivation of cells was observed, but ethanol productivity was recovered by reactivating the cells by sparging air intermittently. It was found that intermittent reactivation during continuous operation was very important for satisfactory performance of the reactor. During operation, gel beads maintained their rigidity. Maximum ethanol concentration (94.9 g/L) was obtained with a feed containing 255 g/L reducing sugar, at a dilution rate of 0.2 hr-1. Maximum volumetric productivity (79.5 g ethanol /L/hr), specific ethanol productivity (0.58 g ethanol/g cells/hr), specific sugar uptake rate (1.12 g sugar/g cells/hr) and ethanol yield coefficient (0.43 g ethanol/g sugar) were obtained with a feed containing 195 g/L reducing sugar at a dilution rate of 1.33 hr-1.

Agar↗
PubMed1997

Stationary-phase gene expression in Saccharomyces cerevisiae during wine fermentation.

Genetic engineering of wine yeast strains requires the identification of gene promoters specifically activated under wine processing conditions. In this study, transcriptional activation of specific genes was followed during the time course of wine fermentation by quantifying mRNA levels in a haploid wine strain of Saccharomyces cerevisiae grown on synthetic or natural winery musts. Northern analyses were performed using radioactive probes from 19 genes previously described as being expressed under laboratory growth conditions or on molasses in S. cerevisiae during the stationary phase and/or under nitrogen starvation. Nine genes, including members of the HSP family, showed a transition-phase induction profile. For three of them, mRNA transcripts could be detected until the end of the fermentation. Expression of one of these genes, HSP30, was further studied using a HSP30::lacZ fusion on both multicopy and monocopy expression vectors. The production of beta-galactosidase by recombinant cells was measured during cell growth and fermentation on synthetic and natural winery musts. We showed that the HSP30 promoter can induce high gene expression during late stationary phase and remains active until the end of the wine fermentation process. Similar expression profiles were obtained on five natural winery musts.

Fermentation↗
PubMed1999

Scale-up of citric acid fermentation by redox potential control

To obtain high citric acid productivity in Aspergillus niger fermentation on beet molasses substrate, a certain redox potential profile with two maxima (260 and 280 mV) and two minima (180 and 80 mV) must be maintained. The most effective regulation of redox potential is by regulation of aeration and agitation. It has been shown that control of redox potential by aeration and agitation is a most successful method for scale-up from 10-L laboratory scale to the 100- and 1000-L pilot-plant scale, even in geometrically dissimilar stirred-tank reactors. Copyright 1999 John Wiley & Sons, Inc.

Journal Article↗
PubMed2000

Measurement of heat evolution and correlation with oxygen consumption during microbial growth. Reprinted from Biotechnology and Bioengineering, Vol. XI, Issue 3, Pages 269-281 (1968).

A procedure for measuring the rate of heat production from a fermentation has been developed. The method is based on measuring the rate of temperature rise of the fermentation broth resulting from metabolism, when the temperature controller is turned off. The heat accumulation measured in this manner is then corrected for heat losses and gains. A sensitive thermistor is used to follow the temperature rise with time. This procedure is shown to be as accurate as previous methods but much simpler in execution. Using this technique, the rate of heat production during metabolism was found to correlate with the rate of oxygen consumption. Experiments were performed using bacteria (E. coli and B. subtilis), a yeast (C. intermedia), and a mold (A. niger). The substrates investigated included glucose, molasses, and soy bean meal. The proportionality constant for the correlation is independent of the growth rate, slightly dependent on the substrate, and possibly dependent on the type of organism growth. This correlation has considerable potential for predicting heat evolution from the metabolism of microorganisms on simple or complex substrates and providing quantitative parameters necessary for heat removal calculations.

Aspergillus niger↗
PubMed2000

Pyrolysis/gas chromatography/mass spectrometry monitoring of fungal-biotreated distillery wastewater using Trametes sp. I-62 (CECT 20197).

Distillery wastewaters generated by ethanol production from fermentation of sugar-cane molasses, named vinasses, lead to important ecological impact due to their high content of soluble organic matter and their intense dark-brown color. Taking advantage of the well-known ability of white-rot fungi to degrade an extensive variety of organic pollutants, the capacity of Trametes sp. I-62 (CECT 20197) to detoxify this type of effluents was evaluated. In this work, pyrolysis/gas chromatography/mass spectrometry was applied to the chemical characterization of several fractions of Cuban distillery wastewater as well as to monitoring the changes which occurred after fungal treatment with this white-rot basidiomycete. Maximum effluent decolorization values and chemical oxygen demand reduction attained after seven days of fungal treatment were 73.3 and 61.7%, respectively, when 20% (v/v) of distillery vinasses was added to the culture medium. Under these conditions a 35-fold increase in laccase production by Trametes sp. I-62 was measured, but no manganese peroxidase activity could be detected. The pyrolysis/gas chromatography/mass spectrometry results showed a decrease in a number of pyrolysis products after seven days of fungal treatment, mainly furan derivatives. The decrease in the relative areas of these compounds could be related to the vinasse color-removal associated with melanoidin degradation. All these results indicated the potential use ofTrametes sp. I-62 in the detoxification of recalcitrant distillery vinasses.

Fermentation↗
PubMed2005

Production of 2-phenylethanol and 2-phenylethylacetate from L-phenylalanine by coupling whole-cell biocatalysis with organophilic pervaporation.

An integrated bioprocess for the production of the natural rose-like aroma compounds, 2-phenylethanol (2-PE) and 2-phenylethylacetate (2-PEAc), from L-phenylalanine (L-phe) with yeasts was investigated. The hydrophobicity of the products leads to product inhibition, which can be compensated by in situ product removal (ISPR). An organophilic pervaporation unit, equipped with a polyoctylmethylsiloxane (POMS) membrane, was coupled via a bypass to a bioreactor and proved to be a suitable technique for the in situ removal of high-boiling products from culture broth. With batch cultures of the thermotolerant yeast Kluyveromyces marxianus CBS 600 in a standard medium at 35 degrees C, the use of pervaporation resulted in a double 2-PE concentration (2.2 g/L) and 1.3 g/L 2-PEAc, which only accumulated transiently in low concentrations during cultivation without ISPR. Using a previously optimized medium, the variation of the temperature from 30 degrees C to 40 degrees C caused an increase in the total conversion yield from 63% to 79%, corresponding to total product concentrations of 5.23 and 5.85 g/L, respectively. In the 40 degrees C batch experiment, the volumetric productivity (2-PE + 2-PEAc) during the exponential phase was 5.2 mmol/L h. While for 2-PE, there is still potential for further optimization, the more hydrophobic 2-PEAc was nearly completely removed from the aqueous culture broth (enrichment factor >400), resulting in highly aroma-enriched permeates. Due to the temperature-correlated performance of the pervaporation, the bioconversion was still efficient even at 45 degrees C (conversion yield: 69%). Surprisingly, at 45 degrees C, the molar ratio of the two products inverted and 2-PEAc turned out to be the main product (4.0 g/L), which opens easy control of the reaction's selectivity by external means. Retrofitting the process with interim heating and cooling equipment to use different temperature levels for cultivation and pervaporation resulted in a decreased yield and product concentration caused by multiple stress factors. The medium composition affected the pervaporation efficiency with molasses acting detrimental.

Acetates↗
PubMed1977

Some observations on oscillatory changes in the growth rate of Saccharomyces cerevisiae in aerobic continuous undisturbed culture.

Oscillatory changes in the growth rate were observed in undisturbed continuous culture of Saccharomyces cerevisiae on sugar-cane molasses media when nitrogen sources (2.56 to 6.17 g/liter of ammonium sulfate or 1.22 g/liter of urea) were added to the feeding mash and when the air rate was 1.3 to 1.6 v/v/m. The oscillations were not affected by the addition of yeast extract. The suppression of the nitrogen source during the continous test leads to a nonoscillatory transient state. No oscillations occured at all when no nitrogen source was added to the medium and/or the air rate was equal to zero or equal to about 3.3 v/v/m. The oscillatory responses of the system were affected by a previous anaerobic continuous cultivation of the yeast.

Aerobiosis↗
PubMed2004

Influence of growth conditions on the production of a bacteriocin by Lactococcus lactis subsp. lactis ST34BR, a strain isolated from barley beer.

Bacteriocin ST34BR, a small polypeptide of 2.9 kDa produced by Lactococcus lactis subsp. lactis ST34BR, inhibits the growth of Enterococcus faecalis, Escherichia coli, Lactobacillus plantarum, Lactobacillus casei, Pseudomonas aeruginosa and Staphylococcus aureus. MRS broth, adjusted to pH 6.0 yielded 6,400 AU/ml, compared to 400 AU/ml recorded in BHI broth, M17 broth, 10% (w/v) soy milk, and 8% and 10% (w/v) molasses. At pH of 4.5 only 800 AU/ml was produced. Based on comparative studies in MRS broth, without organic nitrogen, supplemented with different combinations of tryptone, meat extract and yeast extract, tryptone was identified as the stimulating nitrogen compound. Growth in the presence of 20 g/l glucose, maltose, mannose or sucrose yielded bacteriocin levels of 6,400 AU/ml, whereas the same concentration of lactose and fructose yielded 3,200 AU/ml and 1,600 AU/ml, respectively. No difference in bacteriocin ST34BR activity was recorded in MRS broth supplemented with 2 g/l K2HPO4 and 2 g/l, 5 g/l, 10 g/l or 50 g/l KH2PO4. However, 20 g/l KH2PO4 increased bacteriocin ST34BR production to 12,800 AU/ml. Glycerol at 1g/l to 10 g/l in MRS broth reduced bacteriocin activity to 3,200 AU/ml, whilst 20 g/l and 50 g/l yielded only 1,600 AU/ml. The presence of cyanocobalamin, L-ascorbic acid, thiamine and DL-6,8-thioctic acid in MRS broth at 1.0 ppm, respectively, did not result in increased activity levels.

Animals↗
PubMed2004

Comparison of Botryosphaeran production by the ascomyceteous fungus Botryosphaeria sp., grown on different carbohydrate carbon sources, and their partial structural features.

The influence of glucose concentration and other carbohydrates (monosaccharides: fructose, galactose, mannose; polyols: mannitol and sorbitol; disaccharides: lactose, sucrose and commercial sucrose; and industrial sugarcane molasses) were compared as sole carbon sources for the production of Botryosphaeran, an exopolysaccharide (EPS) produced by Botryosphaeria sp. The optimum glucose concentration for EPS production was 50 g l(-1). With the exception of mannitol, the fungus produced EPS on all carbon sources studied, with highest yields occurring with sucrose followed by glucose. All EPS showed exclusively glucose after acid hydrolysis and monosaccharide analysis. FTIR spectroscopy demonstrated the presence of beta-anomers indicating that all the EPS produced by Botryosphaeria sp. on the different carbon sources were essentially of the beta-D-glucan type.

Ascomycota↗
PubMed1990

Protein extracts for nutritional purposes from fragile strains of Saccharomyces cerevisiae: reduction of the nucleic acid content and applicability of the protein extracts.

92% of the cellular proteins from the osmotically fragile strain Sacch. cerevisiae 211 (MATa srbl srb2 tsl) were extracted by one passage in a high pressure disintegrator at 650 atm. After isoelectric precipitation, 60.1% of the proteins were isolated. The protein extract was rich in proteins (60-70%) but also contained 12-13% nucleic acids and 13-14% carbohydrates. Mild conditions were created for simultaneous reduction of nucleic acids and carbohydrates in the lysate prior to precipitation of proteins. Under these conditions the amount of nucleic acids in the protein extract was reduced to 2%, and that of the carbohydrates to 5.7%. As a result of the whole procedure on a pilot scale, 11 culture of Sacch. cerevisiae 211 grown in molasses based nutritional medium yielded 1 g protein extract. The applicability of this protein extract for nutritional purposes was demonstrated by determination of its amino acid composition, acute toxicity tests with Tetrahymena pyriformis and short-term animal nutrition tests. The results showed that the protein extract is a suitable source of SCP for nutritional purposes.

Amino Acids↗
PubMed1990

Protein extracts for nutritional purposes from fragile strains of Saccharomyces cerevisiae: construction of strains and conditions for lysis.

A superfragile strain, Saccharomyces cerevisiae 211, carrying three nonallelic nuclear determinants of cell lysis by osmotic shock was isolated from the haploid progeny of a cross between two laboratory fragile strains VY 1160 and SY 15. The strain Sacch. cerevisiae 211 is prototrophic, grows well in both laboratory and industrial media, only when supplemented with osmotic stabilizers. The average protein content of its biomass after growth in a molasses-based nutritional medium is 48.7%. In laboratory conditions this strain releases about 60% of its cellular proteins by spontaneous lysis in water. However, on a pilot scale the protein yield decreases to about 25%. After a single disintegration step at 650 atm, practically all of the cellular protein--91.5%, is extracted without any additional chemical treatment. This result cannot be reached in any of the wild type strains tested even after triple treatment at 650 atm.

Dietary Proteins↗
PubMed1997

Physiological and biochemical characterization of intergeneric hybrids of thermotolerant and non-thermotolerant yeasts.

Kluyveromyces-like intergeneric hybrids of thermotolerant Kluyveromyces marxianus and non-thermotolerant Saccharomyces cerevisiae, produced in a previous study by protoplasmic fusion, have been characterized. On molasses, these strains produced ethanol in excess of 6% (v/v) both at 30 and 45 degrees C as against 3% and 4.2% (v/v) by the former parent at 30 and 45 degrees C, respectively. In hybrids, the increase in ethanol production appeared to be a sequel to increased activities of alcohol dehydrogenase and pyruvate kinase, derived probably from S. cerevisiae parent. Hybrid ADH-isozyme pattern on polyacrylamide gel corroborated the presence of S. cerevisiae ADH in the tested hybrids. Regression analyses indicated a positive correlation between ethanol production and ADH or PK or both (r approximately 0.76-0.84).

Hybridization, Genetic↗
PubMed1978

Production of valine by a Bacillus sp.

A bacterium isolated from Burdwan (India) soil was found to accumulate L-valine in the growth medium and identified to be a strain of Bacillus subtilis. The strain is able to grow and accumulate valine in a purely synthetic medium, but supplementation of the synthetic medium with either Casamino acids or yeast extract or with both, significantly improves the yield. The entire fermentation period can be divided into a growth phase and a production phase, which can be prolonged by adjustment of pH to the neutral range. Among the different carbon and nitrogen sources tested glucose at 8.5% and L-glutamic acid at 0.8%, respectively, were found most suitable. Cane sugar molasses tested as a substitute for glucose significantly stimulated growth but valine production was less. Different vitamins tested stimulated growth and valine yield and an inoculum level of 10% (v/v) of the medium was found to be optimal. The yield of valine under optimal conditions was found to be 4.53 g per litre of the medium. Valine has been isolated in crystalline form from the fermented broth by ion exchange resin chromatography and found to be a pure sample of the L-isomer.

Bacillus subtilis↗
PubMed1982

[Utilization of paraffins and other noncarbohydrate carbon sources for microbial citric acid synthesis].

This article reviews the developments achieved in citrate and isocitrate accumulation with non-carbohydrate substrates by microorganisms presented as well in academic publications as in patients. The efficiency of citrate and isocitrate overproducing microorganisms and of mutants obtained thereof with respect to different carbon sources (n-alkanes, triglycerides, organic acids, etc.) is discussed. The influence of environmental conditions (media, pH etc.) and biochemical mechanisms which lead to metabolic overflow are emphasized. The kinetics of fermentation processes are described, calculations concerning carbon balances are involved. The production of by-products and the conversion of isocitrate to citrate is considered. The production of citric acid by yeasts which utilize different carbon sources may be economically feasible and an accession to the practized molasse-Aspergillus-process.

Aconitate Hydratase↗