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PubMed2001

Inhibition of growth of methane-producing bacteria of the ruminant forestomach by hydroxymethylglutaryl-SCoA reductase inhibitors.

Two hydroxymethylglutaryl-SCoA (HMG-CoA) reductase inhibitors, mevastatin and lovastatin, inhibited the in vitro growth and production of CH4 of strains of Methanobrevibacter isolated from the rumen. Mevastatin or lovastatin did not inhibit growth of species of rumen bacteria that are essential for fermenting cellulose, starch and other plant polysaccharides to acetate, propionate, and butyrate. Approximately 4 nmol of lovastatin per milliliter resulted in 50% growth inhibition of Methanobrevibacter strain ZA10 and concentrations > or =10 nmol per milliliter completely inhibited growth and CH4 formation. Results of in vitro growth studies suggest that supplementation of ruminant feeds with HMG-CoA inhibitors could decrease ruminant methane production and increase the efficiency of feed utilization by domestic ruminants.

Animals↗
PubMed1995

New antibiotics phthoxazolins B, C and D produced by Streptomyces sp. KO-7888.

New antibiotics, phthoxazolins B, C and D were isolated from the fermentation broth of Streptomyces sp. KO-7888. They are geometrical isomers of 10-hydroxyphthoxazolin A. They showed selective antifungal activity against Phytophthora parasitica in vitro and modest herbicidal activity in a laboratory test, but the potencies were different among isomers.

Antifungal Agents↗
PubMed1991

Optimization of cultivation and nutrition conditions and substrate pretreatment for solid-substrate fermentation of wheat straw by Coriolus versicolor.

Bioconversion of wheat straw by solid-substrate fermentation (SSF) with Coriolus versicolor was optimized by varying its physiological parameters. Selective delignification (more lignin than holocellulose degradation) and increases in crude protein (CP) content and in vitro dry matter digestibility (IVDMD) were taken as the criteria to select optimum levels of these parameters. The fungus behaved optimally under the following set of cultural and nutritional conditions: pH 5.5, moisture level 55%, temperature 30 degrees C, duration of fermentation 21 d, form of inoculum--grain culture, turning frequency--once at mid-incubation, urea (nitrogen source) 1.5% (sterile) or 3.0% (nonsterile), single superphosphate (phosphorus + sulfur source) 1.0%, no addition of free polysaccharides (as whey or molasses). A maximum of 17.5% increase in IVDMD involving 4.3% degradation of lignin, was attained in the optimized SSF under laboratory conditions. The digestibility improvement could be further increased by using a substrate pretreatment (physical/chemical/biological) in the following order of preference: NaOH treatment, urea or urine treatment, ensiling, steaming, grinding. For practical farm applications, urea treatment and ensiling appeared most feasible. The laboratory optimized process was also scaled up to 4 kg (sterile and unsterile) and 50 kg (unsterile) fermentations.

Animal Feed↗
PubMed1975

Leukaemomycin, an antibiotic with antitumor activity. I. Screening, fermentation, and biological activity.

A Streptomyces strain belonging to S. griseus (Krainski) Waksman et Henrici 1948 sensu Hütter (1967) was found to produce an antibiotic designated as leukaemomycin. The red-pigment antibiotic, having antimicrobial and antitumor activity in vitro and in vivo, was isolated from C-, N-, and Fe-containing cultures of the strains IMET JA 3933, IMET JA 5570, IMET JA 10086, and IMET JA 10431. Leukaemomycin has indicator properties and is produced by the classic procedures of submerged fermentation. The crude base of leukaemomycin consists of 4 main components, designated as leukaemomycin A, B, C, and D. The biological activity of the main components leukaemomycin B and C was compared. The biological activity and the physicochemical properties of leukaemomycin C are identical with known properties of the anthracycline antibiotic daunorubicin.

Animals↗
PubMed2002

Antioxidative activity and safety of the 50 ethanolic extract from red bean fermented by Bacillus subtilis IMR-NK1.

This study aimed at evaluating the antioxidative activities and the safety of 50% ethanolic extract from red bean fermented by Bacillus subtillis IMR-NK1. The antioxidative activities, including alpha,alpha-diphenyl-beta-picryl-hydrazyl (DPPH) radicals scavenging effects, Fe(2+)-chelating ability, and reducing power, were studied in vitro. It was found that the antioxidative activity increased with the concentrations of the extract to a certain extent and then leveled off as the concentration further increased. As compared to the commercial antioxidants, the fermented red bean extract showed less scavenging effect on the DPPH radical and reducing power than alpha-tocopherol and BHT, but better Fe(2+)-chelating ability. No mutagenicity or toxicity effect toward all tester strains was found in the 50% ethanolic extract of fermented red bean by means of the Ames test. The results suggested that the 50% ethanolic extract was safe in genotoxicity.

Antioxidants↗
PubMed1984

Irumamycin, an antifungal 20-membered macrolide produced by a Streptomyces. Taxonomy, fermentation and biological properties.

Irumamycin is a new 20-membered macrolide antibiotic isolated from a culture broth of a soil isolate which was named Streptomyces subflavus subsp. irumaensis AM-3603. It is active in vitro against some phytopathogenic fungi, but inactive against most aerobic and anaerobic bacteria and mycoplasmas. The potent in vitro activity and the results of preliminary pot tests indicated that the antibiotic is practicable as an agricultural antifungal agent.

Anti-Bacterial Agents↗
PubMed1996

In vitro contractile effects of short chain fatty acids in the rat terminal ileum.

Short chain fatty acids (SCFAs), produced in the gut by bacterial fermentation of carbohydrates, change intestinal motility by mechanisms as yet unknown. This study examined the mechanism(s) of action of SCFAs on contractility using isolated rat terminal ileum segments and isolated ileal smooth muscle cells. Strip contractions were recorded under isometric conditions. Intracellular calcium concentration ([Ca2+]i) was measured in single cells loaded with indo-1 penta-acetoxymethyl ester (indo-1 AM). SCFAs (10(-9) to 10(-2) mol/l) induced concentration dependent contractions. The effect was not different among the individual SCFAs. Exogenous acids (namely tartaric and citric acids) caused similar responses as SCFAs, whereas sodium acetate had no effect. The contraction was not blocked by tetrodotoxin, atropine or hexamethonium, showing that it was not mediated through a cholinergic pathway. Moreover, removal of the mucosa or addition of procaine (a local anaesthetic) to the bath did not change the SCFA induced contraction, while verapamil (a calcium-channel antagonist) completely suppressed it. In addition, application of SCFAs to isolated ileal myocytes evoked peaks in [Ca2+]i inhibited by D 600 (a blocker of voltage dependent calcium channels). Taken together, these results suggest that the contractile response stimulated by SCFAs in the rat terminal ileum could result from an acid sensitive calcium dependent myogenic mechanism.

Acetates↗
PubMed1986

In vitro activity of ciprofloxacin against aminoglycoside-sensitive and -resistant gram-negative rods.

Ciprofloxacin's activity against 233 clinically isolated strains of both fermentative and non-fermentative bacilli was tested. In particular the authors studied the sensitivity of aminoglycoside-resistant gram-negative bacilli to ciprofloxacin. The results showed that all fermentative gram-negative bacteria were sensitive to ciprofloxacin (MICs range less than or equal to 0.02 - 1.56 mg/l). Among the non-fermentative bacilli, Pseudomonas were generally susceptible to ciprofloxacin (MIC90 less than or equal to 1.56 mg/l) except for P. cepacia and P. fluorescens (MIC90 less than or equal to 3.12 mg/l). The best antibiotic activity was shown against Moraxella, A. xylosoxidans and A. hydrophila (MICs less than or equal to 0.09 mg/l). MICs for Acinetobacter and A. faecalis were less than or equal to 1.56 mg/l while Flavobacterium were more resistant (range 1.56-3.12 mg/l). Furthermore, ciprofloxacin showed good activity against 44 aminoglycoside-resistant isolates, showing a very low (13%) incidence of resistance.

Aminoglycosides↗
PubMed1978

Effect of lactulose on ammonia production in a fecal incubation system.

An in vitro fecal incubation system was used to demonstrate how lactulose influences ammonia metabolism in the colon. Lactulose and other fermentable substrates (glucose, mannitol, and sorbitol), pH and organic acid were varied independently so that their different effects could be determined. Fermentable substrate caused a fall in ammonia concentration during the period of fermentation. Acidification to pH 5.0 or less, with hydrochloric acid or a lactic-acetic acid mixture, significantly reduced ammonia generation, but unlike fermentable substrates, did not lower the existing ammonia concentration. The lactic-acetic acid mixture did not reduce ammonia generation significantly below that found with acidification by hydrochloric acid. The effect of lactulose in reducing ammonia concentration is attributed to its role as a bacterial substrate in either increasing bacterial assimilation of ammonia or reducing deamination of nitrogenous compounds. The effect of low pH in reducing generation of ammonia appears to be part of a general reduction in bacterial metabolism.

Ammonia↗
PubMed2000

Response of selected poultry cecal probiotic bacteria and a primary poultry Salmonella typhimurium isolate grown with or without glucose in liquid batch culture.

The objective of this study was to determine whether fermentation by a cecal probiotic co-culture of an Enterococcus sp. and Veillonella sp. would inhibit the in vitro growth of a S. typhimurium poultry isolate. The growth rates of S. typhimurium and Enterococcus were significantly reduced at pH 5. At the two pH levels, there was a significant (p < 0.001) increase at 24 h in colony forming units for each of the bacteria enumerated from the mixed culture compared to the respective pure culture enumerations. S. typhimurium was not inhibited in mixed cultures. The mixed cultures produced more acetate than any of the pure cultures and lactate produced by Enterococcus appeared to be utilized by Veillonella.

Animals↗
PubMed2003

Double blind, placebo controlled trial of two probiotic strains in interleukin 10 knockout mice and mechanistic link with cytokine balance.

BACKGROUND: Prophylactic efficacy against colitis following lactobacillus consumption in interleukin 10 (IL-10) knockout (KO) mice has been reported. Whether this applies equally to other probiotic strains is unknown, and the mechanism is unclear. AIMS: (1) To compare the effect of feeding Lactobacillus salivarius subspecies salivarius 433118 and Bifidobacterium infantis 35624 against placebo on enterocolitis, the intestinal microflora, and (2) to compare the systemic immunological response to in vitro microbial challenge in probiotic fed and control IL-10 KO mice. METHODS: Three groups of 10 IL-10 KO mice were fed fermented milk products containing Lb salivarius 433118 at 10(9) CFU/ml, B infantis 35624 at 10(8) CFU/ml, and unmodified milk, respectively, for 19 weeks. Faecal samples were taken at regular intervals to confirm gut transit, recovery of fed probiotics, and to assess the impact on the microflora. At sacrifice, the bowels were histologically scored. Cytokine production from Peyers' patches and splenocytes was measured in vitro by ELISA. RESULTS: Faecal recovery of probiotics was confirmed in all probiotic fed mice but not in controls. Colonic and caecal inflammatory scores were significantly decreased in both groups of probiotic fed mice (p<0.05). Proinflammatory cytokine production by Peyers' patches and splenocytes was significantly reduced in probiotic fed animals whereas transforming growth factor beta (TGF-beta) levels were maintained. CONCLUSION: Both Lactobacillus salivarius 433118 and Bifidobacterium infantis 35624 significantly attenuate colitis in this murine model. Attenuation of colitis is associated with a reduced ability to produce Th1-type cytokines systemically and mucosally, while levels of TGF-beta are maintained.

Animals↗
PubMed1998

Comparison of diarrhea induced by ingestion of fructooligosaccharide Idolax and disaccharide lactulose: role of osmolarity versus fermentation of malabsorbed carbohydrate.

Whether carbohydrate malabsorption causes diarrhea probably depends on the balance between the osmotic force of the carbohydrate and the compensatory capacity of the colon to dispose of the carbohydrate by bacterial fermentation. The present study evaluated the specific role of the osmolarity by comparing the severity of diarrhea after ingestion of two nonabsorbable carbohydrates, the fructooligosaccharide Idolax and the disaccharide lactulose. Both carbohydrates are readily fermented by the colonic flora but differ in osmolarity, the osmotic force being twice as high for lactulose as for Idolax. Twelve subjects were given increasing doses (0, 20, 40, 80, 160 g/d) of Idolax and lactulose in a crossover design. Every dose level was administered for three days with intervals of one week. Stools were collected on the third day to determine 24-hr volume, concentrations of short-chain fatty acids, L- and D-lactate, residues of Idolax or lactulose, sodium, potassium, pH, osmolarity, and in vitro productions of organic acids. Measured by short-chain fatty acid and lactate formation in a fecal incubation system, the fermentation of Idolax and lactulose was identical and very rapid compared with a range of reference carbohydrates. A laxative effect of both Idolax and lactulose was demonstrated. The increment in fecal volume as a function of the dose administered was twice as high for lactulose (slope of the regression line = 7.3, r = 0.64, P< 10(-5)) as for Idolax (slope = 3.7, r = 0.51, P<10(-3)), i.e., isosmolar doses of lactulose and Idolax had the same effect on fecal volume. The variation in fecal volume was substantial (lactulose 80 g/day: 110-1360 g/day; Idolax 160 g/day: 130-1440 g/day). High responders had earlier and larger fecal excretions of the saccharide compared with low-responders. Fecal volume in carbohydrate-induced diarrhea is proportional to the osmotic force of the malabsorbed saccharide, even though all or the majority of the saccharide is degraded by colonic bacteria. The capacity to modify the diarrhea varies considerably from person to person and is associated with colonic saccharide disposal, whereas the variation in response to isosmolar amounts of different saccharides is small within the same individual.

Adult↗
PubMed2006

Nutrition and cancer risk: an overview.

The role of diet in cancer is a major public health issue Foods associated with a low risk of cancer are those typically included in the so-called Mediterranean diet, which is also associated with low mortality rates from cardiovascular disease. Implementing such a diet would involve increasing the consumption of fruits, vegetables, cereals, whole-grain foods and fish, while reducing the intake of refined carbohydrates and red meat. In addition, olive oil should replace saturated fats. Omega-3 fatty acids found in fish inhibit the growth in vitro of colon, breast and prostate cancers. Fibre can bind bile acids, which produce carcinogenic metabolites, and fermented fibre produces volatile fatty acids that can protect against colon cancer. It has been hypothesized that the anti-cancer actions of olive oil may relate to the ability of its mono-unsaturated fatty acid, oleic acid, to regulate oncogenes.

Diet, Mediterranean↗
PubMed2006

Meroparamycin production by newly isolated Streptomyces sp. strain MAR01: taxonomy, fermentation, purification and structural elucidation.

Twelve actinomycete strains were isolated from Egyptian soil. The isolated actinomycete strains were then screened with regard to their potential to generate antibiotics. The most potent of the producer strains was selected and identified. The cultural and physiological characteristics of the strain identified the strain as a member of the genus Streptomyces. The nucleotide sequence of the 16S rRNA gene (1.5 kb) of the most potent strain evidenced a 99% similarity with Streptomyces spp. and S. aureofaciens 16S rRNA genes, and the isolated strain was ultimately identified as Streptomyces sp. MAR01. The extraction of the fermentation broth of this strain resulted in the isolation of one major compound, which was active in vitro against gram-positive, gram-negative representatives and Candida albicans. The chemical structure of this bioactive compound was elucidated based on the spectroscopic data obtained from the application of MS, IR, UV, 1H NMR, 13C NMR, and elemental analysis techniques. Via comparison to the reference data in the relevant literature and in the database search, this antibiotic, which had a molecular formula of C19H29NO2 and a molecular weight of 303.44, was determined to differ from those produced by this genus as well as the available known antibiotics. Therefore, this antibiotic was designated Meroparamycin.

Anti-Bacterial Agents↗
PubMed2005

Mechanisms underlying the effects of inulin-type fructans on calcium absorption in the large intestine of rats.

Inulin-type fructans (inulin, oligofructose, fructooligosaccharides) in the diet do increase intestinal calcium absorption in animals and humans, but the underlying mechanism has not been identified. We therefore assessed the effects of fermentation of inulin-type fructans on transepithelial calcium transport in rat large intestine. Transepithelial calcium fluxes in vitro (Ussing chamber), effects on gene expression, mucosal morphology, and composition of luminal contents were determined in rats fed a standard diet and/or a diet containing 10% (w/w) 1/1 inulin-oligofructose mixture (INOF). Net transepithelial calcium transport in large intestine of rats fed a standard diet was increased by high mucosal calcium concentrations, the presence of 100 mmol/L mucosal short-chain fatty acids (SCFAs), the presence of 10 g/L INOF at the mucosal side, but not by reducing mucosal pH. Tissues from rats fed INOF did not show altered calcium transport when compared to controls. However, when flux data were based on the total caecal surface area, INOF-fed rats nearly doubled absorption rate in caecum. INOF feeding altered transcript levels of several mucosal genes that can be linked to transcellular and paracellular calcium transport processes. In addition, a decreased luminal pH in caecum with markedly increased caecal pools of total, soluble, and ionized calcium resulted from INOF ingestion. Thus, inulin-type fructans increase the large intestinal calcium absorption by different mechanisms including enhanced pools of soluble and ionized calcium, an increase in the absorptive surface predominantly in caecum, the increased concentrations of SCFAs, and by direct interaction with the intestinal tissue.

Animals↗