THE ACTION OF MICRO-ORGANISMS ON FAT: III. OXIDATION AND HYDROLYSIS OF TRIOLEIN BY PURE CULTURES OF BACTERIA

1941 ◽  
Vol 19c (4) ◽  
pp. 106-110 ◽  
Author(s):  
C. H. Castell ◽  
E. H. Garrard
Keyword(s):  
Titratable Acidity ◽  
Hydrolytic Activity ◽  
Oxidative Rancidity ◽  
Bacterial Colony ◽  
Gram Negative ◽  
Pure Cultures ◽  
The Individual ◽  
Micro Organisms ◽  
Oxidase Reaction ◽  
Hydrolysis Of

The hydrolytic activity of 40 pure cultures of bacteria on triolein, as indicated by increased titratable acidity, has been recorded. Schiff and Kreis tests have been made on similar samples of triolein acted upon by pure cultures of bacteria, and the results of these tests are compared with the "oxidase reaction" of the individual cultures.The results indicate that most of the Gram-negative lipolytic organisms also oxidize the fat, and that there appears to be a definite relation between the "oxidase reaction" of a bacterial colony and the ability of the organisms to produce oxidative rancidity.

THE ACTION OF MICRO-ORGANISMS ON FAT: IV. OBSERVATIONS ON THE CHANGES PRODUCED IN GLOBULES OF TRIOLEIN BY PURE CULTURES OF BACTERIA

1941 ◽  
Vol 19c (4) ◽  
pp. 111-120 ◽  
Author(s):  
C. H. Castell ◽  
E. H. Garrard
Keyword(s):  
Lipolytic Activity ◽  
Nile Blue ◽  
Titratable Acidity ◽  
Bacterial Colony ◽  
Oil Emulsion ◽  
Oxidative Reactions ◽  
Pure Cultures ◽  
Agar Media ◽  
Micro Organisms ◽  
Oxidase Reaction

A series of observations have been made on the action of 60 cultures of bacteria on globules of triolein in oil emulsion agar media. Lipolytic activity as indicated by the colour reactions of Nile blue sulphate and methylene blue and the blue soap formation with copper sulphate has been shown to coincide with that of the same organisms as measured by the titratable acidity they produced in larger samples of the oil. Other Eh indicators have been shown to colour the globules around lipolytic colonies.Other changes in the colour and texture of the globules have been shown to coincide with the oxidative activity of the bacteria as measured by Kreis and Schiff tests on larger samples as well as by the oxidase reaction of the bacterial colony. Preliminary hydrolysis appears to hasten and intensify the oxidative reactions as indicated by the globules.Other colour reactions in the globules and the formation of various types of crystals have been observed and their significance discussed.

Analysis of Molecular Size Distributions of Cellulose Molecules during Hydrolysis of Cellulose by Recombinant Cellulomonas fimiβ-1,4-Glucanases

1998 ◽  
Vol 64 (7) ◽  
pp. 2374-2379 ◽  
Author(s):  
Henrik Stålbrand ◽  
Shawn D. Mansfield ◽  
John N. Saddler ◽  
Douglas G. Kilburn ◽  
R. Antony J. Warren ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Size ◽  
Cellulose Hydrolysis ◽  
Hydrolytic Activity ◽  
Cellulolytic Bacterium ◽  
Size Distributions ◽  
Cellulomonas Fimi ◽  
Hydrolysis Of Cellulose ◽  
The Individual ◽  
Hydrolysis Of

ABSTRACT Four β-1,4-glucanases (cellulases) of the cellulolytic bacteriumCellulomonas fimi were purified from Escherichia coli cells transformed with recombinant plasmids. Previous analyses using soluble substrates had suggested that CenA and CenC were endoglucanases while CbhA and CbhB resembled the exo-acting cellobiohydrolases produced by cellulolytic fungi. Analysis of molecular size distributions during cellulose hydrolysis by the individual enzymes confirmed these preliminary findings and provided further evidence that endoglucanase CenC has a more processive hydrolytic activity than CenA. The significant differences between the size distributions obtained during hydrolysis of bacterial microcrystalline cellulose and acid-swollen cellulose can be explained in terms of the accessibility of β-1,4-glucan chains to enzyme attack. Endoglucanases and cellobiohydrolases were much more easily distinguished when the acid-swollen substrate was used.

scholarly journals Animal Models in the Evaluation of the Effectiveness of Phage Therapy for Infections Caused by Gram-Negative Bacteria from the ESKAPE Group and the Reliability of Its Use in Humans

2021 ◽  
Vol 9 (2) ◽  
pp. 206
Author(s):  
Martyna Cieślik ◽  
Natalia Bagińska ◽  
Andrzej Górski ◽  
Ewa Jończyk-Matysiak
Keyword(s):  
Animal Models ◽  
Phage Therapy ◽  
Animal Experiments ◽  
Species Group ◽  
Effectiveness Evaluation ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Enterobacter Species ◽  
The Individual

The authors emphasize how extremely important it is to highlight the role played by animal models in an attempt to determine possible phage interactions with the organism into which it was introduced as well as to determine the safety and effectiveness of phage therapy in vivo taking into account the individual conditions of a given organism and its physiology. Animal models in which phages are used make it possible, among other things, to evaluate the effective therapeutic dose and to choose the possible route of phage administration depending on the type of infection developed. These results cannot be applied in detail to the human body, but the knowledge gained from animal experiments is invaluable and very helpful. We would like to highlight how useful animal models may be for the possible effectiveness evaluation of phage therapy in the case of infections caused by gram-negative bacteria from the ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter species) group of pathogens. In this review, we focus specifically on the data from the last few years.

scholarly journals Anaerobic hydrolysis of complex substrates in full-scale aerobic granular sludge: enzymatic activity determined in different sludge fractions

2021 ◽  
Author(s):  
Sara Toja Ortega ◽  
Mario Pronk ◽  
Merle K. de Kreuk
Keyword(s):  
Hydrolytic Enzymes ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Granular Sludge ◽  
Hydrolytic Activity ◽  
Full Scale ◽  
Aerobic Granular Sludge ◽  
Bulk Liquid ◽  
Granule Formation ◽  
Hydrolysis Of

Abstract Complex substrates, like proteins, carbohydrates, and lipids, are major components of domestic wastewater, and yet their degradation in biofilm-based wastewater treatment technologies, such as aerobic granular sludge (AGS), is not well understood. Hydrolysis is considered the rate-limiting step in the bioconversion of complex substrates, and as such, it will impact the utilization of a large wastewater COD (chemical oxygen demand) fraction by the biofilms or granules. To study the hydrolysis of complex substrates within these types of biomass, this paper investigates the anaerobic activity of major hydrolytic enzymes in the different sludge fractions of a full-scale AGS reactor. Chromogenic substrates were used under fully mixed anaerobic conditions to determine lipase, protease, α-glucosidase, and β-glucosidase activities in large granules (>1 mm in diameter), small granules (0.2–1 mm), flocculent sludge (0.045–0.2 mm), and bulk liquid. Furthermore, composition and hydrolytic activity of influent wastewater samples were determined. Our results showed an overcapacity of the sludge to hydrolyze wastewater soluble and colloidal polymeric substrates. The highest specific hydrolytic activity was associated with the flocculent sludge fraction (1.5–7.5 times that of large and smaller granules), in agreement with its large available surface area. However, the biomass in the full-scale reactor consisted of 84% large granules, making the large granules account for 55–68% of the total hydrolytic activity potential in the reactor. These observations shine a new light on the contribution of large granules to the conversion of polymeric COD and suggest that large granules can hydrolyze a significant amount of this influent fraction. The anaerobic removal of polymeric soluble and colloidal substrates could clarify the stable granule formation that is observed in full-scale installations, even when those are fed with complex wastewaters. Key points • Large and small granules contain >70% of the hydrolysis potential in an AGS reactor. • Flocculent sludge has high hydrolytic activity but constitutes <10% VS in AGS. • AGS has an overcapacity to hydrolyze complex substrates in domestic wastewater. Graphical abstract

scholarly journals Cell-free extracellular enzymatic activity is linked to seasonal temperature changes: a case study in the Baltic Sea

2016 ◽  
Vol 13 (9) ◽  
pp. 2815-2821 ◽  
Author(s):  
Federico Baltar ◽  
Catherine Legrand ◽  
Jarone Pinhassi
Keyword(s):  
Organic Matter ◽  
Baltic Sea ◽  
Extracellular Enzymes ◽  
Seasonal Pattern ◽  
Critical Factor ◽  
Hydrolytic Activity ◽  
Seasonal Temperature ◽  
The Baltic Sea ◽  
The Baltic ◽  
Hydrolysis Of

Abstract. Extracellular enzymatic activities (EEAs) are a crucial step in the degradation of organic matter. Dissolved (cell-free) extracellular enzymes in seawater can make up a significant contribution of the bulk EEA. However, the factors controlling the proportion of dissolved EEA in the marine environment remain unknown. Here we studied the seasonal changes in the proportion of dissolved relative to total EEA (of alkaline phosphatase (APase), β-glucosidase (BGase), and leucine aminopeptidase (LAPase)), in the Baltic Sea for 18 months. The proportion of dissolved EEA ranged between 37 and 100, 0 and 100, and 34 and 100 % for APase, BGase, and LAPase, respectively. A consistent seasonal pattern in the proportion of dissolved EEA was found among all the studied enzymes, with values up to 100 % during winter and  <  40 % during summer. A significant negative relation was found between the proportion of dissolved EEA and temperature, indicating that temperature might be a critical factor controlling the proportion of dissolved relative to total EEA in marine environments. Our results suggest a strong decoupling of hydrolysis rates from microbial dynamics in cold waters. This implies that under cold conditions, cell-free enzymes can contribute to substrate availability at large distances from the producing cell, increasing the dissociation between the hydrolysis of organic compounds and the actual microbes producing the enzymes. This might also suggest a potential effect of global warming on the hydrolysis of organic matter via a reduction of the contribution of cell-free enzymes to the bulk hydrolytic activity.

scholarly journals TLR4-dependent GM-CSF protects against lung injury in Gram-negative bacterial pneumonia

2012 ◽  
Vol 302 (5) ◽  
pp. L447-L454 ◽  
Author(s):  
Louis R. Standiford ◽  
Theodore J. Standiford ◽  
Michael J. Newstead ◽  
Xianying Zeng ◽  
Megan N. Ballinger ◽  
...  
Keyword(s):  
Lung Injury ◽  
Bacterial Pneumonia ◽  
Lavage Fluid ◽  
Alveolar Epithelial Cells ◽  
Intratracheal Administration ◽  
Bacterial Colony ◽  
Gram Negative ◽  
Gm Csf

Toll-like receptors (TLRs) are required for protective host defense against bacterial pathogens. However, the role of TLRs in regulating lung injury during Gram-negative bacterial pneumonia has not been thoroughly investigated. In this study, experiments were performed to evaluate the role of TLR4 in pulmonary responses against Klebsiella pneumoniae (Kp). Compared with wild-type (WT) (Balb/c) mice, mice with defective TLR4 signaling (TLR4lps-d mice) had substantially higher lung bacterial colony-forming units after intratracheal challenge with Kp, which was associated with considerably greater lung permeability and lung cell death. Reduced expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA and protein was noted in lungs and bronchoalveolar lavage fluid of TLR4 mutant mice postintratracheal Kp compared with WT mice, and primary alveolar epithelial cells (AEC) harvested from TLR4lps-d mice produced significantly less GM-CSF in vitro in response to heat-killed Kp compared with WT AEC. TLR4lps-d AEC underwent significantly more apoptosis in response to heat-killed Kp in vitro, and treatment with GM-CSF protected these cells from apoptosis in response to Kp. Finally, intratracheal administration of GM-CSF in TLR4lps-d mice significantly decreased albumin leak, lung cell apoptosis, and bacteremia in Kp-infected mice. Based on these observations, we conclude that TLR4 plays a protective role on lung epithelium during Gram-negative bacterial pneumonia, an effect that is partially mediated by GM-CSF.

scholarly journals Unusual micro-organisms - gram-negative fastidious species

FEBS Letters ◽  
1984 ◽  
Vol 168 (1) ◽  
pp. 188-188
Author(s):  
J.D. Williams
Keyword(s):  
Gram Negative ◽  
Micro Organisms

Atypical Pharyngitis In Suppurative Otitis Media Cases

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P98-P99
Author(s):  
Alaa A Abou-Bieh ◽  
Mona F Salama
Keyword(s):  
Middle Ear ◽  
Causative Organism ◽  
Isolation And Identification ◽  
Middle Ear Mucosa ◽  
Suppurative Otitis Media ◽  
Gram Negative ◽  
Middle Ear Infection ◽  
Gram Negative Organisms ◽  
Micro Organisms ◽  
Middle Ear Cleft

Problem Unexplained persistent or recurrent bacterial pharyngitis in some patients who suffer from infected middle ear cleft. Methods Bacteriological swabs were obtained from both the ears and the pharynx of 37 cases with chronic otorrhea and perforation, whom complain of recurrent or persistent sore-throat. Then isolation and identification of the micro-organisms were done. This included examination of direct Gram stained films and cultures. Isolated Gram negative bacilli were subjected to further identification by the biochemical reactions and antibiotyping. Identical isolates from the same patient (ear and pharyngeal swabs) were subjected to further identification by genotyping using the pulsed field gel electrophoresis technique. Results 6 cases (16%) showed identity in phenotypes and genotypes for ear and pharyngeal samples from the same patient. All pharyngeal isolates were Gram negative organisms. 4 of them were Pseudomonas aeruginosa, 1 was Proteus sp., and 1 was Escherichia coli. All of these 3 species are not known to be among the primary organisms which may cause pharyngitis. Conclusion Bacterial pharyngitis in patients with chronically infected middle ear cleft may be attributed to the same organism invaded the middle ear mucosa. Also this study highlights some organisms as a pharyngeal invaders although they are not among the previously documented causatives of bacterial pharyngitis. But the study do not confirm the method of spread of these organisms and whether this was directly via the eustachian tube. Significance The study correlates the causative organism of the middle ear infection and that infected the pharyngeal mucosa utilizing the advanced bacteriological identification and genotyping techniques.

CHOLESTEROL ESTER HYDROLYSIS BY HOMOGENATES OF WHOLE TESTIS, SEMINIFEROUS TUBULES AND INTERSTITIAL CELLS OF MATURE RATS

1977 ◽  
Vol 75 (2) ◽  
pp. 235-243 ◽  
Author(s):  
J. P. RENSTON ◽  
T. J. IHRIG ◽  
R. H. RENSTON ◽  
B. GONDOS ◽  
R. J. MORIN
Keyword(s):  
Cholesterol Ester ◽  
Incubation Temperature ◽  
Hydrolytic Activity ◽  
Interstitial Cells ◽  
Seminiferous Tubules ◽  
Cholesterol Ester Hydrolase ◽  
Ester Hydrolase ◽  
Optimum Ph ◽  
Hormone Biosynthesis ◽  
Hydrolysis Of

The characteristics and localization of a cholesterol ester hydrolase enzyme in homogenates of whole testis and in isolated seminiferous tubules and interstitial cells of mature rats have been investigated. Hydrolysis of cholesteryl [1-14C]oleate occurred at an optimum pH of 7·0 was linearly related to time up to 5–6 h of incubation and increased linearly up to 0·25 mg protein/incubation. Hydrolytic activity was inhibited by increasing the incubation temperature from 29 to 41 °C and by sonication. Cholesterol ester hydrolase activity/mg protein was three times greater in homogenates of seminiferous tubules than in interstitial cells. Cholesterol ester hydrolase may function to provide precursors for use in seminiferous tubular steroid hormone biosynthesis or germ cell maturation.

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