Why Some Metazoan Mucus Secretions are More Susceptible to Microbial Attack than Others

1979 ◽  
Vol 114 (1) ◽  
pp. 149-152 ◽  
Author(s):  
P. Calow
Keyword(s):  
Microbial Attack

Degradation of natural and Kraft lignins by the microflora of soil and water

1977 ◽  
Vol 23 (4) ◽  
pp. 434-440 ◽  
Author(s):  
Don L. Crawford ◽  
Suellen Floyd ◽  
Anthony L. Pometto III ◽  
Ronald L. Crawford
Keyword(s):  
Molecular Weight ◽  
Microbial Degradation ◽  
Lignin Degradation ◽  
Kraft Lignin ◽  
Lignin Biodegradation ◽  
Incubation Periods ◽  
Molecular Weight Fractions ◽  
Soil And Water ◽  
Different Molecular Weight ◽  
Microbial Attack

The comparative rates of microbial degradation 14C-lignin-labeled lignocelluloses and 14C-Kraft lignins were investigated using selected soil and water samples as sources of microorganisms. Natural lignocelluloses containing 14C primarily in their lignin components were prepared by feeding plants uniformly labeled L-[14C]phenylalanine through their cut stems. 14C-Kraft lignins were prepared by pulping lignin-labeled lignocelluloses. Rates of lignin biodegradation were determined by monitoring 14CO2 evolution from incubation mixtures over incubation periods of up to 1000 h. Observed rates of lignin degradation were slow in all cases. Kraft lignins appeared more resistant to microbial attack than natural lignins, even though they were decomposed more rapidly during the first 100–200 h of incubation. Similar degradation patterns were observed in both soil and water. Individual samples, however, varied greatly in their overall rates of degradation of either lignin type. A Kraft-lignin preparation was separated into a variety of molecular weight fractions by column chromatography on LH-20 Sephadex and the biodegradability of the different molecular weight fractions determined. The lower molecular weight fractions of the Kraft lignin were decomposed at a significantly faster rate by the microflora of soil than were the fractions of higher molecular weight.

scholarly journals A Review of Intermediate Pyrolysis as a Technology of Biomass Conversion for Coproduction of Biooil and Adsorption Biochar

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Deodatus Kazawadi ◽  
Justin Ntalikwa ◽  
Godlisten Kombe
Keyword(s):  
Fossil Fuel ◽  
Biomass Conversion ◽  
Environmental Problems ◽  
Review Article ◽  
Soil Treatment ◽  
Waste Biomass ◽  
High Quality ◽  
Good For ◽  
Intermediate Pyrolysis ◽  
Microbial Attack

The agenda to utilize and efficiently convert biomass has been raised to alleviate environmental problems and pressure on the reliance on fossil fuel. Intermediate pyrolysis has the ability to treat different biomasses and coproduction of biooil and adsorption biochar. This review article aims to evaluate the appropriateness of intermediate pyrolysis for the coproduction of biooil and adsorption biochar. It was observed that coproduced biooil is of high quality, stable, and miscible that can be used directly to existing engines or be easily blended. The biochar coproduced is good for adsorption but is not stable for microbial attack and hence unsuitable in soil treatment but for hydrometallurgy. Since the process is capable of treating waste biomass, it is an opportunity for further investigations in areas where wastes are plenty and less utilized. To increase the effectiveness of this technology for coproduction, optimizing parameters, design of efficient reactors, and use of catalyst must be worked upon.

Acidophilic biodesulphurization of calcined pet coke and coal samples in iron and iron-free leaching media

2020 ◽  
pp. 0958305X2093567
Author(s):  
Srabani Mishra ◽  
Sandeep Panda ◽  
Nilotpala Pradhan ◽  
SK Biswal ◽  
D Satapathy
Keyword(s):  
Scale Up ◽  
Xrd Analysis ◽  
Bacterial Consortium ◽  
Proximate Analysis ◽  
Indian Origin ◽  
Compositional Changes ◽  
Pet Coke ◽  
Assam Coal ◽  
Microbial Attack

Mineralogically distinct coal samples respond differently to microbial attack. In the present study, a mixed meso-acidophilic bacterial consortium predominantly comprising of Acidithiobacillus ferrooxidans strain was investigated for its biodesulphurization abilities for three distinct sulphur bearing samples (Goa CPC, Rajasthan Lignite, Assam Coal) of Indian origin in iron (9K+) and iron-free (9K−) media. A media devoid of Fe (II) iron was more effective for sulphur removal with maximum desulphurization of 45.19% for Assam coal followed by 36.8% for Rajasthan Lignite and 23.38% for CPC respectively. The proximate analysis, FTIR patterns and XRD analysis of the samples provided better insights into understanding the mineralogical and compositional changes in the coal matrix. Owing to the higher efficiency, Assam coal was additionally subjected to further optimization studies and characterization of the treated coal through TGA. The study indicated that the gross calorific values for all the samples increased following microbial treatment in 9K− media thereby providing a scope for further scale-up studies.

scholarly journals Phenylpropanoid Pathway Engineering: An Emerging Approach towards Plant Defense

Pathogens ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 312 ◽  
Author(s):  
Vivek Yadav ◽  
Zhongyuan Wang ◽  
Chunhua Wei ◽  
Aduragbemi Amo ◽  
Bilal Ahmed ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Defense ◽  
Plant Cell Wall ◽  
Shikimate Pathway ◽  
Gene Families ◽  
Phenylpropanoid Pathway ◽  
Pathway Engineering ◽  
Multiple Gene ◽  
Regulator Genes ◽  
Microbial Attack

Pathogens hitting the plant cell wall is the first impetus that triggers the phenylpropanoid pathway for plant defense. The phenylpropanoid pathway bifurcates into the production of an enormous array of compounds based on the few intermediates of the shikimate pathway in response to cell wall breaches by pathogens. The whole metabolomic pathway is a complex network regulated by multiple gene families and it exhibits refined regulatory mechanisms at the transcriptional, post-transcriptional, and post-translational levels. The pathway genes are involved in the production of anti-microbial compounds as well as signaling molecules. The engineering in the metabolic pathway has led to a new plant defense system of which various mechanisms have been proposed including salicylic acid and antimicrobial mediated compounds. In recent years, some key players like phenylalanine ammonia lyases (PALs) from the phenylpropanoid pathway are proposed to have broad spectrum disease resistance (BSR) without yield penalties. Now we have more evidence than ever, yet little understanding about the pathway-based genes that orchestrate rapid, coordinated induction of phenylpropanoid defenses in response to microbial attack. It is not astonishing that mutants of pathway regulator genes can show conflicting results. Therefore, precise engineering of the pathway is an interesting strategy to aim at profitably tailored plants. Here, this review portrays the current progress and challenges for phenylpropanoid pathway-based resistance from the current prospective to provide a deeper understanding.

scholarly journals Maleic anhydride-functionalized graphene nanofillers render epoxy coatings highly resistant to corrosion and microbial attack

Carbon ◽  
2020 ◽  
Vol 159 ◽  
pp. 586-597 ◽  
Author(s):  
Govinda Chilkoor ◽  
Roman Sarder ◽  
Jamil Islam ◽  
K.E. ArunKumar ◽  
Ishara Ratnayake ◽  
...  
Keyword(s):  
Maleic Anhydride ◽  
Functionalized Graphene ◽  
Epoxy Coatings ◽  
Microbial Attack

Composition of callus resin of Norway spruce, Scots pine, European larch and Douglas fir

Holzforschung ◽  
2008 ◽  
Vol 62 (4) ◽  
Author(s):  
Thomas Holmbom ◽  
Markku Reunanen ◽  
Pedro Fardim
Keyword(s):  
Callus Tissue ◽  
Resin Acid ◽  
Hydroxycinnamic Acid ◽  
Resin Acids ◽  
Minor Components ◽  
European Larch ◽  
Hydroxycinnamic Acid Derivatives ◽  
Conifer Trees ◽  
Tree Stem ◽  
Microbial Attack

Abstract On damage of conifer trees, oleoresin is exuded onto the tree stem. The oleoresin is typically composed of monoterpenes and resin acids. It serves to protect the tree from dehydration and microbial attack. Callus resin, in the traditional German term “Überwallungsharz”, is a resin exuded from the callus tissue formed as the wound is closed by annual growth. These resins can usually be found as nodules or lumps on the rim of the closing wound. Both types of resin, collected from Picea abies, Pinus sylvestris, Larix decidua and Pseudotsuga menziesii, were analyzed separately by GC/GC-MS. Expectedly, the oleoresin samples were composed of resin acids. However, the callus resins were of a completely different composition as they are composed primarily of lignans and hydroxycinnamic acid derivatives. In addition, the L. decidua sample contained significant amounts of abietol and abietadiene. The P. abies and L. decidua callus resins were found to be essentially resin acid-free. The components identified in the callus resin samples have previously been identified as minor components in oleoresin and bark samples. The potential for the inadvertent inclusion of callus resin in previously analyzed samples of oleoresin, bark and ingrown (dead) knots is highlighted.

EFFECT OF MUZZLING ON RUMINATION IN SHEEP

1988 ◽  
Vol 68 (2) ◽  
pp. 387-397 ◽  
Author(s):  
K. CHAI ◽  
L. P. MILLIGAN ◽  
G. W. MATHISON
Keyword(s):  
Key Words ◽  
Surface Area ◽  
Retention Time ◽  
Intestinal Tract ◽  
Rumen Fluid ◽  
Fluid Retention ◽  
Input Output ◽  
Reed Canarygrass ◽  
Large Particles ◽  
Microbial Attack

Two experiments were completed using four esophageal-fistulated sheep (two per experiment) to study the breakdown of rumen particles of grass hay (bromegrass or reed canarygrass) when rumination was either allowed to occur normally or was restricted by means of a muzzle. When the sheep were muzzled during the nonfeeding portion of the day, there was a distinct limitation of voluntary hay intake. Muzzled sheep chewed more often than unmuzzled sheep (P < 0.01) during eating and, presumably as a result, the particles in their mastication boluses were smaller (P < 0.05). During rumination the regurgitated and chewed boluses from sheep that had been muzzled were larger (P < 0.05) than those from unmuzzled sheep. The proportion of large particles (LP, particles retained on a 1.00-mm screen) of the regurgitated bolus, rumen contents and feces were greater (P > 0.05) for muzzled than unmuzzled sheep. The effectiveness of breakdown of LP retained for chewing during the rumination cycle increased (P < 0.005) with time after feeding (33% at 3 h postfeeding for bromegrass; 57% at 11 h postfeeding). This increase was eliminated by muzzling. The specific fragility (LP breakdown per chew per unit of LP in mouth) of particles from unmuzzled sheep was consistently greater (P > 0.05) than that of particles from muzzled animals. Muzzling markedly reduced the extent to which specific fragility increased with time after feeding and increased (P > 0.01) rumen fluid retention time from 7.4 to 17.4 h. The rumen input-output balance for hay particles was estimated. It is concluded that rumination is the major factor in decreasing the size of forage particles in the rumen, thereby exposing greater surface area to microbial attack and facilitating passage along the intestinal tract. Key words: Sheep, rumination, muzzle, particle breakdown, specific fragility, rumen retention time

scholarly journals Differentiating Bone Osteonal Turnover Rates By Density Fractionation; Validation Using the Bomb 14C Atmospheric Pulse

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 853-861 ◽  
Author(s):  
Ji Young Shin ◽  
Tamsin O'Connell ◽  
Stuart Black ◽  
Robert Hedges
Keyword(s):  
Post Mortem ◽  
Density Fractionation ◽  
Turnover Rates ◽  
Fractionation Method ◽  
Older Populations ◽  
Microbial Attack

The density (BSG) of bone increases, at the osteon scale, during lifetime aging within the bone. In addition, post-mortem diagenetic change due to microbial attack produces denser bioapatite. Thus, fractionation of finely powdered bone on the basis of density should not only enable younger and older populations of osteons to be separated but also make it possible to separate out a less diagenetically altered component. We show that the density fractionation method can be used as a tool to investigate the isotopic history within an individual's lifetime, both in recent and archaeological contexts, and we use the bomb 14C atmospheric pulse for validating the method.

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