scholarly journals Substrate-Related Factors Affecting Cellulosome-Induced Hydrolysis for Lignocellulose Valorization

2019 ◽  
Vol 20 (13) ◽  
pp. 3354 ◽  
Author(s):  
Ying Wang ◽  
Ling Leng ◽  
Md Khairul Islam ◽  
Fanghua Liu ◽  
Carol Sze Ki Lin ◽  
...  
Keyword(s):  
Lignin Content ◽  
Untreated Wood ◽  
Cellulosic Biomass ◽  
Host Cells ◽  
Lignocellulosic Substrate ◽  
Related Factors ◽  
Factors Affecting ◽  
Lignocellulosic Feedstocks ◽  
Chemical Factors ◽  
Physical And Chemical

Cellulosomes are an extracellular supramolecular multienzyme complex that can efficiently degrade cellulose and hemicelluloses in plant cell walls. The structural and unique subunit arrangement of cellulosomes can promote its adhesion to the insoluble substrates, thus providing individual microbial cells with a direct competence in the utilization of cellulosic biomass. Significant progress has been achieved in revealing the structures and functions of cellulosomes, but a knowledge gap still exists in understanding the interaction between cellulosome and lignocellulosic substrate for those derived from biorefinery pretreatment of agricultural crops. The cellulosomic saccharification of lignocellulose is affected by various substrate-related physical and chemical factors, including native (untreated) wood lignin content, the extent of lignin and xylan removal by pretreatment, lignin structure, substrate size, and of course substrate pore surface area or substrate accessibility to cellulose. Herein, we summarize the cellulosome structure, substrate-related factors, and regulatory mechanisms in the host cells. We discuss the latest advances in specific strategies of cellulosome-induced hydrolysis, which can function in the reaction kinetics and the overall progress of biorefineries based on lignocellulosic feedstocks.

Further Studies upon Chemical Factors Affecting the Breeding of Anopheles in Trinidad

1934 ◽  
Vol 25 (4) ◽  
pp. 491-494 ◽  
Author(s):  
P. A. Buxton
Keyword(s):  
Analytical Study ◽  
Chemical Constituents ◽  
Physical Factors ◽  
Factors Affecting ◽  
Early Stages ◽  
Freshwater Biology ◽  
Chemical Technique ◽  
Chemical Factors ◽  
Physical And Chemical

During the last decade, entomologists have made progress in understanding the environment in which certain insects live; in particular, we begin to understand the effect of certain physical and chemical factors, which make up a part of the environment. With this gain in knowledge, it is sometimes possible to forecast outbreaks of insects and of diseases conveyed by them, and one can sometimes say that a particular alteration of the environment will result in loss or gain. But so far as mosquitos are concerned, one must admit that though much work has been devoted to the analytical study of the water in which the early stages are passed, the results are disappointing. A consideration of the published work suggests several reasons for this. Investigation into the ecology of the mosquito has had a vogue, and much of it has been done by workers who were isolated and whose knowledge of chemical technique and freshwater biology was limited. Apart from that, the inherent difficulties are great, for the worker must hunt for the limiting chemical and physical factors among a host of others which are doubtless unimportant, and there are few clues to indicate which of the chemical constituents of the water affects the mosquito. The data are therefore voluminous and it is difficult to reduce them to order and present them so that they can be readily understood.

Anatomical and chemical factors affecting tensile growth stress in Eucalyptus grandis plantations at different latitudes in Brazil

2012 ◽  
Vol 42 (1) ◽  
pp. 134-140 ◽  
Author(s):  
Miho Kojima ◽  
Hiroyuki Yamamoto ◽  
Koichiro Saegusa ◽  
Fabio Minoru Yamaji ◽  
Masato Yoshida ◽  
...  
Keyword(s):  
Lignin Content ◽  
Microfibril Angle ◽  
Eucalyptus Grandis ◽  
Middle Layer ◽  
Growth Stress ◽  
Cellulose Content ◽  
Factors Affecting ◽  
Wide Range ◽  
Chemical Factors ◽  
Processing Defects

The key to using planted Eucalyptus as timber lies in controlling the characteristic high tensile growth stress that often causes serious processing defects in sawn logs and lumber. In the present study, we investigated variations in the longitudinal released strain (RS) of surface growth stress in stems of Eucalyptus grandis W. Hill ex Maiden planted in a wide range of latitudes in Brazil and established relationships between RS measurements and anatomical and chemical factors. Cellulose and lignin content, RS, and the microfibril angle (MFA) of the middle layer of the secondary wall (S2 layer) differed among latitudes. The increase in cellulose content and decrease in MFA were correlated with the contractive value of RS, which explained the higher tensile growth stress in stems from high-latitude plantations where higher cellulose content and lower MFA were observed. To reduce processing defects due to tensile growth stress, the factors controlling MFA values and cellulose content must be identified.

The response of store lambs to protein supplementation of alkali treated straw based diets

1984 ◽  
Vol 1984 ◽  
pp. 11-11
Author(s):  
Susan M. Marchment ◽  
E.L. Miller
Keyword(s):  
Food Intake ◽  
Microbial Activity ◽  
Dietary Protein ◽  
Protein Supplementation ◽  
Factors Affecting ◽  
Chemical Factors ◽  
Protein Supply ◽  
Physical And Chemical ◽  
Voluntary Food Intake ◽  
Degradable Protein

Factors affecting voluntary food intake (VFI) in ruminants are well documented and suggest that both physical and chemical factors are involved. An understanding of VFI controls is important for the formulation of economical diets to achieve maximum levels of production.The effect of protein supply on VFI is unclear. While the need for rumen degradable protein (RDP) to maximise microbial activity and consequently VFI is clearly established ARC (1960), the effect of undegraded dietary protein (UDP) on VFI is equivocal.

Physical and chemical factors affecting microbial biomass and activity in contaminated subsurface riverine sediments

2006 ◽  
Vol 52 (5) ◽  
pp. 397-403 ◽  
Author(s):  
Jennifer J Mosher ◽  
Robert H Findlay ◽  
Carl G Johnston
Keyword(s):  
Microbial Biomass ◽  
Microbial Activity ◽  
River Sediments ◽  
Environmental Parameters ◽  
Industrial Effluents ◽  
Factors Affecting ◽  
Chemical Factors ◽  
Physical And Chemical ◽  
Water Holding ◽  
Direct Discharge

Over 80 years of direct discharge of industrial effluents into the Mahoning River, located in northeastern Ohio, USA, has led to the accumulation of a wide variety of pollutants within its sediments. This study examined the physical and chemical parameters, including lipophilic pollutants, affecting microbial activity and biomass in subsurface (10–40 cm horizon) sediments. Microbial biomass was higher in anthropogenically contaminated sediments, and step-wise linear regression showed that approximately 82% of the variation in microbial biomass could be explained by total hexane extractable hydrocarbons, sediment particle size, and water content. There was no correlation between microbial activity and biomass. Independent variables influencing anaerobic activity were temperature and water holding capacity. The results of this study indicate that freshwater, sedimentary anaerobic microbial communities respond to a range of environmental parameters, many of which influence subsurface river sediments, and that lipophilic pollutants, when present, can cause increases in total microbial biomass.Key words: microbial activity, microbial biomass, anaerobic sediments, PAH, metals.

scholarly journals Hygienic assessment of the complex of physical and chemical factors affecting a person in rooms of the different purpose in in-patients medical institutions

2021 ◽  
Vol 100 (6) ◽  
pp. 546-554
Author(s):  
Nikolay V. Rusakov ◽  
Natalia V. Kalinina ◽  
Elena B. Gaponova ◽  
Mikhail Ye. Goshin ◽  
Ilya M. Banin
Keyword(s):  
Primary Source ◽  
Hospital Environment ◽  
Physical Factors ◽  
Natural Light ◽  
Artificial Light ◽  
Radiation Level ◽  
Factors Affecting ◽  
Medical Institutions ◽  
Chemical Factors ◽  
Physical And Chemical

Introduction. The paper presents the hygienic assessment of the complex physical and chemical factors affecting patients and staff in the different premises of institutional medical organizations. Material and methods. The comprehensive hygienic assessment of the internal environment of medical institutions was based on three in-patient medical institutions (IMI). The research objects were medical wards, operating rooms, treatment rooms, dressing rooms, physiotherapy rooms, laboratory and diagnostic rooms, utility rooms. The study included measurements of the following parameters: microclimate, noise, electromagnetic fields level in different frequency ranges, ion regime, assessment of natural light, artificial light, insolation, gamma radiation level, measurements of concentrations of carbon dioxide, oxygen, ozone, radon, mercury vapor, and volatile organic compounds. Results. It is shown that in the hospital environment, a person is affected by complex physical factors. Microclimatic parameters are one of the most significant factors in the hospital environment that require constant monitoring. The control of the given factor is exceptionally substantial in IMI buildings that are not equipped with in-patients an air conditioning system. The highest noise levels were found in physiotherapy rooms and diagnostic rooms. The primary source of noise in medical rooms is working equipment, inwards - conversational speech. Both patients and medical workers were established to receive the main electromagnetic load in diagnostic rooms, laboratory rooms, and physiotherapy rooms. The assessment of the light environment showed that each of the examined rooms was provided with a sufficient level of natural light, and the duration of insolation in the treatment rooms corresponded to hygienic requirements. The highest levels of artificial light were in rooms with led lights. In the air of the examined rooms, light ions of both polarities were either absent, or their content was below the minimum required concentration. Higher concentrations of organic acids and chlorine-containing compounds were found in the surveyed premises of IMO compared to the air in other public buildings. The highest concentration of chemical compounds in the air was observed in wards and diagnostic rooms. Conclusion. The need for regular monitoring of physical and chemical factors affecting patients and staff in IMI is justified. A list of physical factors for carrying out risk-oriented control in hospital premises, taking into account their functional purpose, is required.

Sign in / Sign up

Export Citation Format

Share Document