19 research outputs found
Nanochitosan derived from marine bacteria
Nanochitosans are polysaccharides produced by the alkalescent deacetylation of chitin and comprise
a series of 2‐deoxy‐2 (acetylamino) glucose linked by ß‐(1‐4) glycosidic linkages. These are naturally
formed from the deacetylation of shellfish shells and the exoskeleton of aquatic arthropods and
crustaceans. Reports of chitosan production from unicellular marine bacteria inhabiting the sea, and
possessing distinct animal‐ and plant‐like characteristics abound. This capacity to synthesize chitosan
from chitin arises from response to stress under extreme environmental conditions, as a means of
survival. Consequently, the microencapsulation of these nanocarriers results in new and improved
chitosan nanoparticles, nanochitosan. This nontoxic bioactive material which can serve as an
antibacterial agent, gene delivery vector as well as carrier for protein and drug release as compared
with chitosan, is limited by its nonspecific molecular weight and higher composition of deacetylated
chitin. This chapter highlights the biology and diversity of nanochitosan‐producing marine bacteria,
including the factors influencing their activities, survival, and distribution. More so, the applications
of marine bacterial nanochitosans in transfection and gene delivery; wound healing and drug
delivery; feed supplement development and antimicrobial activity are discussed
Chapter 21 - Utilization of nanochitosan in the sterilization of ponds and water treatment for aquaculture
Water pollution constitutes the leading cause of infant mortality,
neonatal deformities, and shrinkage of man’s average life expectancy.
Pollutants come from point and nonpoint sources; and water pollution
arises from the discharge of wastewater containing undesirable
impurities used for domestic, agricultural, and industrial purposes.
More so, high nutrient and wastewater runoffs from fish production
systems contribute to the fouling and eutrophication of recipient water
bodies. Hence, aquaculture which is inextricably linked to the natural
environment is challenged by the dearth of appropriate water quantity
and quality, militating against fish, and fishery production.
Nanochitosans as polysaccharides produced by the alkalescent
deacetylation of chitin, comprise a series of 2-deoxy-2 (acetylamino)
glucose linked by ß-(1-4) glycosidic linkages. They are naturally
formed from the deacetylation of shellfish shells and exoskeletons of
aquatic arthropods and crustaceans. The unique attributes of chitin
confer a wide range of biotechnological applications on the polymer,
observed in flocculation as a wastewater treatment and purification
route initiated by chitosan. This chapter highlights nanochitosan properties of aquaculture relevance; and elucidates the purification
potentials of nanochitosan, compared to inorganic coagulants and
organic polymeric flocculants. Effects of chitosan on contaminants and
microorganisms, as well as applications in fish pathogens detection,
fish disease diagnosis, and control are discussed
Utilization of nanochitosan in the sterilization of ponds and water treatment for aquaculture
Water pollution constitutes the leading cause of infant mortality,
neonatal deformities, and shrinkage of man’s average life expectancy.
Pollutants come from point and nonpoint sources; and water pollution
arises from the discharge of wastewater containing undesirable
impurities used for domestic, agricultural, and industrial purposes.
More so, high nutrient and wastewater runoffs from fish production
systems contribute to the fouling and eutrophication of recipient water
bodies. Hence, aquaculture which is inextricably linked to the natural
environment is challenged by the dearth of appropriate water quantity
and quality, militating against fish, and fishery production.
Nanochitosans as polysaccharides produced by the alkalescent
deacetylation of chitin, comprise a series of 2-deoxy-2 (acetylamino)
glucose linked by ß-(1-4) glycosidic linkages. They are naturally
formed from the deacetylation of shellfish shells and exoskeletons of
aquatic arthropods and crustaceans. The unique attributes of chitin
confer a wide range of biotechnological applications on the polymer,
observed in flocculation as a wastewater treatment and purification
route initiated by chitosan. This chapter highlights nanochitosan
properties of aquaculture relevance; and elucidates the purification
potentials of nanochitosan, compared to inorganic coagulants and
organic polymeric flocculants. Effects of chitosan on contaminants and
microorganisms, as well as applications in fish pathogens detection,
fish disease diagnosis, and control are discussed
Utilization of nanochitosan for enzyme immobilization of aquatic and animal-based food packages
Studies have identified the properties of enzymes, functionalized molecules, and compounds in food industry applications as edible coatings and encapsulations, that assure prolonged food quality and standards. These molecules present benefits of longer shelf-life by delayed deterioration and inhibition of the proliferation of spoilage and mycotoxigenic microorganisms. However, challenges of reduced nutrient levels, miniaturized size, and low chemical stability remain concerning. Chitosan polymers naturally formed from the deacetylation of shellfish shells and exoskeletons of aquatic arthropods and crustaceans offer improved benefits when functionalized into nanoparticles as nanochitosans. These polysaccharides produced by the alkalescent deacetylation of chitin, comprise a series of 2-deoxy-2 (acetylamino) glucose linked by ß-(1-4) glycosidic linkages. This chapter considers the health impacts and
Next Generation Nanochitosan Applications in Animal Husbandry, Aquaculture and Food Conservation
Studies have identified the properties of enzymes, functionalized
molecules, and compounds in food industry applications as edible
coatings and encapsulations, that assure prolonged food quality and
standards. These molecules present benefits of longer shelf-life by
delayed deterioration and inhibition of the proliferation of spoilage and
mycotoxigenic microorganisms. However, challenges of reduced
nutrient levels, miniaturized size, and low chemical stability remain
concerning. Chitosan polymers naturally formed from the
deacetylation of shellfish shells and exoskeletons of aquatic
arthropods and crustaceans offer improved benefits when
functionalized into nanoparticles as nanochitosans. These
polysaccharides produced by the alkalescent deacetylation of chitin,
comprise a series of 2-deoxy-2 (acetylamino) glucose linked by ß-(1-
4) glycosidic linkages. This chapter considers the health impacts and
microbiological health hazards associated with animal feeds quality
and the enzyme immobilization potentials of nanochitosans in animalbased
food and feed packages. Thereafter, nanochitosan properties
and benefits are compared against traditional preservatives from
microbes and plants; with highlights on current challenges in the
application of nanochitosan for enzyme immobilization
Evaluation of appendicitis risk prediction models in adults with suspected appendicitis
Background
Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis.
Methods
A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis).
Results
Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent).
Conclusion
Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified